diff options
| -rw-r--r-- | mm/zswap.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/mm/zswap.c b/mm/zswap.c index 412b1409a0d7..083c693602b8 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -1219,6 +1219,19 @@ bool zswap_store(struct folio *folio) return false; /* + * If this is a duplicate, it must be removed before attempting to store + * it, otherwise, if the store fails the old page won't be removed from + * the tree, and it might be written back overriding the new data. + */ + spin_lock(&tree->lock); + dupentry = zswap_rb_search(&tree->rbroot, offset); + if (dupentry) { + zswap_duplicate_entry++; + zswap_invalidate_entry(tree, dupentry); + } + spin_unlock(&tree->lock); + + /* * XXX: zswap reclaim does not work with cgroups yet. Without a * cgroup-aware entry LRU, we will push out entries system-wide based on * local cgroup limits. @@ -1333,7 +1346,14 @@ insert_entry: /* map */ spin_lock(&tree->lock); + /* + * A duplicate entry should have been removed at the beginning of this + * function. Since the swap entry should be pinned, if a duplicate is + * found again here it means that something went wrong in the swap + * cache. + */ while (zswap_rb_insert(&tree->rbroot, entry, &dupentry) == -EEXIST) { + WARN_ON(1); zswap_duplicate_entry++; zswap_invalidate_entry(tree, dupentry); } |