From fcfa8d95cacf5cbbe6dee6b8d229fe86142266e0 Mon Sep 17 00:00:00 2001 From: Sergey Senozhatsky Date: Mon, 7 Apr 2014 15:38:20 -0700 Subject: [PATCH] zram: return error-valued pointer from zcomp_create() Instead of returning just NULL, return ERR_PTR from zcomp_create() if compressing backend creation has failed. ERR_PTR(-EINVAL) for unsupported compression algorithm request, ERR_PTR(-ENOMEM) for allocation (zcomp or compression stream) error. Perform IS_ERR() check of returned from zcomp_create() value in disksize_store() and set return code to PTR_ERR(). Change suggested by Jerome Marchand. [akpm@linux-foundation.org: clean up error recovery flow] Signed-off-by: Sergey Senozhatsky Reported-by: Jerome Marchand Cc: Minchan Kim Cc: Nitin Gupta Cc: Arnd Bergmann Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/block/zram/zcomp.c | 14 ++++++++------ drivers/block/zram/zram_drv.c | 19 ++++++++++--------- 2 files changed, 18 insertions(+), 15 deletions(-) diff --git a/drivers/block/zram/zcomp.c b/drivers/block/zram/zcomp.c index d5919031ca8b..5647d8fe1dc1 100644 --- a/drivers/block/zram/zcomp.c +++ b/drivers/block/zram/zcomp.c @@ -9,6 +9,7 @@ #include #include +#include #include #include #include @@ -319,9 +320,10 @@ void zcomp_destroy(struct zcomp *comp) /* * search available compressors for requested algorithm. - * allocate new zcomp and initialize it. return NULL - * if requested algorithm is not supported or in case - * of init error + * allocate new zcomp and initialize it. return compressing + * backend pointer or ERR_PTR if things went bad. ERR_PTR(-EINVAL) + * if requested algorithm is not supported, ERR_PTR(-ENOMEM) in + * case of allocation error. */ struct zcomp *zcomp_create(const char *compress, int max_strm) { @@ -330,11 +332,11 @@ struct zcomp *zcomp_create(const char *compress, int max_strm) backend = find_backend(compress); if (!backend) - return NULL; + return ERR_PTR(-EINVAL); comp = kzalloc(sizeof(struct zcomp), GFP_KERNEL); if (!comp) - return NULL; + return ERR_PTR(-ENOMEM); comp->backend = backend; if (max_strm > 1) @@ -343,7 +345,7 @@ struct zcomp *zcomp_create(const char *compress, int max_strm) zcomp_strm_single_create(comp); if (!comp->stream) { kfree(comp); - return NULL; + return ERR_PTR(-ENOMEM); } return comp; } diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index e4d536b485e6..6b462d27e7d7 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -31,6 +31,7 @@ #include #include #include +#include #include "zram_drv.h" @@ -583,7 +584,7 @@ static ssize_t disksize_store(struct device *dev, struct zcomp *comp; struct zram_meta *meta; struct zram *zram = dev_to_zram(dev); - int err = -EINVAL; + int err; disksize = memparse(buf, NULL); if (!disksize) @@ -595,18 +596,18 @@ static ssize_t disksize_store(struct device *dev, return -ENOMEM; comp = zcomp_create(zram->compressor, zram->max_comp_streams); - if (!comp) { + if (IS_ERR(comp)) { pr_info("Cannot initialise %s compressing backend\n", zram->compressor); - goto out_cleanup; + err = PTR_ERR(comp); + goto out_free_meta; } down_write(&zram->init_lock); if (init_done(zram)) { - up_write(&zram->init_lock); pr_info("Cannot change disksize for initialized device\n"); err = -EBUSY; - goto out_cleanup; + goto out_destroy_comp; } zram->meta = meta; @@ -614,12 +615,12 @@ static ssize_t disksize_store(struct device *dev, zram->disksize = disksize; set_capacity(zram->disk, zram->disksize >> SECTOR_SHIFT); up_write(&zram->init_lock); - return len; -out_cleanup: - if (comp) - zcomp_destroy(comp); +out_destroy_comp: + up_write(&zram->init_lock); + zcomp_destroy(comp); +out_free_meta: zram_meta_free(meta); return err; } -- 2.20.1