block: Fix bdi assignment to bdev inode when racing with disk delete

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.

Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Jan Kara 2017-03-23 01:36:53 +01:00 committed by Jens Axboe
parent a83b576c9c
commit 03e2627988

View File

@ -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;