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

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: default avatarSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reported-by: default avatarJerome 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent d61f98c7

drivers/block/zram/zcomp.c

+8 −6
Original line number Diff line number Diff line
@@ -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;

}

drivers/block/zram/zram_drv.c

+10 −9
Original line number Diff line number Diff line
@@ -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;

}

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