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authorArtem Bityutskiy <Artem.Bityutskiy@nokia.com>2011-04-18 06:50:37 +0200
committerDavid Woodhouse <David.Woodhouse@intel.com>2011-05-25 02:53:45 +0200
commit94735ec4044a6d318b83ad3c5794e931ed168d10 (patch)
treea5704163f225330f25102e8daf5668b2215c86ed
parentmtd: atmel_nand: add missing include of linux/dmaengine.h (diff)
downloadlinux-94735ec4044a6d318b83ad3c5794e931ed168d10.tar.xz
linux-94735ec4044a6d318b83ad3c5794e931ed168d10.zip
mtd: mtd_blkdevs: fix error path in blktrans_open
The 'blktrans_open()' does not handle possible '__get_mtd_device()' failures because it does not check the error code. Moreover, the 'dev->tr->open()' failures are not handled correctly because in this case the function just goes ahead and gets the mtd device, then returns an error. But Instead, it should _not_ try to get the mtd device, then it should put back the module and the kref. This patch fixes the issue. Note, I only compile-tested it. This patch was inspired by a bug report about a similar issue in 2.6.34 kernels sent by Mike Turner <admin@islandsoftware.co.uk> to the MTD mailing list: http://lists.infradead.org/pipermail/linux-mtd/2011-April/034980.html Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
-rw-r--r--drivers/mtd/mtd_blkdevs.c24
1 files changed, 21 insertions, 3 deletions
diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
index a534e1f0c348..ca385697446e 100644
--- a/drivers/mtd/mtd_blkdevs.c
+++ b/drivers/mtd/mtd_blkdevs.c
@@ -221,15 +221,33 @@ static int blktrans_open(struct block_device *bdev, fmode_t mode)
kref_get(&dev->ref);
__module_get(dev->tr->owner);
- if (dev->mtd) {
- ret = dev->tr->open ? dev->tr->open(dev) : 0;
- __get_mtd_device(dev->mtd);
+ if (!dev->mtd)
+ goto unlock;
+
+ if (dev->tr->open) {
+ ret = dev->tr->open(dev);
+ if (ret)
+ goto error_put;
}
+ ret = __get_mtd_device(dev->mtd);
+ if (ret)
+ goto error_release;
+
unlock:
mutex_unlock(&dev->lock);
blktrans_dev_put(dev);
return ret;
+
+error_release:
+ if (dev->tr->release)
+ dev->tr->release(dev);
+error_put:
+ module_put(dev->tr->owner);
+ kref_put(&dev->ref, blktrans_dev_release);
+ mutex_unlock(&dev->lock);
+ blktrans_dev_put(dev);
+ return ret;
}
static int blktrans_release(struct gendisk *disk, fmode_t mode)