From c7e6f17b52e9486a9d997368819dfec032b550e2 Mon Sep 17 00:00:00 2001 From: Hui Zhu Date: Thu, 14 Jul 2022 16:07:57 +0800 Subject: zsmalloc: zs_malloc: return ERR_PTR on failure zs_malloc returns 0 if it fails. zs_zpool_malloc will return -1 when zs_malloc return 0. But -1 makes the return value unclear. For example, when zswap_frontswap_store calls zs_malloc through zs_zpool_malloc, it will return -1 to its caller. The other return value is -EINVAL, -ENODEV or something else. This commit changes zs_malloc to return ERR_PTR on failure. It didn't just let zs_zpool_malloc return -ENOMEM becaue zs_malloc has two types of failure: - size is not OK return -EINVAL - memory alloc fail return -ENOMEM. Link: https://lkml.kernel.org/r/20220714080757.12161-1-teawater@gmail.com Signed-off-by: Hui Zhu Cc: Minchan Kim Cc: Nitin Gupta Cc: Sergey Senozhatsky Cc: Jens Axboe Signed-off-by: Andrew Morton --- mm/zsmalloc.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) (limited to 'mm/zsmalloc.c') diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c index f24b71568e83..9e13fd7ee635 100644 --- a/mm/zsmalloc.c +++ b/mm/zsmalloc.c @@ -399,7 +399,10 @@ static int zs_zpool_malloc(void *pool, size_t size, gfp_t gfp, unsigned long *handle) { *handle = zs_malloc(pool, size, gfp); - return *handle ? 0 : -1; + + if (IS_ERR((void *)(*handle))) + return PTR_ERR((void *)*handle); + return 0; } static void zs_zpool_free(void *pool, unsigned long handle) { @@ -1400,7 +1403,7 @@ static unsigned long obj_malloc(struct zs_pool *pool, * @gfp: gfp flags when allocating object * * On success, handle to the allocated object is returned, - * otherwise 0. + * otherwise an ERR_PTR(). * Allocation requests with size > ZS_MAX_ALLOC_SIZE will fail. */ unsigned long zs_malloc(struct zs_pool *pool, size_t size, gfp_t gfp) @@ -1411,11 +1414,11 @@ unsigned long zs_malloc(struct zs_pool *pool, size_t size, gfp_t gfp) struct zspage *zspage; if (unlikely(!size || size > ZS_MAX_ALLOC_SIZE)) - return 0; + return (unsigned long)ERR_PTR(-EINVAL); handle = cache_alloc_handle(pool, gfp); if (!handle) - return 0; + return (unsigned long)ERR_PTR(-ENOMEM); /* extra space in chunk to keep the handle */ size += ZS_HANDLE_SIZE; @@ -1440,7 +1443,7 @@ unsigned long zs_malloc(struct zs_pool *pool, size_t size, gfp_t gfp) zspage = alloc_zspage(pool, class, gfp); if (!zspage) { cache_free_handle(pool, handle); - return 0; + return (unsigned long)ERR_PTR(-ENOMEM); } spin_lock(&class->lock); -- cgit v1.2.3