Liu Bo
2013-Aug-02 08:30 UTC
[PATCH v2] Btrfs: allow compressed extents to be merged during defragment
The rule originally comes from nocow writing, but snapshot-aware
defrag is a different case, the extent has been writen and we''re
not going to change the extent but add a reference on the data.
So we''re able to allow such compressed extents to be merged into
one bigger extent if they''re pointing to the same data.
Reviewed-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
---
v1->v2:
- pass the whole struct instead to keep the code simple.
fs/btrfs/inode.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 55dda87..7c8d2a28 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2229,16 +2229,18 @@ static noinline bool record_extent_backrefs(struct
btrfs_path *path,
static int relink_is_mergable(struct extent_buffer *leaf,
struct btrfs_file_extent_item *fi,
- u64 disk_bytenr)
+ struct new_sa_defrag_extent *new)
{
- if (btrfs_file_extent_disk_bytenr(leaf, fi) != disk_bytenr)
+ if (btrfs_file_extent_disk_bytenr(leaf, fi) != new->bytenr)
return 0;
if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
return 0;
- if (btrfs_file_extent_compression(leaf, fi) ||
- btrfs_file_extent_encryption(leaf, fi) ||
+ if (btrfs_file_extent_compression(leaf, fi) != new->compress_type)
+ return 0;
+
+ if (btrfs_file_extent_encryption(leaf, fi) ||
btrfs_file_extent_other_encoding(leaf, fi))
return 0;
@@ -2382,8 +2384,8 @@ again:
struct btrfs_file_extent_item);
extent_len = btrfs_file_extent_num_bytes(leaf, fi);
- if (relink_is_mergable(leaf, fi, new->bytenr) &&
- extent_len + found_key.offset == start) {
+ if (extent_len + found_key.offset == start &&
+ relink_is_mergable(leaf, fi, new)) {
btrfs_set_file_extent_num_bytes(leaf, fi,
extent_len + len);
btrfs_mark_buffer_dirty(leaf);
--
1.8.1.4
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