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| author | Artem Bityutskiy <Artem.Bityutskiy@nokia.com> | 2011-04-18 07:50:37 +0300 |
|---|---|---|
| committer | David Woodhouse <David.Woodhouse@intel.com> | 2011-05-25 01:53:45 +0100 |
| commit | 94735ec4044a6d318b83ad3c5794e931ed168d10 (patch) | |
| tree | a5704163f225330f25102e8daf5668b2215c86ed | |
| parent | 5c39c4c54c585e13a8d6b5a8f64af682e7c68091 (diff) | |
| download | blackbird-op-linux-94735ec4044a6d318b83ad3c5794e931ed168d10.tar.gz blackbird-op-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.c | 24 |
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) |
