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. Reported-by: Jerome Marchand <[email protected]> Signed-off-by: Sergey Senozhatsky <[email protected]> --- drivers/block/zram/zcomp.c | 13 +++++++------ drivers/block/zram/zram_drv.c | 8 ++++---- 2 files changed, 11 insertions(+), 10 deletions(-) diff --git a/drivers/block/zram/zcomp.c b/drivers/block/zram/zcomp.c index d591903..92a83df 100644 --- a/drivers/block/zram/zcomp.c +++ b/drivers/block/zram/zcomp.c @@ -319,9 +319,10 @@ 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 +331,11 @@ 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 +344,7 @@ 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 e4d536b..9585957 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -583,7 +583,7 @@ 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 = -EBUSY; disksize = memparse(buf, NULL); if (!disksize) @@ -595,9 +595,10 @@ 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); + err = PTR_ERR(comp); goto out_cleanup; } @@ -605,7 +606,6 @@ static ssize_t disksize_store(struct device *dev, if (init_done(zram)) { up_write(&zram->init_lock); pr_info("Cannot change disksize for initialized device\n"); - err = -EBUSY; goto out_cleanup; } @@ -618,7 +618,7 @@ static ssize_t disksize_store(struct device *dev, return len; out_cleanup: - if (comp) + if (!IS_ERR(comp)) zcomp_destroy(comp); zram_meta_free(meta); return err; -- 1.9.0.382.g7f3562c -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
