Btrfs: split up super.c
authorChris Mason <chris.mason@oracle.com>
Tue, 12 Jun 2007 10:35:45 +0000 (06:35 -0400)
committerDavid Woodhouse <dwmw2@hera.kernel.org>
Tue, 12 Jun 2007 10:35:45 +0000 (06:35 -0400)
Signed-off-by: Chris Mason <chris.mason@oracle.com>
fs/btrfs/Makefile
fs/btrfs/TODO
fs/btrfs/ctree.h
fs/btrfs/disk-io.c
fs/btrfs/file.c [new file with mode: 0644]
fs/btrfs/inode.c [new file with mode: 0644]
fs/btrfs/super.c

index 5346f706b2c5d78e3df1319b86c629c98d38712f..5af2426116d3a9246af992809fa70a0dce1b0858 100644 (file)
@@ -4,7 +4,7 @@ ifneq ($(KERNELRELEASE),)
 obj-m  := btrfs.o
 btrfs-y := super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \
           hash.o file-item.o inode-item.o inode-map.o disk-io.o \
-          transaction.o bit-radix.o
+          transaction.o bit-radix.o inode.o file.o
 
 #btrfs-y := ctree.o disk-io.o radix-tree.o extent-tree.o print-tree.o \
 #        root-tree.o dir-item.o hash.o file-item.o inode-item.o \
@@ -16,7 +16,7 @@ else
 
 KERNELDIR := /lib/modules/`uname -r`/build
 all::
-       $(MAKE) C=1 -C $(KERNELDIR) M=`pwd` modules
+       $(MAKE) -C $(KERNELDIR) M=`pwd` modules
 clean::
        rm *.o btrfs.ko
 endif
index d9b6d38c603a81094046e51cad04e1a3a60d0cde..4a48a2365d578c3fc22a02162431afda3f0dacb1 100644 (file)
@@ -1,3 +1,4 @@
+* fix printk warnings
 * cleanup, add more error checking, get rid of BUG_ONs
 * Fix ENOSPC handling
 * Make allocator smarter
index 4e136b7b03aed6f1d8ed828ae110f78a13d064dc..24410d42e3cefe7b617915ae7cc992dfee75a1c4 100644 (file)
@@ -1123,5 +1123,28 @@ struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans,
 int btrfs_csum_truncate(struct btrfs_trans_handle *trans,
                        struct btrfs_root *root, struct btrfs_path *path,
                        u64 isize);
-/* super.c */
+/* inode.c */
+void btrfs_delete_inode(struct inode *inode);
+void btrfs_read_locked_inode(struct inode *inode);
+int btrfs_write_inode(struct inode *inode, int wait);
+void btrfs_dirty_inode(struct inode *inode);
+struct inode *btrfs_alloc_inode(struct super_block *sb);
+void btrfs_destroy_inode(struct inode *inode);
+int btrfs_init_cachep(void);
+void btrfs_destroy_cachep(void);
+int btrfs_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
+               unsigned long arg);
+long btrfs_compat_ioctl(struct file *file, unsigned int cmd,
+                              unsigned long arg);
+struct inode *btrfs_iget_locked(struct super_block *s, u64 objectid,
+                               struct btrfs_root *root);
+int btrfs_commit_write(struct file *file, struct page *page,
+                      unsigned from, unsigned to);
+int btrfs_get_block(struct inode *inode, sector_t iblock,
+                   struct buffer_head *result, int create);
+/* file.c */
+extern struct file_operations btrfs_file_operations;
+int btrfs_drop_extents(struct btrfs_trans_handle *trans,
+                      struct btrfs_root *root, struct inode *inode,
+                      u64 start, u64 end, u64 *hint_block);
 #endif
index 8a88404525e81f921a5fd336da476a3a05b23b01..96bf3ef3a798f17f42c551ff23ecc226a2c0e406 100644 (file)
@@ -22,7 +22,7 @@ static int check_tree_block(struct btrfs_root *root, struct buffer_head *buf)
        if (bh_blocknr(buf) != btrfs_header_blocknr(&node->header)) {
                printk(KERN_CRIT "bh_blocknr(buf) is %Lu, header is %Lu\n",
                       bh_blocknr(buf), btrfs_header_blocknr(&node->header));
-               BUG();
+               return 1;
        }
        return 0;
 }
@@ -253,7 +253,7 @@ uptodate:
                set_buffer_checked(bh);
        }
        if (check_tree_block(root, bh))
-               BUG();
+               goto fail;
        return bh;
 fail:
        brelse(bh);
@@ -398,8 +398,13 @@ struct btrfs_root *open_ctree(struct super_block *sb)
        struct btrfs_fs_info *fs_info = kmalloc(sizeof(*fs_info),
                                                GFP_NOFS);
        int ret;
+       int err = -EIO;
        struct btrfs_super_block *disk_super;
 
+       if (!extent_root || !tree_root || !fs_info) {
+               err = -ENOMEM;
+               goto fail;
+       }
        init_bit_radix(&fs_info->pinned_radix);
        init_bit_radix(&fs_info->pending_del_radix);
        init_bit_radix(&fs_info->extent_map_radix);
@@ -431,9 +436,11 @@ struct btrfs_root *open_ctree(struct super_block *sb)
        mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
        fs_info->hash_tfm = crypto_alloc_hash("crc32c", 0, CRYPTO_ALG_ASYNC);
        spin_lock_init(&fs_info->hash_lock);
+
        if (!fs_info->hash_tfm || IS_ERR(fs_info->hash_tfm)) {
-               printk("failed to allocate digest hash\n");
-               return NULL;
+               printk("btrfs: failed hash setup, modprobe cryptomgr?\n");
+               err = -ENOMEM;
+               goto fail_iput;
        }
        mutex_init(&fs_info->trans_mutex);
        mutex_init(&fs_info->fs_mutex);
@@ -446,30 +453,53 @@ struct btrfs_root *open_ctree(struct super_block *sb)
                                             sb->s_blocksize);
 
        if (!fs_info->sb_buffer)
-               return NULL;
+               goto fail_iput;
        disk_super = (struct btrfs_super_block *)fs_info->sb_buffer->b_data;
+
        if (!btrfs_super_root(disk_super))
-               return NULL;
+               goto fail_sb_buffer;
 
        i_size_write(fs_info->btree_inode,
                     btrfs_super_total_blocks(disk_super) <<
                     fs_info->btree_inode->i_blkbits);
 
        fs_info->disk_super = disk_super;
+
+       if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
+                   sizeof(disk_super->magic))) {
+               printk("btrfs: valid FS not found on %s\n", sb->s_id);
+               goto fail_sb_buffer;
+       }
        tree_root->node = read_tree_block(tree_root,
                                          btrfs_super_root(disk_super));
-       BUG_ON(!tree_root->node);
+       if (!tree_root->node)
+               goto fail_sb_buffer;
 
        mutex_lock(&fs_info->fs_mutex);
        ret = find_and_setup_root(sb->s_blocksize, tree_root, fs_info,
                                  BTRFS_EXTENT_TREE_OBJECTID, extent_root);
-       BUG_ON(ret);
+       if (ret) {
+               mutex_unlock(&fs_info->fs_mutex);
+               goto fail_tree_root;
+       }
 
        btrfs_read_block_groups(extent_root);
 
        fs_info->generation = btrfs_super_generation(disk_super) + 1;
        mutex_unlock(&fs_info->fs_mutex);
        return tree_root;
+
+fail_tree_root:
+       btrfs_block_release(tree_root, tree_root->node);
+fail_sb_buffer:
+       btrfs_block_release(tree_root, fs_info->sb_buffer);
+fail_iput:
+       iput(fs_info->btree_inode);
+fail:
+       kfree(extent_root);
+       kfree(tree_root);
+       kfree(fs_info);
+       return ERR_PTR(err);
 }
 
