This is a note to let you know that I've just added the patch titled
dm snapshot: fix lockup in dm_exception_table_exit
to the 6.8-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:
dm-snapshot-fix-lockup-in-dm_exception_table_exit.patch
and it can be found in the queue-6.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit a21c460bd74304aff94ac8ea5c11d7744e7af33d
Author: Mikulas Patocka <mpatocka@xxxxxxxxxx>
Date: Wed Mar 20 18:43:11 2024 +0100
dm snapshot: fix lockup in dm_exception_table_exit
[ Upstream commit 6e7132ed3c07bd8a6ce3db4bb307ef2852b322dc ]
There was reported lockup when we exit a snapshot with many exceptions.
Fix this by adding "cond_resched" to the loop that frees the exceptions.
Reported-by: John Pittman <jpittman@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index bf7a574499a34..0ace06d1bee38 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -684,8 +684,10 @@ static void dm_exception_table_exit(struct dm_exception_table *et,
for (i = 0; i < size; i++) {
slot = et->table + i;
- hlist_bl_for_each_entry_safe(ex, pos, n, slot, hash_list)
+ hlist_bl_for_each_entry_safe(ex, pos, n, slot, hash_list) {
kmem_cache_free(mem, ex);
+ cond_resched();
+ }
}
kvfree(et->table);
