return 0;
}
+static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
+ u64 num_bytes)
+{
+ struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
+ struct extent_map *em;
+ u64 alloc_hint = 0;
+
+ read_lock(&em_tree->lock);
+ em = search_extent_mapping(em_tree, start, num_bytes);
+ if (em) {
+ /*
+ * if block start isn't an actual block number then find the
+ * first block in this inode and use that as a hint. If that
+ * block is also bogus then just don't worry about it.
+ */
+ if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
+ free_extent_map(em);
+ em = search_extent_mapping(em_tree, 0, 0);
+ if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
+ alloc_hint = em->block_start;
+ if (em)
+ free_extent_map(em);
+ } else {
+ alloc_hint = em->block_start;
+ free_extent_map(em);
+ }
+ }
+ read_unlock(&em_tree->lock);
+
+ return alloc_hint;
+}
+
/*
* when extent_io.c finds a delayed allocation range in the file,
* the call backs end up in this code. The basic idea is to
BUG_ON(disk_num_bytes >
btrfs_super_total_bytes(&root->fs_info->super_copy));
-
- read_lock(&BTRFS_I(inode)->extent_tree.lock);
- em = search_extent_mapping(&BTRFS_I(inode)->extent_tree,
- start, num_bytes);
- if (em) {
- /*
- * if block start isn't an actual block number then find the
- * first block in this inode and use that as a hint. If that
- * block is also bogus then just don't worry about it.
- */
- if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
- free_extent_map(em);
- em = search_extent_mapping(em_tree, 0, 0);
- if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
- alloc_hint = em->block_start;
- if (em)
- free_extent_map(em);
- } else {
- alloc_hint = em->block_start;
- free_extent_map(em);
- }
- }
- read_unlock(&BTRFS_I(inode)->extent_tree.lock);
+ alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
while (disk_num_bytes > 0) {
return em;
}
+static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
+ u64 start, u64 len)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_trans_handle *trans;
+ struct extent_map *em;
+ struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
+ struct btrfs_key ins;
+ u64 alloc_hint;
+ int ret;
+
+ btrfs_drop_extent_cache(inode, start, start + len - 1, 0);
+
+ trans = btrfs_join_transaction(root, 0);
+ if (!trans)
+ return ERR_PTR(-ENOMEM);
+
+ trans->block_rsv = &root->fs_info->delalloc_block_rsv;
+
+ alloc_hint = get_extent_allocation_hint(inode, start, len);
+ ret = btrfs_reserve_extent(trans, root, len, root->sectorsize, 0,
+ alloc_hint, (u64)-1, &ins, 1);
+ if (ret) {
+ em = ERR_PTR(ret);
+ goto out;
+ }
+
+ em = alloc_extent_map(GFP_NOFS);
+ if (!em) {
+ em = ERR_PTR(-ENOMEM);
+ goto out;
+ }
+
+ em->start = start;
+ em->orig_start = em->start;
+ em->len = ins.offset;
+
+ em->block_start = ins.objectid;
+ em->block_len = ins.offset;
+ em->bdev = root->fs_info->fs_devices->latest_bdev;
+ set_bit(EXTENT_FLAG_PINNED, &em->flags);
+
+ while (1) {
+ write_lock(&em_tree->lock);
+ ret = add_extent_mapping(em_tree, em);
+ write_unlock(&em_tree->lock);
+ if (ret != -EEXIST)
+ break;
+ btrfs_drop_extent_cache(inode, start, start + em->len - 1, 0);
+ }
+
+ ret = btrfs_add_ordered_extent_dio(inode, start, ins.objectid,
+ ins.offset, ins.offset, 0);
+ if (ret) {
+ btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
+ em = ERR_PTR(ret);
+ }
+out:
+ btrfs_end_transaction(trans, root);
+ return em;
+}
+
+static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
+ struct buffer_head *bh_result, int create)
+{
+ struct extent_map *em;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ u64 start = iblock << inode->i_blkbits;
+ u64 len = bh_result->b_size;
+
+ em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
+ if (IS_ERR(em))
+ return PTR_ERR(em);
+
+ /*
+ * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
+ * io. INLINE is special, and we could probably kludge it in here, but
+ * it's still buffered so for safety lets just fall back to the generic
+ * buffered path.
