This is a note to let you know that I've just added the patch titled
btrfs: Remove extraneous extent_buffer_get from tree_mod_log_rewind
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
btrfs-remove-extraneous-extent_buffer_get-from-tree_.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 86b7e44255789feb39838585708acb19c3be673f
Author: Nikolay Borisov <nborisov@xxxxxxxx>
Date: Wed Aug 15 18:26:54 2018 +0300
btrfs: Remove extraneous extent_buffer_get from tree_mod_log_rewind
[ 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@xxxxxxxx>
Reviewed-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
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) >