 int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
new file mode 100644 (file)
index 0000000..7f8e303
--- /dev/null
@@ -0,0 +1,783 @@
+#include <linux/module.h>
+#include <linux/buffer_head.h>
+#include <linux/fs.h>
+#include <linux/pagemap.h>
+#include <linux/highmem.h>
+#include <linux/time.h>
+#include <linux/init.h>
+#include <linux/string.h>
+#include <linux/smp_lock.h>
+#include <linux/backing-dev.h>
+#include <linux/mpage.h>
+#include <linux/swap.h>
+#include <linux/writeback.h>
+#include <linux/statfs.h>
+#include <linux/compat.h>
+#include "ctree.h"
+#include "disk-io.h"
+#include "transaction.h"
+#include "btrfs_inode.h"
+#include "ioctl.h"
+#include "print-tree.h"
+
+
+static int btrfs_copy_from_user(loff_t pos, int num_pages, int write_bytes,
+                               struct page **prepared_pages,
+                               const char __user * buf)
+{
+       long page_fault = 0;
+       int i;
+       int offset = pos & (PAGE_CACHE_SIZE - 1);
+
+       for (i = 0; i < num_pages && write_bytes > 0; i++, offset = 0) {
+               size_t count = min_t(size_t,
+                                    PAGE_CACHE_SIZE - offset, write_bytes);
+               struct page *page = prepared_pages[i];
+               fault_in_pages_readable(buf, count);
+
+               /* Copy data from userspace to the current page */
+               kmap(page);
+               page_fault = __copy_from_user(page_address(page) + offset,
+                                             buf, count);
+               /* Flush processor's dcache for this page */
+               flush_dcache_page(page);
+               kunmap(page);
+               buf += count;
+               write_bytes -= count;
+
+               if (page_fault)
+                       break;
+       }
+       return page_fault ? -EFAULT : 0;
+}
+
+static void btrfs_drop_pages(struct page **pages, size_t num_pages)
+{
+       size_t i;
+       for (i = 0; i < num_pages; i++) {
+               if (!pages[i])
+                       break;
+               unlock_page(pages[i]);
+               mark_page_accessed(pages[i]);
+               page_cache_release(pages[i]);
+       }
+}
+
+static int dirty_and_release_pages(struct btrfs_trans_handle *trans,
+                                  struct btrfs_root *root,
+                                  struct file *file,
+                                  struct page **pages,
+                                  size_t num_pages,
+                                  loff_t pos,
+                                  size_t write_bytes)
+{
+       int i;
+       int offset;
+       int err = 0;
+       int ret;
+       int this_write;
+       struct inode *inode = file->f_path.dentry->d_inode;
+       struct buffer_head *bh;
+       struct btrfs_file_extent_item *ei;
+
+       for (i = 0; i < num_pages; i++) {
+               offset = pos & (PAGE_CACHE_SIZE -1);
+               this_write = min(PAGE_CACHE_SIZE - offset, write_bytes);
+               /* FIXME, one block at a time */
+
+               mutex_lock(&root->fs_info->fs_mutex);
+               trans = btrfs_start_transaction(root, 1);
+               btrfs_set_trans_block_group(trans, inode);
+
+               bh = page_buffers(pages[i]);
+
+               if (buffer_mapped(bh) && bh->b_blocknr == 0) {
+                       struct btrfs_key key;
+                       struct btrfs_path *path;
+                       char *ptr;
+                       u32 datasize;
+
+                       /* create an inline extent, and copy the data in */
+                       path = btrfs_alloc_path();
+                       BUG_ON(!path);
+                       key.objectid = inode->i_ino;
+                       key.offset = pages[i]->index << PAGE_CACHE_SHIFT;
+                       key.flags = 0;
+                       btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
+                       BUG_ON(write_bytes >= PAGE_CACHE_SIZE);
+                       datasize = offset +
+                               btrfs_file_extent_calc_inline_size(write_bytes);
+
+                       ret = btrfs_insert_empty_item(trans, root, path, &key,
+                                                     datasize);
+                       BUG_ON(ret);
+                       ei = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
+                              path->slots[0], struct btrfs_file_extent_item);
+                       btrfs_set_file_extent_generation(ei, trans->transid);
+                       btrfs_set_file_extent_type(ei,
+                                                  BTRFS_FILE_EXTENT_INLINE);
+                       ptr = btrfs_file_extent_inline_start(ei);
+                       btrfs_memcpy(root, path->nodes[0]->b_data,
+                                    ptr, bh->b_data, offset + write_bytes);
+                       mark_buffer_dirty(path->nodes[0]);
+                       btrfs_free_path(path);
+               } else if (buffer_mapped(bh)) {
+                       /* csum the file data */
+                       btrfs_csum_file_block(trans, root, inode->i_ino,
+                                     pages[i]->index << PAGE_CACHE_SHIFT,
+                                     kmap(pages[i]), PAGE_CACHE_SIZE);
+                       kunmap(pages[i]);
+               }
+               SetPageChecked(pages[i]);
+               ret = btrfs_end_transaction(trans, root);
+               BUG_ON(ret);
+               mutex_unlock(&root->fs_info->fs_mutex);
+
+               ret = btrfs_commit_write(file, pages[i], offset,
+                                        offset + this_write);
+               pos += this_write;
+               if (ret) {
+                       err = ret;
+                       goto failed;
+               }
+               WARN_ON(this_write > write_bytes);
+               write_bytes -= this_write;
+       }
+failed:
+       return err;
+}
+
+/*
+ * this is very complex, but the basic idea is to drop all extents
+ * in the range start - end.  hint_block is filled in with a block number
+ * that would be a good hint to the block allocator for this file.
+ *
+ * If an extent intersects the range but is not entirely inside the range
+ * it is either truncated or split.  Anything entirely inside the range
+ * is deleted from the tree.
+ */
+int btrfs_drop_extents(struct btrfs_trans_handle *trans,
+                      struct btrfs_root *root, struct inode *inode,
+                      u64 start, u64 end, u64 *hint_block)
+{
+       int ret;
+       struct btrfs_key key;
+       struct btrfs_leaf *leaf;
+       int slot;
+       struct btrfs_file_extent_item *extent;
+       u64 extent_end = 0;
+       int keep;
+       struct btrfs_file_extent_item old;
+       struct btrfs_path *path;
+       u64 search_start = start;
+       int bookend;
+       int found_type;
+       int found_extent;
+       int found_inline;
+
+       path = btrfs_alloc_path();
+       if (!path)
+               return -ENOMEM;
+       while(1) {
+               btrfs_release_path(root, path);
+               ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino,
+                                              search_start, -1);
+               if (ret < 0)
+                       goto out;
+               if (ret > 0) {
+                       if (path->slots[0] == 0) {
+                               ret = 0;
+                               goto out;
+                       }
+                       path->slots[0]--;
+               }
+               keep = 0;
+               bookend = 0;
+               found_extent = 0;
+               found_inline = 0;
+               extent = NULL;
+               leaf = btrfs_buffer_leaf(path->nodes[0]);
+               slot = path->slots[0];
+               btrfs_disk_key_to_cpu(&key, &leaf->items[slot].key);
+               if (key.offset >= end || key.objectid != inode->i_ino) {
+                       ret = 0;
+                       goto out;
+               }
+               if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY) {
+                       ret = 0;
+                       goto out;
+               }
+               extent = btrfs_item_ptr(leaf, slot,
+                                       struct btrfs_file_extent_item);
+               found_type = btrfs_file_extent_type(extent);
+               if (found_type == BTRFS_FILE_EXTENT_REG) {
+                       extent_end = key.offset +
+                               (btrfs_file_extent_num_blocks(extent) <<
+                                inode->i_blkbits);
+                       found_extent = 1;
+               } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
+                       found_inline = 1;
+                       extent_end = key.offset +
+                            btrfs_file_extent_inline_len(leaf->items + slot);
+               }
+
+               /* we found nothing we can drop */
+               if (!found_extent && !found_inline) {
+                       ret = 0;
+                       goto out;
+               }
+
+               /* we found nothing inside the range */
+               if (search_start >= extent_end) {
+                       ret = 0;
+                       goto out;
+               }
+
+               /* FIXME, there's only one inline extent allowed right now */
+               if (found_inline) {
+                       u64 mask = root->blocksize - 1;
+                       search_start = (extent_end + mask) & ~mask;
+               } else
+                       search_start = extent_end;
+
+               if (end < extent_end && end >= key.offset) {
+                       if (found_extent) {
+                               u64 disk_blocknr =
+                                       btrfs_file_extent_disk_blocknr(extent);
+                               u64 disk_num_blocks =
+                                     btrfs_file_extent_disk_num_blocks(extent);
+                               memcpy(&old, extent, sizeof(old));
+                               if (disk_blocknr != 0) {
+                                       ret = btrfs_inc_extent_ref(trans, root,
+                                                disk_blocknr, disk_num_blocks);
+                                       BUG_ON(ret);
+                               }
+                       }
+                       WARN_ON(found_inline);
+                       bookend = 1;
+               }
+
+               /* truncate existing extent */
+               if (start > key.offset) {
+                       u64 new_num;
+                       u64 old_num;
+                       keep = 1;
+                       WARN_ON(start & (root->blocksize - 1));
+                       if (found_extent) {
+                               new_num = (start - key.offset) >>
+                                       inode->i_blkbits;
+                               old_num = btrfs_file_extent_num_blocks(extent);
+                               *hint_block =
+                                       btrfs_file_extent_disk_blocknr(extent);
+                               if (btrfs_file_extent_disk_blocknr(extent)) {
+                                       inode->i_blocks -=
+                                               (old_num - new_num) << 3;
+                               }
+                               btrfs_set_file_extent_num_blocks(extent,
+                                                                new_num);
+                               mark_buffer_dirty(path->nodes[0]);
+                       } else {
+                               WARN_ON(1);
+                       }
+               }
+               /* delete the entire extent */
+               if (!keep) {
+                       u64 disk_blocknr = 0;
+                       u64 disk_num_blocks = 0;
+                       u64 extent_num_blocks = 0;
+                       if (found_extent) {
+                               disk_blocknr =
+                                     btrfs_file_extent_disk_blocknr(extent);
+                               disk_num_blocks =
+                                     btrfs_file_extent_disk_num_blocks(extent);
+                               extent_num_blocks =
+                                     btrfs_file_extent_num_blocks(extent);
+                               *hint_block =
+                                       btrfs_file_extent_disk_blocknr(extent);
+                       }
+                       ret = btrfs_del_item(trans, root, path);
+                       BUG_ON(ret);
+                       btrfs_release_path(root, path);
+                       extent = NULL;
+                       if (found_extent && disk_blocknr != 0) {
+                               inode->i_blocks -= extent_num_blocks << 3;
+                               ret = btrfs_free_extent(trans, root,
+                                                       disk_blocknr,
+                                                       disk_num_blocks, 0);
+                       }
+
+                       BUG_ON(ret);
+                       if (!bookend && search_start >= end) {
+                               ret = 0;
+                               goto out;
+                       }
+                       if (!bookend)
+                               continue;
+               }
+               /* create bookend, splitting the extent in two */
+               if (bookend && found_extent) {
+                       struct btrfs_key ins;
+                       ins.objectid = inode->i_ino;
+                       ins.offset = end;
+                       ins.flags = 0;
+                       btrfs_set_key_type(&ins, BTRFS_EXTENT_DATA_KEY);
+
+                       btrfs_release_path(root, path);
+                       ret = btrfs_insert_empty_item(trans, root, path, &ins,
+                                                     sizeof(*extent));
+                       BUG_ON(ret);
+                       extent = btrfs_item_ptr(
+                                   btrfs_buffer_leaf(path->nodes[0]),
+                                   path->slots[0],
+                                   struct btrfs_file_extent_item);
+                       btrfs_set_file_extent_disk_blocknr(extent,
+                                   btrfs_file_extent_disk_blocknr(&old));
+                       btrfs_set_file_extent_disk_num_blocks(extent,
+                                   btrfs_file_extent_disk_num_blocks(&old));
+
+                       btrfs_set_file_extent_offset(extent,
+                                   btrfs_file_extent_offset(&old) +
+                                   ((end - key.offset) >> inode->i_blkbits));
+                       WARN_ON(btrfs_file_extent_num_blocks(&old) <
+                               (extent_end - end) >> inode->i_blkbits);
+                       btrfs_set_file_extent_num_blocks(extent,
+                                   (extent_end - end) >> inode->i_blkbits);
+
+                       btrfs_set_file_extent_type(extent,
+                                                  BTRFS_FILE_EXTENT_REG);
+                       btrfs_set_file_extent_generation(extent,
+                                   btrfs_file_extent_generation(&old));
+                       btrfs_mark_buffer_dirty(path->nodes[0]);
+                       if (btrfs_file_extent_disk_blocknr(&old) != 0) {
+                               inode->i_blocks +=
+                                     btrfs_file_extent_num_blocks(extent) << 3;
+                       }
+                       ret = 0;
+                       goto out;
+               }
+       }
+out:
+       btrfs_free_path(path);
+       return ret;
+}
+
+/*
+ * this gets pages into the page cache and locks them down
+ */
+static int prepare_pages(struct btrfs_root *root,
+                        struct file *file,
+                        struct page **pages,
+                        size_t num_pages,
+                        loff_t pos,
+                        unsigned long first_index,
+                        unsigned long last_index,
+                        size_t write_bytes,
+                        u64 alloc_extent_start)
+{
+       int i;
+       unsigned long index = pos >> PAGE_CACHE_SHIFT;
+       struct inode *inode = file->f_path.dentry->d_inode;
+       int offset;
+       int err = 0;
+       int this_write;
+       struct buffer_head *bh;
+       struct buffer_head *head;
+       loff_t isize = i_size_read(inode);
+
+       memset(pages, 0, num_pages * sizeof(struct page *));
+
+       for (i = 0; i < num_pages; i++) {
+               pages[i] = grab_cache_page(inode->i_mapping, index + i);
+               if (!pages[i]) {
+                       err = -ENOMEM;
+                       goto failed_release;
+               }
+               cancel_dirty_page(pages[i], PAGE_CACHE_SIZE);
+               wait_on_page_writeback(pages[i]);
+               offset = pos & (PAGE_CACHE_SIZE -1);
+               this_write = min(PAGE_CACHE_SIZE - offset, write_bytes);
+               if (!page_has_buffers(pages[i])) {
+                       create_empty_buffers(pages[i],
+                                            root->fs_info->sb->s_blocksize,
+                                            (1 << BH_Uptodate));
+               }
+               head = page_buffers(pages[i]);
+               bh = head;
+               do {
+                       err = btrfs_map_bh_to_logical(root, bh,
+                                                     alloc_extent_start);
+                       BUG_ON(err);
+                       if (err)
+                               goto failed_truncate;
+                       bh = bh->b_this_page;
+                       if (alloc_extent_start)
+                               alloc_extent_start++;
+               } while (bh != head);
+               pos += this_write;
+               WARN_ON(this_write > write_bytes);
+               write_bytes -= this_write;
+       }
+       return 0;
+
+failed_release:
+       btrfs_drop_pages(pages, num_pages);
+       return err;
+
+failed_truncate:
+       btrfs_drop_pages(pages, num_pages);
+       if (pos > isize)
+               vmtruncate(inode, isize);
+       return err;
+}
+
+static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
+                               size_t count, loff_t *ppos)
+{
+       loff_t pos;
+       size_t num_written = 0;
+       int err = 0;
+       int ret = 0;
+       struct inode *inode = file->f_path.dentry->d_inode;
+       struct btrfs_root *root = BTRFS_I(inode)->root;
+       struct page *pages[8];
+       struct page *pinned[2];
+       unsigned long first_index;
+       unsigned long last_index;
+       u64 start_pos;
+       u64 num_blocks;
+       u64 alloc_extent_start;
+       u64 hint_block;
+       struct btrfs_trans_handle *trans;
+       struct btrfs_key ins;
+       pinned[0] = NULL;
+       pinned[1] = NULL;
+       if (file->f_flags & O_DIRECT)
+               return -EINVAL;
+       pos = *ppos;
+       vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
+       current->backing_dev_info = inode->i_mapping->backing_dev_info;
+       err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
+       if (err)
+               goto out;
+       if (count == 0)
+               goto out;
+       err = remove_suid(file->f_path.dentry);
+       if (err)
+               goto out;
+       file_update_time(file);
+
+       start_pos = pos & ~((u64)PAGE_CACHE_SIZE - 1);
+       num_blocks = (count + pos - start_pos + root->blocksize - 1) >>
+                       inode->i_blkbits;
+
+       mutex_lock(&inode->i_mutex);
+       first_index = pos >> PAGE_CACHE_SHIFT;
+       last_index = (pos + count) >> PAGE_CACHE_SHIFT;
+
+       /*
+        * there are lots of better ways to do this, but this code
+        * makes sure the first and last page in the file range are
+        * up to date and ready for cow
+        */
+       if ((pos & (PAGE_CACHE_SIZE - 1))) {
+               pinned[0] = grab_cache_page(inode->i_mapping, first_index);
+               if (!PageUptodate(pinned[0])) {
+                       ret = mpage_readpage(pinned[0], btrfs_get_block);
+                       BUG_ON(ret);
+                       wait_on_page_locked(pinned[0]);
+               } else {
+                       unlock_page(pinned[0]);
+               }
+       }
+       if ((pos + count) & (PAGE_CACHE_SIZE - 1)) {
+               pinned[1] = grab_cache_page(inode->i_mapping, last_index);
+               if (!PageUptodate(pinned[1])) {
+                       ret = mpage_readpage(pinned[1], btrfs_get_block);
+                       BUG_ON(ret);
+                       wait_on_page_locked(pinned[1]);
+               } else {
+                       unlock_page(pinned[1]);
+               }
+       }
+
+       mutex_lock(&root->fs_info->fs_mutex);
+       trans = btrfs_start_transaction(root, 1);
+       if (!trans) {
+               err = -ENOMEM;
+               mutex_unlock(&root->fs_info->fs_mutex);
+               goto out_unlock;
+       }
+       btrfs_set_trans_block_group(trans, inode);
+       /* FIXME blocksize != 4096 */
+       inode->i_blocks += num_blocks << 3;
+       hint_block = 0;
+
+       /* FIXME...EIEIO, ENOSPC and more */
+
+       /* step one, delete the existing extents in this range */
+       if (start_pos < inode->i_size) {
+               /* FIXME blocksize != pagesize */
+               ret = btrfs_drop_extents(trans, root, inode,
+                                        start_pos,
+                                        (pos + count + root->blocksize -1) &
+                                        ~((u64)root->blocksize - 1),
+                                        &hint_block);
+               BUG_ON(ret);
+       }
+
+       /* insert any holes we need to create */
+       if (inode->i_size < start_pos) {
+               u64 last_pos_in_file;
+               u64 hole_size;
+               u64 mask = root->blocksize - 1;
+               last_pos_in_file = (inode->i_size + mask) & ~mask;
+               hole_size = (start_pos - last_pos_in_file + mask) & ~mask;
+               hole_size >>= inode->i_blkbits;
+               if (last_pos_in_file < start_pos) {
+                       ret = btrfs_insert_file_extent(trans, root,
+                                                      inode->i_ino,
+                                                      last_pos_in_file,
+                                                      0, 0, hole_size);
+               }
+               BUG_ON(ret);
+       }
+
+       /*
+        * either allocate an extent for the new bytes or setup the key
+        * to show we are doing inline data in the extent
+        */
+       if (inode->i_size >= PAGE_CACHE_SIZE || pos + count < inode->i_size ||
+           pos + count - start_pos > BTRFS_MAX_INLINE_DATA_SIZE(root)) {
+               ret = btrfs_alloc_extent(trans, root, inode->i_ino,
+                                        num_blocks, hint_block, (u64)-1,
+                                        &ins, 1);
+               BUG_ON(ret);
+               ret = btrfs_insert_file_extent(trans, root, inode->i_ino,
+                                      start_pos, ins.objectid, ins.offset,
+                                      ins.offset);
+               BUG_ON(ret);
+       } else {
+               ins.offset = 0;
+               ins.objectid = 0;
+       }
+       BUG_ON(ret);
+       alloc_extent_start = ins.objectid;
+       ret = btrfs_end_transaction(trans, root);
+       mutex_unlock(&root->fs_info->fs_mutex);
+
+       while(count > 0) {
+               size_t offset = pos & (PAGE_CACHE_SIZE - 1);
+               size_t write_bytes = min(count, PAGE_CACHE_SIZE - offset);
+               size_t num_pages = (write_bytes + PAGE_CACHE_SIZE - 1) >>
+                                       PAGE_CACHE_SHIFT;
+
+               memset(pages, 0, sizeof(pages));
+               ret = prepare_pages(root, file, pages, num_pages,
+                                   pos, first_index, last_index,
+                                   write_bytes, alloc_extent_start);
+               BUG_ON(ret);
+
+               /* FIXME blocks != pagesize */
+               if (alloc_extent_start)
+                       alloc_extent_start += num_pages;
+               ret = btrfs_copy_from_user(pos, num_pages,
+                                          write_bytes, pages, buf);
+               BUG_ON(ret);
+
+               ret = dirty_and_release_pages(NULL, root, file, pages,
+                                             num_pages, pos, write_bytes);
+               BUG_ON(ret);
+               btrfs_drop_pages(pages, num_pages);
+
+               buf += write_bytes;
+               count -= write_bytes;
+               pos += write_bytes;
+               num_written += write_bytes;
+
+               balance_dirty_pages_ratelimited(inode->i_mapping);
+               btrfs_btree_balance_dirty(root);
+               cond_resched();
+       }
+out_unlock:
+       mutex_unlock(&inode->i_mutex);
+out:
+       if (pinned[0])
+               page_cache_release(pinned[0]);
+       if (pinned[1])
+               page_cache_release(pinned[1]);
+       *ppos = pos;
+       current->backing_dev_info = NULL;
+       mark_inode_dirty(inode);
+       return num_written ? num_written : err;
+}
+
+/*
+ * FIXME, do this by stuffing the csum we want in the info hanging off
+ * page->private.  For now, verify file csums on read
+ */
+static int btrfs_read_actor(read_descriptor_t *desc, struct page *page,
+                       unsigned long offset, unsigned long size)
+{
+       char *kaddr;
+       unsigned long left, count = desc->count;
+       struct inode *inode = page->mapping->host;
+
+       if (size > count)
+               size = count;
+
+       if (!PageChecked(page)) {
+               /* FIXME, do it per block */
+               struct btrfs_root *root = BTRFS_I(inode)->root;
+               int ret;
+               struct buffer_head *bh;
+
+               if (page_has_buffers(page)) {
+                       bh = page_buffers(page);
+                       if (!buffer_mapped(bh)) {
+                               SetPageChecked(page);
+                               goto checked;
+                       }
+               }
+
+               ret = btrfs_csum_verify_file_block(root,
+                                 page->mapping->host->i_ino,
+                                 page->index << PAGE_CACHE_SHIFT,
+                                 kmap(page), PAGE_CACHE_SIZE);
+               if (ret) {
+                       if (ret != -ENOENT) {
+                               printk("failed to verify ino %lu page %lu ret %d\n",
+                                      page->mapping->host->i_ino,
+                                      page->index, ret);
+                               memset(page_address(page), 1, PAGE_CACHE_SIZE);
+                               flush_dcache_page(page);
+                       }
+               }
+               SetPageChecked(page);
+               kunmap(page);
+       }
+checked:
+       /*
+        * Faults on the destination of a read are common, so do it before
+        * taking the kmap.
+        */
+       if (!fault_in_pages_writeable(desc->arg.buf, size)) {
+               kaddr = kmap_atomic(page, KM_USER0);
+               left = __copy_to_user_inatomic(desc->arg.buf,
+                                               kaddr + offset, size);
+               kunmap_atomic(kaddr, KM_USER0);
+               if (left == 0)
+                       goto success;
+       }
+
+       /* Do it the slow way */
+       kaddr = kmap(page);
+       left = __copy_to_user(desc->arg.buf, kaddr + offset, size);
+       kunmap(page);
+
+       if (left) {
+               size -= left;
+               desc->error = -EFAULT;
+       }
+success:
+       desc->count = count - size;
+       desc->written += size;
+       desc->arg.buf += size;
+       return size;
+}
+
+/**
+ * btrfs_file_aio_read - filesystem read routine, with a mod to csum verify
+ * @iocb:      kernel I/O control block
+ * @iov:       io vector request
+ * @nr_segs:   number of segments in the iovec
+ * @pos:       current file position
+ */
+static ssize_t btrfs_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
+                                  unsigned long nr_segs, loff_t pos)
+{
+       struct file *filp = iocb->ki_filp;
+       ssize_t retval;
+       unsigned long seg;
+       size_t count;
+       loff_t *ppos = &iocb->ki_pos;
+
+       count = 0;
+       for (seg = 0; seg < nr_segs; seg++) {
+               const struct iovec *iv = &iov[seg];
+
+               /*
+                * If any segment has a negative length, or the cumulative
+                * length ever wraps negative then return -EINVAL.
+                */
+               count += iv->iov_len;
+               if (unlikely((ssize_t)(count|iv->iov_len) < 0))
+                       return -EINVAL;
+               if (access_ok(VERIFY_WRITE, iv->iov_base, iv->iov_len))
+                       continue;
+               if (seg == 0)
+                       return -EFAULT;
+               nr_segs = seg;
+               count -= iv->iov_len;   /* This segment is no good */
+               break;
+       }
+       retval = 0;
+       if (count) {
+               for (seg = 0; seg < nr_segs; seg++) {
+                       read_descriptor_t desc;
+
+                       desc.written = 0;
+                       desc.arg.buf = iov[seg].iov_base;
+                       desc.count = iov[seg].iov_len;
+                       if (desc.count == 0)
+                               continue;
+                       desc.error = 0;
+                       do_generic_file_read(filp, ppos, &desc,
+                                            btrfs_read_actor);
+                       retval += desc.written;
+                       if (desc.error) {
+                               retval = retval ?: desc.error;
+                               break;
+                       }
+               }
+       }
+       return retval;
+}
+
+static int btrfs_sync_file(struct file *file,
+                          struct dentry *dentry, int datasync)
+{
+       struct inode *inode = dentry->d_inode;
+       struct btrfs_root *root = BTRFS_I(inode)->root;
+       int ret;
+       struct btrfs_trans_handle *trans;
+
+       /*
+        * FIXME, use inode generation number to check if we can skip the
+        * commit
+        */
+       mutex_lock(&root->fs_info->fs_mutex);
+       trans = btrfs_start_transaction(root, 1);
+       if (!trans) {
+               ret = -ENOMEM;
+               goto out;
+       }
+       ret = btrfs_commit_transaction(trans, root);
+       mutex_unlock(&root->fs_info->fs_mutex);
+out:
+       return ret > 0 ? EIO : ret;
+}
+
+struct file_operations btrfs_file_operations = {
+       .llseek         = generic_file_llseek,
+       .read           = do_sync_read,
+       .aio_read       = btrfs_file_aio_read,
+       .write          = btrfs_file_write,
+       .mmap           = generic_file_mmap,
+       .open           = generic_file_open,
+       .ioctl          = btrfs_ioctl,
+       .fsync          = btrfs_sync_file,
+#ifdef CONFIG_COMPAT
+       .compat_ioctl   = btrfs_compat_ioctl,
+#endif
+};
+
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
new file mode 100644 (file)
index 0000000..62a3a77
--- /dev/null
@@ -0,0 +1,2210 @@
+#include <linux/module.h>
+#include <linux/buffer_head.h>
+#include <linux/fs.h>
+#include <linux/pagemap.h>
+#include <linux/highmem.h>
+#include <linux/time.h>
+#include <linux/init.h>
+#include <linux/string.h>
+#include <linux/smp_lock.h>
+#include <linux/backing-dev.h>
+#include <linux/mpage.h>
+#include <linux/swap.h>
+#include <linux/writeback.h>
+#include <linux/statfs.h>
+#include <linux/compat.h>
+#include "ctree.h"
+#include "disk-io.h"
+#include "transaction.h"
+#include "btrfs_inode.h"
+#include "ioctl.h"
+#include "print-tree.h"
+
+struct btrfs_iget_args {
+       u64 ino;
+       struct btrfs_root *root;
+};
+
+static struct inode_operations btrfs_dir_inode_operations;
+static struct inode_operations btrfs_symlink_inode_operations;
+static struct inode_operations btrfs_dir_ro_inode_operations;
+static struct inode_operations btrfs_file_inode_operations;
+static struct address_space_operations btrfs_aops;
+static struct address_space_operations btrfs_symlink_aops;
+static struct file_operations btrfs_dir_file_operations;
+
+static struct kmem_cache *btrfs_inode_cachep;
+struct kmem_cache *btrfs_trans_handle_cachep;
+struct kmem_cache *btrfs_transaction_cachep;
+struct kmem_cache *btrfs_bit_radix_cachep;
+struct kmem_cache *btrfs_path_cachep;
+
+#define S_SHIFT 12
+static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
+       [S_IFREG >> S_SHIFT]    = BTRFS_FT_REG_FILE,
+       [S_IFDIR >> S_SHIFT]    = BTRFS_FT_DIR,
+       [S_IFCHR >> S_SHIFT]    = BTRFS_FT_CHRDEV,
+       [S_IFBLK >> S_SHIFT]    = BTRFS_FT_BLKDEV,
+       [S_IFIFO >> S_SHIFT]    = BTRFS_FT_FIFO,
+       [S_IFSOCK >> S_SHIFT]   = BTRFS_FT_SOCK,
+       [S_IFLNK >> S_SHIFT]    = BTRFS_FT_SYMLINK,
+};
+
+void btrfs_read_locked_inode(struct inode *inode)
+{
+       struct btrfs_path *path;
+       struct btrfs_inode_item *inode_item;
+       struct btrfs_root *root = BTRFS_I(inode)->root;
+       struct btrfs_key location;
+       u64 alloc_group_block;
+       int ret;
+
+       path = btrfs_alloc_path();
+       BUG_ON(!path);
+       btrfs_init_path(path);
+       mutex_lock(&root->fs_info->fs_mutex);
+
+       memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
+       ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
+       if (ret) {
+               btrfs_free_path(path);
+               goto make_bad;
+       }
+       inode_item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
+                                 path->slots[0],
+                                 struct btrfs_inode_item);
+
+       inode->i_mode = btrfs_inode_mode(inode_item);
+       inode->i_nlink = btrfs_inode_nlink(inode_item);
+       inode->i_uid = btrfs_inode_uid(inode_item);
+       inode->i_gid = btrfs_inode_gid(inode_item);
+       inode->i_size = btrfs_inode_size(inode_item);
+       inode->i_atime.tv_sec = btrfs_timespec_sec(&inode_item->atime);
+       inode->i_atime.tv_nsec = btrfs_timespec_nsec(&inode_item->atime);
+       inode->i_mtime.tv_sec = btrfs_timespec_sec(&inode_item->mtime);
+       inode->i_mtime.tv_nsec = btrfs_timespec_nsec(&inode_item->mtime);
+       inode->i_ctime.tv_sec = btrfs_timespec_sec(&inode_item->ctime);
+       inode->i_ctime.tv_nsec = btrfs_timespec_nsec(&inode_item->ctime);
+       inode->i_blocks = btrfs_inode_nblocks(inode_item);
+       inode->i_generation = btrfs_inode_generation(inode_item);
+       alloc_group_block = btrfs_inode_block_group(inode_item);
+       BTRFS_I(inode)->block_group = btrfs_lookup_block_group(root->fs_info,
+                                                      alloc_group_block);
+
+       btrfs_free_path(path);
+       inode_item = NULL;
+
+       mutex_unlock(&root->fs_info->fs_mutex);
+
+       switch (inode->i_mode & S_IFMT) {
+#if 0
+       default:
+               init_special_inode(inode, inode->i_mode,
+                                  btrfs_inode_rdev(inode_item));
+               break;
+#endif
+       case S_IFREG:
+               inode->i_mapping->a_ops = &btrfs_aops;
+               inode->i_fop = &btrfs_file_operations;
+               inode->i_op = &btrfs_file_inode_operations;
+               break;
+       case S_IFDIR:
+               inode->i_fop = &btrfs_dir_file_operations;
+               if (root == root->fs_info->tree_root)
+                       inode->i_op = &btrfs_dir_ro_inode_operations;
+               else
+                       inode->i_op = &btrfs_dir_inode_operations;
+               break;
+       case S_IFLNK:
+               inode->i_op = &btrfs_symlink_inode_operations;
+               inode->i_mapping->a_ops = &btrfs_symlink_aops;
+               break;
+       }
+       return;
+
+make_bad:
+       btrfs_release_path(root, path);
+       btrfs_free_path(path);
+       mutex_unlock(&root->fs_info->fs_mutex);
+       make_bad_inode(inode);
+}
+
+static void fill_inode_item(struct btrfs_inode_item *item,
+                           struct inode *inode)
+{
+       btrfs_set_inode_uid(item, inode->i_uid);
+       btrfs_set_inode_gid(item, inode->i_gid);
+       btrfs_set_inode_size(item, inode->i_size);
+       btrfs_set_inode_mode(item, inode->i_mode);
+       btrfs_set_inode_nlink(item, inode->i_nlink);
+       btrfs_set_timespec_sec(&item->atime, inode->i_atime.tv_sec);
+       btrfs_set_timespec_nsec(&item->atime, inode->i_atime.tv_nsec);
+       btrfs_set_timespec_sec(&item->mtime, inode->i_mtime.tv_sec);
+       btrfs_set_timespec_nsec(&item->mtime, inode->i_mtime.tv_nsec);
+       btrfs_set_timespec_sec(&item->ctime, inode->i_ctime.tv_sec);
+       btrfs_set_timespec_nsec(&item->ctime, inode->i_ctime.tv_nsec);
+       btrfs_set_inode_nblocks(item, inode->i_blocks);
+       btrfs_set_inode_generation(item, inode->i_generation);
+       btrfs_set_inode_block_group(item,
+                                   BTRFS_I(inode)->block_group->key.objectid);
+}
+
+static int btrfs_update_inode(struct btrfs_trans_handle *trans,
+                             struct btrfs_root *root,
+                             struct inode *inode)
+{
+       struct btrfs_inode_item *inode_item;
+       struct btrfs_path *path;
+       int ret;
+
+       path = btrfs_alloc_path();
+       BUG_ON(!path);
+       btrfs_init_path(path);
+       ret = btrfs_lookup_inode(trans, root, path,
+                                &BTRFS_I(inode)->location, 1);
+       if (ret) {
+               if (ret > 0)
+                       ret = -ENOENT;
+               goto failed;
+       }
+
+       inode_item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
+                                 path->slots[0],
+                                 struct btrfs_inode_item);
+
+       fill_inode_item(inode_item, inode);
+       btrfs_mark_buffer_dirty(path->nodes[0]);
+       ret = 0;
+failed:
+       btrfs_release_path(root, path);
+       btrfs_free_path(path);
+       return ret;
+}
+
+
+static int btrfs_unlink_trans(struct btrfs_trans_handle *trans,
+                             struct btrfs_root *root,
+                             struct inode *dir,
+                             struct dentry *dentry)
+{
+       struct btrfs_path *path;
+       const char *name = dentry->d_name.name;
+       int name_len = dentry->d_name.len;
+       int ret = 0;
+       u64 objectid;
+       struct btrfs_dir_item *di;
+
+       path = btrfs_alloc_path();
+       BUG_ON(!path);
+       btrfs_init_path(path);
+       di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
+                                   name, name_len, -1);
+       if (IS_ERR(di)) {
+               ret = PTR_ERR(di);
+               goto err;
+       }
+       if (!di) {
+               ret = -ENOENT;
+               goto err;
+       }
+       objectid = btrfs_disk_key_objectid(&di->location);
+       ret = btrfs_delete_one_dir_name(trans, root, path, di);
+       BUG_ON(ret);
+       btrfs_release_path(root, path);
+
+       di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
+                                        objectid, name, name_len, -1);
+       if (IS_ERR(di)) {
+               ret = PTR_ERR(di);
+               goto err;
+       }
+       if (!di) {
+               ret = -ENOENT;
+               goto err;
+       }
+       ret = btrfs_delete_one_dir_name(trans, root, path, di);
+       BUG_ON(ret);
+
+       dentry->d_inode->i_ctime = dir->i_ctime;
+err:
+       btrfs_free_path(path);
+       if (!ret) {
+               dir->i_size -= name_len * 2;
+               btrfs_update_inode(trans, root, dir);
+               drop_nlink(dentry->d_inode);
+               btrfs_update_inode(trans, root, dentry->d_inode);
+               dir->i_sb->s_dirt = 1;
+       }
+       return ret;
+}
+
+static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
+{
+       struct btrfs_root *root;
+       struct btrfs_trans_handle *trans;
+       int ret;
+
+       root = BTRFS_I(dir)->root;
+       mutex_lock(&root->fs_info->fs_mutex);
+       trans = btrfs_start_transaction(root, 1);
+       btrfs_set_trans_block_group(trans, dir);
+       ret = btrfs_unlink_trans(trans, root, dir, dentry);
+       btrfs_end_transaction(trans, root);
+       mutex_unlock(&root->fs_info->fs_mutex);
+       btrfs_btree_balance_dirty(root);
+       return ret;
+}
+
+static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
+{
+       struct inode *inode = dentry->d_inode;
+       int err;
+       int ret;
+       struct btrfs_root *root = BTRFS_I(dir)->root;
+       struct btrfs_path *path;
+       struct btrfs_key key;
+       struct btrfs_trans_handle *trans;
+       struct btrfs_key found_key;
+       int found_type;
+       struct btrfs_leaf *leaf;
+       char *goodnames = "..";
+
+       path = btrfs_alloc_path();
+       BUG_ON(!path);
+       btrfs_init_path(path);
+       mutex_lock(&root->fs_info->fs_mutex);
+       trans = btrfs_start_transaction(root, 1);
+       btrfs_set_trans_block_group(trans, dir);
+       key.objectid = inode->i_ino;
+       key.offset = (u64)-1;
+       key.flags = (u32)-1;
+       while(1) {
+               ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+               if (ret < 0) {
+                       err = ret;
+                       goto out;
+               }
+               BUG_ON(ret == 0);
+               if (path->slots[0] == 0) {
+                       err = -ENOENT;
+                       goto out;
+               }
+               path->slots[0]--;
+               leaf = btrfs_buffer_leaf(path->nodes[0]);
+               btrfs_disk_key_to_cpu(&found_key,
+                                     &leaf->items[path->slots[0]].key);
+               found_type = btrfs_key_type(&found_key);
+               if (found_key.objectid != inode->i_ino) {
+                       err = -ENOENT;
+                       goto out;
+               }
+               if ((found_type != BTRFS_DIR_ITEM_KEY &&
+                    found_type != BTRFS_DIR_INDEX_KEY) ||
+                   (!btrfs_match_dir_item_name(root, path, goodnames, 2) &&
+                   !btrfs_match_dir_item_name(root, path, goodnames, 1))) {
+                       err = -ENOTEMPTY;
+                       goto out;
+               }
+               ret = btrfs_del_item(trans, root, path);
+               BUG_ON(ret);
+
+               if (found_type == BTRFS_DIR_ITEM_KEY && found_key.offset == 1)
+                       break;
+               btrfs_release_path(root, path);
+       }
+       ret = 0;
+       btrfs_release_path(root, path);
+
+       /* now the directory is empty */
+       err = btrfs_unlink_trans(trans, root, dir, dentry);
+       if (!err) {
+               inode->i_size = 0;
+       }
+out:
+       btrfs_release_path(root, path);
+       btrfs_free_path(path);
+       mutex_unlock(&root->fs_info->fs_mutex);
+       ret = btrfs_end_transaction(trans, root);
+       btrfs_btree_balance_dirty(root);
+       if (ret && !err)
+               err = ret;
+       return err;
+}
+
+static int btrfs_free_inode(struct btrfs_trans_handle *trans,
+                           struct btrfs_root *root,
+                           struct inode *inode)
+{
+       struct btrfs_path *path;
+       int ret;
+
+       clear_inode(inode);
+
+       path = btrfs_alloc_path();
+       BUG_ON(!path);
+       btrfs_init_path(path);
+       ret = btrfs_lookup_inode(trans, root, path,
+                                &BTRFS_I(inode)->location, -1);
+       BUG_ON(ret);
+       ret = btrfs_del_item(trans, root, path);
+       BUG_ON(ret);
+       btrfs_free_path(path);
+       return ret;
+}
+
+/*
+ * truncates go from a high offset to a low offset.  So, walk
+ * from hi to lo in the node and issue readas.  Stop when you find
+ * keys from a different objectid
+ */
+static void reada_truncate(struct btrfs_root *root, struct btrfs_path *path,
+                          u64 objectid)
+{
+       struct btrfs_node *node;
+       int i;
+       int nritems;
+       u64 item_objectid;
+       u64 blocknr;
+       int slot;
+       int ret;
+
+       if (!path->nodes[1])
+               return;
+       node = btrfs_buffer_node(path->nodes[1]);
+       slot = path->slots[1];
+       if (slot == 0)
+               return;
+       nritems = btrfs_header_nritems(&node->header);
+       for (i = slot - 1; i >= 0; i--) {
+               item_objectid = btrfs_disk_key_objectid(&node->ptrs[i].key);
+               if (item_objectid != objectid)
+                       break;
+               blocknr = btrfs_node_blockptr(node, i);
+               ret = readahead_tree_block(root, blocknr);
+               if (ret)
+                       break;
+       }
+}
+
+/*
+ * this can truncate away extent items, csum items and directory items.
+ * It starts at a high offset and removes keys until it can't find
+ * any higher than i_size.
+ *
+ * csum items that cross the new i_size are truncated to the new size
+ * as well.
+ */
+static int btrfs_truncate_in_trans(struct btrfs_trans_handle *trans,
+                                  struct btrfs_root *root,
+                                  struct inode *inode)
+{
+       int ret;
+       struct btrfs_path *path;
+       struct btrfs_key key;
+       struct btrfs_disk_key *found_key;
+       u32 found_type;
+       struct btrfs_leaf *leaf;
+       struct btrfs_file_extent_item *fi;
+       u64 extent_start = 0;
+       u64 extent_num_blocks = 0;
+       u64 item_end = 0;
+       int found_extent;
+       int del_item;
+
+       path = btrfs_alloc_path();
+       BUG_ON(!path);
+       /* FIXME, add redo link to tree so we don't leak on crash */
+       key.objectid = inode->i_ino;
+       key.offset = (u64)-1;
+       key.flags = (u32)-1;
+       while(1) {
+               btrfs_init_path(path);
+               fi = NULL;
+               ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+               if (ret < 0) {
+                       goto error;
+               }
+               if (ret > 0) {
+                       BUG_ON(path->slots[0] == 0);
+                       path->slots[0]--;
+               }
+               reada_truncate(root, path, inode->i_ino);
+               leaf = btrfs_buffer_leaf(path->nodes[0]);
+               found_key = &leaf->items[path->slots[0]].key;
+               found_type = btrfs_disk_key_type(found_key);
+
+               if (btrfs_disk_key_objectid(found_key) != inode->i_ino)
+                       break;
+               if (found_type != BTRFS_CSUM_ITEM_KEY &&
+                   found_type != BTRFS_DIR_ITEM_KEY &&
+                   found_type != BTRFS_DIR_INDEX_KEY &&
+                   found_type != BTRFS_EXTENT_DATA_KEY)
+                       break;
+
+               item_end = btrfs_disk_key_offset(found_key);
+               if (found_type == BTRFS_EXTENT_DATA_KEY) {
+                       fi = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
+                                           path->slots[0],
+                                           struct btrfs_file_extent_item);
+                       if (btrfs_file_extent_type(fi) !=
+                           BTRFS_FILE_EXTENT_INLINE) {
+                               item_end += btrfs_file_extent_num_blocks(fi) <<
+                                               inode->i_blkbits;
+                       }
+               }
+               if (found_type == BTRFS_CSUM_ITEM_KEY) {
+                       ret = btrfs_csum_truncate(trans, root, path,
+                                                 inode->i_size);
+                       BUG_ON(ret);
+               }
+               if (item_end < inode->i_size) {
+                       if (found_type) {
+                               btrfs_set_key_type(&key, found_type - 1);
+                               continue;
+                       }
+                       break;
+               }
+               if (btrfs_disk_key_offset(found_key) >= inode->i_size)
+                       del_item = 1;
+               else
+                       del_item = 0;
+               found_extent = 0;
+
+               /* FIXME, shrink the extent if the ref count is only 1 */
+               if (found_type == BTRFS_EXTENT_DATA_KEY &&
+                          btrfs_file_extent_type(fi) !=
+                          BTRFS_FILE_EXTENT_INLINE) {
+                       u64 num_dec;
+                       if (!del_item) {
+                               u64 orig_num_blocks =
+                                       btrfs_file_extent_num_blocks(fi);
+                               extent_num_blocks = inode->i_size -
+                                       btrfs_disk_key_offset(found_key) +
+                                       root->blocksize - 1;
+                               extent_num_blocks >>= inode->i_blkbits;
+                               btrfs_set_file_extent_num_blocks(fi,
+                                                        extent_num_blocks);
+                               inode->i_blocks -= (orig_num_blocks -
+                                       extent_num_blocks) << 3;
+                               mark_buffer_dirty(path->nodes[0]);
+                       } else {
+                               extent_start =
+                                       btrfs_file_extent_disk_blocknr(fi);
+                               extent_num_blocks =
+                                       btrfs_file_extent_disk_num_blocks(fi);
+                               /* FIXME blocksize != 4096 */
+                               num_dec = btrfs_file_extent_num_blocks(fi) << 3;
+                               if (extent_start != 0) {
+                                       found_extent = 1;
+                                       inode->i_blocks -= num_dec;
+                               }
+                       }
+               }
+               if (del_item) {
+                       ret = btrfs_del_item(trans, root, path);
+                       BUG_ON(ret);
+               } else {
+                       break;
+               }
+               btrfs_release_path(root, path);
+               if (found_extent) {
+                       ret = btrfs_free_extent(trans, root, extent_start,
+                                               extent_num_blocks, 0);
+                       BUG_ON(ret);
+               }
+       }
+       ret = 0;
+error:
+       btrfs_release_path(root, path);
+       btrfs_free_path(path);
+       inode->i_sb->s_dirt = 1;
+       return ret;
+}
+
+/*
+ * taken from block_truncate_page, but does cow as it zeros out
+ * any bytes left in the last page in the file.
+ */
+static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
+{
+       struct inode *inode = mapping->host;
+       unsigned blocksize = 1 << inode->i_blkbits;
+       pgoff_t index = from >> PAGE_CACHE_SHIFT;
+       unsigned offset = from & (PAGE_CACHE_SIZE-1);
+       struct page *page;
+       char *kaddr;
+       int ret = 0;
+       struct btrfs_root *root = BTRFS_I(inode)->root;
+       u64 alloc_hint = 0;
+       struct btrfs_key ins;
+       struct btrfs_trans_handle *trans;
+
+       if ((offset & (blocksize - 1)) == 0)
+               goto out;
+
+       ret = -ENOMEM;
+       page = grab_cache_page(mapping, index);
+       if (!page)
+               goto out;
+
+       if (!PageUptodate(page)) {
+               ret = mpage_readpage(page, btrfs_get_block);
+               lock_page(page);
+               if (!PageUptodate(page)) {
+                       ret = -EIO;
+                       goto out;
+               }
+       }
+       mutex_lock(&root->fs_info->fs_mutex);
+       trans = btrfs_start_transaction(root, 1);
+       btrfs_set_trans_block_group(trans, inode);
+
+       ret = btrfs_drop_extents(trans, root, inode,
+                                page->index << PAGE_CACHE_SHIFT,
+                                (page->index + 1) << PAGE_CACHE_SHIFT,
+                                &alloc_hint);
+       BUG_ON(ret);
+       ret = btrfs_alloc_extent(trans, root, inode->i_ino, 1,
+                                alloc_hint, (u64)-1, &ins, 1);
+       BUG_ON(ret);
+       ret = btrfs_insert_file_extent(trans, root, inode->i_ino,
+                                      page->index << PAGE_CACHE_SHIFT,
+                                      ins.objectid, 1, 1);
+       BUG_ON(ret);
+       SetPageChecked(page);
+       kaddr = kmap(page);
+       memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset);
+       flush_dcache_page(page);
+       btrfs_csum_file_block(trans, root, inode->i_ino,
+                             page->index << PAGE_CACHE_SHIFT,
+                             kaddr, PAGE_CACHE_SIZE);
+       kunmap(page);
+       btrfs_end_transaction(trans, root);
+       mutex_unlock(&root->fs_info->fs_mutex);
+
+       set_page_dirty(page);
+       unlock_page(page);
+       page_cache_release(page);
+out:
+       return ret;
+}
+
+static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
+{
+       struct inode *inode = dentry->d_inode;
+       int err;
+
+       err = inode_change_ok(inode, attr);
+       if (err)
+               return err;
+
+       if (S_ISREG(inode->i_mode) &&
+           attr->ia_valid & ATTR_SIZE && attr->ia_size > inode->i_size) {
+               struct btrfs_trans_handle *trans;
+               struct btrfs_root *root = BTRFS_I(inode)->root;
+               u64 mask = root->blocksize - 1;
+               u64 pos = (inode->i_size + mask) & ~mask;
+               u64 hole_size;
+
+               if (attr->ia_size <= pos)
+                       goto out;
+
+               btrfs_truncate_page(inode->i_mapping, inode->i_size);
+
+               hole_size = (attr->ia_size - pos + mask) & ~mask;
+               hole_size >>= inode->i_blkbits;
+
+               mutex_lock(&root->fs_info->fs_mutex);
+               trans = btrfs_start_transaction(root, 1);
+               btrfs_set_trans_block_group(trans, inode);
+               err = btrfs_insert_file_extent(trans, root, inode->i_ino,
+                                              pos, 0, 0, hole_size);
+               BUG_ON(err);
+               btrfs_end_transaction(trans, root);
+               mutex_unlock(&root->fs_info->fs_mutex);
+       }
+out:
+       err = inode_setattr(inode, attr);
+
+       return err;
+}
+void btrfs_delete_inode(struct inode *inode)
+{
+       struct btrfs_trans_handle *trans;
+       struct btrfs_root *root = BTRFS_I(inode)->root;
+       int ret;
+
+       truncate_inode_pages(&inode->i_data, 0);
+       if (is_bad_inode(inode)) {
+               goto no_delete;
+       }
+       inode->i_size = 0;
+       mutex_lock(&root->fs_info->fs_mutex);
+       trans = btrfs_start_transaction(root, 1);
+       btrfs_set_trans_block_group(trans, inode);
+       ret = btrfs_truncate_in_trans(trans, root, inode);
+       BUG_ON(ret);
+       btrfs_free_inode(trans, root, inode);
+       btrfs_end_transaction(trans, root);
+       mutex_unlock(&root->fs_info->fs_mutex);
+       btrfs_btree_balance_dirty(root);
+       return;
+no_delete:
+       clear_inode(inode);
+}
+
+/*
+ * this returns the key found in the dir entry in the location pointer.
