Commit 116e0024 authored by Liu Bo's avatar Liu Bo Committed by Chris Mason
Browse files

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: default avatarMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: default avatarLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: default avatarJosef Bacik <jbacik@fusionio.com>
Signed-off-by: default avatarChris Mason <chris.mason@fusionio.com>
parent 8b87dc17

fs/btrfs/inode.c

+8 −6
Original line number Diff line number Diff line
@@ -2212,16 +2212,18 @@ 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;
@@ -2365,8 +2367,8 @@ 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);

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