Commit fcfa8d95 authored by Sergey Senozhatsky's avatar Sergey Senozhatsky Committed by Linus Torvalds

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.

[ clean up error recovery flow]
Signed-off-by: default avatarSergey Senozhatsky <>
Reported-by: default avatarJerome Marchand <>
Cc: Minchan Kim <>
Cc: Nitin Gupta <>
Cc: Arnd Bergmann <>
Signed-off-by: default avatarAndrew Morton <>
Signed-off-by: default avatarLinus Torvalds <>
parent d61f98c7
......@@ -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)
if (!comp->stream) {
return NULL;
return ERR_PTR(-ENOMEM);
return comp;
......@@ -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",
goto out_cleanup;
err = PTR_ERR(comp);
goto out_free_meta;
if (init_done(zram)) {
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);
return len;
if (comp)
return err;
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