This is a note to let you know that I've just added the patch titled
f2fs: avoid down_write on nat_tree_lock during checkpoint
to the 5.15-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:
f2fs-avoid-down_write-on-nat_tree_lock-during-checkp.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 47bba10c64d2f1798553fa213aa214e06276e147
Author: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
Date: Mon Dec 13 13:28:40 2021 -0800
f2fs: avoid down_write on nat_tree_lock during checkpoint
[ Upstream commit 0df035c7208c5e3e2ae7685548353ae536a19015 ]
Let's cache nat entry if there's no lock contention only.
Reviewed-by: Chao Yu <chao@xxxxxxxxxx>
Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
Stable-dep-of: 3aa51c61cb4a ("f2fs: retry to update the inode page given data corruption")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index f810c6bbeff02..7f00f3004a665 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -430,6 +430,10 @@ static void cache_nat_entry(struct f2fs_sb_info *sbi, nid_t nid,
struct f2fs_nm_info *nm_i = NM_I(sbi);
struct nat_entry *new, *e;
+ /* Let's mitigate lock contention of nat_tree_lock during checkpoint */
+ if (rwsem_is_locked(&sbi->cp_global_sem))
+ return;
+
new = __alloc_nat_entry(sbi, nid, false);
if (!new)
return;
