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mm: zswap: increase reject_compress_poor but not reject_compress_fail if compression returns ENOSPC

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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
744e188592 ("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: 744e188592 ("crypto: scomp - fix req->dst buffer overflow")
Signed-off-by: Barry Song <v-songbaohua@oppo.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Acked-by: Yosry Ahmed <yosryahmed@google.com>
Reviewed-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Barry Song 2024-02-20 10:19:35 +13:00 committed by Andrew Morton
parent 929e4c3534
commit 55e78c933d
1 changed files with 13 additions and 14 deletions
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27
mm/zswap.c
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@ -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++;
alloc_ret = zpool_malloc(zpool, dlen, gfp, &handle);
if (alloc_ret)
goto unlock;
}
if (ret) {
zswap_reject_alloc_fail++;
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)