+ *
+ * For COMPRESSED we _have_ to read the entire extent in so we can
+ * decompress it, so there will be buffering required no matter what we
+ * do, so go ahead and fallback to buffered.
+ *
+ * We return -ENOTBLK because thats what makes DIO go ahead and go back
+ * to buffered IO. Don't blame me, this is the price we pay for using
+ * the generic code.
+ */
+ if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
+ em->block_start == EXTENT_MAP_INLINE) {
+ free_extent_map(em);
+ return -ENOTBLK;
+ }
+
+ /* Just a good old fashioned hole, return */
+ if (!create && (em->block_start == EXTENT_MAP_HOLE ||
+ test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
+ free_extent_map(em);
+ /* DIO will do one hole at a time, so just unlock a sector */
+ unlock_extent(&BTRFS_I(inode)->io_tree, start,
+ start + root->sectorsize - 1, GFP_NOFS);
+ return 0;
+ }
+
+ /*
+ * We don't allocate a new extent in the following cases
+ *
+ * 1) The inode is marked as NODATACOW. In this case we'll just use the
+ * existing extent.
+ * 2) The extent is marked as PREALLOC. We're good to go here and can
+ * just use the extent.
+ *
+ */
+ if (!create)
+ goto map;
+
+ if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
+ ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
+ em->block_start != EXTENT_MAP_HOLE)) {
+ u64 block_start;
+ int type;
+ int ret;
+
+ if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
+ type = BTRFS_ORDERED_PREALLOC;
+ else
+ type = BTRFS_ORDERED_NOCOW;
+ len = min(len, em->block_len - (start - em->start));
+ block_start = em->block_start + (start - em->start);
+ ret = btrfs_add_ordered_extent_dio(inode, start,
+ start, len, len, type);
+ if (ret) {
+ free_extent_map(em);
+ return ret;
+ }
+ } else {
+ free_extent_map(em);
+ em = btrfs_new_extent_direct(inode, start, len);
+ if (IS_ERR(em))
+ return PTR_ERR(em);
+ len = min(len, em->block_len);
+ }
+ unlock_extent(&BTRFS_I(inode)->io_tree, start, start + len - 1,
+ GFP_NOFS);
+map:
+ bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
+ inode->i_blkbits;
+ bh_result->b_size = em->len - (start - em->start);
+ bh_result->b_bdev = em->bdev;
+ set_buffer_mapped(bh_result);
+ if (create && !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
+ set_buffer_new(bh_result);
+
+ free_extent_map(em);
+
+ return 0;
+}
+
+struct btrfs_dio_private {
+ struct inode *inode;
+ u64 logical_offset;
+ u64 disk_bytenr;
+ u64 bytes;
+ u32 *csums;
+ void *private;
+};
+
+static void btrfs_endio_direct_read(struct bio *bio, int err)
+{
+ struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1;
+ struct bio_vec *bvec = bio->bi_io_vec;
+ struct btrfs_dio_private *dip = bio->bi_private;
+ struct inode *inode = dip->inode;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ u64 start;
+ u32 *private = dip->csums;
+
+ start = dip->logical_offset;
+ do {
+ if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
+ struct page *page = bvec->bv_page;
+ char *kaddr;
+ u32 csum = ~(u32)0;
+ unsigned long flags;
+
+ local_irq_save(flags);
+ kaddr = kmap_atomic(page, KM_IRQ0);
+ csum = btrfs_csum_data(root, kaddr + bvec->bv_offset,
