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Commit 6db02784 authored by Martijn Coenen's avatar Martijn Coenen Committed by Greg Kroah-Hartman
Browse files

loop: Factor out configuring loop from status 



[ Upstream commit 0c3796c244598122a5d59d56f30d19390096817f ]

Factor out this code into a separate function, so it can be reused by
other code more easily.

Signed-off-by: default avatarMartijn Coenen <maco@android.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
Signed-off-by: default avatarGenjian Zhang <zhanggenjian@kylinos.cn>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 9b021c7f

drivers/block/loop.c

+67 −50
Original line number Diff line number Diff line
@@ -1231,75 +1231,43 @@ static int loop_clr_fd(struct loop_device *lo) 
	return __loop_clr_fd(lo, false);

}



/**

 * loop_set_status_from_info - configure device from loop_info

 * @lo: struct loop_device to configure

 * @info: struct loop_info64 to configure the device with

 *

 * Configures the loop device parameters according to the passed

 * in loop_info64 configuration.

 */

static int

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

loop_set_status_from_info(struct loop_device *lo,

			  const struct loop_info64 *info)

{

	int err;

	struct loop_func_table *xfer;

	kuid_t uid = current_uid();

	struct block_device *bdev;

	bool partscan = false;

	bool size_changed = false;



	err = mutex_lock_killable(&loop_ctl_mutex);

	if (err)

		return err;

	if (lo->lo_encrypt_key_size &&

	    !uid_eq(lo->lo_key_owner, uid) &&

	    !capable(CAP_SYS_ADMIN)) {

		err = -EPERM;

		goto out_unlock;

	}

	if (lo->lo_state != Lo_bound) {

		err = -ENXIO;

		goto out_unlock;

	}

	if ((unsigned int) info->lo_encrypt_key_size > LO_KEY_SIZE) {

		err = -EINVAL;

		goto out_unlock;

	}



	if (lo->lo_offset != info->lo_offset ||

	    lo->lo_sizelimit != info->lo_sizelimit) {

		size_changed = true;

		sync_blockdev(lo->lo_device);

		invalidate_bdev(lo->lo_device);

	}



	/* I/O need to be drained during transfer transition */

	blk_mq_freeze_queue(lo->lo_queue);



	if (size_changed && lo->lo_device->bd_inode->i_mapping->nrpages) {

		/* If any pages were dirtied after invalidate_bdev(), try again */

		err = -EAGAIN;

		pr_warn("%s: loop%d (%s) has still dirty pages (nrpages=%lu)\n",

			__func__, lo->lo_number, lo->lo_file_name,

			lo->lo_device->bd_inode->i_mapping->nrpages);

		goto out_unfreeze;

	}

	if ((unsigned int) info->lo_encrypt_key_size > LO_KEY_SIZE)

		return -EINVAL;



	err = loop_release_xfer(lo);

	if (err)

		goto out_unfreeze;

		return err;



	if (info->lo_encrypt_type) {

		unsigned int type = info->lo_encrypt_type;



		if (type >= MAX_LO_CRYPT) {

			err = -EINVAL;

			goto out_unfreeze;

		}

		if (type >= MAX_LO_CRYPT)

			return -EINVAL;

		xfer = xfer_funcs[type];

		if (xfer == NULL) {

			err = -EINVAL;

			goto out_unfreeze;

		}

		if (xfer == NULL)

			return -EINVAL;

	} else

		xfer = NULL;



	err = loop_init_xfer(lo, xfer, info);

	if (err)

		goto out_unfreeze;

		return err;



	lo->lo_offset = info->lo_offset;

	lo->lo_sizelimit = info->lo_sizelimit;
@@ -1326,6 +1294,55 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info) 
		lo->lo_key_owner = uid;

	}



	return 0;

}



static int

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

{

	int err;

	struct block_device *bdev;

	kuid_t uid = current_uid();

	bool partscan = false;

	bool size_changed = false;



	err = mutex_lock_killable(&loop_ctl_mutex);

	if (err)

		return err;

	if (lo->lo_encrypt_key_size &&

	    !uid_eq(lo->lo_key_owner, uid) &&

	    !capable(CAP_SYS_ADMIN)) {

		err = -EPERM;

		goto out_unlock;

	}

	if (lo->lo_state != Lo_bound) {

		err = -ENXIO;

		goto out_unlock;

	}



	if (lo->lo_offset != info->lo_offset ||

	    lo->lo_sizelimit != info->lo_sizelimit) {

		size_changed = true;

		sync_blockdev(lo->lo_device);

		invalidate_bdev(lo->lo_device);

	}



	/* I/O need to be drained during transfer transition */

	blk_mq_freeze_queue(lo->lo_queue);



	if (size_changed && lo->lo_device->bd_inode->i_mapping->nrpages) {

		/* If any pages were dirtied after invalidate_bdev(), try again */

		err = -EAGAIN;

		pr_warn("%s: loop%d (%s) has still dirty pages (nrpages=%lu)\n",

			__func__, lo->lo_number, lo->lo_file_name,

			lo->lo_device->bd_inode->i_mapping->nrpages);

		goto out_unfreeze;

	}



	err = loop_set_status_from_info(lo, info);

	if (err)

		goto out_unfreeze;



	if (size_changed) {

		loff_t new_size = get_size(lo->lo_offset, lo->lo_sizelimit,

					   lo->lo_backing_file);