Commit 18d1f200 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

loop: move loop_ctl_mutex locking into loop_add 



Move acquiring and releasing loop_ctl_mutex from the callers into
loop_add.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Link: https://lore.kernel.org/r/20210623145908.92973-7-hch@lst.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent f9d10764

drivers/block/loop.c

+13 −24
Original line number Diff line number Diff line
@@ -2247,9 +2247,12 @@ static int loop_add(int i) 
	lo = kzalloc(sizeof(*lo), GFP_KERNEL);

	if (!lo)

		goto out;



	lo->lo_state = Lo_unbound;



	err = mutex_lock_killable(&loop_ctl_mutex);

	if (err)

		goto out_free_dev;



	/* allocate id, if @id >= 0, we're requesting that specific id */

	if (i >= 0) {

		err = idr_alloc(&loop_index_idr, lo, i, i + 1, GFP_KERNEL);
@@ -2259,7 +2262,7 @@ static int loop_add(int i) 
		err = idr_alloc(&loop_index_idr, lo, 0, 0, GFP_KERNEL);

	}

	if (err < 0)

		goto out_free_dev;

		goto out_unlock;

	i = err;



	err = -ENOMEM;
@@ -2326,12 +2329,15 @@ static int loop_add(int i) 
	disk->queue		= lo->lo_queue;

	sprintf(disk->disk_name, "loop%d", i);

	add_disk(disk);

	return lo->lo_number;

	mutex_unlock(&loop_ctl_mutex);

	return i;



out_cleanup_tags:

	blk_mq_free_tag_set(&lo->tag_set);

out_free_idr:

	idr_remove(&loop_index_idr, i);

out_unlock:

	mutex_unlock(&loop_ctl_mutex);

out_free_dev:

	kfree(lo);

out:
@@ -2391,22 +2397,7 @@ static void loop_probe(dev_t dev) 


	if (max_loop && idx >= max_loop)

		return;



	mutex_lock(&loop_ctl_mutex);

	loop_add(idx);

	mutex_unlock(&loop_ctl_mutex);

}



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)
@@ -2450,11 +2441,11 @@ static int loop_control_get_free(int idx) 
	if (ret)

		return ret;

	ret = loop_lookup(&lo, -1);

	if (ret < 0)

		ret = loop_add(-1);

	mutex_unlock(&loop_ctl_mutex);



	if (ret >= 0)

		return ret;

	return loop_add(-1);

}



static long loop_control_ioctl(struct file *file, unsigned int cmd,
@@ -2462,7 +2453,7 @@ static long loop_control_ioctl(struct file *file, unsigned int cmd, 
{

	switch (cmd) {

	case LOOP_CTL_ADD:

		return loop_control_add(parm);

		return loop_add(parm);

	case LOOP_CTL_REMOVE:

		return loop_control_remove(parm);

	case LOOP_CTL_GET_FREE:
@@ -2543,10 +2534,8 @@ static int __init loop_init(void) 
	}



	/* pre-create number of devices given by config or max_loop */

	mutex_lock(&loop_ctl_mutex);

	for (i = 0; i < nr; i++)

		loop_add(i);

	mutex_unlock(&loop_ctl_mutex);



	printk(KERN_INFO "loop: module loaded\n");

	return 0;