Commit a6abd64e authored by Jens Axboe's avatar Jens Axboe
Browse files

loop: revert exclusive opener loop status change 



This commit effectively reverts the following two commits:

2704024d ("loop: add missing bd_abort_claiming in loop_set_status")
08e136eb ("loop: don't change loop device under exclusive opener in loop_set_status")

as there are reports of them causing issues with unmounting. As we're
close to the 6.19 kernel release and the original author hasn't taken a
closer look at this yet, revert them for release.

Reported-by: default avatarnokangaroo <nokangaroo@aon.at>
Link: https://lore.kernel.org/all/62de4453-17e8-47f6-a10b-39bf5a49fdee@leemhuis.info/


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 7e210d5e

drivers/block/loop.c

+12 −33
Original line number Diff line number Diff line
@@ -1225,28 +1225,16 @@ static int loop_clr_fd(struct loop_device *lo) 
}



static int

loop_set_status(struct loop_device *lo, blk_mode_t mode,

		struct block_device *bdev, const struct loop_info64 *info)

loop_set_status(struct loop_device *lo, const struct loop_info64 *info)

{

	int err;

	bool partscan = false;

	bool size_changed = false;

	unsigned int memflags;



	/*

	 * If we don't hold exclusive handle for the device, upgrade to it

	 * here to avoid changing device under exclusive owner.

	 */

	if (!(mode & BLK_OPEN_EXCL)) {

		err = bd_prepare_to_claim(bdev, loop_set_status, NULL);

		if (err)

			goto out_reread_partitions;

	}



	err = mutex_lock_killable(&lo->lo_mutex);

	if (err)

		goto out_abort_claiming;



		return err;

	if (lo->lo_state != Lo_bound) {

		err = -ENXIO;

		goto out_unlock;
@@ -1285,10 +1273,6 @@ loop_set_status(struct loop_device *lo, blk_mode_t mode, 
	}

out_unlock:

	mutex_unlock(&lo->lo_mutex);

out_abort_claiming:

	if (!(mode & BLK_OPEN_EXCL))

		bd_abort_claiming(bdev, loop_set_status);

out_reread_partitions:

	if (partscan)

		loop_reread_partitions(lo);
@@ -1368,9 +1352,7 @@ loop_info64_to_old(const struct loop_info64 *info64, struct loop_info *info) 
}



static int

loop_set_status_old(struct loop_device *lo, blk_mode_t mode,

		    struct block_device *bdev,

		    const struct loop_info __user *arg)

loop_set_status_old(struct loop_device *lo, const struct loop_info __user *arg)

{

	struct loop_info info;

	struct loop_info64 info64;
@@ -1378,19 +1360,17 @@ loop_set_status_old(struct loop_device *lo, blk_mode_t mode, 
	if (copy_from_user(&info, arg, sizeof (struct loop_info)))

		return -EFAULT;

	loop_info64_from_old(&info, &info64);

	return loop_set_status(lo, mode, bdev, &info64);

	return loop_set_status(lo, &info64);

}



static int

loop_set_status64(struct loop_device *lo, blk_mode_t mode,

		  struct block_device *bdev,

		  const struct loop_info64 __user *arg)

loop_set_status64(struct loop_device *lo, const struct loop_info64 __user *arg)

{

	struct loop_info64 info64;



	if (copy_from_user(&info64, arg, sizeof (struct loop_info64)))

		return -EFAULT;

	return loop_set_status(lo, mode, bdev, &info64);

	return loop_set_status(lo, &info64);

}



static int
@@ -1569,14 +1549,14 @@ static int lo_ioctl(struct block_device *bdev, blk_mode_t mode, 
	case LOOP_SET_STATUS:

		err = -EPERM;

		if ((mode & BLK_OPEN_WRITE) || capable(CAP_SYS_ADMIN))

			err = loop_set_status_old(lo, mode, bdev, argp);

			err = loop_set_status_old(lo, argp);

		break;

	case LOOP_GET_STATUS:

		return loop_get_status_old(lo, argp);

	case LOOP_SET_STATUS64:

		err = -EPERM;

		if ((mode & BLK_OPEN_WRITE) || capable(CAP_SYS_ADMIN))

			err = loop_set_status64(lo, mode, bdev, argp);

			err = loop_set_status64(lo, argp);

		break;

	case LOOP_GET_STATUS64:

		return loop_get_status64(lo, argp);
@@ -1670,8 +1650,7 @@ loop_info64_to_compat(const struct loop_info64 *info64, 
}



static int

loop_set_status_compat(struct loop_device *lo, blk_mode_t mode,

		    struct block_device *bdev,

loop_set_status_compat(struct loop_device *lo,

		       const struct compat_loop_info __user *arg)

{

	struct loop_info64 info64;
@@ -1680,7 +1659,7 @@ loop_set_status_compat(struct loop_device *lo, blk_mode_t mode, 
	ret = loop_info64_from_compat(arg, &info64);

	if (ret < 0)

		return ret;

	return loop_set_status(lo, mode, bdev, &info64);

	return loop_set_status(lo, &info64);

}



static int
@@ -1706,7 +1685,7 @@ static int lo_compat_ioctl(struct block_device *bdev, blk_mode_t mode, 


	switch(cmd) {

	case LOOP_SET_STATUS:

		err = loop_set_status_compat(lo, mode, bdev,

		err = loop_set_status_compat(lo,

			     (const struct compat_loop_info __user *)arg);

		break;

	case LOOP_GET_STATUS: