loop: prevent bdev freeing while device in use

[pandora-kernel.git] / drivers / block / loop.c

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 8c6787a..a365562 100644 (file)
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -907,6 +907,11 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode,
                lo->lo_flags |= LO_FLAGS_PARTSCAN;
        if (lo->lo_flags & LO_FLAGS_PARTSCAN)
                ioctl_by_bdev(bdev, BLKRRPART, 0);
+
+       /* Grab the block_device to prevent its destruction after we
+        * put /dev/loopXX inode. Later in loop_clr_fd() we bdput(bdev).
+        */
+       bdgrab(bdev);
        return 0;
 
 out_clr:
@@ -1003,8 +1008,10 @@ static int loop_clr_fd(struct loop_device *lo)
        memset(lo->lo_encrypt_key, 0, LO_KEY_SIZE);
        memset(lo->lo_crypt_name, 0, LO_NAME_SIZE);
        memset(lo->lo_file_name, 0, LO_NAME_SIZE);
-       if (bdev)
+       if (bdev) {
+               bdput(bdev);
                invalidate_bdev(bdev);
+       }
        set_capacity(lo->lo_disk, 0);
        loop_sysfs_exit(lo);
        if (bdev) {