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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 09:44:05 -0700
commit705962ccc9d21a08b74b6b6e1d3cf10f98968a67 (patch)
treec9c534aa1be76b790b0d8a4415fd7d46f920c77c
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>
-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 e2fc4b6734c..5526eadb659 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printk(KERN_INFO "loop: the max_loop option is obsolete "