diff options
author | Liu Bo <bo.li.liu@oracle.com> | 2018-01-05 12:51:10 -0700 |
---|---|---|
committer | David Sterba <dsterba@suse.com> | 2018-01-22 16:08:21 +0100 |
commit | 7b4df058b051fb67db61ea371f7d278131cb6e7b (patch) | |
tree | ae12edbe7dc44fbe99ad4aaa4c3b7fb8739a97a9 /fs | |
parent | 18e83ac75bfe67009c4ddcdd581bba8eb16f4030 (diff) | |
download | op-kernel-dev-7b4df058b051fb67db61ea371f7d278131cb6e7b.zip op-kernel-dev-7b4df058b051fb67db61ea371f7d278131cb6e7b.tar.gz |
Btrfs: add helper for em merge logic
This is a prepare work for the following extent map selftest, which
runs tests against em merge logic.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/btrfs/ctree.h | 2 | ||||
-rw-r--r-- | fs/btrfs/inode.c | 80 |
2 files changed, 48 insertions, 34 deletions
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 1a462ab..1e05fc7 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -3143,6 +3143,8 @@ struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode, int delay_iput); void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work); +int btrfs_add_extent_mapping(struct extent_map_tree *em_tree, + struct extent_map **em_in, u64 start, u64 len); struct extent_map *btrfs_get_extent_fiemap(struct btrfs_inode *inode, struct page *page, size_t pg_offset, u64 start, u64 len, int create); diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 4ab713b..c6a05ee 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -6925,6 +6925,51 @@ static noinline int uncompress_inline(struct btrfs_path *path, return ret; } +int btrfs_add_extent_mapping(struct extent_map_tree *em_tree, + struct extent_map **em_in, u64 start, u64 len) +{ + int ret; + struct extent_map *em = *em_in; + + ret = add_extent_mapping(em_tree, em, 0); + /* it is possible that someone inserted the extent into the tree + * while we had the lock dropped. It is also possible that + * an overlapping map exists in the tree + */ + if (ret == -EEXIST) { + struct extent_map *existing; + + ret = 0; + + existing = search_extent_mapping(em_tree, start, len); + /* + * existing will always be non-NULL, since there must be + * extent causing the -EEXIST. + */ + if (start >= existing->start && + start < extent_map_end(existing)) { + free_extent_map(em); + *em_in = existing; + ret = 0; + } else { + /* + * The existing extent map is the one nearest to + * the [start, start + len) range which overlaps + */ + ret = merge_extent_mapping(em_tree, existing, + em, start); + free_extent_map(existing); + if (ret) { + free_extent_map(em); + *em_in = NULL; + } + } + } + + ASSERT(ret == 0 || ret == -EEXIST); + return ret; +} + /* * a bit scary, this does extent mapping from logical file offset to the disk. * the ugly parts come from merging extents from the disk with the in-ram @@ -7138,40 +7183,7 @@ insert: err = 0; write_lock(&em_tree->lock); - ret = add_extent_mapping(em_tree, em, 0); - /* it is possible that someone inserted the extent into the tree - * while we had the lock dropped. It is also possible that - * an overlapping map exists in the tree - */ - if (ret == -EEXIST) { - struct extent_map *existing; - - ret = 0; - - existing = search_extent_mapping(em_tree, start, len); - /* - * existing will always be non-NULL, since there must be - * extent causing the -EEXIST. - */ - if (start >= existing->start && - start < extent_map_end(existing)) { - free_extent_map(em); - em = existing; - err = 0; - } else { - /* - * The existing extent map is the one nearest to - * the [start, start + len) range which overlaps - */ - err = merge_extent_mapping(em_tree, existing, - em, start); - free_extent_map(existing); - if (err) { - free_extent_map(em); - em = NULL; - } - } - } + err = btrfs_add_extent_mapping(em_tree, &em, start, len); write_unlock(&em_tree->lock); out: |