Commit f9d10764 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

loop: split loop_control_ioctl 



Split loop_control_ioctl into a helper for each command.  This keeps the
code nicely separated for the upcoming locking changes.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Link: https://lore.kernel.org/r/20210623145908.92973-6-hch@lst.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 4157fe0b

drivers/block/loop.c

+60 −33
Original line number Diff line number Diff line
@@ -2397,8 +2397,19 @@ static void loop_probe(dev_t dev) 
	mutex_unlock(&loop_ctl_mutex);

}



static long loop_control_ioctl(struct file *file, unsigned int cmd,

			       unsigned long parm)

static int loop_control_add(int idx)

{

	int ret;

		

	ret = mutex_lock_killable(&loop_ctl_mutex);

	if (ret)

		return ret;

	ret = loop_add(idx);

	mutex_unlock(&loop_ctl_mutex);

	return ret;

}



static int loop_control_remove(int idx)

{

	struct loop_device *lo;

	int ret;
@@ -2407,44 +2418,60 @@ static long loop_control_ioctl(struct file *file, unsigned int cmd, 
	if (ret)

		return ret;



	ret = -ENOSYS;

	switch (cmd) {

	case LOOP_CTL_ADD:

		ret = loop_add(parm);

		break;

	case LOOP_CTL_REMOVE:

		ret = loop_lookup(&lo, parm);

	ret = loop_lookup(&lo, idx);

	if (ret < 0)

			break;

		goto out_unlock_ctrl;



	ret = mutex_lock_killable(&lo->lo_mutex);

	if (ret)

			break;

		if (lo->lo_state != Lo_unbound) {

			ret = -EBUSY;

		goto out_unlock_ctrl;

	if (lo->lo_state != Lo_unbound ||

	    atomic_read(&lo->lo_refcnt) > 0) {

		mutex_unlock(&lo->lo_mutex);

			break;

		}

		if (atomic_read(&lo->lo_refcnt) > 0) {

		ret = -EBUSY;

			mutex_unlock(&lo->lo_mutex);

			break;

		goto out_unlock_ctrl;

	}

	lo->lo_state = Lo_deleting;

	mutex_unlock(&lo->lo_mutex);



	idr_remove(&loop_index_idr, lo->lo_number);

	loop_remove(lo);

		break;

	case LOOP_CTL_GET_FREE:

out_unlock_ctrl:

	mutex_unlock(&loop_ctl_mutex);

	return ret;

}



static int loop_control_get_free(int idx)

{

	struct loop_device *lo;

	int ret;



	ret = mutex_lock_killable(&loop_ctl_mutex);

	if (ret)

		return ret;

	ret = loop_lookup(&lo, -1);

		if (ret >= 0)

			break;

	if (ret < 0)

		ret = loop_add(-1);

	}

	mutex_unlock(&loop_ctl_mutex);



	return ret;

}



static long loop_control_ioctl(struct file *file, unsigned int cmd,

			       unsigned long parm)

{

	switch (cmd) {

	case LOOP_CTL_ADD:

		return loop_control_add(parm);

	case LOOP_CTL_REMOVE:

		return loop_control_remove(parm);

	case LOOP_CTL_GET_FREE:

		return loop_control_get_free(parm);

	default:

		return -ENOSYS;

	}

}



static const struct file_operations loop_ctl_fops = {

	.open		= nonseekable_open,

	.unlocked_ioctl	= loop_control_ioctl,