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authorJohannes Weiner <hannes@cmpxchg.org>2023-07-27 19:22:24 +0300
committerAndrew Morton <akpm@linux-foundation.org>2023-08-21 23:37:28 +0300
commit7310895779624a11153d74a2132f01be6e360b7c (patch)
tree7552378271a332f192177e176fc80e4d7efb3711
parent56c67049c0ee135868e83ce36ac8d3e037e03f82 (diff)
downloadlinux-7310895779624a11153d74a2132f01be6e360b7c.tar.xz
mm: zswap: tighten up entry invalidation
Removing a zswap entry from the tree is tied to an explicit operation that's supposed to drop the base reference: swap invalidation, exclusive load, duplicate store. Don't silently remove the entry on final put, but instead warn if an entry is in tree without reference. While in that diff context, convert a BUG_ON to a WARN_ON_ONCE. No need to crash on a refcount underflow. Link: https://lkml.kernel.org/r/20230727162343.1415598-3-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Yosry Ahmed <yosryahmed@google.com> Cc: Barry Song <song.bao.hua@hisilicon.com> Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Seth Jennings <sjenning@redhat.com> Cc: Vitaly Wool <vitaly.wool@konsulko.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
-rw-r--r--mm/zswap.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/mm/zswap.c b/mm/zswap.c
index 93707a1799b8..ea921b25c245 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -417,9 +417,9 @@ static void zswap_entry_put(struct zswap_tree *tree,
{
int refcount = --entry->refcount;
- BUG_ON(refcount < 0);
+ WARN_ON_ONCE(refcount < 0);
if (refcount == 0) {
- zswap_rb_erase(&tree->rbroot, entry);
+ WARN_ON_ONCE(!RB_EMPTY_NODE(&entry->rbnode));
zswap_free_entry(entry);
}
}