+ * If no dir entries were found, location->objectid is 0.
+ */
+static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
+                              struct btrfs_key *location)
+{
+       const char *name = dentry->d_name.name;
+       int namelen = dentry->d_name.len;
+       struct btrfs_dir_item *di;
+       struct btrfs_path *path;
+       struct btrfs_root *root = BTRFS_I(dir)->root;
+       int ret;
+
+       path = btrfs_alloc_path();
+       BUG_ON(!path);
+       btrfs_init_path(path);
+       di = btrfs_lookup_dir_item(NULL, root, path, dir->i_ino, name,
+                                   namelen, 0);
+       if (!di || IS_ERR(di)) {
+               location->objectid = 0;
+               ret = 0;
+               goto out;
+       }
+       btrfs_disk_key_to_cpu(location, &di->location);
+out:
+       btrfs_release_path(root, path);
+       btrfs_free_path(path);
+       return ret;
+}
+
+/*
+ * when we hit a tree root in a directory, the btrfs part of the inode
+ * needs to be changed to reflect the root directory of the tree root.  This
+ * is kind of like crossing a mount point.
+ */
+static int fixup_tree_root_location(struct btrfs_root *root,
+                            struct btrfs_key *location,
+                            struct btrfs_root **sub_root)
+{
+       struct btrfs_path *path;
+       struct btrfs_root_item *ri;
+
+       if (btrfs_key_type(location) != BTRFS_ROOT_ITEM_KEY)
+               return 0;
+       if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
+               return 0;
+
+       path = btrfs_alloc_path();
+       BUG_ON(!path);
+       mutex_lock(&root->fs_info->fs_mutex);
+
+       *sub_root = btrfs_read_fs_root(root->fs_info, location);
+       if (IS_ERR(*sub_root))
+               return PTR_ERR(*sub_root);
+
+       ri = &(*sub_root)->root_item;
+       location->objectid = btrfs_root_dirid(ri);
+       location->flags = 0;
+       btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
+       location->offset = 0;
+
+       btrfs_free_path(path);
+       mutex_unlock(&root->fs_info->fs_mutex);
+       return 0;
+}
+
+static int btrfs_init_locked_inode(struct inode *inode, void *p)
+{
+       struct btrfs_iget_args *args = p;
+       inode->i_ino = args->ino;
+       BTRFS_I(inode)->root = args->root;
+       return 0;
+}
+
+static int btrfs_find_actor(struct inode *inode, void *opaque)
+{
+       struct btrfs_iget_args *args = opaque;
+       return (args->ino == inode->i_ino &&
+               args->root == BTRFS_I(inode)->root);
+}
+
+struct inode *btrfs_iget_locked(struct super_block *s, u64 objectid,
+                               struct btrfs_root *root)
+{
+       struct inode *inode;
+       struct btrfs_iget_args args;
+       args.ino = objectid;
+       args.root = root;
+
+       inode = iget5_locked(s, objectid, btrfs_find_actor,
+                            btrfs_init_locked_inode,
+                            (void *)&args);
+       return inode;
+}
+
+static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
+                                  struct nameidata *nd)
+{
+       struct inode * inode;
+       struct btrfs_inode *bi = BTRFS_I(dir);
+       struct btrfs_root *root = bi->root;
+       struct btrfs_root *sub_root = root;
+       struct btrfs_key location;
+       int ret;
+
+       if (dentry->d_name.len > BTRFS_NAME_LEN)
+               return ERR_PTR(-ENAMETOOLONG);
+       mutex_lock(&root->fs_info->fs_mutex);
+       ret = btrfs_inode_by_name(dir, dentry, &location);
+       mutex_unlock(&root->fs_info->fs_mutex);
+       if (ret < 0)
+               return ERR_PTR(ret);
+       inode = NULL;
+       if (location.objectid) {
+               ret = fixup_tree_root_location(root, &location, &sub_root);
+               if (ret < 0)
+                       return ERR_PTR(ret);
+               if (ret > 0)
+                       return ERR_PTR(-ENOENT);
+               inode = btrfs_iget_locked(dir->i_sb, location.objectid,
+                                         sub_root);
+               if (!inode)
+                       return ERR_PTR(-EACCES);
+               if (inode->i_state & I_NEW) {
+                       /* the inode and parent dir are two different roots */
+                       if (sub_root != root) {
+                               igrab(inode);
+                               sub_root->inode = inode;
+                       }
+                       BTRFS_I(inode)->root = sub_root;
+                       memcpy(&BTRFS_I(inode)->location, &location,
+                              sizeof(location));
+                       btrfs_read_locked_inode(inode);
+                       unlock_new_inode(inode);
+               }
+       }
+       return d_splice_alias(inode, dentry);
+}
+
+/*
+ * readahead one full node of leaves as long as their keys include
+ * the objectid supplied
+ */
+static void reada_leaves(struct btrfs_root *root, struct btrfs_path *path,
+                        u64 objectid)
+{
+       struct btrfs_node *node;
+       int i;
+       u32 nritems;
+       u64 item_objectid;
+       u64 blocknr;
+       int slot;
+       int ret;
+
+       if (!path->nodes[1])
+               return;
+       node = btrfs_buffer_node(path->nodes[1]);
+       slot = path->slots[1];
+       nritems = btrfs_header_nritems(&node->header);
+       for (i = slot + 1; i < nritems; i++) {
+               item_objectid = btrfs_disk_key_objectid(&node->ptrs[i].key);
+               if (item_objectid != objectid)
+                       break;
+               blocknr = btrfs_node_blockptr(node, i);
+               ret = readahead_tree_block(root, blocknr);
+               if (ret)
+                       break;
+       }
+}
+static unsigned char btrfs_filetype_table[] = {
+       DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
+};
+
+static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
+{
+       struct inode *inode = filp->f_path.dentry->d_inode;
+       struct btrfs_root *root = BTRFS_I(inode)->root;
+       struct btrfs_item *item;
+       struct btrfs_dir_item *di;
+       struct btrfs_key key;
+       struct btrfs_path *path;
+       int ret;
+       u32 nritems;
+       struct btrfs_leaf *leaf;
+       int slot;
+       int advance;
+       unsigned char d_type;
+       int over = 0;
+       u32 di_cur;
+       u32 di_total;
+       u32 di_len;
+       int key_type = BTRFS_DIR_INDEX_KEY;
+
+       /* FIXME, use a real flag for deciding about the key type */
+       if (root->fs_info->tree_root == root)
+               key_type = BTRFS_DIR_ITEM_KEY;
+       mutex_lock(&root->fs_info->fs_mutex);
+       key.objectid = inode->i_ino;
+       key.flags = 0;
+       btrfs_set_key_type(&key, key_type);
+       key.offset = filp->f_pos;
+       path = btrfs_alloc_path();
+       btrfs_init_path(path);
+       ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+       if (ret < 0)
+               goto err;
+       advance = 0;
+       reada_leaves(root, path, inode->i_ino);
+       while(1) {
+               leaf = btrfs_buffer_leaf(path->nodes[0]);
+               nritems = btrfs_header_nritems(&leaf->header);
+               slot = path->slots[0];
+               if (advance || slot >= nritems) {
+                       if (slot >= nritems -1) {
+                               reada_leaves(root, path, inode->i_ino);
+                               ret = btrfs_next_leaf(root, path);
+                               if (ret)
+                                       break;
+                               leaf = btrfs_buffer_leaf(path->nodes[0]);
+                               nritems = btrfs_header_nritems(&leaf->header);
+                               slot = path->slots[0];
+                       } else {
+                               slot++;
+                               path->slots[0]++;
+                       }
+               }
+               advance = 1;
+               item = leaf->items + slot;
+               if (btrfs_disk_key_objectid(&item->key) != key.objectid)
+                       break;
+               if (btrfs_disk_key_type(&item->key) != key_type)
+                       break;
+               if (btrfs_disk_key_offset(&item->key) < filp->f_pos)
+                       continue;
+               filp->f_pos = btrfs_disk_key_offset(&item->key);
+               advance = 1;
+               di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
+               di_cur = 0;
+               di_total = btrfs_item_size(leaf->items + slot);
+               while(di_cur < di_total) {
+                       d_type = btrfs_filetype_table[btrfs_dir_type(di)];
+                       over = filldir(dirent, (const char *)(di + 1),
+                                      btrfs_dir_name_len(di),
+                                      btrfs_disk_key_offset(&item->key),
+                                      btrfs_disk_key_objectid(&di->location),
+                                      d_type);
+                       if (over)
+                               goto nopos;
+                       di_len = btrfs_dir_name_len(di) + sizeof(*di);
+                       di_cur += di_len;
+                       di = (struct btrfs_dir_item *)((char *)di + di_len);
+               }
+       }
+       filp->f_pos++;
+nopos:
+       ret = 0;
+err:
+       btrfs_release_path(root, path);
+       btrfs_free_path(path);
+       mutex_unlock(&root->fs_info->fs_mutex);
+       return ret;
+}
+
+int btrfs_write_inode(struct inode *inode, int wait)
+{
+       struct btrfs_root *root = BTRFS_I(inode)->root;
+       struct btrfs_trans_handle *trans;
+       int ret = 0;
+
+       if (wait) {
+               mutex_lock(&root->fs_info->fs_mutex);
+               trans = btrfs_start_transaction(root, 1);
+               btrfs_set_trans_block_group(trans, inode);
+               ret = btrfs_commit_transaction(trans, root);
+               mutex_unlock(&root->fs_info->fs_mutex);
+       }
+       return ret;
+}
+
+/*
+ * This is somewhat expense, updating the tree every time the
+ * inode changes.  But, it is most likely to find the inode in cache.
+ * FIXME, needs more benchmarking...there are no reasons other than performance
+ * to keep or drop this code.
+ */
+void btrfs_dirty_inode(struct inode *inode)
+{
+       struct btrfs_root *root = BTRFS_I(inode)->root;
+       struct btrfs_trans_handle *trans;
+
+       mutex_lock(&root->fs_info->fs_mutex);
+       trans = btrfs_start_transaction(root, 1);
+       btrfs_set_trans_block_group(trans, inode);
+       btrfs_update_inode(trans, root, inode);
+       btrfs_end_transaction(trans, root);
+       mutex_unlock(&root->fs_info->fs_mutex);
+       btrfs_btree_balance_dirty(root);
+}
+
+static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
+                                    struct btrfs_root *root,
+                                    u64 objectid,
+                                    struct btrfs_block_group_cache *group,
+                                    int mode)
+{
+       struct inode *inode;
+       struct btrfs_inode_item inode_item;
+       struct btrfs_key *location;
+       int ret;
+       int owner;
+
+       inode = new_inode(root->fs_info->sb);
+       if (!inode)
+               return ERR_PTR(-ENOMEM);
+
+       BTRFS_I(inode)->root = root;
+       if (mode & S_IFDIR)
+               owner = 0;
+       else
+               owner = 1;
+       group = btrfs_find_block_group(root, group, 0, 0, owner);
+       BTRFS_I(inode)->block_group = group;
+
+       inode->i_uid = current->fsuid;
+       inode->i_gid = current->fsgid;
+       inode->i_mode = mode;
+       inode->i_ino = objectid;
+       inode->i_blocks = 0;
+       inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
+       fill_inode_item(&inode_item, inode);
+       location = &BTRFS_I(inode)->location;
+       location->objectid = objectid;
+       location->flags = 0;
+       location->offset = 0;
+       btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
+
+       ret = btrfs_insert_inode(trans, root, objectid, &inode_item);
+       BUG_ON(ret);
+
+       insert_inode_hash(inode);
+       return inode;
+}
+
+static inline u8 btrfs_inode_type(struct inode *inode)
+{
+       return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
+}
+
+static int btrfs_add_link(struct btrfs_trans_handle *trans,
+                           struct dentry *dentry, struct inode *inode)
+{
+       int ret;
+       struct btrfs_key key;
+       struct btrfs_root *root = BTRFS_I(dentry->d_parent->d_inode)->root;
+       key.objectid = inode->i_ino;
+       key.flags = 0;
+       btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
+       key.offset = 0;
+
+       ret = btrfs_insert_dir_item(trans, root,
+                                   dentry->d_name.name, dentry->d_name.len,
+                                   dentry->d_parent->d_inode->i_ino,
+                                   &key, btrfs_inode_type(inode));
+       if (ret == 0) {
+               dentry->d_parent->d_inode->i_size += dentry->d_name.len * 2;
+               ret = btrfs_update_inode(trans, root,
+                                        dentry->d_parent->d_inode);
+       }
+       return ret;
+}
+
+static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
+                           struct dentry *dentry, struct inode *inode)
+{
+       int err = btrfs_add_link(trans, dentry, inode);
+       if (!err) {
+               d_instantiate(dentry, inode);
+               return 0;
+       }
+       if (err > 0)
+               err = -EEXIST;
+       return err;
+}
+
+static int btrfs_create(struct inode *dir, struct dentry *dentry,
+                       int mode, struct nameidata *nd)
+{
+       struct btrfs_trans_handle *trans;
+       struct btrfs_root *root = BTRFS_I(dir)->root;
+       struct inode *inode;
+       int err;
+       int drop_inode = 0;
+       u64 objectid;
+
+       mutex_lock(&root->fs_info->fs_mutex);
+       trans = btrfs_start_transaction(root, 1);
+       btrfs_set_trans_block_group(trans, dir);
+
+       err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
+       if (err) {
+               err = -ENOSPC;
+               goto out_unlock;
+       }
+
+       inode = btrfs_new_inode(trans, root, objectid,
+                               BTRFS_I(dir)->block_group, mode);
+       err = PTR_ERR(inode);
+       if (IS_ERR(inode))
+               goto out_unlock;
+
+       btrfs_set_trans_block_group(trans, inode);
+       err = btrfs_add_nondir(trans, dentry, inode);
+       if (err)
+               drop_inode = 1;
+       else {
+               inode->i_mapping->a_ops = &btrfs_aops;
+               inode->i_fop = &btrfs_file_operations;
+               inode->i_op = &btrfs_file_inode_operations;
+       }
+       dir->i_sb->s_dirt = 1;
+       btrfs_update_inode_block_group(trans, inode);
+       btrfs_update_inode_block_group(trans, dir);
+out_unlock:
+       btrfs_end_transaction(trans, root);
+       mutex_unlock(&root->fs_info->fs_mutex);
+
+       if (drop_inode) {
+               inode_dec_link_count(inode);
+               iput(inode);
+       }
+       btrfs_btree_balance_dirty(root);
+       return err;
+}
+
+static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
+                     struct dentry *dentry)
+{
+       struct btrfs_trans_handle *trans;
+       struct btrfs_root *root = BTRFS_I(dir)->root;
+       struct inode *inode = old_dentry->d_inode;
+       int err;
+       int drop_inode = 0;
+
+       if (inode->i_nlink == 0)
+               return -ENOENT;
+
+       inc_nlink(inode);
+       mutex_lock(&root->fs_info->fs_mutex);
+       trans = btrfs_start_transaction(root, 1);
+       btrfs_set_trans_block_group(trans, dir);
+       atomic_inc(&inode->i_count);
+       err = btrfs_add_nondir(trans, dentry, inode);
+       if (err)
+               drop_inode = 1;
+       dir->i_sb->s_dirt = 1;
+       btrfs_update_inode_block_group(trans, dir);
+       btrfs_update_inode(trans, root, inode);
+
+       btrfs_end_transaction(trans, root);
+       mutex_unlock(&root->fs_info->fs_mutex);
+
+       if (drop_inode) {
+               inode_dec_link_count(inode);
+               iput(inode);
+       }
+       btrfs_btree_balance_dirty(root);
+       return err;
+}
+
+static int btrfs_make_empty_dir(struct btrfs_trans_handle *trans,
+                               struct btrfs_root *root,
+                               u64 objectid, u64 dirid)
+{
+       int ret;
+       char buf[2];
+       struct btrfs_key key;
+
+       buf[0] = '.';
+       buf[1] = '.';
+
+       key.objectid = objectid;
+       key.offset = 0;
+       key.flags = 0;
+       btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
+
+       ret = btrfs_insert_dir_item(trans, root, buf, 1, objectid,
+                                   &key, BTRFS_FT_DIR);
+       if (ret)
+               goto error;
+       key.objectid = dirid;
+       ret = btrfs_insert_dir_item(trans, root, buf, 2, objectid,
+                                   &key, BTRFS_FT_DIR);
+       if (ret)
+               goto error;
+error:
+       return ret;
+}
+
+static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
+{
+       struct inode *inode;
+       struct btrfs_trans_handle *trans;
+       struct btrfs_root *root = BTRFS_I(dir)->root;
+       int err = 0;
+       int drop_on_err = 0;
+       u64 objectid;
+
+       mutex_lock(&root->fs_info->fs_mutex);
+       trans = btrfs_start_transaction(root, 1);
+       btrfs_set_trans_block_group(trans, dir);
+       if (IS_ERR(trans)) {
+               err = PTR_ERR(trans);
+               goto out_unlock;
+       }
+
+       err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
+       if (err) {
+               err = -ENOSPC;
+               goto out_unlock;
+       }
+
+       inode = btrfs_new_inode(trans, root, objectid,
+                               BTRFS_I(dir)->block_group, S_IFDIR | mode);
+       if (IS_ERR(inode)) {
+               err = PTR_ERR(inode);
+               goto out_fail;
+       }
+       drop_on_err = 1;
+       inode->i_op = &btrfs_dir_inode_operations;
+       inode->i_fop = &btrfs_dir_file_operations;
+       btrfs_set_trans_block_group(trans, inode);
+
+       err = btrfs_make_empty_dir(trans, root, inode->i_ino, dir->i_ino);
+       if (err)
+               goto out_fail;
+
+       inode->i_size = 6;
+       err = btrfs_update_inode(trans, root, inode);
+       if (err)
+               goto out_fail;
+       err = btrfs_add_link(trans, dentry, inode);
+       if (err)
+               goto out_fail;
+       d_instantiate(dentry, inode);
+       drop_on_err = 0;
+       dir->i_sb->s_dirt = 1;
+       btrfs_update_inode_block_group(trans, inode);
+       btrfs_update_inode_block_group(trans, dir);
+
+out_fail:
+       btrfs_end_transaction(trans, root);
+out_unlock:
+       mutex_unlock(&root->fs_info->fs_mutex);
+       if (drop_on_err)
+               iput(inode);
+       btrfs_btree_balance_dirty(root);
+       return err;
+}
+
+/*
+ * FIBMAP and others want to pass in a fake buffer head.  They need to
+ * use BTRFS_GET_BLOCK_NO_DIRECT to make sure we don't try to memcpy
+ * any packed file data into the fake bh
+ */
+#define BTRFS_GET_BLOCK_NO_CREATE 0
+#define BTRFS_GET_BLOCK_CREATE 1
+#define BTRFS_GET_BLOCK_NO_DIRECT 2
+
+/*
+ * FIXME create==1 doe not work.
+ */
+static int btrfs_get_block_lock(struct inode *inode, sector_t iblock,
+                               struct buffer_head *result, int create)
+{
+       int ret;
+       int err = 0;
+       u64 blocknr;
+       u64 extent_start = 0;
+       u64 extent_end = 0;
+       u64 objectid = inode->i_ino;
+       u32 found_type;
+       u64 alloc_hint = 0;
+       struct btrfs_path *path;
+       struct btrfs_root *root = BTRFS_I(inode)->root;
+       struct btrfs_file_extent_item *item;
+       struct btrfs_leaf *leaf;
+       struct btrfs_disk_key *found_key;
+       struct btrfs_trans_handle *trans = NULL;
+
+       path = btrfs_alloc_path();
+       BUG_ON(!path);
+       btrfs_init_path(path);
+       if (create & BTRFS_GET_BLOCK_CREATE) {
+               WARN_ON(1);
+               /* this almost but not quite works */
+               trans = btrfs_start_transaction(root, 1);
+               if (!trans) {
+                       err = -ENOMEM;
+                       goto out;
+               }
+               ret = btrfs_drop_extents(trans, root, inode,
+                                        iblock << inode->i_blkbits,
+                                        (iblock + 1) << inode->i_blkbits,
+                                        &alloc_hint);
+               BUG_ON(ret);
+       }
+
+       ret = btrfs_lookup_file_extent(NULL, root, path,
+                                      inode->i_ino,
+                                      iblock << inode->i_blkbits, 0);
+       if (ret < 0) {
+               err = ret;
+               goto out;
+       }
+
+       if (ret != 0) {
+               if (path->slots[0] == 0) {
+                       btrfs_release_path(root, path);
+                       goto not_found;
+               }
+               path->slots[0]--;
+       }
+
+       item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
+                             struct btrfs_file_extent_item);
+       leaf = btrfs_buffer_leaf(path->nodes[0]);
+       blocknr = btrfs_file_extent_disk_blocknr(item);
+       blocknr += btrfs_file_extent_offset(item);
+
+       /* are we inside the extent that was found? */
+       found_key = &leaf->items[path->slots[0]].key;
+       found_type = btrfs_disk_key_type(found_key);
+       if (btrfs_disk_key_objectid(found_key) != objectid ||
+           found_type != BTRFS_EXTENT_DATA_KEY) {
+               extent_end = 0;
+               extent_start = 0;
+               goto not_found;
+       }
+       found_type = btrfs_file_extent_type(item);
+       extent_start = btrfs_disk_key_offset(&leaf->items[path->slots[0]].key);
+       if (found_type == BTRFS_FILE_EXTENT_REG) {
+               extent_start = extent_start >> inode->i_blkbits;
+               extent_end = extent_start + btrfs_file_extent_num_blocks(item);
+               err = 0;
+               if (btrfs_file_extent_disk_blocknr(item) == 0)
+                       goto out;
+               if (iblock >= extent_start && iblock < extent_end) {
+                       btrfs_map_bh_to_logical(root, result, blocknr +
+                                               iblock - extent_start);
+                       goto out;
+               }
+       } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
+               char *ptr;
+               char *map;
+               u32 size;
+
+               if (create & BTRFS_GET_BLOCK_NO_DIRECT) {
+                       err = -EINVAL;
+                       goto out;
+               }
+               size = btrfs_file_extent_inline_len(leaf->items +
+                                                   path->slots[0]);
+               extent_end = (extent_start + size) >> inode->i_blkbits;
+               extent_start >>= inode->i_blkbits;
+               if (iblock < extent_start || iblock > extent_end) {
+                       goto not_found;
+               }
+               ptr = btrfs_file_extent_inline_start(item);
+               map = kmap(result->b_page);
+               memcpy(map, ptr, size);
+               memset(map + size, 0, PAGE_CACHE_SIZE - size);
+               flush_dcache_page(result->b_page);
+               kunmap(result->b_page);
+               set_buffer_uptodate(result);
+               SetPageChecked(result->b_page);
+               btrfs_map_bh_to_logical(root, result, 0);
+       }
+not_found:
+       if (create & BTRFS_GET_BLOCK_CREATE) {
+               struct btrfs_key ins;
+               ret = btrfs_alloc_extent(trans, root, inode->i_ino,
+                                        1, alloc_hint, (u64)-1,
+                                        &ins, 1);
+               BUG_ON(ret);
+               ret = btrfs_insert_file_extent(trans, root, inode->i_ino,
+                                              iblock << inode->i_blkbits,
+                                              ins.objectid, ins.offset,
+                                              ins.offset);
+               BUG_ON(ret);
+               SetPageChecked(result->b_page);
+               btrfs_map_bh_to_logical(root, result, ins.objectid);
+       }
+out:
+       if (trans)
+               err = btrfs_end_transaction(trans, root);
+       btrfs_free_path(path);
+       return err;
+}
+
+int btrfs_get_block(struct inode *inode, sector_t iblock,
+                   struct buffer_head *result, int create)
+{
+       int err;
+       struct btrfs_root *root = BTRFS_I(inode)->root;
+       mutex_lock(&root->fs_info->fs_mutex);
+       err = btrfs_get_block_lock(inode, iblock, result, create);
+       mutex_unlock(&root->fs_info->fs_mutex);
+       return err;
+}
+
+static int btrfs_get_block_bmap(struct inode *inode, sector_t iblock,
+                          struct buffer_head *result, int create)
+{
+       struct btrfs_root *root = BTRFS_I(inode)->root;
+       mutex_lock(&root->fs_info->fs_mutex);
+       btrfs_get_block_lock(inode, iblock, result, BTRFS_GET_BLOCK_NO_DIRECT);
+       mutex_unlock(&root->fs_info->fs_mutex);
+       return 0;
+}
+
+static sector_t btrfs_bmap(struct address_space *as, sector_t block)
+{
+       return generic_block_bmap(as, block, btrfs_get_block_bmap);
+}
+
+static int btrfs_prepare_write(struct file *file, struct page *page,
+                              unsigned from, unsigned to)
+{
+       return block_prepare_write(page, from, to, btrfs_get_block);
+}
+
+static int btrfs_readpage(struct file *file, struct page *page)
+{
+       return mpage_readpage(page, btrfs_get_block);
+}
+
+/*
+ * Aside from a tiny bit of packed file data handling, this is the
+ * same as the generic code.
+ *
+ * While block_write_full_page is writing back the dirty buffers under
+ * the page lock, whoever dirtied the buffers may decide to clean them
+ * again at any time.  We handle that by only looking at the buffer
+ * state inside lock_buffer().
+ *
+ * If block_write_full_page() is called for regular writeback
+ * (wbc->sync_mode == WB_SYNC_NONE) then it will redirty a page which has a
+ * locked buffer.   This only can happen if someone has written the buffer
+ * directly, with submit_bh().  At the address_space level PageWriteback
+ * prevents this contention from occurring.
+ */
+static int __btrfs_write_full_page(struct inode *inode, struct page *page,
+                                  struct writeback_control *wbc)
+{
+       int err;
+       sector_t block;
+       sector_t last_block;
+       struct buffer_head *bh, *head;
+       const unsigned blocksize = 1 << inode->i_blkbits;
+       int nr_underway = 0;
+
+       BUG_ON(!PageLocked(page));
+
+       last_block = (i_size_read(inode) - 1) >> inode->i_blkbits;
+
+       if (!page_has_buffers(page)) {
+               create_empty_buffers(page, blocksize,
+                                       (1 << BH_Dirty)|(1 << BH_Uptodate));
+       }
+
+       /*
+        * Be very careful.  We have no exclusion from __set_page_dirty_buffers
+        * here, and the (potentially unmapped) buffers may become dirty at
+        * any time.  If a buffer becomes dirty here after we've inspected it
+        * then we just miss that fact, and the page stays dirty.
+        *
+        * Buffers outside i_size may be dirtied by __set_page_dirty_buffers;
+        * handle that here by just cleaning them.
+        */
+
+       block = (sector_t)page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
+       head = page_buffers(page);
+       bh = head;
+
+       /*
+        * Get all the dirty buffers mapped to disk addresses and
+        * handle any aliases from the underlying blockdev's mapping.
+        */
+       do {
+               if (block > last_block) {
+                       /*
+                        * mapped buffers outside i_size will occur, because
+                        * this page can be outside i_size when there is a
+                        * truncate in progress.
+                        */
+                       /*
+                        * The buffer was zeroed by block_write_full_page()
+                        */
+                       clear_buffer_dirty(bh);
+                       set_buffer_uptodate(bh);
+               } else if (!buffer_mapped(bh) && buffer_dirty(bh)) {
+                       WARN_ON(bh->b_size != blocksize);
+                       err = btrfs_get_block(inode, block, bh, 0);
+                       if (err) {
+                               goto recover;
+                       }
+                       if (buffer_new(bh)) {
+                               /* blockdev mappings never come here */
+                               clear_buffer_new(bh);
+                       }
+               }
+               bh = bh->b_this_page;
+               block++;
+       } while (bh != head);
+
+       do {
+               if (!buffer_mapped(bh))
+                       continue;
+               /*
+                * If it's a fully non-blocking write attempt and we cannot
+                * lock the buffer then redirty the page.  Note that this can
+                * potentially cause a busy-wait loop from pdflush and kswapd
+                * activity, but those code paths have their own higher-level
+                * throttling.
+                */
+               if (wbc->sync_mode != WB_SYNC_NONE || !wbc->nonblocking) {
+                       lock_buffer(bh);
+               } else if (test_set_buffer_locked(bh)) {
+                       redirty_page_for_writepage(wbc, page);
+                       continue;
+               }
+               if (test_clear_buffer_dirty(bh) && bh->b_blocknr != 0) {
+                       mark_buffer_async_write(bh);
+               } else {
+                       unlock_buffer(bh);
+               }
+       } while ((bh = bh->b_this_page) != head);
+
+       /*
+        * The page and its buffers are protected by PageWriteback(), so we can
+        * drop the bh refcounts early.
+        */
+       BUG_ON(PageWriteback(page));
+       set_page_writeback(page);
+
+       do {
+               struct buffer_head *next = bh->b_this_page;
+               if (buffer_async_write(bh)) {
+                       submit_bh(WRITE, bh);
+                       nr_underway++;
+               }
+               bh = next;
+       } while (bh != head);
+       unlock_page(page);
+
+       err = 0;
+done:
+       if (nr_underway == 0) {
+               /*
+                * The page was marked dirty, but the buffers were
+                * clean.  Someone wrote them back by hand with
+                * ll_rw_block/submit_bh.  A rare case.
+                */
+               int uptodate = 1;
+               do {
+                       if (!buffer_uptodate(bh)) {
+                               uptodate = 0;
+                               break;
+                       }
+                       bh = bh->b_this_page;
+               } while (bh != head);
+               if (uptodate)
+                       SetPageUptodate(page);
+               end_page_writeback(page);
+       }
+       return err;
+
+recover:
+       /*
+        * ENOSPC, or some other error.  We may already have added some
+        * blocks to the file, so we need to write these out to avoid
+        * exposing stale data.
+        * The page is currently locked and not marked for writeback
+        */
+       bh = head;
+       /* Recovery: lock and submit the mapped buffers */
+       do {
+               if (buffer_mapped(bh) && buffer_dirty(bh)) {
+                       lock_buffer(bh);
+                       mark_buffer_async_write(bh);
+               } else {
+                       /*
+                        * The buffer may have been set dirty during
+                        * attachment to a dirty page.
+                        */
+                       clear_buffer_dirty(bh);
+               }
+       } while ((bh = bh->b_this_page) != head);
+       SetPageError(page);
+       BUG_ON(PageWriteback(page));
+       set_page_writeback(page);
+       do {
+               struct buffer_head *next = bh->b_this_page;
+               if (buffer_async_write(bh)) {
+                       clear_buffer_dirty(bh);
+                       submit_bh(WRITE, bh);
+                       nr_underway++;
+               }
+               bh = next;
+       } while (bh != head);
+       unlock_page(page);
+       goto done;
+}
+
+static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
+{
+       struct inode * const inode = page->mapping->host;
+       loff_t i_size = i_size_read(inode);
+       const pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
+       unsigned offset;
+       void *kaddr;
+
+       /* Is the page fully inside i_size? */
+       if (page->index < end_index)
+               return __btrfs_write_full_page(inode, page, wbc);
+
+       /* Is the page fully outside i_size? (truncate in progress) */
+       offset = i_size & (PAGE_CACHE_SIZE-1);
+       if (page->index >= end_index+1 || !offset) {
+               /*
+                * The page may have dirty, unmapped buffers.  For example,
+                * they may have been added in ext3_writepage().  Make them
+                * freeable here, so the page does not leak.
+                */
+               block_invalidatepage(page, 0);
+               unlock_page(page);
+               return 0; /* don't care */
+       }
+
+       /*
+        * The page straddles i_size.  It must be zeroed out on each and every
+        * writepage invokation because it may be mmapped.  "A file is mapped
+        * in multiples of the page size.  For a file that is not a multiple of
+        * the  page size, the remaining memory is zeroed when mapped, and
+        * writes to that region are not written out to the file."
+        */
+       kaddr = kmap_atomic(page, KM_USER0);
+       memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset);
+       flush_dcache_page(page);
+       kunmap_atomic(kaddr, KM_USER0);
+       return __btrfs_write_full_page(inode, page, wbc);
+}
+
+static void btrfs_truncate(struct inode *inode)
+{
+       struct btrfs_root *root = BTRFS_I(inode)->root;
+       int ret;
+       struct btrfs_trans_handle *trans;
+
+       if (!S_ISREG(inode->i_mode))
+               return;
+       if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
+               return;
+
+       btrfs_truncate_page(inode->i_mapping, inode->i_size);
+
+       mutex_lock(&root->fs_info->fs_mutex);
+       trans = btrfs_start_transaction(root, 1);
+       btrfs_set_trans_block_group(trans, inode);
+
+       /* FIXME, add redo link to tree so we don't leak on crash */
+       ret = btrfs_truncate_in_trans(trans, root, inode);
+       BUG_ON(ret);
+       btrfs_update_inode(trans, root, inode);
+       ret = btrfs_end_transaction(trans, root);
+       BUG_ON(ret);
+       mutex_unlock(&root->fs_info->fs_mutex);
+       btrfs_btree_balance_dirty(root);
+}
+
+int btrfs_commit_write(struct file *file, struct page *page,
+                      unsigned from, unsigned to)
+{
+       struct inode *inode = page->mapping->host;
+       struct buffer_head *bh;
+       loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
+
+       SetPageUptodate(page);
+       bh = page_buffers(page);
+       set_buffer_uptodate(bh);
+       if (buffer_mapped(bh) && bh->b_blocknr != 0) {
+               set_page_dirty(page);
+       }
+       if (pos > inode->i_size) {
+               i_size_write(inode, pos);
+               mark_inode_dirty(inode);
+       }
+       return 0;
+}
+
+static int create_subvol(struct btrfs_root *root, char *name, int namelen)
+{
+       struct btrfs_trans_handle *trans;
+       struct btrfs_key key;
+       struct btrfs_root_item root_item;
+       struct btrfs_inode_item *inode_item;
+       struct buffer_head *subvol;
+       struct btrfs_leaf *leaf;
+       struct btrfs_root *new_root;
+       struct inode *inode;
+       struct inode *dir;
+       int ret;
+       u64 objectid;
+       u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
+
+       mutex_lock(&root->fs_info->fs_mutex);
+       trans = btrfs_start_transaction(root, 1);
+       BUG_ON(!trans);
+
+       subvol = btrfs_alloc_free_block(trans, root, 0);
+       if (subvol == NULL)
+               return -ENOSPC;
+       leaf = btrfs_buffer_leaf(subvol);
+       btrfs_set_header_nritems(&leaf->header, 0);
+       btrfs_set_header_level(&leaf->header, 0);
+       btrfs_set_header_blocknr(&leaf->header, bh_blocknr(subvol));
+       btrfs_set_header_generation(&leaf->header, trans->transid);
+       btrfs_set_header_owner(&leaf->header, root->root_key.objectid);
+       memcpy(leaf->header.fsid, root->fs_info->disk_super->fsid,
+              sizeof(leaf->header.fsid));
+       mark_buffer_dirty(subvol);
+
+       inode_item = &root_item.inode;
+       memset(inode_item, 0, sizeof(*inode_item));
+       btrfs_set_inode_generation(inode_item, 1);
+       btrfs_set_inode_size(inode_item, 3);
+       btrfs_set_inode_nlink(inode_item, 1);
+       btrfs_set_inode_nblocks(inode_item, 1);
+       btrfs_set_inode_mode(inode_item, S_IFDIR | 0755);
+
+       btrfs_set_root_blocknr(&root_item, bh_blocknr(subvol));
+       btrfs_set_root_refs(&root_item, 1);
+       brelse(subvol);
+       subvol = NULL;
+
+       ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
+                                      0, &objectid);
+       BUG_ON(ret);
+
+       btrfs_set_root_dirid(&root_item, new_dirid);
+
+       key.objectid = objectid;
+       key.offset = 1;
+       key.flags = 0;
+       btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
+       ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
+                               &root_item);
+       BUG_ON(ret);
+
+       /*
+        * insert the directory item
+        */
+       key.offset = (u64)-1;
+       dir = root->fs_info->sb->s_root->d_inode;
+       ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
+                                   name, namelen, dir->i_ino, &key,
+                                   BTRFS_FT_DIR);
+       BUG_ON(ret);
+
+       ret = btrfs_commit_transaction(trans, root);
+       BUG_ON(ret);
+
+       new_root = btrfs_read_fs_root(root->fs_info, &key);
+       BUG_ON(!new_root);
+
+       trans = btrfs_start_transaction(new_root, 1);
+       BUG_ON(!trans);
+
+       inode = btrfs_new_inode(trans, new_root, new_dirid,
+                               BTRFS_I(dir)->block_group, S_IFDIR | 0700);
+       inode->i_op = &btrfs_dir_inode_operations;
+       inode->i_fop = &btrfs_dir_file_operations;
+
+       ret = btrfs_make_empty_dir(trans, new_root, new_dirid, new_dirid);
+       BUG_ON(ret);
+
+       inode->i_nlink = 1;
+       inode->i_size = 6;
+       ret = btrfs_update_inode(trans, new_root, inode);
+       BUG_ON(ret);
+
+       ret = btrfs_commit_transaction(trans, new_root);
+       BUG_ON(ret);
+
+       iput(inode);
+
+       mutex_unlock(&root->fs_info->fs_mutex);
+       btrfs_btree_balance_dirty(root);
+       return 0;
+}
+
+static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
+{
+       struct btrfs_trans_handle *trans;
+       struct btrfs_key key;
+       struct btrfs_root_item new_root_item;
+       int ret;
+       u64 objectid;
+
+       if (!root->ref_cows)
+               return -EINVAL;
+
+       mutex_lock(&root->fs_info->fs_mutex);
+       trans = btrfs_start_transaction(root, 1);
+       BUG_ON(!trans);
+
+       ret = btrfs_update_inode(trans, root, root->inode);
+       BUG_ON(ret);
+
+       ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
+                                      0, &objectid);
+       BUG_ON(ret);
+
+       memcpy(&new_root_item, &root->root_item,
+              sizeof(new_root_item));
+
+       key.objectid = objectid;
+       key.offset = 1;
+       key.flags = 0;
+       btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
+       btrfs_set_root_blocknr(&new_root_item, bh_blocknr(root->node));
+
+       ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
+                               &new_root_item);
+       BUG_ON(ret);
+
+       /*
+        * insert the directory item
+        */
+       key.offset = (u64)-1;
+       ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
+                                   name, namelen,
+                                   root->fs_info->sb->s_root->d_inode->i_ino,
+                                   &key, BTRFS_FT_DIR);
+
+       BUG_ON(ret);
+
+       ret = btrfs_inc_root_ref(trans, root);
+       BUG_ON(ret);
+
+       ret = btrfs_commit_transaction(trans, root);
+       BUG_ON(ret);
+       mutex_unlock(&root->fs_info->fs_mutex);
+       btrfs_btree_balance_dirty(root);
+       return 0;
+}
+
+int btrfs_ioctl(struct inode *inode, struct file *filp, unsigned int
+               cmd, unsigned long arg)
+{
+       struct btrfs_root *root = BTRFS_I(inode)->root;
+       struct btrfs_ioctl_vol_args vol_args;
+       int ret = 0;
+       struct btrfs_dir_item *di;
+       int namelen;
+       struct btrfs_path *path;
+       u64 root_dirid;
+
+       switch (cmd) {
+       case BTRFS_IOC_SNAP_CREATE:
+               if (copy_from_user(&vol_args,
+                                  (struct btrfs_ioctl_vol_args __user *)arg,
+                                  sizeof(vol_args)))
+                       return -EFAULT;
+               namelen = strlen(vol_args.name);
+               if (namelen > BTRFS_VOL_NAME_MAX)
+                       return -EINVAL;
+               path = btrfs_alloc_path();
+               if (!path)
+                       return -ENOMEM;
+               root_dirid = root->fs_info->sb->s_root->d_inode->i_ino,
+               mutex_lock(&root->fs_info->fs_mutex);
+               di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root,
+                                   path, root_dirid,
+                                   vol_args.name, namelen, 0);
+               mutex_unlock(&root->fs_info->fs_mutex);
+               btrfs_free_path(path);
+               if (di && !IS_ERR(di))
+                       return -EEXIST;
+
+               if (root == root->fs_info->tree_root)
+                       ret = create_subvol(root, vol_args.name, namelen);
+               else
+                       ret = create_snapshot(root, vol_args.name, namelen);
+               WARN_ON(ret);
+               break;
+       default:
+               return -ENOTTY;
+       }
+       return ret;
+}
+
+#ifdef CONFIG_COMPAT
+long btrfs_compat_ioctl(struct file *file, unsigned int cmd,
+                              unsigned long arg)
+{
+       struct inode *inode = file->f_path.dentry->d_inode;
+       int ret;
+       lock_kernel();
+       ret = btrfs_ioctl(inode, file, cmd, (unsigned long) compat_ptr(arg));
+       unlock_kernel();
+       return ret;
+
+}
+#endif
+
+/*
+ * Called inside transaction, so use GFP_NOFS
+ */
+struct inode *btrfs_alloc_inode(struct super_block *sb)
+{
+       struct btrfs_inode *ei;
+
+       ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
+       if (!ei)
+               return NULL;
+       return &ei->vfs_inode;
+}
+
+void btrfs_destroy_inode(struct inode *inode)
+{
+       WARN_ON(!list_empty(&inode->i_dentry));
+       WARN_ON(inode->i_data.nrpages);
+
+       kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
+}
+
+static void init_once(void * foo, struct kmem_cache * cachep,
+                     unsigned long flags)
+{
+       struct btrfs_inode *ei = (struct btrfs_inode *) foo;
+
+       inode_init_once(&ei->vfs_inode);
+}
+
+void btrfs_destroy_cachep(void)
+{
+       if (btrfs_inode_cachep)
+               kmem_cache_destroy(btrfs_inode_cachep);
+       if (btrfs_trans_handle_cachep)
+               kmem_cache_destroy(btrfs_trans_handle_cachep);
+       if (btrfs_transaction_cachep)
+               kmem_cache_destroy(btrfs_transaction_cachep);
+       if (btrfs_bit_radix_cachep)
+               kmem_cache_destroy(btrfs_bit_radix_cachep);
+       if (btrfs_path_cachep)
+               kmem_cache_destroy(btrfs_path_cachep);
+}
+
+int btrfs_init_cachep(void)
+{
+       btrfs_inode_cachep = kmem_cache_create("btrfs_inode_cache",
+                                            sizeof(struct btrfs_inode),
+                                            0, (SLAB_RECLAIM_ACCOUNT|
+                                               SLAB_MEM_SPREAD),
+                                            init_once, NULL);
+       if (!btrfs_inode_cachep)
+               goto fail;
+       btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle_cache",
+                                            sizeof(struct btrfs_trans_handle),
+                                            0, (SLAB_RECLAIM_ACCOUNT|
+                                               SLAB_MEM_SPREAD),
+                                            NULL, NULL);
+       if (!btrfs_trans_handle_cachep)
+               goto fail;
+       btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction_cache",
+                                            sizeof(struct btrfs_transaction),
+                                            0, (SLAB_RECLAIM_ACCOUNT|
+                                               SLAB_MEM_SPREAD),
+                                            NULL, NULL);
+       if (!btrfs_transaction_cachep)
+               goto fail;
+       btrfs_path_cachep = kmem_cache_create("btrfs_path_cache",
+                                            sizeof(struct btrfs_transaction),
+                                            0, (SLAB_RECLAIM_ACCOUNT|
+                                               SLAB_MEM_SPREAD),
+                                            NULL, NULL);
+       if (!btrfs_path_cachep)
+               goto fail;
+       btrfs_bit_radix_cachep = kmem_cache_create("btrfs_radix",
+                                            256,
+                                            0, (SLAB_RECLAIM_ACCOUNT|
+                                               SLAB_MEM_SPREAD |
+                                               SLAB_DESTROY_BY_RCU),
+                                            NULL, NULL);
+       if (!btrfs_bit_radix_cachep)
+               goto fail;
+       return 0;
+fail:
+       btrfs_destroy_cachep();
+       return -ENOMEM;
+}
+
+static int btrfs_getattr(struct vfsmount *mnt,
+                        struct dentry *dentry, struct kstat *stat)
+{
+       struct inode *inode = dentry->d_inode;
+       generic_fillattr(inode, stat);
+       stat->blksize = 256 * 1024;
+       return 0;
+}
+
+static int btrfs_rename(struct inode * old_dir, struct dentry *old_dentry,
+                          struct inode * new_dir,struct dentry *new_dentry)
+{
+       struct btrfs_trans_handle *trans;
+       struct btrfs_root *root = BTRFS_I(old_dir)->root;
+       struct inode *new_inode = new_dentry->d_inode;
+       struct inode *old_inode = old_dentry->d_inode;
+       struct timespec ctime = CURRENT_TIME;
+       struct btrfs_path *path;
+       struct btrfs_dir_item *di;
+       int ret;
+
+       if (S_ISDIR(old_inode->i_mode) && new_inode &&
+           new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) {
+               return -ENOTEMPTY;
+       }
+       mutex_lock(&root->fs_info->fs_mutex);
+       trans = btrfs_start_transaction(root, 1);
+       btrfs_set_trans_block_group(trans, new_dir);
+       path = btrfs_alloc_path();
+       if (!path) {
+               ret = -ENOMEM;
+               goto out_fail;
+       }
+
+       old_dentry->d_inode->i_nlink++;
+       old_dir->i_ctime = old_dir->i_mtime = ctime;
+       new_dir->i_ctime = new_dir->i_mtime = ctime;
+       old_inode->i_ctime = ctime;
+       if (S_ISDIR(old_inode->i_mode) && old_dir != new_dir) {
+               struct btrfs_key *location = &BTRFS_I(new_dir)->location;
+               u64 old_parent_oid;
+               di = btrfs_lookup_dir_item(trans, root, path, old_inode->i_ino,
+                                          "..", 2, -1);
+               if (IS_ERR(di)) {
+                       ret = PTR_ERR(di);
+                       goto out_fail;
+               }
+               if (!di) {
+                       ret = -ENOENT;
+                       goto out_fail;
+               }
+               old_parent_oid = btrfs_disk_key_objectid(&di->location);
+               ret = btrfs_del_item(trans, root, path);
+               if (ret) {
+                       ret = -EIO;
+                       goto out_fail;
+               }
+               btrfs_release_path(root, path);
+
+               di = btrfs_lookup_dir_index_item(trans, root, path,
+                                                old_inode->i_ino,
+                                                old_parent_oid,
+                                                "..", 2, -1);
+               if (IS_ERR(di)) {
+                       ret = PTR_ERR(di);
+                       goto out_fail;
+               }
+               if (!di) {
+                       ret = -ENOENT;
+                       goto out_fail;
+               }
+               ret = btrfs_del_item(trans, root, path);
+               if (ret) {
+                       ret = -EIO;
+                       goto out_fail;
+               }
+               btrfs_release_path(root, path);
+
+               ret = btrfs_insert_dir_item(trans, root, "..", 2,
+                                           old_inode->i_ino, location,
+                                           BTRFS_FT_DIR);
+               if (ret)
+                       goto out_fail;
+       }
+
+
+       ret = btrfs_unlink_trans(trans, root, old_dir, old_dentry);
+       if (ret)
+               goto out_fail;
+
+       if (new_inode) {
+               new_inode->i_ctime = CURRENT_TIME;
+               ret = btrfs_unlink_trans(trans, root, new_dir, new_dentry);
+               if (ret)
+                       goto out_fail;
+               if (S_ISDIR(new_inode->i_mode))
+                       clear_nlink(new_inode);
+               else
+                       drop_nlink(new_inode);
+               btrfs_update_inode(trans, root, new_inode);
+       }
+       ret = btrfs_add_link(trans, new_dentry, old_inode);
+       if (ret)
+               goto out_fail;
+
+out_fail:
+       btrfs_free_path(path);
+       btrfs_end_transaction(trans, root);
+       mutex_unlock(&root->fs_info->fs_mutex);
+       return ret;
+}
+
+static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
+                        const char *symname)
+{
+       struct btrfs_trans_handle *trans;
+       struct btrfs_root *root = BTRFS_I(dir)->root;
+       struct btrfs_path *path;
+       struct btrfs_key key;
+       struct inode *inode;
+       int err;
+       int drop_inode = 0;
+       u64 objectid;
+       int name_len;
+       int datasize;
+       char *ptr;
+       struct btrfs_file_extent_item *ei;
+
+       name_len = strlen(symname) + 1;
+       if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
+               return -ENAMETOOLONG;
+       mutex_lock(&root->fs_info->fs_mutex);
+       trans = btrfs_start_transaction(root, 1);
+       btrfs_set_trans_block_group(trans, dir);
+
+       err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
+       if (err) {
+               err = -ENOSPC;
+               goto out_unlock;
+       }
+
+       inode = btrfs_new_inode(trans, root, objectid,
+                               BTRFS_I(dir)->block_group, S_IFLNK|S_IRWXUGO);
+       err = PTR_ERR(inode);
+       if (IS_ERR(inode))
+               goto out_unlock;
+
+       btrfs_set_trans_block_group(trans, inode);
+       err = btrfs_add_nondir(trans, dentry, inode);
+       if (err)
+               drop_inode = 1;
+       else {
+               inode->i_mapping->a_ops = &btrfs_aops;
+               inode->i_fop = &btrfs_file_operations;
+               inode->i_op = &btrfs_file_inode_operations;
+       }
+       dir->i_sb->s_dirt = 1;
+       btrfs_update_inode_block_group(trans, inode);
+       btrfs_update_inode_block_group(trans, dir);
+       if (drop_inode)
+               goto out_unlock;
+
+       path = btrfs_alloc_path();
+       BUG_ON(!path);
+       key.objectid = inode->i_ino;
+       key.offset = 0;
+       key.flags = 0;
+       btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
+       datasize = btrfs_file_extent_calc_inline_size(name_len);
+       err = btrfs_insert_empty_item(trans, root, path, &key,
+                                     datasize);
+       BUG_ON(err);
+       ei = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
+              path->slots[0], struct btrfs_file_extent_item);
+       btrfs_set_file_extent_generation(ei, trans->transid);
+       btrfs_set_file_extent_type(ei,
+                                  BTRFS_FILE_EXTENT_INLINE);
+       ptr = btrfs_file_extent_inline_start(ei);
+       btrfs_memcpy(root, path->nodes[0]->b_data,
+                    ptr, symname, name_len);
+       mark_buffer_dirty(path->nodes[0]);
+       btrfs_free_path(path);
+       inode->i_op = &btrfs_symlink_inode_operations;
+       inode->i_mapping->a_ops = &btrfs_symlink_aops;
+       inode->i_size = name_len - 1;
+       btrfs_update_inode(trans, root, inode);
+       err = 0;
+
+out_unlock:
+       btrfs_end_transaction(trans, root);
+       mutex_unlock(&root->fs_info->fs_mutex);
+
+       if (drop_inode) {
+               inode_dec_link_count(inode);
+               iput(inode);
+       }
+       btrfs_btree_balance_dirty(root);
+       return err;
+}
+
+static struct inode_operations btrfs_dir_inode_operations = {
+       .lookup         = btrfs_lookup,
+       .create         = btrfs_create,
+       .unlink         = btrfs_unlink,
+       .link           = btrfs_link,
+       .mkdir          = btrfs_mkdir,
+       .rmdir          = btrfs_rmdir,
+       .rename         = btrfs_rename,
+       .symlink        = btrfs_symlink,
+       .setattr        = btrfs_setattr,
+};
+
+static struct inode_operations btrfs_dir_ro_inode_operations = {
+       .lookup         = btrfs_lookup,
+};
+
+static struct file_operations btrfs_dir_file_operations = {
+       .llseek         = generic_file_llseek,
+       .read           = generic_read_dir,
+       .readdir        = btrfs_readdir,
+       .ioctl          = btrfs_ioctl,
+#ifdef CONFIG_COMPAT
+       .compat_ioctl   = btrfs_compat_ioctl,
+#endif
+};
+
+static struct address_space_operations btrfs_aops = {
+       .readpage       = btrfs_readpage,
+       .writepage      = btrfs_writepage,
+       .sync_page      = block_sync_page,
+       .prepare_write  = btrfs_prepare_write,
+       .commit_write   = btrfs_commit_write,
+       .bmap           = btrfs_bmap,
+};
+
+static struct address_space_operations btrfs_symlink_aops = {
+       .readpage       = btrfs_readpage,
+       .writepage      = btrfs_writepage,
+};
+
+static struct inode_operations btrfs_file_inode_operations = {
+       .truncate       = btrfs_truncate,
+       .getattr        = btrfs_getattr,
+       .setattr        = btrfs_setattr,
+};
+
+static struct inode_operations btrfs_symlink_inode_operations = {
+       .readlink       = generic_readlink,
+       .follow_link    = page_follow_link_light,
+       .put_link       = page_put_link,
+};
index 9749090cfbb8ac1385eccab3e4e44fd0c0778b7d..94b3535a2a110832cd32ec3a68daeb5718889327 100644 (file)
 #include "ioctl.h"
 #include "print-tree.h"
 
