From: Tejun Heo Date: Sat, 13 Nov 2010 10:55:16 +0000 (+0100) Subject: mtd: fix bdev exclusive open bugs in block2mtd::add_device() X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=731edacb7567c15f25b1fccac18a203bd432ae5e;p=openwrt%2Fstaging%2Fblogic.git mtd: fix bdev exclusive open bugs in block2mtd::add_device() There are two bdev exclusive open bugs. * open_bdev_exclusive() must not be called with NULL holder. Use dev as the holder. * open_by_devnum() doesn't open the bdev exclusively but block2mtd_free_device() always assumes it. Explicitly claim the bdev. The latter is rather clumsy but will be simplified with future blkdev_get/put() cleanups. - Updated to use local variable @mode to cache FMODE_* masks as suggested by Artem Bityutskiy. Signed-off-by: Tejun Heo Cc: linux-mtd@lists.infradead.org Cc: Artem Bityutskiy --- diff --git a/drivers/mtd/devices/block2mtd.c b/drivers/mtd/devices/block2mtd.c index 2cf0cc6a4189..a9e2d3b38aeb 100644 --- a/drivers/mtd/devices/block2mtd.c +++ b/drivers/mtd/devices/block2mtd.c @@ -234,6 +234,7 @@ static void block2mtd_free_device(struct block2mtd_dev *dev) /* FIXME: ensure that mtd->size % erase_size == 0 */ static struct block2mtd_dev *add_device(char *devname, int erase_size) { + const fmode_t mode = FMODE_READ | FMODE_WRITE; struct block_device *bdev; struct block2mtd_dev *dev; char *name; @@ -246,7 +247,7 @@ static struct block2mtd_dev *add_device(char *devname, int erase_size) return NULL; /* Get a handle on the device */ - bdev = open_bdev_exclusive(devname, FMODE_READ|FMODE_WRITE, NULL); + bdev = open_bdev_exclusive(devname, mode, dev); #ifndef MODULE if (IS_ERR(bdev)) { @@ -255,7 +256,15 @@ static struct block2mtd_dev *add_device(char *devname, int erase_size) dev_t devt = name_to_dev_t(devname); if (devt) { - bdev = open_by_devnum(devt, FMODE_WRITE | FMODE_READ); + bdev = open_by_devnum(devt, mode); + if (!IS_ERR(bdev)) { + int ret; + ret = bd_claim(bdev, dev); + if (ret) { + blkdev_put(bdev, mode); + bdev = ERR_PTR(ret); + } + } } } #endif