Commit 705962cc authored by Al Viro's avatar Al Viro Committed by Linus Torvalds
Browse files

fix deadlock in loop.c 



... doh

Jeremy Fitzhardinge noted that the recent loop.c cleanups worked, but
cause lockdep to complain.

Ouch.  OK, the deadlock is real and yes, I'm an idiot.  Speaking of which,
we probably want to s/lock/pin/ in drivers/base/map.c to avoid such
brainos again.  And yes, this stuff needs clear documentation.  Will try
to put one together once I get some sleep...

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 39403865

drivers/block/loop.c

+9 −8
Original line number Diff line number Diff line
@@ -1399,6 +1399,11 @@ static struct loop_device *loop_init_one(int i) 
	struct loop_device *lo;

	struct gendisk *disk;



	list_for_each_entry(lo, &loop_devices, lo_list) {

		if (lo->lo_number == i)

			return lo;

	}



	lo = kzalloc(sizeof(*lo), GFP_KERNEL);

	if (!lo)

		goto out;
@@ -1443,17 +1448,13 @@ static void loop_del_one(struct loop_device *lo) 
	kfree(lo);

}



static int loop_lock(dev_t dev, void *data)

{

	mutex_lock(&loop_devices_mutex);

	return 0;

}



static struct kobject *loop_probe(dev_t dev, int *part, void *data)

{

	struct loop_device *lo = loop_init_one(dev & MINORMASK);

	struct loop_device *lo;

	struct kobject *kobj;



	mutex_lock(&loop_devices_mutex);

	lo = loop_init_one(dev & MINORMASK);

	kobj = lo ? get_disk(lo->lo_disk) : ERR_PTR(-ENOMEM);

	mutex_unlock(&loop_devices_mutex);
@@ -1466,7 +1467,7 @@ static int __init loop_init(void) 
	if (register_blkdev(LOOP_MAJOR, "loop"))

		return -EIO;

	blk_register_region(MKDEV(LOOP_MAJOR, 0), 1UL << MINORBITS,

				  THIS_MODULE, loop_probe, loop_lock, NULL);

				  THIS_MODULE, loop_probe, NULL, NULL);



	if (max_loop) {

		printk(KERN_INFO "loop: the max_loop option is obsolete "

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