-struct btrfs_iget_args {
-       u64 ino;
-       struct btrfs_root *root;
-};
-
-#define BTRFS_SUPER_MAGIC 0x9123682E
-
-static struct inode_operations btrfs_dir_inode_operations;
-static struct inode_operations btrfs_symlink_inode_operations;
-static struct inode_operations btrfs_dir_ro_inode_operations;
-static struct super_operations btrfs_super_ops;
-static struct file_operations btrfs_dir_file_operations;
-static struct inode_operations btrfs_file_inode_operations;
-static struct address_space_operations btrfs_aops;
-static struct address_space_operations btrfs_symlink_aops;
-static struct file_operations btrfs_file_operations;
-
-static int drop_extents(struct btrfs_trans_handle *trans,
-                         struct btrfs_root *root,
-                         struct inode *inode,
-                         u64 start, u64 end, u64 *hint_block);
-static int btrfs_get_block(struct inode *inode, sector_t iblock,
-                          struct buffer_head *result, int create);
-
-
-#define S_SHIFT 12
-static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
-       [S_IFREG >> S_SHIFT]    = BTRFS_FT_REG_FILE,
-       [S_IFDIR >> S_SHIFT]    = BTRFS_FT_DIR,
-       [S_IFCHR >> S_SHIFT]    = BTRFS_FT_CHRDEV,
-       [S_IFBLK >> S_SHIFT]    = BTRFS_FT_BLKDEV,
-       [S_IFIFO >> S_SHIFT]    = BTRFS_FT_FIFO,
-       [S_IFSOCK >> S_SHIFT]   = BTRFS_FT_SOCK,
-       [S_IFLNK >> S_SHIFT]    = BTRFS_FT_SYMLINK,
-};
-
-static void btrfs_read_locked_inode(struct inode *inode)
-{
-       struct btrfs_path *path;
-       struct btrfs_inode_item *inode_item;
-       struct btrfs_root *root = BTRFS_I(inode)->root;
-       struct btrfs_key location;
-       u64 alloc_group_block;
-       int ret;
-
-       path = btrfs_alloc_path();
-       BUG_ON(!path);
-       btrfs_init_path(path);
-       mutex_lock(&root->fs_info->fs_mutex);
-
-       memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
-       ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
-       if (ret) {
-               btrfs_free_path(path);
-               goto make_bad;
-       }
-       inode_item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
-                                 path->slots[0],
-                                 struct btrfs_inode_item);
-
-       inode->i_mode = btrfs_inode_mode(inode_item);
-       inode->i_nlink = btrfs_inode_nlink(inode_item);
-       inode->i_uid = btrfs_inode_uid(inode_item);
-       inode->i_gid = btrfs_inode_gid(inode_item);
-       inode->i_size = btrfs_inode_size(inode_item);
-       inode->i_atime.tv_sec = btrfs_timespec_sec(&inode_item->atime);
-       inode->i_atime.tv_nsec = btrfs_timespec_nsec(&inode_item->atime);
-       inode->i_mtime.tv_sec = btrfs_timespec_sec(&inode_item->mtime);
-       inode->i_mtime.tv_nsec = btrfs_timespec_nsec(&inode_item->mtime);
-       inode->i_ctime.tv_sec = btrfs_timespec_sec(&inode_item->ctime);
-       inode->i_ctime.tv_nsec = btrfs_timespec_nsec(&inode_item->ctime);
-       inode->i_blocks = btrfs_inode_nblocks(inode_item);
-       inode->i_generation = btrfs_inode_generation(inode_item);
-       alloc_group_block = btrfs_inode_block_group(inode_item);
-       BTRFS_I(inode)->block_group = btrfs_lookup_block_group(root->fs_info,
-                                                      alloc_group_block);
-
-       btrfs_free_path(path);
-       inode_item = NULL;
-
-       mutex_unlock(&root->fs_info->fs_mutex);
-
-       switch (inode->i_mode & S_IFMT) {
-#if 0
-       default:
-               init_special_inode(inode, inode->i_mode,
-                                  btrfs_inode_rdev(inode_item));
-               break;
-#endif
-       case S_IFREG:
-               inode->i_mapping->a_ops = &btrfs_aops;
-               inode->i_fop = &btrfs_file_operations;
-               inode->i_op = &btrfs_file_inode_operations;
-               break;
-       case S_IFDIR:
-               inode->i_fop = &btrfs_dir_file_operations;
-               if (root == root->fs_info->tree_root)
-                       inode->i_op = &btrfs_dir_ro_inode_operations;
-               else
-                       inode->i_op = &btrfs_dir_inode_operations;
-               break;
-       case S_IFLNK:
-               inode->i_op = &btrfs_symlink_inode_operations;
-               inode->i_mapping->a_ops = &btrfs_symlink_aops;
-               break;
-       }
-       return;
-
-make_bad:
-       btrfs_release_path(root, path);
-       btrfs_free_path(path);
-       mutex_unlock(&root->fs_info->fs_mutex);
-       make_bad_inode(inode);
-}
-
-static void fill_inode_item(struct btrfs_inode_item *item,
-                           struct inode *inode)
-{
-       btrfs_set_inode_uid(item, inode->i_uid);
-       btrfs_set_inode_gid(item, inode->i_gid);
-       btrfs_set_inode_size(item, inode->i_size);
-       btrfs_set_inode_mode(item, inode->i_mode);
-       btrfs_set_inode_nlink(item, inode->i_nlink);
-       btrfs_set_timespec_sec(&item->atime, inode->i_atime.tv_sec);
-       btrfs_set_timespec_nsec(&item->atime, inode->i_atime.tv_nsec);
-       btrfs_set_timespec_sec(&item->mtime, inode->i_mtime.tv_sec);
-       btrfs_set_timespec_nsec(&item->mtime, inode->i_mtime.tv_nsec);
-       btrfs_set_timespec_sec(&item->ctime, inode->i_ctime.tv_sec);
-       btrfs_set_timespec_nsec(&item->ctime, inode->i_ctime.tv_nsec);
-       btrfs_set_inode_nblocks(item, inode->i_blocks);
-       btrfs_set_inode_generation(item, inode->i_generation);
-       btrfs_set_inode_block_group(item,
-                                   BTRFS_I(inode)->block_group->key.objectid);
-}
-
-static int btrfs_update_inode(struct btrfs_trans_handle *trans,
-                             struct btrfs_root *root,
-                             struct inode *inode)
-{
-       struct btrfs_inode_item *inode_item;
-       struct btrfs_path *path;
-       int ret;
-
-       path = btrfs_alloc_path();
-       BUG_ON(!path);
-       btrfs_init_path(path);
-       ret = btrfs_lookup_inode(trans, root, path,
-                                &BTRFS_I(inode)->location, 1);
-       if (ret) {
-               if (ret > 0)
-                       ret = -ENOENT;
-               goto failed;
-       }
-
-       inode_item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
-                                 path->slots[0],
-                                 struct btrfs_inode_item);
-
-       fill_inode_item(inode_item, inode);
-       btrfs_mark_buffer_dirty(path->nodes[0]);
-       ret = 0;
-failed:
-       btrfs_release_path(root, path);
-       btrfs_free_path(path);
-       return ret;
-}
-
-
-static int btrfs_unlink_trans(struct btrfs_trans_handle *trans,
-                             struct btrfs_root *root,
-                             struct inode *dir,
-                             struct dentry *dentry)
-{
-       struct btrfs_path *path;
-       const char *name = dentry->d_name.name;
-       int name_len = dentry->d_name.len;
-       int ret = 0;
-       u64 objectid;
-       struct btrfs_dir_item *di;
-
-       path = btrfs_alloc_path();
-       BUG_ON(!path);
-       btrfs_init_path(path);
-       di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
-                                   name, name_len, -1);
-       if (IS_ERR(di)) {
-               ret = PTR_ERR(di);
-               goto err;
-       }
-       if (!di) {
-               ret = -ENOENT;
-               goto err;
-       }
-       objectid = btrfs_disk_key_objectid(&di->location);
-       ret = btrfs_delete_one_dir_name(trans, root, path, di);
-       BUG_ON(ret);
-       btrfs_release_path(root, path);
-
-       di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
-                                        objectid, name, name_len, -1);
-       if (IS_ERR(di)) {
-               ret = PTR_ERR(di);
-               goto err;
-       }
-       if (!di) {
-               ret = -ENOENT;
-               goto err;
-       }
-       ret = btrfs_delete_one_dir_name(trans, root, path, di);
-       BUG_ON(ret);
-
-       dentry->d_inode->i_ctime = dir->i_ctime;
-err:
-       btrfs_free_path(path);
-       if (!ret) {
-               dir->i_size -= name_len * 2;
-               btrfs_update_inode(trans, root, dir);
-               drop_nlink(dentry->d_inode);
-               btrfs_update_inode(trans, root, dentry->d_inode);
-               dir->i_sb->s_dirt = 1;
-       }
-       return ret;
-}
-
-static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
-{
-       struct btrfs_root *root;
-       struct btrfs_trans_handle *trans;
-       int ret;
-
-       root = BTRFS_I(dir)->root;
-       mutex_lock(&root->fs_info->fs_mutex);
-       trans = btrfs_start_transaction(root, 1);
-       btrfs_set_trans_block_group(trans, dir);
-       ret = btrfs_unlink_trans(trans, root, dir, dentry);
-       btrfs_end_transaction(trans, root);
-       mutex_unlock(&root->fs_info->fs_mutex);
-       btrfs_btree_balance_dirty(root);
-       return ret;
-}
-
-static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
-{
-       struct inode *inode = dentry->d_inode;
-       int err;
-       int ret;
-       struct btrfs_root *root = BTRFS_I(dir)->root;
-       struct btrfs_path *path;
-       struct btrfs_key key;
-       struct btrfs_trans_handle *trans;
-       struct btrfs_key found_key;
-       int found_type;
-       struct btrfs_leaf *leaf;
-       char *goodnames = "..";
-
-       path = btrfs_alloc_path();
-       BUG_ON(!path);
-       btrfs_init_path(path);
-       mutex_lock(&root->fs_info->fs_mutex);
-       trans = btrfs_start_transaction(root, 1);
-       btrfs_set_trans_block_group(trans, dir);
-       key.objectid = inode->i_ino;
-       key.offset = (u64)-1;
-       key.flags = (u32)-1;
-       while(1) {
-               ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
-               if (ret < 0) {
-                       err = ret;
-                       goto out;
-               }
-               BUG_ON(ret == 0);
-               if (path->slots[0] == 0) {
-                       err = -ENOENT;
-                       goto out;
-               }
-               path->slots[0]--;
-               leaf = btrfs_buffer_leaf(path->nodes[0]);
-               btrfs_disk_key_to_cpu(&found_key,
-                                     &leaf->items[path->slots[0]].key);
-               found_type = btrfs_key_type(&found_key);
-               if (found_key.objectid != inode->i_ino) {
-                       err = -ENOENT;
-                       goto out;
-               }
-               if ((found_type != BTRFS_DIR_ITEM_KEY &&
-                    found_type != BTRFS_DIR_INDEX_KEY) ||
-                   (!btrfs_match_dir_item_name(root, path, goodnames, 2) &&
-                   !btrfs_match_dir_item_name(root, path, goodnames, 1))) {
-                       err = -ENOTEMPTY;
-                       goto out;
-               }
-               ret = btrfs_del_item(trans, root, path);
-               BUG_ON(ret);
-
-               if (found_type == BTRFS_DIR_ITEM_KEY && found_key.offset == 1)
-                       break;
-               btrfs_release_path(root, path);
-       }
-       ret = 0;
-       btrfs_release_path(root, path);
-
-       /* now the directory is empty */
-       err = btrfs_unlink_trans(trans, root, dir, dentry);
-       if (!err) {
-               inode->i_size = 0;
-       }
-out:
-       btrfs_release_path(root, path);
-       btrfs_free_path(path);
-       mutex_unlock(&root->fs_info->fs_mutex);
-       ret = btrfs_end_transaction(trans, root);
-       btrfs_btree_balance_dirty(root);
-       if (ret && !err)
-               err = ret;
-       return err;
-}
-
-static int btrfs_free_inode(struct btrfs_trans_handle *trans,
-                           struct btrfs_root *root,
-                           struct inode *inode)
-{
-       struct btrfs_path *path;
-       int ret;
-
-       clear_inode(inode);
-
-       path = btrfs_alloc_path();
-       BUG_ON(!path);
-       btrfs_init_path(path);
-       ret = btrfs_lookup_inode(trans, root, path,
-                                &BTRFS_I(inode)->location, -1);
-       BUG_ON(ret);
-       ret = btrfs_del_item(trans, root, path);
-       BUG_ON(ret);
-       btrfs_free_path(path);
-       return ret;
-}
-
-static void reada_truncate(struct btrfs_root *root, struct btrfs_path *path,
-                          u64 objectid)
-{
-       struct btrfs_node *node;
-       int i;
-       int nritems;
-       u64 item_objectid;
-       u64 blocknr;
-       int slot;
-       int ret;
-
-       if (!path->nodes[1])
-               return;
-       node = btrfs_buffer_node(path->nodes[1]);
-       slot = path->slots[1];
-       if (slot == 0)
-               return;
-       nritems = btrfs_header_nritems(&node->header);
-       for (i = slot - 1; i >= 0; i--) {
-               item_objectid = btrfs_disk_key_objectid(&node->ptrs[i].key);
-               if (item_objectid != objectid)
-                       break;
-               blocknr = btrfs_node_blockptr(node, i);
-               ret = readahead_tree_block(root, blocknr);
-               if (ret)
-                       break;
-       }
-}
-
-static int btrfs_truncate_in_trans(struct btrfs_trans_handle *trans,
-                                  struct btrfs_root *root,
-                                  struct inode *inode)
-{
-       int ret;
-       struct btrfs_path *path;
-       struct btrfs_key key;
-       struct btrfs_disk_key *found_key;
-       u32 found_type;
-       struct btrfs_leaf *leaf;
-       struct btrfs_file_extent_item *fi;
-       u64 extent_start = 0;
-       u64 extent_num_blocks = 0;
-       u64 item_end = 0;
-       int found_extent;
-       int del_item;
-
-       path = btrfs_alloc_path();
-       BUG_ON(!path);
-       /* FIXME, add redo link to tree so we don't leak on crash */
-       key.objectid = inode->i_ino;
-       key.offset = (u64)-1;
-       key.flags = (u32)-1;
-       while(1) {
-               btrfs_init_path(path);
-               fi = NULL;
-               ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
-               if (ret < 0) {
-                       goto error;
-               }
-               if (ret > 0) {
-                       BUG_ON(path->slots[0] == 0);
-                       path->slots[0]--;
-               }
-               reada_truncate(root, path, inode->i_ino);
-               leaf = btrfs_buffer_leaf(path->nodes[0]);
-               found_key = &leaf->items[path->slots[0]].key;
-               found_type = btrfs_disk_key_type(found_key);
-               if (btrfs_disk_key_objectid(found_key) != inode->i_ino)
-                       break;
-               if (found_type != BTRFS_CSUM_ITEM_KEY &&
-                   found_type != BTRFS_DIR_ITEM_KEY &&
-                   found_type != BTRFS_DIR_INDEX_KEY &&
-                   found_type != BTRFS_EXTENT_DATA_KEY)
-                       break;
-               item_end = btrfs_disk_key_offset(found_key);
-               if (found_type == BTRFS_EXTENT_DATA_KEY) {
-                       fi = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
-                                           path->slots[0],
-                                           struct btrfs_file_extent_item);
-                       if (btrfs_file_extent_type(fi) !=
-                           BTRFS_FILE_EXTENT_INLINE) {
-                               item_end += btrfs_file_extent_num_blocks(fi) <<
-                                               inode->i_blkbits;
-                       }
-               }
-               if (found_type == BTRFS_CSUM_ITEM_KEY) {
-                       ret = btrfs_csum_truncate(trans, root, path,
-                                                 inode->i_size);
-                       BUG_ON(ret);
-               }
-               if (item_end < inode->i_size) {
-                       if (found_type) {
-                               btrfs_set_key_type(&key, found_type - 1);
-                               continue;
-                       }
-                       break;
-               }
-               if (btrfs_disk_key_offset(found_key) >= inode->i_size)
-                       del_item = 1;
-               else
-                       del_item = 0;
-               found_extent = 0;
-
-               if (found_type == BTRFS_EXTENT_DATA_KEY &&
-                          btrfs_file_extent_type(fi) !=
-                          BTRFS_FILE_EXTENT_INLINE) {
-                       u64 num_dec;
-                       if (!del_item) {
-                               u64 orig_num_blocks =
-                                       btrfs_file_extent_num_blocks(fi);
-                               extent_num_blocks = inode->i_size -
-                                       btrfs_disk_key_offset(found_key) +
-                                       root->blocksize - 1;
-                               extent_num_blocks >>= inode->i_blkbits;
-                               btrfs_set_file_extent_num_blocks(fi,
-                                                        extent_num_blocks);
-                               inode->i_blocks -= (orig_num_blocks -
-                                       extent_num_blocks) << 3;
-                               mark_buffer_dirty(path->nodes[0]);
-                       } else {
-                               extent_start =
-                                       btrfs_file_extent_disk_blocknr(fi);
-                               extent_num_blocks =
-                                       btrfs_file_extent_disk_num_blocks(fi);
-                               /* FIXME blocksize != 4096 */
-                               num_dec = btrfs_file_extent_num_blocks(fi) << 3;
-                               if (extent_start != 0) {
-                                       found_extent = 1;
-                                       inode->i_blocks -= num_dec;
-                               }
-                       }
-               }
-               if (del_item) {
-                       ret = btrfs_del_item(trans, root, path);
-                       BUG_ON(ret);
-               } else {
-                       break;
-               }
-               btrfs_release_path(root, path);
-               if (found_extent) {
-                       ret = btrfs_free_extent(trans, root, extent_start,
-                                               extent_num_blocks, 0);
-                       BUG_ON(ret);
-               }
-       }
-       ret = 0;
-error:
-       btrfs_release_path(root, path);
-       btrfs_free_path(path);
-       inode->i_sb->s_dirt = 1;
-       return ret;
-}
-
-static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
-{
-       struct inode *inode = mapping->host;
-       unsigned blocksize = 1 << inode->i_blkbits;
-       pgoff_t index = from >> PAGE_CACHE_SHIFT;
-       unsigned offset = from & (PAGE_CACHE_SIZE-1);
-       struct page *page;
-       char *kaddr;
-       int ret = 0;
-       struct btrfs_root *root = BTRFS_I(inode)->root;
-       u64 alloc_hint;
-       struct btrfs_key ins;
-       struct btrfs_trans_handle *trans;
-
-       if ((offset & (blocksize - 1)) == 0)
-               goto out;
-
-       ret = -ENOMEM;
-       page = grab_cache_page(mapping, index);
-       if (!page)
-               goto out;
-
-       if (!PageUptodate(page)) {
-               ret = mpage_readpage(page, btrfs_get_block);
-               lock_page(page);
-               if (!PageUptodate(page)) {
-                       ret = -EIO;
-                       goto out;
-               }
-       }
-       mutex_lock(&root->fs_info->fs_mutex);
-       trans = btrfs_start_transaction(root, 1);
-       btrfs_set_trans_block_group(trans, inode);
-
-       ret = drop_extents(trans, root, inode, page->index << PAGE_CACHE_SHIFT,
-                          (page->index + 1) << PAGE_CACHE_SHIFT, &alloc_hint);
-       BUG_ON(ret);
-       ret = btrfs_alloc_extent(trans, root, inode->i_ino, 1,
-                                alloc_hint, (u64)-1, &ins, 1);
-       BUG_ON(ret);
-       ret = btrfs_insert_file_extent(trans, root, inode->i_ino,
-                                      page->index << PAGE_CACHE_SHIFT,
-                                      ins.objectid, 1, 1);
-       BUG_ON(ret);
-       SetPageChecked(page);
-       kaddr = kmap(page);
-       memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset);
-       flush_dcache_page(page);
-       btrfs_csum_file_block(trans, root, inode->i_ino,
-                             page->index << PAGE_CACHE_SHIFT,
-                             kaddr, PAGE_CACHE_SIZE);
-       kunmap(page);
-       btrfs_end_transaction(trans, root);
-       mutex_unlock(&root->fs_info->fs_mutex);
-
-       set_page_dirty(page);
-       unlock_page(page);
-       page_cache_release(page);
-out:
-       return ret;
-}
-
-static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
-{
-       struct inode *inode = dentry->d_inode;
-       int err;
-
-       err = inode_change_ok(inode, attr);
-       if (err)
-               return err;
-
-       if (S_ISREG(inode->i_mode) &&
-           attr->ia_valid & ATTR_SIZE && attr->ia_size > inode->i_size) {
-               struct btrfs_trans_handle *trans;
-               struct btrfs_root *root = BTRFS_I(inode)->root;
-               u64 mask = root->blocksize - 1;
-               u64 pos = (inode->i_size + mask) & ~mask;
-               u64 hole_size;
-
-               if (attr->ia_size <= pos)
-                       goto out;
-
-               btrfs_truncate_page(inode->i_mapping, inode->i_size);
-
-               hole_size = (attr->ia_size - pos + mask) & ~mask;
-               hole_size >>= inode->i_blkbits;
-
-               mutex_lock(&root->fs_info->fs_mutex);
-               trans = btrfs_start_transaction(root, 1);
-               btrfs_set_trans_block_group(trans, inode);
-               err = btrfs_insert_file_extent(trans, root, inode->i_ino,
-                                              pos, 0, 0, hole_size);
-               BUG_ON(err);
-               btrfs_end_transaction(trans, root);
-               mutex_unlock(&root->fs_info->fs_mutex);
-       }
-out:
-       err = inode_setattr(inode, attr);
-
-       return err;
-}
-static void btrfs_delete_inode(struct inode *inode)
-{
-       struct btrfs_trans_handle *trans;
-       struct btrfs_root *root = BTRFS_I(inode)->root;
-       int ret;
-
-       truncate_inode_pages(&inode->i_data, 0);
-       if (is_bad_inode(inode)) {
-               goto no_delete;
-       }
-       inode->i_size = 0;
-       mutex_lock(&root->fs_info->fs_mutex);
-       trans = btrfs_start_transaction(root, 1);
-       btrfs_set_trans_block_group(trans, inode);
-       ret = btrfs_truncate_in_trans(trans, root, inode);
-       BUG_ON(ret);
-       btrfs_free_inode(trans, root, inode);
-       btrfs_end_transaction(trans, root);
-       mutex_unlock(&root->fs_info->fs_mutex);
-       btrfs_btree_balance_dirty(root);
-       return;
-no_delete:
-       clear_inode(inode);
-}
-
-static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
-                              struct btrfs_key *location)
-{
-       const char *name = dentry->d_name.name;
-       int namelen = dentry->d_name.len;
-       struct btrfs_dir_item *di;
-       struct btrfs_path *path;
-       struct btrfs_root *root = BTRFS_I(dir)->root;
-       int ret;
-
-       path = btrfs_alloc_path();
-       BUG_ON(!path);
-       btrfs_init_path(path);
-       di = btrfs_lookup_dir_item(NULL, root, path, dir->i_ino, name,
-                                   namelen, 0);
-       if (!di || IS_ERR(di)) {
-               location->objectid = 0;
-               ret = 0;
-               goto out;
-       }
-       btrfs_disk_key_to_cpu(location, &di->location);
-out:
-       btrfs_release_path(root, path);
-       btrfs_free_path(path);
-       return ret;
-}
-
-static int fixup_tree_root_location(struct btrfs_root *root,
-                            struct btrfs_key *location,
-                            struct btrfs_root **sub_root)
-{
-       struct btrfs_path *path;
-       struct btrfs_root_item *ri;
-
-       if (btrfs_key_type(location) != BTRFS_ROOT_ITEM_KEY)
-               return 0;
-       if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
-               return 0;
-
-       path = btrfs_alloc_path();
-       BUG_ON(!path);
-       mutex_lock(&root->fs_info->fs_mutex);
-
-       *sub_root = btrfs_read_fs_root(root->fs_info, location);
-       if (IS_ERR(*sub_root))
-               return PTR_ERR(*sub_root);
-
-       ri = &(*sub_root)->root_item;
-       location->objectid = btrfs_root_dirid(ri);
-       location->flags = 0;
-       btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
-       location->offset = 0;
-
-       btrfs_free_path(path);
-       mutex_unlock(&root->fs_info->fs_mutex);
-       return 0;
-}
-
-static int btrfs_init_locked_inode(struct inode *inode, void *p)
-{
-       struct btrfs_iget_args *args = p;
-       inode->i_ino = args->ino;
-       BTRFS_I(inode)->root = args->root;
-       return 0;
-}
-
-static int btrfs_find_actor(struct inode *inode, void *opaque)
-{
-       struct btrfs_iget_args *args = opaque;
-       return (args->ino == inode->i_ino &&
-               args->root == BTRFS_I(inode)->root);
-}
-
-static struct inode *btrfs_iget_locked(struct super_block *s, u64 objectid,
-                                      struct btrfs_root *root)
-{
-       struct inode *inode;
-       struct btrfs_iget_args args;
-       args.ino = objectid;
-       args.root = root;
-
-       inode = iget5_locked(s, objectid, btrfs_find_actor,
-                            btrfs_init_locked_inode,
-                            (void *)&args);
-       return inode;
-}
-
-static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
-                                  struct nameidata *nd)
-{
-       struct inode * inode;
-       struct btrfs_inode *bi = BTRFS_I(dir);
-       struct btrfs_root *root = bi->root;
-       struct btrfs_root *sub_root = root;
-       struct btrfs_key location;
-       int ret;
-
-       if (dentry->d_name.len > BTRFS_NAME_LEN)
-               return ERR_PTR(-ENAMETOOLONG);
-       mutex_lock(&root->fs_info->fs_mutex);
-       ret = btrfs_inode_by_name(dir, dentry, &location);
-       mutex_unlock(&root->fs_info->fs_mutex);
-       if (ret < 0)
-               return ERR_PTR(ret);
-       inode = NULL;
-       if (location.objectid) {
-               ret = fixup_tree_root_location(root, &location, &sub_root);
-               if (ret < 0)
-                       return ERR_PTR(ret);
-               if (ret > 0)
-                       return ERR_PTR(-ENOENT);
-               inode = btrfs_iget_locked(dir->i_sb, location.objectid,
-                                         sub_root);
-               if (!inode)
-                       return ERR_PTR(-EACCES);
-               if (inode->i_state & I_NEW) {
-                       if (sub_root != root) {
-printk("adding new root for inode %lu root %p (found %p)\n", inode->i_ino, sub_root, BTRFS_I(inode)->root);
-                               igrab(inode);
-                               sub_root->inode = inode;
-                       }
-                       BTRFS_I(inode)->root = sub_root;
-                       memcpy(&BTRFS_I(inode)->location, &location,
-                              sizeof(location));
-                       btrfs_read_locked_inode(inode);
-                       unlock_new_inode(inode);
-               }
-       }
-       return d_splice_alias(inode, dentry);
-}
-
-static void reada_leaves(struct btrfs_root *root, struct btrfs_path *path,
-                        u64 objectid)
-{
-       struct btrfs_node *node;
-       int i;
-       u32 nritems;
-       u64 item_objectid;
-       u64 blocknr;
-       int slot;
-       int ret;
-
-       if (!path->nodes[1])
-               return;
-       node = btrfs_buffer_node(path->nodes[1]);
-       slot = path->slots[1];
-       nritems = btrfs_header_nritems(&node->header);
-       for (i = slot + 1; i < nritems; i++) {
-               item_objectid = btrfs_disk_key_objectid(&node->ptrs[i].key);
-               if (item_objectid != objectid)
-                       break;
-               blocknr = btrfs_node_blockptr(node, i);
-               ret = readahead_tree_block(root, blocknr);
-               if (ret)
-                       break;
-       }
-}
-static unsigned char btrfs_filetype_table[] = {
-       DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
-};
-
-static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
-{
-       struct inode *inode = filp->f_path.dentry->d_inode;
-       struct btrfs_root *root = BTRFS_I(inode)->root;
-       struct btrfs_item *item;
-       struct btrfs_dir_item *di;
-       struct btrfs_key key;
-       struct btrfs_path *path;
-       int ret;
-       u32 nritems;
-       struct btrfs_leaf *leaf;
-       int slot;
-       int advance;
-       unsigned char d_type;
-       int over = 0;
-       u32 di_cur;
-       u32 di_total;
-       u32 di_len;
-       int key_type = BTRFS_DIR_INDEX_KEY;
-
-       /* FIXME, use a real flag for deciding about the key type */
-       if (root->fs_info->tree_root == root)
-               key_type = BTRFS_DIR_ITEM_KEY;
-       mutex_lock(&root->fs_info->fs_mutex);
-       key.objectid = inode->i_ino;
-       key.flags = 0;
-       btrfs_set_key_type(&key, key_type);
-       key.offset = filp->f_pos;
-       path = btrfs_alloc_path();
-       btrfs_init_path(path);
-       ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
-       if (ret < 0)
-               goto err;
-       advance = 0;
-       reada_leaves(root, path, inode->i_ino);
-       while(1) {
-               leaf = btrfs_buffer_leaf(path->nodes[0]);
-               nritems = btrfs_header_nritems(&leaf->header);
-               slot = path->slots[0];
-               if (advance || slot >= nritems) {
-                       if (slot >= nritems -1) {
-                               reada_leaves(root, path, inode->i_ino);
-                               ret = btrfs_next_leaf(root, path);
-                               if (ret)
-                                       break;
-                               leaf = btrfs_buffer_leaf(path->nodes[0]);
-                               nritems = btrfs_header_nritems(&leaf->header);
-                               slot = path->slots[0];
-                       } else {
-                               slot++;
-                               path->slots[0]++;
-                       }
-               }
-               advance = 1;
-               item = leaf->items + slot;
-               if (btrfs_disk_key_objectid(&item->key) != key.objectid)
-                       break;
-               if (btrfs_disk_key_type(&item->key) != key_type)
-                       break;
-               if (btrfs_disk_key_offset(&item->key) < filp->f_pos)
-                       continue;
-               filp->f_pos = btrfs_disk_key_offset(&item->key);
-               advance = 1;
-               di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
-               di_cur = 0;
-               di_total = btrfs_item_size(leaf->items + slot);
-               while(di_cur < di_total) {
-                       d_type = btrfs_filetype_table[btrfs_dir_type(di)];
-                       over = filldir(dirent, (const char *)(di + 1),
-                                      btrfs_dir_name_len(di),
-                                      btrfs_disk_key_offset(&item->key),
-                                      btrfs_disk_key_objectid(&di->location),
-                                      d_type);
-                       if (over)
-                               goto nopos;
-                       di_len = btrfs_dir_name_len(di) + sizeof(*di);
-                       di_cur += di_len;
-                       di = (struct btrfs_dir_item *)((char *)di + di_len);
-               }
-       }
-       filp->f_pos++;
-nopos:
-       ret = 0;
-err:
-       btrfs_release_path(root, path);
-       btrfs_free_path(path);
-       mutex_unlock(&root->fs_info->fs_mutex);
-       return ret;
-}
-
-static void btrfs_put_super (struct super_block * sb)
-{
-       struct btrfs_root *root = btrfs_sb(sb);
-       int ret;
-
-       ret = close_ctree(root);
-       if (ret) {
-               printk("close ctree returns %d\n", ret);
-       }
-       sb->s_fs_info = NULL;
-}
-
-static int btrfs_fill_super(struct super_block * sb, void * data, int silent)
-{
-       struct inode * inode;
-       struct dentry * root_dentry;
-       struct btrfs_super_block *disk_super;
-       struct btrfs_root *tree_root;
-       struct btrfs_inode *bi;
-
-       sb->s_maxbytes = MAX_LFS_FILESIZE;
-       sb->s_magic = BTRFS_SUPER_MAGIC;
-       sb->s_op = &btrfs_super_ops;
-       sb->s_time_gran = 1;
-
-       tree_root = open_ctree(sb);
-
-       if (!tree_root) {
-               printk("btrfs: open_ctree failed\n");
-               return -EIO;
-       }
-       sb->s_fs_info = tree_root;
-       disk_super = tree_root->fs_info->disk_super;
-       printk("read in super total blocks %Lu root %Lu\n",
-              btrfs_super_total_blocks(disk_super),
-              btrfs_super_root_dir(disk_super));
-
-       inode = btrfs_iget_locked(sb, btrfs_super_root_dir(disk_super),
-                                 tree_root);
-       bi = BTRFS_I(inode);
-       bi->location.objectid = inode->i_ino;
-       bi->location.offset = 0;
-       bi->location.flags = 0;
-       bi->root = tree_root;
-       btrfs_set_key_type(&bi->location, BTRFS_INODE_ITEM_KEY);
-
-       if (!inode)
-               return -ENOMEM;
-       if (inode->i_state & I_NEW) {
-               btrfs_read_locked_inode(inode);
-               unlock_new_inode(inode);
-       }
-
-       root_dentry = d_alloc_root(inode);
-       if (!root_dentry) {
-               iput(inode);
-               return -ENOMEM;
-       }
-       sb->s_root = root_dentry;
-       btrfs_transaction_queue_work(tree_root, HZ * 30);
-       return 0;
-}
-
-static int btrfs_write_inode(struct inode *inode, int wait)
-{
-       struct btrfs_root *root = BTRFS_I(inode)->root;
-       struct btrfs_trans_handle *trans;
-       int ret = 0;
-
-       if (wait) {
-               mutex_lock(&root->fs_info->fs_mutex);
-               trans = btrfs_start_transaction(root, 1);
-               btrfs_set_trans_block_group(trans, inode);
-               ret = btrfs_commit_transaction(trans, root);
-               mutex_unlock(&root->fs_info->fs_mutex);
-       }
-       return ret;
-}
-
-static void btrfs_dirty_inode(struct inode *inode)
-{
-       struct btrfs_root *root = BTRFS_I(inode)->root;
-       struct btrfs_trans_handle *trans;
-
-       mutex_lock(&root->fs_info->fs_mutex);
-       trans = btrfs_start_transaction(root, 1);
-       btrfs_set_trans_block_group(trans, inode);
-       btrfs_update_inode(trans, root, inode);
-       btrfs_end_transaction(trans, root);
-       mutex_unlock(&root->fs_info->fs_mutex);
-       btrfs_btree_balance_dirty(root);
-}
-
-static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
-                                    struct btrfs_root *root,
-                                    u64 objectid,
-                                    struct btrfs_block_group_cache *group,
-                                    int mode)
-{
-       struct inode *inode;
-       struct btrfs_inode_item inode_item;
-       struct btrfs_key *location;
-       int ret;
-       int owner;
-
-       inode = new_inode(root->fs_info->sb);
-       if (!inode)
-               return ERR_PTR(-ENOMEM);
-
-       BTRFS_I(inode)->root = root;
-       if (mode & S_IFDIR)
-               owner = 0;
-       else
-               owner = 1;
-       group = btrfs_find_block_group(root, group, 0, 0, owner);
-       BTRFS_I(inode)->block_group = group;
-
-       inode->i_uid = current->fsuid;
-       inode->i_gid = current->fsgid;
-       inode->i_mode = mode;
-       inode->i_ino = objectid;
-       inode->i_blocks = 0;
-       inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
-       fill_inode_item(&inode_item, inode);
-       location = &BTRFS_I(inode)->location;
-       location->objectid = objectid;
-       location->flags = 0;
-       location->offset = 0;
-       btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
-
-       ret = btrfs_insert_inode(trans, root, objectid, &inode_item);
-       BUG_ON(ret);
-
-       insert_inode_hash(inode);
-       return inode;
-}
-
-static inline u8 btrfs_inode_type(struct inode *inode)
-{
-       return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
-}
-
-static int btrfs_add_link(struct btrfs_trans_handle *trans,
-                           struct dentry *dentry, struct inode *inode)
-{
-       int ret;
-       struct btrfs_key key;
-       struct btrfs_root *root = BTRFS_I(dentry->d_parent->d_inode)->root;
-       key.objectid = inode->i_ino;
-       key.flags = 0;
-       btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
-       key.offset = 0;
-
-       ret = btrfs_insert_dir_item(trans, root,
-                                   dentry->d_name.name, dentry->d_name.len,
-                                   dentry->d_parent->d_inode->i_ino,
-                                   &key, btrfs_inode_type(inode));
-       if (ret == 0) {
-               dentry->d_parent->d_inode->i_size += dentry->d_name.len * 2;
-               ret = btrfs_update_inode(trans, root,
-                                        dentry->d_parent->d_inode);
-       }
-       return ret;
-}
-
-static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
-                           struct dentry *dentry, struct inode *inode)
-{
-       int err = btrfs_add_link(trans, dentry, inode);
-       if (!err) {
-               d_instantiate(dentry, inode);
-               return 0;
-       }
-       if (err > 0)
-               err = -EEXIST;
-       return err;
-}
-
-static int btrfs_create(struct inode *dir, struct dentry *dentry,
-                       int mode, struct nameidata *nd)
-{
-       struct btrfs_trans_handle *trans;
-       struct btrfs_root *root = BTRFS_I(dir)->root;
-       struct inode *inode;
-       int err;
-       int drop_inode = 0;
-       u64 objectid;
-
-       mutex_lock(&root->fs_info->fs_mutex);
-       trans = btrfs_start_transaction(root, 1);
-       btrfs_set_trans_block_group(trans, dir);
-
-       err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
-       if (err) {
-               err = -ENOSPC;
-               goto out_unlock;
-       }
-
-       inode = btrfs_new_inode(trans, root, objectid,
-                               BTRFS_I(dir)->block_group, mode);
-       err = PTR_ERR(inode);
-       if (IS_ERR(inode))
-               goto out_unlock;
-
-       btrfs_set_trans_block_group(trans, inode);
-       err = btrfs_add_nondir(trans, dentry, inode);
-       if (err)
-               drop_inode = 1;
-       else {
-               inode->i_mapping->a_ops = &btrfs_aops;
-               inode->i_fop = &btrfs_file_operations;
-               inode->i_op = &btrfs_file_inode_operations;
-       }
-       dir->i_sb->s_dirt = 1;
-       btrfs_update_inode_block_group(trans, inode);
-       btrfs_update_inode_block_group(trans, dir);
-out_unlock:
-       btrfs_end_transaction(trans, root);
-       mutex_unlock(&root->fs_info->fs_mutex);
-
-       if (drop_inode) {
-               inode_dec_link_count(inode);
-               iput(inode);
-       }
-       btrfs_btree_balance_dirty(root);
-       return err;
-}
-
-static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
-                     struct dentry *dentry)
-{
-       struct btrfs_trans_handle *trans;
-       struct btrfs_root *root = BTRFS_I(dir)->root;
-       struct inode *inode = old_dentry->d_inode;
-       int err;
-       int drop_inode = 0;
-
-       if (inode->i_nlink == 0)
-               return -ENOENT;
-
-       inc_nlink(inode);
-       mutex_lock(&root->fs_info->fs_mutex);
-       trans = btrfs_start_transaction(root, 1);
-       btrfs_set_trans_block_group(trans, dir);
-       atomic_inc(&inode->i_count);
-       err = btrfs_add_nondir(trans, dentry, inode);
-       if (err)
-               drop_inode = 1;
-       dir->i_sb->s_dirt = 1;
-       btrfs_update_inode_block_group(trans, dir);
-       btrfs_update_inode(trans, root, inode);
-
-       btrfs_end_transaction(trans, root);
-       mutex_unlock(&root->fs_info->fs_mutex);
-
-       if (drop_inode) {
-               inode_dec_link_count(inode);
-               iput(inode);
-       }
-       btrfs_btree_balance_dirty(root);
-       return err;
-}
-
-static int btrfs_make_empty_dir(struct btrfs_trans_handle *trans,
-                               struct btrfs_root *root,
-                               u64 objectid, u64 dirid)
-{
-       int ret;
-       char buf[2];
-       struct btrfs_key key;
-
-       buf[0] = '.';
-       buf[1] = '.';
-
-       key.objectid = objectid;
-       key.offset = 0;
-       key.flags = 0;
-       btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
-
-       ret = btrfs_insert_dir_item(trans, root, buf, 1, objectid,
-                                   &key, BTRFS_FT_DIR);
-       if (ret)
-               goto error;
-       key.objectid = dirid;
-       ret = btrfs_insert_dir_item(trans, root, buf, 2, objectid,
-                                   &key, BTRFS_FT_DIR);
-       if (ret)
-               goto error;
-error:
-       return ret;
-}
-
-static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
-{
-       struct inode *inode;
-       struct btrfs_trans_handle *trans;
-       struct btrfs_root *root = BTRFS_I(dir)->root;
-       int err = 0;
-       int drop_on_err = 0;
-       u64 objectid;
-
-       mutex_lock(&root->fs_info->fs_mutex);
-       trans = btrfs_start_transaction(root, 1);
-       btrfs_set_trans_block_group(trans, dir);
-       if (IS_ERR(trans)) {
-               err = PTR_ERR(trans);
-               goto out_unlock;
-       }
-
-       err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
-       if (err) {
-               err = -ENOSPC;
-               goto out_unlock;
-       }
-
-       inode = btrfs_new_inode(trans, root, objectid,
-                               BTRFS_I(dir)->block_group, S_IFDIR | mode);
-       if (IS_ERR(inode)) {
-               err = PTR_ERR(inode);
-               goto out_fail;
-       }
-       drop_on_err = 1;
-       inode->i_op = &btrfs_dir_inode_operations;
-       inode->i_fop = &btrfs_dir_file_operations;
-       btrfs_set_trans_block_group(trans, inode);
-
-       err = btrfs_make_empty_dir(trans, root, inode->i_ino, dir->i_ino);
-       if (err)
-               goto out_fail;
-
-       inode->i_size = 6;
-       err = btrfs_update_inode(trans, root, inode);
-       if (err)
-               goto out_fail;
-       err = btrfs_add_link(trans, dentry, inode);
-       if (err)
-               goto out_fail;
-       d_instantiate(dentry, inode);
-       drop_on_err = 0;
-       dir->i_sb->s_dirt = 1;
-       btrfs_update_inode_block_group(trans, inode);
-       btrfs_update_inode_block_group(trans, dir);
-
-out_fail:
-       btrfs_end_transaction(trans, root);
-out_unlock:
-       mutex_unlock(&root->fs_info->fs_mutex);
-       if (drop_on_err)
-               iput(inode);
-       btrfs_btree_balance_dirty(root);
-       return err;
-}
-
-static int btrfs_sync_file(struct file *file,
-                          struct dentry *dentry, int datasync)
-{
-       struct inode *inode = dentry->d_inode;
-       struct btrfs_root *root = BTRFS_I(inode)->root;
-       int ret;
-       struct btrfs_trans_handle *trans;
-
-       mutex_lock(&root->fs_info->fs_mutex);
-       trans = btrfs_start_transaction(root, 1);
-       if (!trans) {
-               ret = -ENOMEM;
-               goto out;
-       }
-       ret = btrfs_commit_transaction(trans, root);
-       mutex_unlock(&root->fs_info->fs_mutex);
-out:
-       return ret > 0 ? EIO : ret;
-}
-
-static int btrfs_sync_fs(struct super_block *sb, int wait)
-{
-       struct btrfs_trans_handle *trans;
-       struct btrfs_root *root;
-       int ret;
-       root = btrfs_sb(sb);
-
-       sb->s_dirt = 0;
-       if (!wait) {
-               filemap_flush(root->fs_info->btree_inode->i_mapping);
-               return 0;
-       }
-       mutex_lock(&root->fs_info->fs_mutex);
-       trans = btrfs_start_transaction(root, 1);
-       ret = btrfs_commit_transaction(trans, root);
-       sb->s_dirt = 0;
-       BUG_ON(ret);
-printk("btrfs sync_fs\n");
-       mutex_unlock(&root->fs_info->fs_mutex);
-       return 0;
-}
-
-#define BTRFS_GET_BLOCK_NO_CREATE 0
-#define BTRFS_GET_BLOCK_CREATE 1
-#define BTRFS_GET_BLOCK_NO_DIRECT 2
-
-static int btrfs_get_block_lock(struct inode *inode, sector_t iblock,
-                          struct buffer_head *result, int create)
-{
-       int ret;
-       int err = 0;
-       u64 blocknr;
-       u64 extent_start = 0;
-       u64 extent_end = 0;
-       u64 objectid = inode->i_ino;
-       u32 found_type;
-       u64 alloc_hint = 0;
-       struct btrfs_path *path;
-       struct btrfs_root *root = BTRFS_I(inode)->root;
-       struct btrfs_file_extent_item *item;
-       struct btrfs_leaf *leaf;
-       struct btrfs_disk_key *found_key;
-       struct btrfs_trans_handle *trans = NULL;
-
-       path = btrfs_alloc_path();
-       BUG_ON(!path);
-       btrfs_init_path(path);
-       if (create & BTRFS_GET_BLOCK_CREATE) {
-               WARN_ON(1);
-               /* this almost but not quite works */
-               trans = btrfs_start_transaction(root, 1);
-               if (!trans) {
-                       err = -ENOMEM;
-                       goto out;
-               }
-               ret = drop_extents(trans, root, inode,
-                                  iblock << inode->i_blkbits,
-                                  (iblock + 1) << inode->i_blkbits,
-                                  &alloc_hint);
-               BUG_ON(ret);
-       }
-
-       ret = btrfs_lookup_file_extent(NULL, root, path,
-                                      inode->i_ino,
-                                      iblock << inode->i_blkbits, 0);
-       if (ret < 0) {
-               err = ret;
-               goto out;
-       }
-
-       if (ret != 0) {
-               if (path->slots[0] == 0) {
-                       btrfs_release_path(root, path);
-                       goto not_found;
-               }
-               path->slots[0]--;
-       }
-
-       item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
-                             struct btrfs_file_extent_item);
-       leaf = btrfs_buffer_leaf(path->nodes[0]);
-       blocknr = btrfs_file_extent_disk_blocknr(item);
-       blocknr += btrfs_file_extent_offset(item);
-
-       /* are we inside the extent that was found? */
-       found_key = &leaf->items[path->slots[0]].key;
-       found_type = btrfs_disk_key_type(found_key);
-       if (btrfs_disk_key_objectid(found_key) != objectid ||
-           found_type != BTRFS_EXTENT_DATA_KEY) {
-               extent_end = 0;
-               extent_start = 0;
-               goto not_found;
-       }
-       found_type = btrfs_file_extent_type(item);
-       extent_start = btrfs_disk_key_offset(&leaf->items[path->slots[0]].key);
-       if (found_type == BTRFS_FILE_EXTENT_REG) {
-               extent_start = extent_start >> inode->i_blkbits;
-               extent_end = extent_start + btrfs_file_extent_num_blocks(item);
-               err = 0;
-               if (btrfs_file_extent_disk_blocknr(item) == 0)
-                       goto out;
-               if (iblock >= extent_start && iblock < extent_end) {
-                       btrfs_map_bh_to_logical(root, result, blocknr +
-                                               iblock - extent_start);
-                       goto out;
-               }
-       } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
-               char *ptr;
-               char *map;
-               u32 size;
-
-               if (create & BTRFS_GET_BLOCK_NO_DIRECT) {
-                       err = -EINVAL;
-                       goto out;
-               }
-               size = btrfs_file_extent_inline_len(leaf->items +
-                                                   path->slots[0]);
-               extent_end = (extent_start + size) >> inode->i_blkbits;
-               extent_start >>= inode->i_blkbits;
-               if (iblock < extent_start || iblock > extent_end) {
-                       goto not_found;
-               }
-               ptr = btrfs_file_extent_inline_start(item);
-               map = kmap(result->b_page);
-               memcpy(map, ptr, size);
-               memset(map + size, 0, PAGE_CACHE_SIZE - size);
-               flush_dcache_page(result->b_page);
-               kunmap(result->b_page);
-               set_buffer_uptodate(result);
-               SetPageChecked(result->b_page);
-               btrfs_map_bh_to_logical(root, result, 0);
-       }
-not_found:
-       if (create & BTRFS_GET_BLOCK_CREATE) {
-               struct btrfs_key ins;
-               ret = btrfs_alloc_extent(trans, root, inode->i_ino,
-                                        1, alloc_hint, (u64)-1,
-                                        &ins, 1);
-               BUG_ON(ret);
-               ret = btrfs_insert_file_extent(trans, root, inode->i_ino,
-                                              iblock << inode->i_blkbits,
-                                              ins.objectid, ins.offset,
-                                              ins.offset);
-               BUG_ON(ret);
-               SetPageChecked(result->b_page);
-               btrfs_map_bh_to_logical(root, result, ins.objectid);
-       }
-out:
-       if (trans)
-               err = btrfs_end_transaction(trans, root);
-       btrfs_free_path(path);
-       return err;
-}
-
-static int btrfs_get_block(struct inode *inode, sector_t iblock,
-                          struct buffer_head *result, int create)
-{
-       int err;
-       struct btrfs_root *root = BTRFS_I(inode)->root;
-       mutex_lock(&root->fs_info->fs_mutex);
-       err = btrfs_get_block_lock(inode, iblock, result, create);
-       mutex_unlock(&root->fs_info->fs_mutex);
-       return err;
-}
-
-static int btrfs_get_block_bmap(struct inode *inode, sector_t iblock,
-                          struct buffer_head *result, int create)
-{
-       struct btrfs_root *root = BTRFS_I(inode)->root;
-       mutex_lock(&root->fs_info->fs_mutex);
-       btrfs_get_block_lock(inode, iblock, result, BTRFS_GET_BLOCK_NO_DIRECT);
-       mutex_unlock(&root->fs_info->fs_mutex);
-       return 0;
-}
-
-static sector_t btrfs_bmap(struct address_space *as, sector_t block)
-{
-       return generic_block_bmap(as, block, btrfs_get_block_bmap);
-}
-
-static int btrfs_prepare_write(struct file *file, struct page *page,
-                              unsigned from, unsigned to)
-{
-       return block_prepare_write(page, from, to, btrfs_get_block);
-}
-
-static void btrfs_write_super(struct super_block *sb)
-{
-       sb->s_dirt = 0;
-}
-
-static int btrfs_readpage(struct file *file, struct page *page)
-{
-       return mpage_readpage(page, btrfs_get_block);
-}
-
-/*
- * While block_write_full_page is writing back the dirty buffers under
- * the page lock, whoever dirtied the buffers may decide to clean them
- * again at any time.  We handle that by only looking at the buffer
- * state inside lock_buffer().
- *
- * If block_write_full_page() is called for regular writeback
- * (wbc->sync_mode == WB_SYNC_NONE) then it will redirty a page which has a
- * locked buffer.   This only can happen if someone has written the buffer
- * directly, with submit_bh().  At the address_space level PageWriteback
- * prevents this contention from occurring.
- */
-static int __btrfs_write_full_page(struct inode *inode, struct page *page,
-                                  struct writeback_control *wbc)
-{
-       int err;
-       sector_t block;
-       sector_t last_block;
-       struct buffer_head *bh, *head;
-       const unsigned blocksize = 1 << inode->i_blkbits;
-       int nr_underway = 0;
-
-       BUG_ON(!PageLocked(page));
-
-       last_block = (i_size_read(inode) - 1) >> inode->i_blkbits;
-
-       if (!page_has_buffers(page)) {
-               create_empty_buffers(page, blocksize,
-                                       (1 << BH_Dirty)|(1 << BH_Uptodate));
-       }
-
-       /*
-        * Be very careful.  We have no exclusion from __set_page_dirty_buffers
-        * here, and the (potentially unmapped) buffers may become dirty at
-        * any time.  If a buffer becomes dirty here after we've inspected it
-        * then we just miss that fact, and the page stays dirty.
-        *
-        * Buffers outside i_size may be dirtied by __set_page_dirty_buffers;
-        * handle that here by just cleaning them.
-        */
-
-       block = (sector_t)page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
-       head = page_buffers(page);
-       bh = head;
-
-       /*
-        * Get all the dirty buffers mapped to disk addresses and
-        * handle any aliases from the underlying blockdev's mapping.
-        */
-       do {
-               if (block > last_block) {
-                       /*
-                        * mapped buffers outside i_size will occur, because
-                        * this page can be outside i_size when there is a
-                        * truncate in progress.
-                        */
-                       /*
-                        * The buffer was zeroed by block_write_full_page()
-                        */
-                       clear_buffer_dirty(bh);
-                       set_buffer_uptodate(bh);
-               } else if (!buffer_mapped(bh) && buffer_dirty(bh)) {
-                       WARN_ON(bh->b_size != blocksize);
-                       err = btrfs_get_block(inode, block, bh, 0);
-                       if (err) {
-printk("writepage going to recovery err %d\n", err);
-                               goto recover;
-                       }
-                       if (buffer_new(bh)) {
-                               /* blockdev mappings never come here */
-                               clear_buffer_new(bh);
-                       }
-               }
-               bh = bh->b_this_page;
-               block++;
-       } while (bh != head);
-
-       do {
-               if (!buffer_mapped(bh))
-                       continue;
-               /*
-                * If it's a fully non-blocking write attempt and we cannot
-                * lock the buffer then redirty the page.  Note that this can
-                * potentially cause a busy-wait loop from pdflush and kswapd
-                * activity, but those code paths have their own higher-level
-                * throttling.
-                */
-               if (wbc->sync_mode != WB_SYNC_NONE || !wbc->nonblocking) {
-                       lock_buffer(bh);
-               } else if (test_set_buffer_locked(bh)) {
-                       redirty_page_for_writepage(wbc, page);
-                       continue;
-               }
-               if (test_clear_buffer_dirty(bh) && bh->b_blocknr != 0) {
-                       mark_buffer_async_write(bh);
-               } else {
-                       unlock_buffer(bh);
-               }
-       } while ((bh = bh->b_this_page) != head);
-
-       /*
-        * The page and its buffers are protected by PageWriteback(), so we can
-        * drop the bh refcounts early.
-        */
-       BUG_ON(PageWriteback(page));
-       set_page_writeback(page);
-
-       do {
-               struct buffer_head *next = bh->b_this_page;
-               if (buffer_async_write(bh)) {
-                       submit_bh(WRITE, bh);
-                       nr_underway++;
-               }
-               bh = next;
-       } while (bh != head);
-       unlock_page(page);
-
-       err = 0;
-done:
-       if (nr_underway == 0) {
-               /*
-                * The page was marked dirty, but the buffers were
-                * clean.  Someone wrote them back by hand with
-                * ll_rw_block/submit_bh.  A rare case.
-                */
-               int uptodate = 1;
-               do {
-                       if (!buffer_uptodate(bh)) {
-                               uptodate = 0;
-                               break;
-                       }
-                       bh = bh->b_this_page;
-               } while (bh != head);
-               if (uptodate)
-                       SetPageUptodate(page);
-               end_page_writeback(page);
-       }
-       return err;
-
-recover:
-       /*
-        * ENOSPC, or some other error.  We may already have added some
-        * blocks to the file, so we need to write these out to avoid
-        * exposing stale data.
-        * The page is currently locked and not marked for writeback
-        */
-       bh = head;
-       /* Recovery: lock and submit the mapped buffers */
-       do {
-               if (buffer_mapped(bh) && buffer_dirty(bh)) {
-                       lock_buffer(bh);
-                       mark_buffer_async_write(bh);
-               } else {
-                       /*
-                        * The buffer may have been set dirty during
-                        * attachment to a dirty page.
-                        */
-                       clear_buffer_dirty(bh);
-               }
-       } while ((bh = bh->b_this_page) != head);
-       SetPageError(page);
-       BUG_ON(PageWriteback(page));
-       set_page_writeback(page);
-       do {
-               struct buffer_head *next = bh->b_this_page;
-               if (buffer_async_write(bh)) {
-                       clear_buffer_dirty(bh);
-                       submit_bh(WRITE, bh);
-                       nr_underway++;
-               }
-               bh = next;
-       } while (bh != head);
-       unlock_page(page);
-       goto done;
-}
-
-/*
- * The generic ->writepage function for buffer-backed address_spaces
- */
-static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
-{
-       struct inode * const inode = page->mapping->host;
-       loff_t i_size = i_size_read(inode);
-       const pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
-       unsigned offset;
-       void *kaddr;
-
-       /* Is the page fully inside i_size? */
-       if (page->index < end_index)
-               return __btrfs_write_full_page(inode, page, wbc);
-
-       /* Is the page fully outside i_size? (truncate in progress) */
-       offset = i_size & (PAGE_CACHE_SIZE-1);
-       if (page->index >= end_index+1 || !offset) {
-               /*
-                * The page may have dirty, unmapped buffers.  For example,
-                * they may have been added in ext3_writepage().  Make them
-                * freeable here, so the page does not leak.
-                */
-               block_invalidatepage(page, 0);
-               unlock_page(page);
-               return 0; /* don't care */
-       }
-
-       /*
-        * The page straddles i_size.  It must be zeroed out on each and every
-        * writepage invokation because it may be mmapped.  "A file is mapped
-        * in multiples of the page size.  For a file that is not a multiple of
-        * the  page size, the remaining memory is zeroed when mapped, and
-        * writes to that region are not written out to the file."
-        */
-       kaddr = kmap_atomic(page, KM_USER0);
-       memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset);
-       flush_dcache_page(page);
-       kunmap_atomic(kaddr, KM_USER0);
-       return __btrfs_write_full_page(inode, page, wbc);
-}
-
-static void btrfs_truncate(struct inode *inode)
-{
-       struct btrfs_root *root = BTRFS_I(inode)->root;
-       int ret;
-       struct btrfs_trans_handle *trans;
-
-       if (!S_ISREG(inode->i_mode))
-               return;
-       if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
-               return;
-
-       btrfs_truncate_page(inode->i_mapping, inode->i_size);
-
-       mutex_lock(&root->fs_info->fs_mutex);
-       trans = btrfs_start_transaction(root, 1);
-       btrfs_set_trans_block_group(trans, inode);
-
-       /* FIXME, add redo link to tree so we don't leak on crash */
-       ret = btrfs_truncate_in_trans(trans, root, inode);
-       BUG_ON(ret);
-       btrfs_update_inode(trans, root, inode);
-       ret = btrfs_end_transaction(trans, root);
-       BUG_ON(ret);
-       mutex_unlock(&root->fs_info->fs_mutex);
-       btrfs_btree_balance_dirty(root);
-}
-
-static int btrfs_commit_write(struct file *file, struct page *page,
-                             unsigned from, unsigned to)
-{
-       struct inode *inode = page->mapping->host;
-       struct buffer_head *bh;
-       loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
-
-       SetPageUptodate(page);
-       bh = page_buffers(page);
-       set_buffer_uptodate(bh);
-       if (buffer_mapped(bh) && bh->b_blocknr != 0) {
-               set_page_dirty(page);
-       }
-       if (pos > inode->i_size) {
-               i_size_write(inode, pos);
-               mark_inode_dirty(inode);
-       }
-       return 0;
-}
-
-static int btrfs_copy_from_user(loff_t pos, int num_pages, int write_bytes,
-                               struct page **prepared_pages,
-                               const char __user * buf)
-{
-       long page_fault = 0;
-       int i;
-       int offset = pos & (PAGE_CACHE_SIZE - 1);
-
-       for (i = 0; i < num_pages && write_bytes > 0; i++, offset = 0) {
-               size_t count = min_t(size_t,
-                                    PAGE_CACHE_SIZE - offset, write_bytes);
-               struct page *page = prepared_pages[i];
-               fault_in_pages_readable(buf, count);
-
-               /* Copy data from userspace to the current page */
-               kmap(page);
-               page_fault = __copy_from_user(page_address(page) + offset,
-                                             buf, count);
-               /* Flush processor's dcache for this page */
-               flush_dcache_page(page);
-               kunmap(page);
-               buf += count;
-               write_bytes -= count;
-
-               if (page_fault)
-                       break;
-       }
-       return page_fault ? -EFAULT : 0;
-}
-
-static void btrfs_drop_pages(struct page **pages, size_t num_pages)
-{
-       size_t i;
-       for (i = 0; i < num_pages; i++) {
-               if (!pages[i])
-                       break;
-               unlock_page(pages[i]);
-               mark_page_accessed(pages[i]);
-               page_cache_release(pages[i]);
-       }
-}
-static int dirty_and_release_pages(struct btrfs_trans_handle *trans,
-                                  struct btrfs_root *root,
-                                  struct file *file,
-                                  struct page **pages,
-                                  size_t num_pages,
-                                  loff_t pos,
-                                  size_t write_bytes)
-{
-       int i;
-       int offset;
-       int err = 0;
-       int ret;
-       int this_write;
-       struct inode *inode = file->f_path.dentry->d_inode;
-       struct buffer_head *bh;
-       struct btrfs_file_extent_item *ei;
-
-       for (i = 0; i < num_pages; i++) {
-               offset = pos & (PAGE_CACHE_SIZE -1);
-               this_write = min(PAGE_CACHE_SIZE - offset, write_bytes);
-               /* FIXME, one block at a time */
-
-               mutex_lock(&root->fs_info->fs_mutex);
-               trans = btrfs_start_transaction(root, 1);
-               btrfs_set_trans_block_group(trans, inode);
-
-               bh = page_buffers(pages[i]);
-               if (buffer_mapped(bh) && bh->b_blocknr == 0) {
-                       struct btrfs_key key;
-                       struct btrfs_path *path;
-                       char *ptr;
-                       u32 datasize;
-
-                       path = btrfs_alloc_path();
-                       BUG_ON(!path);
-                       key.objectid = inode->i_ino;
-                       key.offset = pages[i]->index << PAGE_CACHE_SHIFT;
-                       key.flags = 0;
-                       btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
-                       BUG_ON(write_bytes >= PAGE_CACHE_SIZE);
-                       datasize = offset +
-                               btrfs_file_extent_calc_inline_size(write_bytes);
-                       ret = btrfs_insert_empty_item(trans, root, path, &key,
-                                                     datasize);
-                       BUG_ON(ret);
-                       ei = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
-                              path->slots[0], struct btrfs_file_extent_item);
-                       btrfs_set_file_extent_generation(ei, trans->transid);
-                       btrfs_set_file_extent_type(ei,
-                                                  BTRFS_FILE_EXTENT_INLINE);
-                       ptr = btrfs_file_extent_inline_start(ei);
-                       btrfs_memcpy(root, path->nodes[0]->b_data,
-                                    ptr, bh->b_data, offset + write_bytes);
-                       mark_buffer_dirty(path->nodes[0]);
-                       btrfs_free_path(path);
-               } else if (buffer_mapped(bh)) {
-                       btrfs_csum_file_block(trans, root, inode->i_ino,
-                                     pages[i]->index << PAGE_CACHE_SHIFT,
-                                     kmap(pages[i]), PAGE_CACHE_SIZE);
-                       kunmap(pages[i]);
-               }
-               SetPageChecked(pages[i]);
-               // btrfs_update_inode_block_group(trans, inode);
-               ret = btrfs_end_transaction(trans, root);
-               BUG_ON(ret);
-               mutex_unlock(&root->fs_info->fs_mutex);
+#define BTRFS_SUPER_MAGIC 0x9123682E
 