+ csum, bvec->bv_len);
+ btrfs_csum_final(csum, (char *)&csum);
+ kunmap_atomic(kaddr, KM_IRQ0);
+ local_irq_restore(flags);
+
+ flush_dcache_page(bvec->bv_page);
+ if (csum != *private) {
+ printk(KERN_ERR "btrfs csum failed ino %lu off"
+ " %llu csum %u private %u\n",
+ inode->i_ino, (unsigned long long)start,
+ csum, *private);
+ err = -EIO;
+ }
+ }
+
+ start += bvec->bv_len;
+ private++;
+ bvec++;
+ } while (bvec <= bvec_end);
+
+ unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
+ dip->logical_offset + dip->bytes - 1, GFP_NOFS);
+ bio->bi_private = dip->private;
+
+ kfree(dip->csums);
+ kfree(dip);
+ dio_end_io(bio, err);
+}
+
+static void btrfs_endio_direct_write(struct bio *bio, int err)
+{
+ struct btrfs_dio_private *dip = bio->bi_private;
+ struct inode *inode = dip->inode;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_trans_handle *trans;
+ struct btrfs_ordered_extent *ordered = NULL;
+ struct extent_state *cached_state = NULL;
+ int ret;
+
+ if (err)
+ goto out_done;
+
+ ret = btrfs_dec_test_ordered_pending(inode, &ordered,
+ dip->logical_offset, dip->bytes);
+ if (!ret)
+ goto out_done;
+
+ BUG_ON(!ordered);
+
+ trans = btrfs_join_transaction(root, 1);
+ if (!trans) {
+ err = -ENOMEM;
+ goto out;
+ }
+ trans->block_rsv = &root->fs_info->delalloc_block_rsv;
+
+ if (test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags)) {
+ ret = btrfs_ordered_update_i_size(inode, 0, ordered);
+ if (!ret)
+ ret = btrfs_update_inode(trans, root, inode);
+ err = ret;
+ goto out;
+ }
+
+ lock_extent_bits(&BTRFS_I(inode)->io_tree, ordered->file_offset,
+ ordered->file_offset + ordered->len - 1, 0,
+ &cached_state, GFP_NOFS);
+
+ if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags)) {
+ ret = btrfs_mark_extent_written(trans, inode,
+ ordered->file_offset,
+ ordered->file_offset +
+ ordered->len);
+ if (ret) {
+ err = ret;
+ goto out_unlock;
+ }
+ } else {
+ ret = insert_reserved_file_extent(trans, inode,
+ ordered->file_offset,
+ ordered->start,
+ ordered->disk_len,
+ ordered->len,
+ ordered->len,
+ 0, 0, 0,
+ BTRFS_FILE_EXTENT_REG);
+ unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
+ ordered->file_offset, ordered->len);
+ if (ret) {
+ err = ret;
+ WARN_ON(1);
+ goto out_unlock;
+ }
+ }
+
+ add_pending_csums(trans, inode, ordered->file_offset, &ordered->list);
+ btrfs_ordered_update_i_size(inode, 0, ordered);
+ btrfs_update_inode(trans, root, inode);
+out_unlock:
+ unlock_extent_cached(&BTRFS_I(inode)->io_tree, ordered->file_offset,
+ ordered->file_offset + ordered->len - 1,
+ &cached_state, GFP_NOFS);
+out:
+ btrfs_delalloc_release_metadata(inode, ordered->len);
+ btrfs_end_transaction(trans, root);
+ btrfs_put_ordered_extent(ordered);
+ btrfs_put_ordered_extent(ordered);
+out_done:
+ bio->bi_private = dip->private;
+
+ kfree(dip->csums);
+ kfree(dip);
+ dio_end_io(bio, err);
+}
+
+static void btrfs_submit_direct(int rw, struct bio *bio, struct inode *inode,
+ loff_t file_offset)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_dio_private *dip;
+ struct bio_vec *bvec = bio->bi_io_vec;
+ u64 start;
+ int skip_sum;
