5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mikulas Patocka <mpatocka@xxxxxxxxxx> [ 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> --- drivers/md/dm-snap.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c index e902aae685af9..d8902d2b6aa66 100644 --- a/drivers/md/dm-snap.c +++ b/drivers/md/dm-snap.c @@ -685,8 +685,10 @@ 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(); + } } vfree(et->table); -- 2.43.0