-               ret = btrfs_commit_write(file, pages[i], offset,
-                                        offset + this_write);
-               pos += this_write;
-               if (ret) {
-                       err = ret;
-                       goto failed;
-               }
-               WARN_ON(this_write > write_bytes);
-               write_bytes -= this_write;
-       }
-failed:
-       return err;
-}
+static struct super_operations btrfs_super_ops;
 
-static int drop_extents(struct btrfs_trans_handle *trans,
-                         struct btrfs_root *root,
-                         struct inode *inode,
-                         u64 start, u64 end, u64 *hint_block)
+static void btrfs_put_super (struct super_block * sb)
 {
+       struct btrfs_root *root = btrfs_sb(sb);
        int ret;
-       struct btrfs_key key;
-       struct btrfs_leaf *leaf;
-       int slot;
-       struct btrfs_file_extent_item *extent;
-       u64 extent_end = 0;
-       int keep;
-       struct btrfs_file_extent_item old;
-       struct btrfs_path *path;
-       u64 search_start = start;
-       int bookend;
-       int found_type;
-       int found_extent;
-       int found_inline;
-
-       path = btrfs_alloc_path();
-       if (!path)
-               return -ENOMEM;
-       while(1) {
-               btrfs_release_path(root, path);
-               ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino,
-                                              search_start, -1);
-               if (ret < 0)
-                       goto out;
-               if (ret > 0) {
-                       if (path->slots[0] == 0) {
-                               ret = 0;
-                               goto out;
-                       }
-                       path->slots[0]--;
-               }
-               keep = 0;
-               bookend = 0;
-               found_extent = 0;
-               found_inline = 0;
-               extent = NULL;
-               leaf = btrfs_buffer_leaf(path->nodes[0]);
-               slot = path->slots[0];
-               btrfs_disk_key_to_cpu(&key, &leaf->items[slot].key);
-               if (key.offset >= end || key.objectid != inode->i_ino) {
-                       ret = 0;
-                       goto out;
-               }
-               if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY) {
-                       ret = 0;
-                       goto out;
-               }
-               extent = btrfs_item_ptr(leaf, slot,
-                                       struct btrfs_file_extent_item);
-               found_type = btrfs_file_extent_type(extent);
-               if (found_type == BTRFS_FILE_EXTENT_REG) {
-                       extent_end = key.offset +
-                               (btrfs_file_extent_num_blocks(extent) <<
-                                inode->i_blkbits);
-                       found_extent = 1;
-               } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
-                       found_inline = 1;
-                       extent_end = key.offset +
-                            btrfs_file_extent_inline_len(leaf->items + slot);
-               }
-
-               if (!found_extent && !found_inline) {
-                       ret = 0;
-                       goto out;
-               }
-
-               if (search_start >= extent_end) {
-                       ret = 0;
-                       goto out;
-               }
-
-               if (found_inline) {
-                       u64 mask = root->blocksize - 1;
-                       search_start = (extent_end + mask) & ~mask;
-               } else
-                       search_start = extent_end;
 
