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authorAl Viro <viro@zeniv.linux.org.uk>2007-05-13 05:52:32 -0400
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-05-13 12:44:05 -0400
commit705962ccc9d21a08b74b6b6e1d3cf10f98968a67 (patch)
treec9c534aa1be76b790b0d8a4415fd7d46f920c77c /drivers/block/loop.c
parent39403865d2e4590802553370a56c9ab93131e4ee (diff)
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 <viro@zeniv.linux.org.uk> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/block/loop.c')
-rw-r--r--drivers/block/loop.c17
1 files 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)
1399 struct loop_device *lo; 1399 struct loop_device *lo;
1400 struct gendisk *disk; 1400 struct gendisk *disk;
1401 1401
1402 list_for_each_entry(lo, &loop_devices, lo_list) {
1403 if (lo->lo_number == i)
1404 return lo;
1405 }
1406
1402 lo = kzalloc(sizeof(*lo), GFP_KERNEL); 1407 lo = kzalloc(sizeof(*lo), GFP_KERNEL);
1403 if (!lo) 1408 if (!lo)
1404 goto out; 1409 goto out;
@@ -1443,17 +1448,13 @@ static void loop_del_one(struct loop_device *lo)
1443 kfree(lo); 1448 kfree(lo);
1444} 1449}
1445 1450
1446static int loop_lock(dev_t dev, void *data)
1447{
1448 mutex_lock(&loop_devices_mutex);
1449 return 0;
1450}
1451
1452static struct kobject *loop_probe(dev_t dev, int *part, void *data) 1451static struct kobject *loop_probe(dev_t dev, int *part, void *data)
1453{ 1452{
1454 struct loop_device *lo = loop_init_one(dev & MINORMASK); 1453 struct loop_device *lo;
1455 struct kobject *kobj; 1454 struct kobject *kobj;
1456 1455
1456 mutex_lock(&loop_devices_mutex);
1457 lo = loop_init_one(dev & MINORMASK);
1457 kobj = lo ? get_disk(lo->lo_disk) : ERR_PTR(-ENOMEM); 1458 kobj = lo ? get_disk(lo->lo_disk) : ERR_PTR(-ENOMEM);
1458 mutex_unlock(&loop_devices_mutex); 1459 mutex_unlock(&loop_devices_mutex);
1459 1460
@@ -1466,7 +1467,7 @@ static int __init loop_init(void)
1466 if (register_blkdev(LOOP_MAJOR, "loop")) 1467 if (register_blkdev(LOOP_MAJOR, "loop"))
1467 return -EIO; 1468 return -EIO;
1468 blk_register_region(MKDEV(LOOP_MAJOR, 0), 1UL << MINORBITS, 1469 blk_register_region(MKDEV(LOOP_MAJOR, 0), 1UL << MINORBITS,
1469 THIS_MODULE, loop_probe, loop_lock, NULL); 1470 THIS_MODULE, loop_probe, NULL, NULL);
1470 1471
1471 if (max_loop) { 1472 if (max_loop) {
1472 printk(KERN_INFO "loop: the max_loop option is obsolete " 1473 printk(KERN_INFO "loop: the max_loop option is obsolete "