diff options
| -rw-r--r-- | fs/btrfs/inode.c | 56 |
1 files changed, 43 insertions, 13 deletions
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index f81a48c47fe0..4f8fb1130cf3 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -7540,6 +7540,27 @@ static struct extent_map *create_io_em(struct inode *inode, u64 start, u64 len, return em; } + +static int btrfs_get_blocks_direct_read(struct extent_map *em, + struct buffer_head *bh_result, + struct inode *inode, + u64 start, u64 len) +{ + if (em->block_start == EXTENT_MAP_HOLE || + test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) + return -ENOENT; + + len = min(len, em->len - (start - em->start)); + + bh_result->b_blocknr = (em->block_start + (start - em->start)) >> + inode->i_blkbits; + bh_result->b_size = len; + bh_result->b_bdev = em->bdev; + set_buffer_mapped(bh_result); + + return 0; +} + static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) { @@ -7608,11 +7629,29 @@ static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock, goto unlock_err; } - /* Just a good old fashioned hole, return */ - if (!create && (em->block_start == EXTENT_MAP_HOLE || - test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) { + if (!create) { + ret = btrfs_get_blocks_direct_read(em, bh_result, inode, + start, len); + /* Can be negative only if we read from a hole */ + if (ret < 0) { + ret = 0; + free_extent_map(em); + goto unlock_err; + } + /* + * We need to unlock only the end area that we aren't using. + * The rest is going to be unlocked by the endio routine. + */ + lockstart = start + bh_result->b_size; + if (lockstart < lockend) { + clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, + lockend, unlock_bits, 1, 0, + &cached_state); + } else { + free_extent_state(cached_state); + } free_extent_map(em); - goto unlock_err; + return 0; } /* @@ -7624,12 +7663,6 @@ static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock, * just use the extent. * */ - if (!create) { - len = min(len, em->len - (start - em->start)); - lockstart = start + len; - goto unlock; - } - if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) || ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) && em->block_start != EXTENT_MAP_HOLE)) { @@ -7716,10 +7749,7 @@ unlock: clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend, unlock_bits, 1, 0, &cached_state); - } else { - free_extent_state(cached_state); } - free_extent_map(em); return 0; |