-               if (end < extent_end && end >= key.offset) {
-                       if (found_extent) {
-                               u64 disk_blocknr =
-                                       btrfs_file_extent_disk_blocknr(extent);
-                               u64 disk_num_blocks =
-                                     btrfs_file_extent_disk_num_blocks(extent);
-                               memcpy(&old, extent, sizeof(old));
-                               if (disk_blocknr != 0) {
-                                       ret = btrfs_inc_extent_ref(trans, root,
-                                                disk_blocknr, disk_num_blocks);
-                                       BUG_ON(ret);
-                               }
-                       }
-                       WARN_ON(found_inline);
-                       bookend = 1;
-               }
-
-               if (start > key.offset) {
-                       u64 new_num;
-                       u64 old_num;
-                       /* truncate existing extent */
-                       keep = 1;
-                       WARN_ON(start & (root->blocksize - 1));
-                       if (found_extent) {
-                               new_num = (start - key.offset) >>
-                                       inode->i_blkbits;
-                               old_num = btrfs_file_extent_num_blocks(extent);
-                               *hint_block =
-                                       btrfs_file_extent_disk_blocknr(extent);
-                               if (btrfs_file_extent_disk_blocknr(extent)) {
-                                       inode->i_blocks -=
-                                               (old_num - new_num) << 3;
-                               }
-                               btrfs_set_file_extent_num_blocks(extent,
-                                                                new_num);
-                               mark_buffer_dirty(path->nodes[0]);
-                       } else {
-                               WARN_ON(1);
-                       }
-               }
-               if (!keep) {
-                       u64 disk_blocknr = 0;
-                       u64 disk_num_blocks = 0;
-                       u64 extent_num_blocks = 0;
-                       if (found_extent) {
-                               disk_blocknr =
-                                     btrfs_file_extent_disk_blocknr(extent);
-                               disk_num_blocks =
-                                     btrfs_file_extent_disk_num_blocks(extent);
-                               extent_num_blocks =
-                                     btrfs_file_extent_num_blocks(extent);
-                               *hint_block =
-                                       btrfs_file_extent_disk_blocknr(extent);
-                       }
-                       ret = btrfs_del_item(trans, root, path);
-                       BUG_ON(ret);
-                       btrfs_release_path(root, path);
-                       extent = NULL;
-                       if (found_extent && disk_blocknr != 0) {
-                               inode->i_blocks -= extent_num_blocks << 3;
-                               ret = btrfs_free_extent(trans, root,
-                                                       disk_blocknr,
-                                                       disk_num_blocks, 0);
-                       }
-
-                       BUG_ON(ret);
-                       if (!bookend && search_start >= end) {
-                               ret = 0;
-                               goto out;
-                       }
-                       if (!bookend)
-                               continue;
-               }
-               if (bookend && found_extent) {
-                       /* create bookend */
-                       struct btrfs_key ins;
-                       ins.objectid = inode->i_ino;
-                       ins.offset = end;
-                       ins.flags = 0;
-                       btrfs_set_key_type(&ins, BTRFS_EXTENT_DATA_KEY);
-
-                       btrfs_release_path(root, path);
-                       ret = btrfs_insert_empty_item(trans, root, path, &ins,
-                                                     sizeof(*extent));
-                       BUG_ON(ret);
-                       extent = btrfs_item_ptr(
-                                   btrfs_buffer_leaf(path->nodes[0]),
-                                   path->slots[0],
-                                   struct btrfs_file_extent_item);
-                       btrfs_set_file_extent_disk_blocknr(extent,
-                                   btrfs_file_extent_disk_blocknr(&old));
-                       btrfs_set_file_extent_disk_num_blocks(extent,
-                                   btrfs_file_extent_disk_num_blocks(&old));
-
-                       btrfs_set_file_extent_offset(extent,
-                                   btrfs_file_extent_offset(&old) +
-                                   ((end - key.offset) >> inode->i_blkbits));
-                       WARN_ON(btrfs_file_extent_num_blocks(&old) <
-                               (extent_end - end) >> inode->i_blkbits);
-                       btrfs_set_file_extent_num_blocks(extent,
-                                   (extent_end - end) >> inode->i_blkbits);
-
-                       btrfs_set_file_extent_type(extent,
-                                                  BTRFS_FILE_EXTENT_REG);
-                       btrfs_set_file_extent_generation(extent,
-                                   btrfs_file_extent_generation(&old));
-                       btrfs_mark_buffer_dirty(path->nodes[0]);
-                       if (btrfs_file_extent_disk_blocknr(&old) != 0) {
-                               inode->i_blocks +=
-                                     btrfs_file_extent_num_blocks(extent) << 3;
-                       }
-                       ret = 0;
-                       goto out;
-               }
-       }
-out:
-       btrfs_free_path(path);
-       return ret;
-}
-
-static int prepare_pages(struct btrfs_root *root,
-                        struct file *file,
-                        struct page **pages,
-                        size_t num_pages,
-                        loff_t pos,
-                        unsigned long first_index,
-                        unsigned long last_index,
-                        size_t write_bytes,
-                        u64 alloc_extent_start)
-{
-       int i;
-       unsigned long index = pos >> PAGE_CACHE_SHIFT;
-       struct inode *inode = file->f_path.dentry->d_inode;
-       int offset;
-       int err = 0;
-       int this_write;
-       struct buffer_head *bh;
-       struct buffer_head *head;
-       loff_t isize = i_size_read(inode);
-
-       memset(pages, 0, num_pages * sizeof(struct page *));
-
-       for (i = 0; i < num_pages; i++) {
-               pages[i] = grab_cache_page(inode->i_mapping, index + i);
-               if (!pages[i]) {
-                       err = -ENOMEM;
-                       goto failed_release;
-               }
-               cancel_dirty_page(pages[i], PAGE_CACHE_SIZE);
-               wait_on_page_writeback(pages[i]);
-               offset = pos & (PAGE_CACHE_SIZE -1);
-               this_write = min(PAGE_CACHE_SIZE - offset, write_bytes);
-               if (!page_has_buffers(pages[i])) {
-                       create_empty_buffers(pages[i],
-                                            root->fs_info->sb->s_blocksize,
-                                            (1 << BH_Uptodate));
-               }
-               head = page_buffers(pages[i]);
-               bh = head;
-               do {
-                       err = btrfs_map_bh_to_logical(root, bh,
-                                                     alloc_extent_start);
-                       BUG_ON(err);
-                       if (err)
-                               goto failed_truncate;
-                       bh = bh->b_this_page;
-                       if (alloc_extent_start)
-                               alloc_extent_start++;
-               } while (bh != head);
-               pos += this_write;
-               WARN_ON(this_write > write_bytes);
-               write_bytes -= this_write;
+       ret = close_ctree(root);
+       if (ret) {
+               printk("close ctree returns %d\n", ret);
        }
-       return 0;
-
-failed_release:
-       btrfs_drop_pages(pages, num_pages);
-       return err;
-
-failed_truncate:
-       btrfs_drop_pages(pages, num_pages);
-       if (pos > isize)
-               vmtruncate(inode, isize);
-       return err;
+       sb->s_fs_info = NULL;
 }
 
