Btrfs: early inline file data code

Signed-off-by: Chris Mason <chris.mason@oracle.com>

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 453ce835209ae437772ca404e2213d3a474dd01e..9ef65e2ecf51dbeb204d75f2ab3ab86e51448e97 100644 (file)
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -16,19 +16,24 @@ static int balance_node_right(struct btrfs_trans_handle *trans, struct
 static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                   struct btrfs_path *path, int level, int slot);
 
-struct btrfs_path *btrfs_alloc_path(void)
+inline void btrfs_init_path(struct btrfs_path *p)
 {
-       return kmem_cache_alloc(btrfs_path_cachep, GFP_NOFS);
+       memset(p, 0, sizeof(*p));
 }
 
-void btrfs_free_path(struct btrfs_path *p)
+struct btrfs_path *btrfs_alloc_path(void)
 {
-       kmem_cache_free(btrfs_path_cachep, p);
+       struct btrfs_path *path;
+       path = kmem_cache_alloc(btrfs_path_cachep, GFP_NOFS);
+       if (path)
+               btrfs_init_path(path);
+       return path;
 }
 
-inline void btrfs_init_path(struct btrfs_path *p)
+void btrfs_free_path(struct btrfs_path *p)
 {
-       memset(p, 0, sizeof(*p));
+       btrfs_release_path(NULL, p);
+       kmem_cache_free(btrfs_path_cachep, p);
 }
 
 void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p)
@@ -77,6 +82,7 @@ static int btrfs_cow_block(struct btrfs_trans_handle *trans, struct btrfs_root
                btrfs_free_extent(trans, root, buf->b_blocknr, 1, 1);
        }
        btrfs_block_release(root, buf);
+       mark_buffer_dirty(cow);
        *cow_ret = cow;
        return 0;
 }

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index fbc26eafc58c109f3aafbf498e802f931193faa9..68127b8462abca96f1caab00eb1c7cd5c456f3f7 100644 (file)
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -816,6 +816,73 @@ printk("btrfs sync_fs\n");
        return 0;
 }
 
+static int btrfs_get_block_inline(struct inode *inode, sector_t iblock,
+                          struct buffer_head *result, int create)
+{
+       struct btrfs_root *root = btrfs_sb(inode->i_sb);
+       struct btrfs_path *path;
+       struct btrfs_key key;
+       struct btrfs_leaf *leaf;
+       int num_bytes = result->b_size;
+       int item_size;
+       int ret;
+       u64 pos;
+       char *ptr;
+       int copy_size;
+       int err = 0;
+       char *safe_ptr;
+       char *data_ptr;
+
+       path = btrfs_alloc_path();
+       BUG_ON(!path);
+
+       WARN_ON(create);
+       if (create) {
+               return 0;
+       }
+       pos = iblock << inode->i_blkbits;
+       key.objectid = inode->i_ino;
+       key.flags = 0;
+       btrfs_set_key_type(&key, BTRFS_INLINE_DATA_KEY);
+       ptr = kmap(result->b_page);
+       safe_ptr = ptr;
+       ptr += (pos & (PAGE_CACHE_SIZE -1));
+again:
+       key.offset = pos;
+       ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+       if (ret) {
+               if (ret < 0)
+                       err = ret;
+               else
+                       err = 0;
+               goto out;
+       }
+       leaf = btrfs_buffer_leaf(path->nodes[0]);
+       item_size = btrfs_item_size(leaf->items + path->slots[0]);
+       copy_size = min(num_bytes, item_size);
+       data_ptr = btrfs_item_ptr(leaf, path->slots[0], char);
+       WARN_ON(safe_ptr + PAGE_CACHE_SIZE < ptr + copy_size);
+       memcpy(ptr, data_ptr, copy_size);
+       pos += copy_size;
+       num_bytes -= copy_size;
+       WARN_ON(num_bytes < 0);
+       ptr += copy_size;
+       btrfs_release_path(root, path);
+       if (num_bytes != 0) {
+               if (pos >= i_size_read(inode))
+                       memset(ptr, 0, num_bytes);
+               else
+                       goto again;
+       }
+       set_buffer_uptodate(result);
+       map_bh(result, inode->i_sb, 0);
+       err = 0;
+out:
+       btrfs_free_path(path);
+       kunmap(result->b_page);
+       return err;
+}
+
 static int btrfs_get_block_lock(struct inode *inode, sector_t iblock,
                           struct buffer_head *result, int create)
 {
@@ -918,7 +985,8 @@ static int btrfs_get_block(struct inode *inode, sector_t iblock,
        int err;
        struct btrfs_root *root = btrfs_sb(inode->i_sb);
        mutex_lock(&root->fs_info->fs_mutex);
-       err = btrfs_get_block_lock(inode, iblock, result, create);
+       // err = btrfs_get_block_lock(inode, iblock, result, create);
+       err = btrfs_get_block_inline(inode, iblock, result, create);
        mutex_unlock(&root->fs_info->fs_mutex);
        return err;
 }
@@ -1177,6 +1245,170 @@ out:
        return num_written ? num_written : err;
 }
 
