diff options
| -rw-r--r-- | mm/zswap.c | 34 |
1 files changed, 16 insertions, 18 deletions
diff --git a/mm/zswap.c b/mm/zswap.c index 96664cdee207..62fe307521c9 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -1517,19 +1517,8 @@ bool zswap_store(struct folio *folio) if (folio_test_large(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); - entry = zswap_rb_search(&tree->rbroot, offset); - if (entry) - zswap_invalidate_entry(tree, entry); - spin_unlock(&tree->lock); - if (!zswap_enabled) - return false; + goto check_old; objcg = get_obj_cgroup_from_folio(folio); if (objcg && !obj_cgroup_may_zswap(objcg)) { @@ -1609,14 +1598,12 @@ 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. + * The folio may have been dirtied again, invalidate the + * possibly stale entry before inserting the new entry. */ - while (zswap_rb_insert(&tree->rbroot, entry, &dupentry) == -EEXIST) { - WARN_ON(1); + if (zswap_rb_insert(&tree->rbroot, entry, &dupentry) == -EEXIST) { zswap_invalidate_entry(tree, dupentry); + WARN_ON(zswap_rb_insert(&tree->rbroot, entry, &dupentry)); } if (entry->length) { INIT_LIST_HEAD(&entry->lru); @@ -1639,6 +1626,17 @@ freepage: reject: if (objcg) obj_cgroup_put(objcg); +check_old: + /* + * If the zswap store fails or zswap is disabled, we must invalidate the + * possibly stale entry which was previously stored at this offset. + * Otherwise, writeback could overwrite the new data in the swapfile. + */ + spin_lock(&tree->lock); + entry = zswap_rb_search(&tree->rbroot, offset); + if (entry) + zswap_invalidate_entry(tree, entry); + spin_unlock(&tree->lock); return false; shrink: |