This is a note to let you know that I've just added the patch titled
btrfs: Remove redundant extent_buffer_get in get_old_root
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-redundant-extent_buffer_get-in-get_old_.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 dd93fcfe869fa80e51739139620e79c18b57738d
Author: Nikolay Borisov <nborisov@xxxxxxxx>
Date: Wed Aug 15 18:26:53 2018 +0300
btrfs: Remove redundant extent_buffer_get in get_old_root
[ Upstream commit 6c122e2a0c515cfb3f3a9cefb5dad4cb62109c78 ]
get_old_root used used only by btrfs_search_old_slot to initialise the
path structure. The old root is always a cloned buffer (either via alloc
dummy or via btrfs_clone_extent_buffer) and its reference count is 2: 1
from allocation, 1 from extent_buffer_get call in get_old_root.
This latter explicit ref count acquire operation is in fact unnecessary
since the semantic is such that the newly allocated buffer is handed
over to the btrfs_path for lifetime management. Considering this just
remove the extra extent_buffer_get in get_old_root.
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 8eac5f75bca36..8765312743f16 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -1441,7 +1441,6 @@ get_old_root(struct btrfs_root *root, u64 time_seq)
if (!eb)
return NULL;
- extent_buffer_get(eb);
btrfs_tree_read_lock(eb);
if (old_root) {
btrfs_set_header_bytenr(eb, eb->start);