+static ssize_t inline_one_page(struct btrfs_root *root, struct inode *inode,
+                          struct page *page, loff_t pos,
+                          size_t offset, size_t write_bytes)
+{
+       struct btrfs_path *path;
+       struct btrfs_trans_handle *trans;
+       struct btrfs_key key;
+       struct btrfs_leaf *leaf;
+       struct btrfs_key found_key;
+       int ret;
+       size_t copy_size = 0;
+       char *dst = NULL;
+       int err = 0;
+       size_t num_written = 0;
+
+       path = btrfs_alloc_path();
+       BUG_ON(!path);
+       mutex_lock(&root->fs_info->fs_mutex);
+       trans = btrfs_start_transaction(root, 1);
+       key.objectid = inode->i_ino;
+       key.flags = 0;
+       btrfs_set_key_type(&key, BTRFS_INLINE_DATA_KEY);
+
+again:
+       key.offset = pos;
+       ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
+       if (ret < 0) {
+               err = ret;
+               goto out;
+       }
+       if (ret == 0) {
+               leaf = btrfs_buffer_leaf(path->nodes[0]);
+               btrfs_disk_key_to_cpu(&found_key,
+                                     &leaf->items[path->slots[0]].key);
+               copy_size = btrfs_item_size(leaf->items + path->slots[0]);
+               dst = btrfs_item_ptr(leaf, path->slots[0], char);
+               copy_size = min(write_bytes, copy_size);
+               goto copyit;
+       } else {
+               int slot = path->slots[0];
+               if (slot > 0) {
+                       slot--;
+               }
+               // FIXME find max key
+               leaf = btrfs_buffer_leaf(path->nodes[0]);
+               btrfs_disk_key_to_cpu(&found_key,
+                                     &leaf->items[slot].key);
+               if (found_key.objectid != inode->i_ino)
+                       goto insert;
+               if (btrfs_key_type(&found_key) != BTRFS_INLINE_DATA_KEY)
+                       goto insert;
+               copy_size = btrfs_item_size(leaf->items + slot);
+               if (found_key.offset + copy_size <= pos)
+                       goto insert;
+               dst = btrfs_item_ptr(leaf, path->slots[0], char);
+               dst += pos - found_key.offset;
+               copy_size = copy_size - (pos - found_key.offset);
+               BUG_ON(copy_size < 0);
+               copy_size = min(write_bytes, copy_size);
+               WARN_ON(copy_size == 0);
+               goto copyit;
+       }
+insert:
+       btrfs_release_path(root, path);
+       copy_size = min(write_bytes, (size_t)512);
+       ret = btrfs_insert_empty_item(trans, root, path, &key, copy_size);
+       BUG_ON(ret);
+       dst = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
+                            path->slots[0], char);
+copyit:
+       WARN_ON(copy_size == 0);
+       WARN_ON(dst + copy_size >
+               btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
+                                                path->slots[0], char) +
+               btrfs_item_size(btrfs_buffer_leaf(path->nodes[0])->items +
+                                                 path->slots[0]));
+       btrfs_memcpy(root, path->nodes[0]->b_data, dst,
+                    page_address(page) + offset, copy_size);
+       mark_buffer_dirty(path->nodes[0]);
+       btrfs_release_path(root, path);
+       pos += copy_size;
+       offset += copy_size;
+       num_written += copy_size;
+       write_bytes -= copy_size;
+       if (write_bytes)
+               goto again;
+out:
+       btrfs_free_path(path);
+       ret = btrfs_end_transaction(trans, root);
+       BUG_ON(ret);
+       mutex_unlock(&root->fs_info->fs_mutex);
+       return num_written ? num_written : err;
+}
+
+static ssize_t btrfs_file_inline_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_sb(inode->i_sb);
+       unsigned long page_index;
+
+       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);
+       mutex_lock(&inode->i_mutex);
+       while(count > 0) {
+               size_t offset = pos & (PAGE_CACHE_SIZE - 1);
+               size_t write_bytes = min(count, PAGE_CACHE_SIZE - offset);
+               struct page *page;
+
+               page_index = pos >> PAGE_CACHE_SHIFT;
+               page = grab_cache_page(inode->i_mapping, page_index);
+               if (!PageUptodate(page)) {
+                       ret = mpage_readpage(page, btrfs_get_block);
+                       BUG_ON(ret);
+                       lock_page(page);
+               }
+               ret = btrfs_copy_from_user(pos, 1,
+                                          write_bytes, &page, buf);
+               BUG_ON(ret);
+               write_bytes = inline_one_page(root, inode, page, pos,
+                                     offset, write_bytes);
+               SetPageUptodate(page);
+               if (write_bytes > 0 && pos + write_bytes > inode->i_size) {
+                       i_size_write(inode, pos + write_bytes);
+                       mark_inode_dirty(inode);
+               }
+               page_cache_release(page);
+               unlock_page(page);
+               if (write_bytes < 0)
+                       goto out_unlock;
+               buf += write_bytes;
+               count -= write_bytes;
+               pos += write_bytes;
+               num_written += write_bytes;
+
+               balance_dirty_pages_ratelimited(inode->i_mapping);
+               cond_resched();
+       }
+out_unlock:
+       mutex_unlock(&inode->i_mutex);
+out:
+       *ppos = pos;
+       current->backing_dev_info = NULL;
+       return num_written ? num_written : err;
+}
+
 static int btrfs_read_actor(read_descriptor_t *desc, struct page *page,
                        unsigned long offset, unsigned long size)
 {
@@ -1420,7 +1652,7 @@ static struct file_operations btrfs_dir_file_operations = {
 
 static struct address_space_operations btrfs_aops = {
        .readpage       = btrfs_readpage,
-       .readpages      = btrfs_readpages,
+       // .readpages   = btrfs_readpages,
        .writepage      = btrfs_writepage,
        .sync_page      = block_sync_page,
        .prepare_write  = btrfs_prepare_write,
@@ -1434,8 +1666,8 @@ static struct inode_operations btrfs_file_inode_operations = {
 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,
+       .aio_read       = generic_file_aio_read,
+       .write          = btrfs_file_inline_write,
        .mmap           = generic_file_mmap,
        .open           = generic_file_open,
 };