-static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
-                               size_t count, loff_t *ppos)
+static int btrfs_fill_super(struct super_block * sb, void * data, int silent)
 {
-       loff_t pos;
-       size_t num_written = 0;
-       int err = 0;
-       int ret = 0;
-       struct inode *inode = file->f_path.dentry->d_inode;
-       struct btrfs_root *root = BTRFS_I(inode)->root;
-       struct page *pages[8];
-       struct page *pinned[2];
-       unsigned long first_index;
-       unsigned long last_index;
-       u64 start_pos;
-       u64 num_blocks;
-       u64 alloc_extent_start;
-       u64 hint_block;
-       struct btrfs_trans_handle *trans;
-       struct btrfs_key ins;
-       pinned[0] = NULL;
-       pinned[1] = NULL;
-       if (file->f_flags & O_DIRECT)
-               return -EINVAL;
-       pos = *ppos;
-       vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
-       current->backing_dev_info = inode->i_mapping->backing_dev_info;
-       err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
-       if (err)
-               goto out;
-       if (count == 0)
-               goto out;
-       err = remove_suid(file->f_path.dentry);
-       if (err)
-               goto out;
-       file_update_time(file);
+       struct inode * inode;
+       struct dentry * root_dentry;
+       struct btrfs_super_block *disk_super;
+       struct btrfs_root *tree_root;
+       struct btrfs_inode *bi;
+       int err;
 
-       start_pos = pos & ~((u64)PAGE_CACHE_SIZE - 1);
-       num_blocks = (count + pos - start_pos + root->blocksize - 1) >>
-                       inode->i_blkbits;
+       sb->s_maxbytes = MAX_LFS_FILESIZE;
+       sb->s_magic = BTRFS_SUPER_MAGIC;
+       sb->s_op = &btrfs_super_ops;
+       sb->s_time_gran = 1;
 
-       mutex_lock(&inode->i_mutex);
-       first_index = pos >> PAGE_CACHE_SHIFT;
-       last_index = (pos + count) >> PAGE_CACHE_SHIFT;
+       tree_root = open_ctree(sb);
 
-       if ((pos & (PAGE_CACHE_SIZE - 1))) {
-               pinned[0] = grab_cache_page(inode->i_mapping, first_index);
-               if (!PageUptodate(pinned[0])) {
-                       ret = mpage_readpage(pinned[0], btrfs_get_block);
-                       BUG_ON(ret);
-                       wait_on_page_locked(pinned[0]);
-               } else {
-                       unlock_page(pinned[0]);
-               }
-       }
-       if ((pos + count) & (PAGE_CACHE_SIZE - 1)) {
-               pinned[1] = grab_cache_page(inode->i_mapping, last_index);
-               if (!PageUptodate(pinned[1])) {
-                       ret = mpage_readpage(pinned[1], btrfs_get_block);
-                       BUG_ON(ret);
-                       wait_on_page_locked(pinned[1]);
-               } else {
-                       unlock_page(pinned[1]);
-               }
+       if (!tree_root || IS_ERR(tree_root)) {
+               printk("btrfs: open_ctree failed\n");
+               return -EIO;
        }
+       sb->s_fs_info = tree_root;
+       disk_super = tree_root->fs_info->disk_super;
+       inode = btrfs_iget_locked(sb, btrfs_super_root_dir(disk_super),
+                                 tree_root);
+       bi = BTRFS_I(inode);
+       bi->location.objectid = inode->i_ino;
+       bi->location.offset = 0;
+       bi->location.flags = 0;
+       bi->root = tree_root;
+       btrfs_set_key_type(&bi->location, BTRFS_INODE_ITEM_KEY);
 
