This patch fixes "mm: zcache: core functions added" patch, available at https://lkml.org/lkml/2013/7/20/90. It regards incorrect implementation of zcache_cleancache_flush_fs(). Function above should be effective only if cleancache pool referred by pool_id is valid. This issue is checked by testing whether zpool points to NULL. Unfortunately, if filesystem mount fails, such pool is never created and fs/super.c calls cleancache_invalidate_fs() function with pool_id parameter set to -1. This results in assigning zpool with pools[-1], which causes zpool to be not NULL and thus whole function hangs on uninitialized read-write lock. To prevent that behaviour, pool_id should be checked for being positive before assigning zpool variable with pools[pool_id]. Signed-off-by: Piotr Sarna <p.sarna@xxxxxxxxxxxxxxxxxxx> Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx> Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx> --- mm/zcache.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/mm/zcache.c b/mm/zcache.c index a2408e8..7e6d2e7 100644 --- a/mm/zcache.c +++ b/mm/zcache.c @@ -600,8 +600,12 @@ static void zcache_cleancache_flush_fs(int pool_id) struct zcache_rb_entry *entry = NULL; struct rb_node *node; unsigned long flags1, flags2; - struct zcache_pool *zpool = zcache.pools[pool_id]; + struct zcache_pool *zpool; + + if (pool_id < 0) + return; + zpool = zcache.pools[pool_id]; if (!zpool) return; -- 1.7.9.5 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>