+ int write = rw & (1 << BIO_RW);
+ int ret = 0;
+
+ skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
+
+ dip = kmalloc(sizeof(*dip), GFP_NOFS);
+ if (!dip) {
+ ret = -ENOMEM;
+ goto free_ordered;
+ }
+ dip->csums = NULL;
+
+ if (!skip_sum) {
+ dip->csums = kmalloc(sizeof(u32) * bio->bi_vcnt, GFP_NOFS);
+ if (!dip->csums) {
+ ret = -ENOMEM;
+ goto free_ordered;
+ }
+ }
+
+ dip->private = bio->bi_private;
+ dip->inode = inode;
+ dip->logical_offset = file_offset;
+
+ start = dip->logical_offset;
+ dip->bytes = 0;
+ do {
+ dip->bytes += bvec->bv_len;
+ bvec++;
+ } while (bvec <= (bio->bi_io_vec + bio->bi_vcnt - 1));
+
+ dip->disk_bytenr = bio->bi_sector << 9;
+ bio->bi_private = dip;
+
+ if (write)
+ bio->bi_end_io = btrfs_endio_direct_write;
+ else
+ bio->bi_end_io = btrfs_endio_direct_read;
+
+ ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
+ if (ret)
+ goto out_err;
+
+ if (write && !skip_sum)
+ btrfs_csum_one_bio(root, inode, bio, dip->logical_offset, 1);
+ else if (!skip_sum)
+ btrfs_lookup_bio_sums_dio(root, inode, bio,
+ dip->logical_offset, dip->csums);
+
+ ret = btrfs_map_bio(root, rw, bio, 0, 0);
+ if (ret)
+ goto out_err;
+ return;
+out_err:
+ kfree(dip->csums);
+ kfree(dip);
+free_ordered:
+ /*
+ * If this is a write, we need to clean up the reserved space and kill
+ * the ordered extent.
+ */
+ if (write) {
+ struct btrfs_ordered_extent *ordered;
+ ordered = btrfs_lookup_ordered_extent(inode,
+ dip->logical_offset);
+ if (!test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags) &&
+ !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags))
+ btrfs_free_reserved_extent(root, ordered->start,
+ ordered->disk_len);
+ btrfs_put_ordered_extent(ordered);
+ btrfs_put_ordered_extent(ordered);
+ }
+ bio_endio(bio, ret);
+}
+
static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
const struct iovec *iov, loff_t offset,
unsigned long nr_segs)
{
- return -EINVAL;
+ struct file *file = iocb->ki_filp;
+ struct inode *inode = file->f_mapping->host;
+ struct btrfs_ordered_extent *ordered;
+ u64 lockstart, lockend;
+ ssize_t ret;
+
+ lockstart = offset;
+ lockend = offset + iov_length(iov, nr_segs) - 1;
+ while (1) {
+ lock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend,
+ GFP_NOFS);
+ /*
+ * We're concerned with the entire range that we're going to be
+ * doing DIO to, so we need to make sure theres no ordered
+ * extents in this range.
+ */
+ ordered = btrfs_lookup_ordered_range(inode, lockstart,
+ lockend - lockstart + 1);
+ if (!ordered)
+ break;
+ unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend,
+ GFP_NOFS);
+ btrfs_start_ordered_extent(inode, ordered, 1);
+ btrfs_put_ordered_extent(ordered);
+ cond_resched();
+ }
+
+ ret = __blockdev_direct_IO(rw, iocb, inode, NULL, iov, offset, nr_segs,
+ btrfs_get_blocks_direct, NULL,
+ btrfs_submit_direct, 0);
+
+ if (ret < 0 && ret != -EIOCBQUEUED) {
+ unlock_extent(&BTRFS_I(inode)->io_tree, offset,
+ offset + iov_length(iov, nr_segs) - 1, GFP_NOFS);
+ } else if (ret >= 0 && ret < iov_length(iov, nr_segs)) {
+ /*
+ * We're falling back to buffered, unlock the section we didn't
+ * do IO on.