-       mutex_lock(&root->fs_info->fs_mutex);
-       trans = btrfs_start_transaction(root, 1);
-       if (!trans) {
+       if (!inode) {
                err = -ENOMEM;
-               mutex_unlock(&root->fs_info->fs_mutex);
-               goto out_unlock;
-       }
-       btrfs_set_trans_block_group(trans, inode);
-       /* FIXME blocksize != 4096 */
-       inode->i_blocks += num_blocks << 3;
-       hint_block = 0;
-       if (start_pos < inode->i_size) {
-               /* FIXME blocksize != pagesize */
-               ret = drop_extents(trans, root, inode,
-                                  start_pos,
-                                  (pos + count + root->blocksize -1) &
-                                  ~((u64)root->blocksize - 1), &hint_block);
-               BUG_ON(ret);
-       }
-       if (inode->i_size < start_pos) {
-               u64 last_pos_in_file;
-               u64 hole_size;
-               u64 mask = root->blocksize - 1;
-               last_pos_in_file = (inode->i_size + mask) & ~mask;
-               hole_size = (start_pos - last_pos_in_file + mask) & ~mask;
-               hole_size >>= inode->i_blkbits;
-               if (last_pos_in_file < start_pos) {
-                       ret = btrfs_insert_file_extent(trans, root,
-                                                      inode->i_ino,
-                                                      last_pos_in_file,
-                                                      0, 0, hole_size);
-               }
-               BUG_ON(ret);
-       }
-       if (inode->i_size >= PAGE_CACHE_SIZE || pos + count < inode->i_size ||
-           pos + count - start_pos > BTRFS_MAX_INLINE_DATA_SIZE(root)) {
-               ret = btrfs_alloc_extent(trans, root, inode->i_ino,
-                                        num_blocks, hint_block, (u64)-1,
-                                        &ins, 1);
-               BUG_ON(ret);
-               ret = btrfs_insert_file_extent(trans, root, inode->i_ino,
-                                      start_pos, ins.objectid, ins.offset,
-                                      ins.offset);
-               BUG_ON(ret);
-       } else {
-               ins.offset = 0;
-               ins.objectid = 0;
-       }
-       BUG_ON(ret);
-       alloc_extent_start = ins.objectid;
-       // btrfs_update_inode_block_group(trans, inode);
-       ret = btrfs_end_transaction(trans, root);
-       mutex_unlock(&root->fs_info->fs_mutex);
-
-       while(count > 0) {
-               size_t offset = pos & (PAGE_CACHE_SIZE - 1);
-               size_t write_bytes = min(count, PAGE_CACHE_SIZE - offset);
-               size_t num_pages = (write_bytes + PAGE_CACHE_SIZE - 1) >>
-                                       PAGE_CACHE_SHIFT;
-
-               memset(pages, 0, sizeof(pages));
-               ret = prepare_pages(root, file, pages, num_pages,
-                                   pos, first_index, last_index,
-                                   write_bytes, alloc_extent_start);
-               BUG_ON(ret);
-
-               /* FIXME blocks != pagesize */
-               if (alloc_extent_start)
-                       alloc_extent_start += num_pages;
-               ret = btrfs_copy_from_user(pos, num_pages,
-                                          write_bytes, pages, buf);
-               BUG_ON(ret);
-
-               ret = dirty_and_release_pages(NULL, root, file, pages,
-                                             num_pages, pos, write_bytes);
-               BUG_ON(ret);
-               btrfs_drop_pages(pages, num_pages);
-
-               buf += write_bytes;
-               count -= write_bytes;
-               pos += write_bytes;
-               num_written += write_bytes;
-
-               balance_dirty_pages_ratelimited(inode->i_mapping);
-               btrfs_btree_balance_dirty(root);
-               cond_resched();
-       }
-out_unlock:
-       mutex_unlock(&inode->i_mutex);
-out:
-       if (pinned[0])
-               page_cache_release(pinned[0]);
-       if (pinned[1])
-               page_cache_release(pinned[1]);
-       *ppos = pos;
-       current->backing_dev_info = NULL;
-       mark_inode_dirty(inode);
-       return num_written ? num_written : err;
-}
-
-static int btrfs_read_actor(read_descriptor_t *desc, struct page *page,
-                       unsigned long offset, unsigned long size)
-{
-       char *kaddr;
-       unsigned long left, count = desc->count;
-       struct inode *inode = page->mapping->host;
-
-       if (size > count)
-               size = count;
-
-       if (!PageChecked(page)) {
-               /* FIXME, do it per block */
-               struct btrfs_root *root = BTRFS_I(inode)->root;
-               int ret;
-               struct buffer_head *bh;
-
-               if (page_has_buffers(page)) {
-                       bh = page_buffers(page);
-                       if (!buffer_mapped(bh)) {
-                               SetPageChecked(page);
-                               goto checked;
-                       }
-               }
-
-               ret = btrfs_csum_verify_file_block(root,
-                                 page->mapping->host->i_ino,
-                                 page->index << PAGE_CACHE_SHIFT,
-                                 kmap(page), PAGE_CACHE_SIZE);
-               if (ret) {
-                       if (ret != -ENOENT) {
-                               printk("failed to verify ino %lu page %lu ret %d\n",
-                                      page->mapping->host->i_ino,
-                                      page->index, ret);
-                               memset(page_address(page), 1, PAGE_CACHE_SIZE);
-                               flush_dcache_page(page);
-                       }
-               }
-               SetPageChecked(page);
-               kunmap(page);
-       }
-checked:
-       /*
-        * Faults on the destination of a read are common, so do it before
-        * taking the kmap.
-        */
-       if (!fault_in_pages_writeable(desc->arg.buf, size)) {
-               kaddr = kmap_atomic(page, KM_USER0);
-               left = __copy_to_user_inatomic(desc->arg.buf,
-                                               kaddr + offset, size);
-               kunmap_atomic(kaddr, KM_USER0);
-               if (left == 0)
-                       goto success;
-       }
-
-       /* Do it the slow way */
-       kaddr = kmap(page);
-       left = __copy_to_user(desc->arg.buf, kaddr + offset, size);
-       kunmap(page);
-
-       if (left) {
-               size -= left;
-               desc->error = -EFAULT;
+               goto fail_close;
        }
-success:
-       desc->count = count - size;
-       desc->written += size;
-       desc->arg.buf += size;
-       return size;
-}
-
-/**
- * btrfs_file_aio_read - filesystem read routine
- * @iocb:      kernel I/O control block
- * @iov:       io vector request
- * @nr_segs:   number of segments in the iovec
- * @pos:       current file position
- */
-static ssize_t btrfs_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
-                                  unsigned long nr_segs, loff_t pos)
-{
-       struct file *filp = iocb->ki_filp;
-       ssize_t retval;
-       unsigned long seg;
-       size_t count;
-       loff_t *ppos = &iocb->ki_pos;
-
-       count = 0;
-       for (seg = 0; seg < nr_segs; seg++) {
-               const struct iovec *iv = &iov[seg];
-
-               /*
-                * If any segment has a negative length, or the cumulative
-                * length ever wraps negative then return -EINVAL.
-                */
-               count += iv->iov_len;
-               if (unlikely((ssize_t)(count|iv->iov_len) < 0))
-                       return -EINVAL;
-               if (access_ok(VERIFY_WRITE, iv->iov_base, iv->iov_len))
-                       continue;
-               if (seg == 0)
-                       return -EFAULT;
-               nr_segs = seg;
-               count -= iv->iov_len;   /* This segment is no good */
-               break;
+       if (inode->i_state & I_NEW) {
+               btrfs_read_locked_inode(inode);
+               unlock_new_inode(inode);
        }
-       retval = 0;
-       if (count) {
-               for (seg = 0; seg < nr_segs; seg++) {
-                       read_descriptor_t desc;
 
-                       desc.written = 0;
-                       desc.arg.buf = iov[seg].iov_base;
-                       desc.count = iov[seg].iov_len;
-                       if (desc.count == 0)
-                               continue;
-                       desc.error = 0;
-                       do_generic_file_read(filp, ppos, &desc,
-                                            btrfs_read_actor);
-                       retval += desc.written;
-                       if (desc.error) {
-                               retval = retval ?: desc.error;
-                               break;
-                       }
-               }
+       root_dentry = d_alloc_root(inode);
+       if (!root_dentry) {
+               iput(inode);
+               err = -ENOMEM;
+               goto fail_close;
        }
-       return retval;
-}
-
-static int create_subvol(struct btrfs_root *root, char *name, int namelen)
-{
-       struct btrfs_trans_handle *trans;
-       struct btrfs_key key;
-       struct btrfs_root_item root_item;
-       struct btrfs_inode_item *inode_item;
-       struct buffer_head *subvol;
-       struct btrfs_leaf *leaf;
-       struct btrfs_root *new_root;
-       struct inode *inode;
-       struct inode *dir;
-       int ret;
-       u64 objectid;
-       u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
-
-       mutex_lock(&root->fs_info->fs_mutex);
-       trans = btrfs_start_transaction(root, 1);
-       BUG_ON(!trans);
-
-       subvol = btrfs_alloc_free_block(trans, root, 0);
-       if (subvol == NULL)
-               return -ENOSPC;
-       leaf = btrfs_buffer_leaf(subvol);
-       btrfs_set_header_nritems(&leaf->header, 0);
-       btrfs_set_header_level(&leaf->header, 0);
-       btrfs_set_header_blocknr(&leaf->header, bh_blocknr(subvol));
-       btrfs_set_header_generation(&leaf->header, trans->transid);
-       btrfs_set_header_owner(&leaf->header, root->root_key.objectid);
-       memcpy(leaf->header.fsid, root->fs_info->disk_super->fsid,
-              sizeof(leaf->header.fsid));
-       mark_buffer_dirty(subvol);
-
-       inode_item = &root_item.inode;
-       memset(inode_item, 0, sizeof(*inode_item));
-       btrfs_set_inode_generation(inode_item, 1);
-       btrfs_set_inode_size(inode_item, 3);
-       btrfs_set_inode_nlink(inode_item, 1);
-       btrfs_set_inode_nblocks(inode_item, 1);
-       btrfs_set_inode_mode(inode_item, S_IFDIR | 0755);
-
-       btrfs_set_root_blocknr(&root_item, bh_blocknr(subvol));
-       btrfs_set_root_refs(&root_item, 1);
-       brelse(subvol);
-       subvol = NULL;
-
-       ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
-                                      0, &objectid);
-       BUG_ON(ret);
-
-       btrfs_set_root_dirid(&root_item, new_dirid);
-
-       key.objectid = objectid;
-       key.offset = 1;
-       key.flags = 0;
-       btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
-       ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
-                               &root_item);
-       BUG_ON(ret);
-
-       /*
-        * insert the directory item
-        */
-       key.offset = (u64)-1;
-       dir = root->fs_info->sb->s_root->d_inode;
-       ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
-                                   name, namelen, dir->i_ino, &key,
-                                   BTRFS_FT_DIR);
-       BUG_ON(ret);
-
-       ret = btrfs_commit_transaction(trans, root);
-       BUG_ON(ret);
-
-       new_root = btrfs_read_fs_root(root->fs_info, &key);
-       BUG_ON(!new_root);
-
-       trans = btrfs_start_transaction(new_root, 1);
-       BUG_ON(!trans);
-
-       inode = btrfs_new_inode(trans, new_root, new_dirid,
-                               BTRFS_I(dir)->block_group, S_IFDIR | 0700);
-       inode->i_op = &btrfs_dir_inode_operations;
-       inode->i_fop = &btrfs_dir_file_operations;
-
-       ret = btrfs_make_empty_dir(trans, new_root, new_dirid, new_dirid);
-       BUG_ON(ret);
-
-       inode->i_nlink = 1;
-       inode->i_size = 6;
-       ret = btrfs_update_inode(trans, new_root, inode);
-       BUG_ON(ret);
-
-       ret = btrfs_commit_transaction(trans, new_root);
-       BUG_ON(ret);
-
-       iput(inode);
-
-       mutex_unlock(&root->fs_info->fs_mutex);
-       btrfs_btree_balance_dirty(root);
+       sb->s_root = root_dentry;
+       btrfs_transaction_queue_work(tree_root, HZ * 30);
        return 0;
+
+fail_close:
+       close_ctree(tree_root);
+       return err;
 }
 
-static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
+static int btrfs_sync_fs(struct super_block *sb, int wait)
 {
        struct btrfs_trans_handle *trans;
-       struct btrfs_key key;
-       struct btrfs_root_item new_root_item;
+       struct btrfs_root *root;
        int ret;
-       u64 objectid;
-
-       if (!root->ref_cows)
-               return -EINVAL;
+       root = btrfs_sb(sb);
 
+       sb->s_dirt = 0;
+       if (!wait) {
+               filemap_flush(root->fs_info->btree_inode->i_mapping);
+               return 0;
+       }
        mutex_lock(&root->fs_info->fs_mutex);
        trans = btrfs_start_transaction(root, 1);
-       BUG_ON(!trans);
-
-       ret = btrfs_update_inode(trans, root, root->inode);
-       BUG_ON(ret);
-
-       ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
-                                      0, &objectid);
-       BUG_ON(ret);
-
-       memcpy(&new_root_item, &root->root_item,
-              sizeof(new_root_item));
-
-       key.objectid = objectid;
-       key.offset = 1;
-       key.flags = 0;
-       btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
-       btrfs_set_root_blocknr(&new_root_item, bh_blocknr(root->node));
-
-       ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
-                               &new_root_item);
-       BUG_ON(ret);
-
-       /*
-        * insert the directory item
-        */
-       key.offset = (u64)-1;
-       ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
-                                   name, namelen,
-                                   root->fs_info->sb->s_root->d_inode->i_ino,
-                                   &key, BTRFS_FT_DIR);
-
-       BUG_ON(ret);
-
-       ret = btrfs_inc_root_ref(trans, root);
-       BUG_ON(ret);
-
        ret = btrfs_commit_transaction(trans, root);
+       sb->s_dirt = 0;
        BUG_ON(ret);
        mutex_unlock(&root->fs_info->fs_mutex);
-       btrfs_btree_balance_dirty(root);
-       return 0;
-}
-
-static int btrfs_ioctl(struct inode *inode, struct file *filp, unsigned int
-                      cmd, unsigned long arg)
-{
-       struct btrfs_root *root = BTRFS_I(inode)->root;
-       struct btrfs_ioctl_vol_args vol_args;
-       int ret = 0;
-       struct btrfs_dir_item *di;
-       int namelen;
-       struct btrfs_path *path;
-       u64 root_dirid;
-
-       switch (cmd) {
-       case BTRFS_IOC_SNAP_CREATE:
-               if (copy_from_user(&vol_args,
-                                  (struct btrfs_ioctl_vol_args __user *)arg,
-                                  sizeof(vol_args)))
-                       return -EFAULT;
-               namelen = strlen(vol_args.name);
-               if (namelen > BTRFS_VOL_NAME_MAX)
-                       return -EINVAL;
-               path = btrfs_alloc_path();
-               if (!path)
-                       return -ENOMEM;
-               root_dirid = root->fs_info->sb->s_root->d_inode->i_ino,
-               mutex_lock(&root->fs_info->fs_mutex);
-               di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root,
-                                   path, root_dirid,
-                                   vol_args.name, namelen, 0);
-               mutex_unlock(&root->fs_info->fs_mutex);
-               btrfs_free_path(path);
-               if (di && !IS_ERR(di))
-                       return -EEXIST;
-
-               if (root == root->fs_info->tree_root)
-                       ret = create_subvol(root, vol_args.name, namelen);
-               else
-                       ret = create_snapshot(root, vol_args.name, namelen);
-               WARN_ON(ret);
-               break;
-       default:
-               return -ENOTTY;
-       }
-       return ret;
-}
-
-#ifdef CONFIG_COMPAT
-static long btrfs_compat_ioctl(struct file *file, unsigned int cmd,
-                              unsigned long arg)
-{
-       struct inode *inode = file->f_path.dentry->d_inode;
-       int ret;
-       lock_kernel();
-       ret = btrfs_ioctl(inode, file, cmd, (unsigned long) compat_ptr(arg));
-       unlock_kernel();
-       return ret;
-
-}
-#endif
-
-static struct kmem_cache *btrfs_inode_cachep;
-struct kmem_cache *btrfs_trans_handle_cachep;
-struct kmem_cache *btrfs_transaction_cachep;
-struct kmem_cache *btrfs_bit_radix_cachep;
-struct kmem_cache *btrfs_path_cachep;
-
-/*
- * Called inside transaction, so use GFP_NOFS
- */
-static struct inode *btrfs_alloc_inode(struct super_block *sb)
-{
-       struct btrfs_inode *ei;
-
-       ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
-       if (!ei)
-               return NULL;
-       return &ei->vfs_inode;
-}
-
-static void btrfs_destroy_inode(struct inode *inode)
-{
-       WARN_ON(!list_empty(&inode->i_dentry));
-       WARN_ON(inode->i_data.nrpages);
-
-       kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
-}
-
-static void init_once(void * foo, struct kmem_cache * cachep,
-                     unsigned long flags)
-{
-       struct btrfs_inode *ei = (struct btrfs_inode *) foo;
-
-       if ((flags & (SLAB_CTOR_CONSTRUCTOR)) ==
-           SLAB_CTOR_CONSTRUCTOR) {
-               inode_init_once(&ei->vfs_inode);
-       }
-}
-
-static int init_inodecache(void)
-{
-       btrfs_inode_cachep = kmem_cache_create("btrfs_inode_cache",
-                                            sizeof(struct btrfs_inode),
-                                            0, (SLAB_RECLAIM_ACCOUNT|
-                                               SLAB_MEM_SPREAD),
-                                            init_once, NULL);
-       btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle_cache",
-                                            sizeof(struct btrfs_trans_handle),
-                                            0, (SLAB_RECLAIM_ACCOUNT|
-                                               SLAB_MEM_SPREAD),
-                                            NULL, NULL);
-       btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction_cache",
-                                            sizeof(struct btrfs_transaction),
-                                            0, (SLAB_RECLAIM_ACCOUNT|
-                                               SLAB_MEM_SPREAD),
-                                            NULL, NULL);
-       btrfs_path_cachep = kmem_cache_create("btrfs_path_cache",
-                                            sizeof(struct btrfs_transaction),
-                                            0, (SLAB_RECLAIM_ACCOUNT|
-                                               SLAB_MEM_SPREAD),
-                                            NULL, NULL);
-       btrfs_bit_radix_cachep = kmem_cache_create("btrfs_radix",
-                                            256,
-                                            0, (SLAB_RECLAIM_ACCOUNT|
-                                               SLAB_MEM_SPREAD |
-                                               SLAB_DESTROY_BY_RCU),
-                                            NULL, NULL);
-       if (btrfs_inode_cachep == NULL || btrfs_trans_handle_cachep == NULL ||
-           btrfs_transaction_cachep == NULL || btrfs_bit_radix_cachep == NULL)
-               return -ENOMEM;
        return 0;
 }
 
-static void destroy_inodecache(void)
+static void btrfs_write_super(struct super_block *sb)
 {
-       kmem_cache_destroy(btrfs_inode_cachep);
-       kmem_cache_destroy(btrfs_trans_handle_cachep);
-       kmem_cache_destroy(btrfs_transaction_cachep);
-       kmem_cache_destroy(btrfs_bit_radix_cachep);
-       kmem_cache_destroy(btrfs_path_cachep);
+       sb->s_dirt = 0;
 }
 
 static int btrfs_get_sb(struct file_system_type *fs_type,
@@ -2709,15 +124,6 @@ static int btrfs_get_sb(struct file_system_type *fs_type,
                           btrfs_fill_super, mnt);
 }
 
-static int btrfs_getattr(struct vfsmount *mnt,
-                        struct dentry *dentry, struct kstat *stat)
-{
-       struct inode *inode = dentry->d_inode;
-       generic_fillattr(inode, stat);
-       stat->blksize = 256 * 1024;
-       return 0;
-}
-
 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 {
        struct btrfs_root *root = btrfs_sb(dentry->d_sb);
@@ -2732,197 +138,6 @@ static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
        return 0;
 }
 
-static int btrfs_rename(struct inode * old_dir, struct dentry *old_dentry,
-                          struct inode * new_dir,struct dentry *new_dentry)
-{
-       struct btrfs_trans_handle *trans;
-       struct btrfs_root *root = BTRFS_I(old_dir)->root;
-       struct inode *new_inode = new_dentry->d_inode;
-       struct inode *old_inode = old_dentry->d_inode;
-       struct timespec ctime = CURRENT_TIME;
-       struct btrfs_path *path;
-       struct btrfs_dir_item *di;
-       int ret;
-
-       if (S_ISDIR(old_inode->i_mode) && new_inode &&
-           new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) {
-               return -ENOTEMPTY;
-       }
-       mutex_lock(&root->fs_info->fs_mutex);
-       trans = btrfs_start_transaction(root, 1);
-       btrfs_set_trans_block_group(trans, new_dir);
-       path = btrfs_alloc_path();
-       if (!path) {
-               ret = -ENOMEM;
-               goto out_fail;
-       }
-
-       old_dentry->d_inode->i_nlink++;
-       old_dir->i_ctime = old_dir->i_mtime = ctime;
-       new_dir->i_ctime = new_dir->i_mtime = ctime;
-       old_inode->i_ctime = ctime;
-       if (S_ISDIR(old_inode->i_mode) && old_dir != new_dir) {
-               struct btrfs_key *location = &BTRFS_I(new_dir)->location;
-               u64 old_parent_oid;
-               di = btrfs_lookup_dir_item(trans, root, path, old_inode->i_ino,
-                                          "..", 2, -1);
-               if (IS_ERR(di)) {
-                       ret = PTR_ERR(di);
-                       goto out_fail;
-               }
-               if (!di) {
-                       ret = -ENOENT;
-                       goto out_fail;
-               }
-               old_parent_oid = btrfs_disk_key_objectid(&di->location);
-               ret = btrfs_del_item(trans, root, path);
-               if (ret) {
-                       ret = -EIO;
-                       goto out_fail;
-               }
-               btrfs_release_path(root, path);
-
-               di = btrfs_lookup_dir_index_item(trans, root, path,
-                                                old_inode->i_ino,
-                                                old_parent_oid,
-                                                "..", 2, -1);
-               if (IS_ERR(di)) {
-                       ret = PTR_ERR(di);
-                       goto out_fail;
-               }
-               if (!di) {
-                       ret = -ENOENT;
-                       goto out_fail;
-               }
-               ret = btrfs_del_item(trans, root, path);
-               if (ret) {
-                       ret = -EIO;
-                       goto out_fail;
-               }
-               btrfs_release_path(root, path);
-
-               ret = btrfs_insert_dir_item(trans, root, "..", 2,
-                                           old_inode->i_ino, location,
-                                           BTRFS_FT_DIR);
-               if (ret)
-                       goto out_fail;
-       }
-
-
-       ret = btrfs_unlink_trans(trans, root, old_dir, old_dentry);
-       if (ret)
-               goto out_fail;
-
-       if (new_inode) {
-               new_inode->i_ctime = CURRENT_TIME;
-               ret = btrfs_unlink_trans(trans, root, new_dir, new_dentry);
-               if (ret)
-                       goto out_fail;
-               if (S_ISDIR(new_inode->i_mode))
-                       clear_nlink(new_inode);
-               else
-                       drop_nlink(new_inode);
-               btrfs_update_inode(trans, root, new_inode);
-       }
-       ret = btrfs_add_link(trans, new_dentry, old_inode);
-       if (ret)
-               goto out_fail;
-
-out_fail:
-       btrfs_free_path(path);
-       btrfs_end_transaction(trans, root);
-       mutex_unlock(&root->fs_info->fs_mutex);
-       return ret;
-}
-
-static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
-                        const char *symname)
-{
-       struct btrfs_trans_handle *trans;
-       struct btrfs_root *root = BTRFS_I(dir)->root;
-       struct btrfs_path *path;
-       struct btrfs_key key;
-       struct inode *inode;
-       int err;
-       int drop_inode = 0;
-       u64 objectid;
-       int name_len;
-       int datasize;
-       char *ptr;
-       struct btrfs_file_extent_item *ei;
-
-       name_len = strlen(symname) + 1;
-       if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
-               return -ENAMETOOLONG;
-       mutex_lock(&root->fs_info->fs_mutex);
-       trans = btrfs_start_transaction(root, 1);
-       btrfs_set_trans_block_group(trans, dir);
-
-       err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
-       if (err) {
-               err = -ENOSPC;
-               goto out_unlock;
-       }
-
-       inode = btrfs_new_inode(trans, root, objectid,
-                               BTRFS_I(dir)->block_group, S_IFLNK|S_IRWXUGO);
-       err = PTR_ERR(inode);
-       if (IS_ERR(inode))
-               goto out_unlock;
-
-       btrfs_set_trans_block_group(trans, inode);
-       err = btrfs_add_nondir(trans, dentry, inode);
-       if (err)
-               drop_inode = 1;
-       else {
-               inode->i_mapping->a_ops = &btrfs_aops;
-               inode->i_fop = &btrfs_file_operations;
-               inode->i_op = &btrfs_file_inode_operations;
-       }
-       dir->i_sb->s_dirt = 1;
-       btrfs_update_inode_block_group(trans, inode);
-       btrfs_update_inode_block_group(trans, dir);
-       if (drop_inode)
-               goto out_unlock;
-
-       path = btrfs_alloc_path();
-       BUG_ON(!path);
-       key.objectid = inode->i_ino;
-       key.offset = 0;
-       key.flags = 0;
-       btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
-       datasize = btrfs_file_extent_calc_inline_size(name_len);
-       err = btrfs_insert_empty_item(trans, root, path, &key,
-                                     datasize);
-       BUG_ON(err);
-       ei = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
-              path->slots[0], struct btrfs_file_extent_item);
-       btrfs_set_file_extent_generation(ei, trans->transid);
-       btrfs_set_file_extent_type(ei,
-                                  BTRFS_FILE_EXTENT_INLINE);
-       ptr = btrfs_file_extent_inline_start(ei);
-       btrfs_memcpy(root, path->nodes[0]->b_data,
-                    ptr, symname, name_len);
-       mark_buffer_dirty(path->nodes[0]);
-       btrfs_free_path(path);
-       inode->i_op = &btrfs_symlink_inode_operations;
-       inode->i_mapping->a_ops = &btrfs_symlink_aops;
-       inode->i_size = name_len - 1;
-       btrfs_update_inode(trans, root, inode);
-       err = 0;
-
-out_unlock:
-       btrfs_end_transaction(trans, root);
-       mutex_unlock(&root->fs_info->fs_mutex);
-
-       if (drop_inode) {
-               inode_dec_link_count(inode);
-               iput(inode);
-       }
-       btrfs_btree_balance_dirty(root);
-       return err;
-}
-
 static struct file_system_type btrfs_fs_type = {
        .owner          = THIS_MODULE,
        .name           = "btrfs",
@@ -2944,91 +159,21 @@ static struct super_operations btrfs_super_ops = {
        .statfs         = btrfs_statfs,
 };
 
-static struct inode_operations btrfs_dir_inode_operations = {
-       .lookup         = btrfs_lookup,
-       .create         = btrfs_create,
-       .unlink         = btrfs_unlink,
-       .link           = btrfs_link,
-       .mkdir          = btrfs_mkdir,
-       .rmdir          = btrfs_rmdir,
-       .rename         = btrfs_rename,
-       .symlink        = btrfs_symlink,
-       .setattr        = btrfs_setattr,
-};
-
-static struct inode_operations btrfs_dir_ro_inode_operations = {
-       .lookup         = btrfs_lookup,
-};
-
-static struct file_operations btrfs_dir_file_operations = {
-       .llseek         = generic_file_llseek,
-       .read           = generic_read_dir,
-       .readdir        = btrfs_readdir,
-       .ioctl          = btrfs_ioctl,
-#ifdef CONFIG_COMPAT
-       .compat_ioctl   = btrfs_compat_ioctl,
-#endif
-};
-
-static struct address_space_operations btrfs_aops = {
-       .readpage       = btrfs_readpage,
-       .writepage      = btrfs_writepage,
-       .sync_page      = block_sync_page,
-       .prepare_write  = btrfs_prepare_write,
-       .commit_write   = btrfs_commit_write,
-       .bmap           = btrfs_bmap,
-};
-
-static struct address_space_operations btrfs_symlink_aops = {
-       .readpage       = btrfs_readpage,
-       .writepage      = btrfs_writepage,
-};
-
-static struct inode_operations btrfs_file_inode_operations = {
-       .truncate       = btrfs_truncate,
-       .getattr        = btrfs_getattr,
-       .setattr        = btrfs_setattr,
-};
-
-static struct file_operations btrfs_file_operations = {
-       .llseek         = generic_file_llseek,
-       .read           = do_sync_read,
-       .aio_read       = btrfs_file_aio_read,
-       .write          = btrfs_file_write,
-       .mmap           = generic_file_mmap,
-       .open           = generic_file_open,
-       .ioctl          = btrfs_ioctl,
-       .fsync          = btrfs_sync_file,
-#ifdef CONFIG_COMPAT
-       .compat_ioctl   = btrfs_compat_ioctl,
-#endif
-};
-
-static struct inode_operations btrfs_symlink_inode_operations = {
-       .readlink       = generic_readlink,
-       .follow_link    = page_follow_link_light,
-       .put_link       = page_put_link,
-};
-
 static int __init init_btrfs_fs(void)
 {
        int err;
-       printk("btrfs loaded!\n");
        btrfs_init_transaction_sys();
-       err = init_inodecache();
+       err = btrfs_init_cachep();
        if (err)
                return err;
        return register_filesystem(&btrfs_fs_type);
-       destroy_inodecache();
-       return err;
 }
 
 static void __exit exit_btrfs_fs(void)
 {
        btrfs_exit_transaction_sys();
-       destroy_inodecache();
+       btrfs_destroy_cachep();
        unregister_filesystem(&btrfs_fs_type);
-       printk("btrfs unloaded\n");
 }
 
 module_init(init_btrfs_fs)