block: Fix bdi assignment to bdev inode when racing with disk delete (03e26279) · Commits · 戴 / test

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>

fs/block_dev.c

+3 −4

Original line number	Diff line number	Diff line
		@@ -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;

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