evie/android_kernel_oneplus_msm8998
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block: Fix bdi assignment to bdev inode when racing with disk delete

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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>
Change-Id: I6736ed1aba8732d3146284311c718f48b9c06578
Git-repo:
git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git
Git-commit: 03e262798884b0a5f948b17433afd80606cb3497
Signed-off-by: Ritesh Harjani <riteshh@codeaurora.org>
This commit is contained in:
Jan Kara 2017-03-23 01:36:53 +01:00 • committed by Ritesh Harjani
parent 16d289189c
commit f4f6d3c0b0
1 changed files with 3 additions and 4 deletions
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7
fs/block_dev.c
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@ -1221,8 +1221,6 @@ 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);
bdev->bd_inode->i_flags = disk->fops->direct_access ? S_DAX : 0;
if (!partno) {
@ -1294,6 +1292,9 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
(bdev->bd_part->nr_sects % (PAGE_SIZE / 512)))
bdev->bd_inode->i_flags &= ~S_DAX;
}
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;
@ -1325,8 +1326,6 @@ 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;