[PATCH 4.4 24/62] btrfs: Remove extraneous extent_buffer_get from tree_mod_log_rewind

Greg Kroah-Hartman
2020-09-11T17:31:40Z

From: Nikolay Borisov <nborisov@suse.com>

[ Upstream commit 24cee18a1c1d7c731ea5987e0c99daea22ae7f4a ]

When a rewound buffer is created it already has a ref count of 1 and the
dummy flag set. Then another ref is taken bumping the count to 2.
Finally when this buffer is released from btrfs_release_path the extra
reference is decremented by the special handling code in
free_extent_buffer.

However, this special code is in fact redundant sinca ref count of 1 is
still correct since the buffer is only accessed via btrfs_path struct.
This paves the way forward of removing the special handling in
free_extent_buffer.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/btrfs/ctree.c | 1 -
1 file changed, 1 deletion(-)

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 8765312743f16..a8660b503bf36 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -1372,7 +1372,6 @@ tree_mod_log_rewind(struct btrfs_fs_info *fs_info, struct btrfs_path *path,
btrfs_tree_read_unlock_blocking(eb);
free_extent_buffer(eb);

- extent_buffer_get(eb_rewin);
btrfs_tree_read_lock(eb_rewin);
__tree_mod_log_rewind(fs_info, eb_rewin, time_seq, tm);
WARN_ON(btrfs_header_nritems(eb_rewin) >
--
2.25.1