From 705962ccc9d21a08b74b6b6e1d3cf10f98968a67 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 13 May 2007 05:52:32 -0400 Subject: [PATCH] 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: Al Viro Cc: Jeremy Fitzhardinge Signed-off-by: Linus Torvalds --- drivers/block/loop.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index e2fc4b6734cf..5526eadb6592 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -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loop_lock, NULL); + THIS_MODULE, loop_probe, NULL, NULL); if (max_loop) { printk(KERN_INFO "loop: the max_loop option is obsolete " -- 2.39.2