Commit 36369f46 authored by Jan Kara's avatar Jan Kara Committed by Jens Axboe
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block: Do not reread partition table on exclusively open device 

Since commit 10c70d95 ("block: remove the bd_openers checks in
blk_drop_partitions") we allow rereading of partition table although
there are users of the block device. This has an undesirable consequence
that e.g. if sda and sdb are assembled to a RAID1 device md0 with
partitions, BLKRRPART ioctl on sda will rescan partition table and
create sda1 device. This partition device under a raid device confuses
some programs (such as libstorage-ng used for initial partitioning for
distribution installation) leading to failures.

Fix the problem refusing to rescan partitions if there is another user
that has the block device exclusively open.

Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/20221130135344.2ul4cyfstfs3znxg@quack3


Fixes: 10c70d95 ("block: remove the bd_openers checks in blk_drop_partitions")
Signed-off-by: default avatarJan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20221130175653.24299-1-jack@suse.cz


[axboe: fold in followup fix]
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 92a34c46

block/blk.h

+1 −1
Original line number Diff line number Diff line
@@ -426,7 +426,7 @@ int bio_add_hw_page(struct request_queue *q, struct bio *bio, 


struct request_queue *blk_alloc_queue(int node_id);



int disk_scan_partitions(struct gendisk *disk, fmode_t mode);

int disk_scan_partitions(struct gendisk *disk, fmode_t mode, void *owner);



int disk_alloc_events(struct gendisk *disk);

void disk_add_events(struct gendisk *disk);

block/genhd.c

+5 −2
Original line number Diff line number Diff line
@@ -356,7 +356,7 @@ void disk_uevent(struct gendisk *disk, enum kobject_action action) 
}

EXPORT_SYMBOL_GPL(disk_uevent);



int disk_scan_partitions(struct gendisk *disk, fmode_t mode)

int disk_scan_partitions(struct gendisk *disk, fmode_t mode, void *owner)

{

	struct block_device *bdev;
@@ -366,6 +366,9 @@ int disk_scan_partitions(struct gendisk *disk, fmode_t mode) 
		return -EINVAL;

	if (disk->open_partitions)

		return -EBUSY;

	/* Someone else has bdev exclusively open? */

	if (disk->part0->bd_holder && disk->part0->bd_holder != owner)

		return -EBUSY;



	set_bit(GD_NEED_PART_SCAN, &disk->state);

	bdev = blkdev_get_by_dev(disk_devt(disk), mode, NULL);
@@ -495,7 +498,7 @@ int __must_check device_add_disk(struct device *parent, struct gendisk *disk, 


		bdev_add(disk->part0, ddev->devt);

		if (get_capacity(disk))

			disk_scan_partitions(disk, FMODE_READ);

			disk_scan_partitions(disk, FMODE_READ, NULL);



		/*

		 * Announce the disk and partitions after all partitions are

block/ioctl.c

+7 −5
Original line number Diff line number Diff line
@@ -467,9 +467,10 @@ static int blkdev_bszset(struct block_device *bdev, fmode_t mode, 
 * user space. Note the separate arg/argp parameters that are needed

 * to deal with the compat_ptr() conversion.

 */

static int blkdev_common_ioctl(struct block_device *bdev, fmode_t mode,

				unsigned cmd, unsigned long arg, void __user *argp)

static int blkdev_common_ioctl(struct file *file, fmode_t mode, unsigned cmd,

			       unsigned long arg, void __user *argp)

{

	struct block_device *bdev = I_BDEV(file->f_mapping->host);

	unsigned int max_sectors;



	switch (cmd) {
@@ -527,7 +528,8 @@ static int blkdev_common_ioctl(struct block_device *bdev, fmode_t mode, 
			return -EACCES;

		if (bdev_is_partition(bdev))

			return -EINVAL;

		return disk_scan_partitions(bdev->bd_disk, mode & ~FMODE_EXCL);

		return disk_scan_partitions(bdev->bd_disk, mode & ~FMODE_EXCL,

					    file);

	case BLKTRACESTART:

	case BLKTRACESTOP:

	case BLKTRACETEARDOWN:
@@ -605,7 +607,7 @@ long blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg) 
		break;

	}



	ret = blkdev_common_ioctl(bdev, mode, cmd, arg, argp);

	ret = blkdev_common_ioctl(file, mode, cmd, arg, argp);

	if (ret != -ENOIOCTLCMD)

		return ret;
@@ -674,7 +676,7 @@ long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg) 
		break;

	}



	ret = blkdev_common_ioctl(bdev, mode, cmd, arg, argp);

	ret = blkdev_common_ioctl(file, mode, cmd, arg, argp);

	if (ret == -ENOIOCTLCMD && disk->fops->compat_ioctl)

		ret = disk->fops->compat_ioctl(bdev, mode, cmd, arg);