+ */
+ unlock_extent(&BTRFS_I(inode)->io_tree, offset + ret,
+ offset + iov_length(iov, nr_segs) - 1, GFP_NOFS);
+ }
+
+ return ret;
}
static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
return 1;
}
+static int range_overlaps(struct btrfs_ordered_extent *entry, u64 file_offset,
+ u64 len)
+{
+ if (file_offset + len <= entry->file_offset ||
+ entry->file_offset + entry->len <= file_offset)
+ return 0;
+ return 1;
+}
+
/*
* look find the first ordered struct that has this offset, otherwise
* the first one less than this offset
* The tree is given a single reference on the ordered extent that was
* inserted.
*/
-int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
- u64 start, u64 len, u64 disk_len, int type)
+static int __btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
+ u64 start, u64 len, u64 disk_len,
+ int type, int dio)
{
struct btrfs_ordered_inode_tree *tree;
struct rb_node *node;
if (type != BTRFS_ORDERED_IO_DONE && type != BTRFS_ORDERED_COMPLETE)
set_bit(type, &entry->flags);
+ if (dio)
+ set_bit(BTRFS_ORDERED_DIRECT, &entry->flags);
+
/* one ref for the tree */
atomic_set(&entry->refs, 1);
init_waitqueue_head(&entry->wait);
return 0;
}
+int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
+ u64 start, u64 len, u64 disk_len, int type)
+{
+ return __btrfs_add_ordered_extent(inode, file_offset, start, len,
+ disk_len, type, 0);
+}
+
+int btrfs_add_ordered_extent_dio(struct inode *inode, u64 file_offset,
+ u64 start, u64 len, u64 disk_len, int type)
+{
+ return __btrfs_add_ordered_extent(inode, file_offset, start, len,
+ disk_len, type, 1);
+}
+
/*
* Add a struct btrfs_ordered_sum into the list of checksums to be inserted
* when an ordered extent is finished. If the list covers more than one
* start IO on any dirty ones so the wait doesn't stall waiting
* for pdflush to find them
*/
- filemap_fdatawrite_range(inode->i_mapping, start, end);
+ if (!test_bit(BTRFS_ORDERED_DIRECT, &entry->flags))
+ filemap_fdatawrite_range(inode->i_mapping, start, end);
if (wait) {
wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE,
&entry->flags));
return entry;
}
+/* Since the DIO code tries to lock a wide area we need to look for any ordered
+ * extents that exist in the range, rather than just the start of the range.
+ */
+struct btrfs_ordered_extent *btrfs_lookup_ordered_range(struct inode *inode,
+ u64 file_offset,
+ u64 len)
+{
+ struct btrfs_ordered_inode_tree *tree;
+ struct rb_node *node;
+ struct btrfs_ordered_extent *entry = NULL;
+
+ tree = &BTRFS_I(inode)->ordered_tree;
+ spin_lock(&tree->lock);
+ node = tree_search(tree, file_offset);
+ if (!node) {
+ node = tree_search(tree, file_offset + len);
+ if (!node)
+ goto out;
+ }
+
+ while (1) {
+ entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
+ if (range_overlaps(entry, file_offset, len))
+ break;
+
+ if (entry->file_offset >= file_offset + len) {
+ entry = NULL;
+ break;
+ }
+ entry = NULL;
+ node = rb_next(node);
+ if (!node)
+ break;
+ }
+out:
+ if (entry)
+ atomic_inc(&entry->refs);
+ spin_unlock(&tree->lock);
+ return entry;
+}
+
/*
* lookup and return any extent before 'file_offset'. NULL is returned
* if none is found
projects / GitHub / moto-9609 / android_kernel_motorola_exynos9610.git / commitdiff