From 55e78c933d747ed44b2b22879e6a55e5af34b9f7 Mon Sep 17 00:00:00 2001 From: Barry Song Date: Tue, 20 Feb 2024 10:19:35 +1300 Subject: mm: zswap: increase reject_compress_poor but not reject_compress_fail if compression returns ENOSPC We used to rely on the returned -ENOSPC of zpool_malloc() to increase reject_compress_poor. But the code wouldn't get to there after commit 744e1885922a ("crypto: scomp - fix req->dst buffer overflow") as the new code will goto out immediately after the special compression case happens. So there might be no longer a chance to execute zpool_malloc now. We are incorrectly increasing zswap_reject_compress_fail instead. Thus, we need to fix the counters handling right after compressions return ENOSPC. This patch also centralizes the counters handling for all of compress_poor, compress_fail and alloc_fail. Link: https://lkml.kernel.org/r/20240219211935.72394-1-21cnbao@gmail.com Fixes: 744e1885922a ("crypto: scomp - fix req->dst buffer overflow") Signed-off-by: Barry Song Cc: Sergey Senozhatsky Reviewed-by: Nhat Pham Acked-by: Yosry Ahmed Reviewed-by: Chengming Zhou Signed-off-by: Andrew Morton --- mm/zswap.c | 27 +++++++++++++-------------- 1 file changed, 13 insertions(+), 14 deletions(-) (limited to 'mm/zswap.c') diff --git a/mm/zswap.c b/mm/zswap.c index 62fe307521c9..51de79aa8659 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -1021,12 +1021,12 @@ static bool zswap_compress(struct folio *folio, struct zswap_entry *entry) { struct crypto_acomp_ctx *acomp_ctx; struct scatterlist input, output; + int comp_ret = 0, alloc_ret = 0; unsigned int dlen = PAGE_SIZE; unsigned long handle; struct zpool *zpool; char *buf; gfp_t gfp; - int ret; u8 *dst; acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx); @@ -1057,26 +1057,18 @@ static bool zswap_compress(struct folio *folio, struct zswap_entry *entry) * but in different threads running on different cpu, we have different * acomp instance, so multiple threads can do (de)compression in parallel. */ - ret = crypto_wait_req(crypto_acomp_compress(acomp_ctx->req), &acomp_ctx->wait); + comp_ret = crypto_wait_req(crypto_acomp_compress(acomp_ctx->req), &acomp_ctx->wait); dlen = acomp_ctx->req->dlen; - if (ret) { - zswap_reject_compress_fail++; + if (comp_ret) goto unlock; - } zpool = zswap_find_zpool(entry); gfp = __GFP_NORETRY | __GFP_NOWARN | __GFP_KSWAPD_RECLAIM; if (zpool_malloc_support_movable(zpool)) gfp |= __GFP_HIGHMEM | __GFP_MOVABLE; - ret = zpool_malloc(zpool, dlen, gfp, &handle); - if (ret == -ENOSPC) { - zswap_reject_compress_poor++; - goto unlock; - } - if (ret) { - zswap_reject_alloc_fail++; + alloc_ret = zpool_malloc(zpool, dlen, gfp, &handle); + if (alloc_ret) goto unlock; - } buf = zpool_map_handle(zpool, handle, ZPOOL_MM_WO); memcpy(buf, dst, dlen); @@ -1086,8 +1078,15 @@ static bool zswap_compress(struct folio *folio, struct zswap_entry *entry) entry->length = dlen; unlock: + if (comp_ret == -ENOSPC || alloc_ret == -ENOSPC) + zswap_reject_compress_poor++; + else if (comp_ret) + zswap_reject_compress_fail++; + else if (alloc_ret) + zswap_reject_alloc_fail++; + mutex_unlock(&acomp_ctx->mutex); - return ret == 0; + return comp_ret == 0 && alloc_ret == 0; } static void zswap_decompress(struct zswap_entry *entry, struct page *page) -- cgit v1.2.3