diff mbox

[01/11] block: Fix bdi assignment to bdev inode when racing with disk delete

Message ID 20170306163404.1238-2-jack@suse.cz (mailing list archive)
State New, archived
Headers show

Commit Message

Jan Kara March 6, 2017, 4:33 p.m. UTC
When disk->fops->open() in __blkdev_get() returns -ERESTARTSYS, we
restart the process of opening the block device. However we forget to
switch bdev->bd_bdi back to noop_backing_dev_info and as a result bdev
inode will be pointing to a stale bdi. Fix the problem by setting
bdev->bd_bdi later when __blkdev_get() is already guaranteed to succeed.

Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/block_dev.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

Comments

Tejun Heo March 6, 2017, 10:01 p.m. UTC | #1
On Mon, Mar 06, 2017 at 05:33:54PM +0100, Jan Kara wrote:
> When disk->fops->open() in __blkdev_get() returns -ERESTARTSYS, we
> restart the process of opening the block device. However we forget to
> switch bdev->bd_bdi back to noop_backing_dev_info and as a result bdev
> inode will be pointing to a stale bdi. Fix the problem by setting
> bdev->bd_bdi later when __blkdev_get() is already guaranteed to succeed.
> 
> Signed-off-by: Jan Kara <jack@suse.cz>

Acked-by: Tejun Heo <tj@kernel.org>

Thanks.
Hannes Reinecke March 7, 2017, 6:47 a.m. UTC | #2
On 03/06/2017 05:33 PM, Jan Kara wrote:
> When disk->fops->open() in __blkdev_get() returns -ERESTARTSYS, we
> restart the process of opening the block device. However we forget to
> switch bdev->bd_bdi back to noop_backing_dev_info and as a result bdev
> inode will be pointing to a stale bdi. Fix the problem by setting
> bdev->bd_bdi later when __blkdev_get() is already guaranteed to succeed.
> 
> Signed-off-by: Jan Kara <jack@suse.cz>
> ---
>  fs/block_dev.c | 7 +++----
>  1 file changed, 3 insertions(+), 4 deletions(-)
> 
Reviewed-by: Hannes Reinecke <hare@suse.com>

Cheers,

Hannes
diff mbox

Patch

diff --git a/fs/block_dev.c b/fs/block_dev.c
index 2eca00ec4370..53e2389ae4d4 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1556,8 +1556,6 @@  static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
 		bdev->bd_disk = disk;
 		bdev->bd_queue = disk->queue;
 		bdev->bd_contains = bdev;
-		if (bdev->bd_bdi == &noop_backing_dev_info)
-			bdev->bd_bdi = bdi_get(disk->queue->backing_dev_info);
 
 		if (!partno) {
 			ret = -ENXIO;
@@ -1622,6 +1620,9 @@  static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
 			}
 			bd_set_size(bdev, (loff_t)bdev->bd_part->nr_sects << 9);
 		}
+
+		if (bdev->bd_bdi == &noop_backing_dev_info)
+			bdev->bd_bdi = bdi_get(disk->queue->backing_dev_info);
 	} else {
 		if (bdev->bd_contains == bdev) {
 			ret = 0;
@@ -1653,8 +1654,6 @@  static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
 	bdev->bd_disk = NULL;
 	bdev->bd_part = NULL;
 	bdev->bd_queue = NULL;
-	bdi_put(bdev->bd_bdi);
-	bdev->bd_bdi = &noop_backing_dev_info;
 	if (bdev != bdev->bd_contains)
 		__blkdev_put(bdev->bd_contains, mode, 1);
 	bdev->bd_contains = NULL;