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 <sergey.senozhatsky@gmail.com>
Reported-by: Jerome Marchand <jmarchan@redhat.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Sergey Senozhatsky 2014-04-07 15:38:20 -07:00 committed by Linus Torvalds
parent d61f98c70e
commit fcfa8d95ca
2 changed files with 18 additions and 15 deletions

View File

@ -9,6 +9,7 @@
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/wait.h>
#include <linux/sched.h>
@ -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;
}

View File

@ -31,6 +31,7 @@
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/vmalloc.h>
#include <linux/err.h>
#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)
out_destroy_comp:
up_write(&zram->init_lock);
zcomp_destroy(comp);
out_free_meta:
zram_meta_free(meta);
return err;
}