Commit c7e6f17b authored by Hui Zhu's avatar Hui Zhu Committed by Andrew Morton
Browse files

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: default avatarHui Zhu <teawater@antgroup.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent fef3e906

drivers/block/zram/zram_drv.c

+2 −2
Original line number Diff line number Diff line
@@ -1389,9 +1389,9 @@ static int __zram_bvec_write(struct zram *zram, struct bio_vec *bvec, 
			__GFP_HIGHMEM |

			__GFP_MOVABLE);



	if (unlikely(!handle)) {

	if (IS_ERR((void *)handle)) {

		zcomp_stream_put(zram->comp);

		return -ENOMEM;

		return PTR_ERR((void *)handle);

	}



	alloced_pages = zs_get_total_pages(zram->mem_pool);

mm/zsmalloc.c

+8 −5
Original line number Diff line number Diff line
@@ -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);