fix the dynamic allocation and probe in loop.c
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Ken Chen <kenchen@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 18cdd8c..e2fc4b6 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1317,18 +1317,6 @@
}
#endif
-static struct loop_device *loop_find_dev(int number)
-{
- struct loop_device *lo;
-
- list_for_each_entry(lo, &loop_devices, lo_list) {
- if (lo->lo_number == number)
- return lo;
- }
- return NULL;
-}
-
-static struct loop_device *loop_init_one(int i);
static int lo_open(struct inode *inode, struct file *file)
{
struct loop_device *lo = inode->i_bdev->bd_disk->private_data;
@@ -1337,11 +1325,6 @@
lo->lo_refcnt++;
mutex_unlock(&lo->lo_ctl_mutex);
- mutex_lock(&loop_devices_mutex);
- if (!loop_find_dev(lo->lo_number + 1))
- loop_init_one(lo->lo_number + 1);
- mutex_unlock(&loop_devices_mutex);
-
return 0;
}
@@ -1448,7 +1431,7 @@
out_free_dev:
kfree(lo);
out:
- return ERR_PTR(-ENOMEM);
+ return NULL;
}
static void loop_del_one(struct loop_device *lo)
@@ -1460,36 +1443,30 @@
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)
{
- unsigned int number = dev & MINORMASK;
- struct loop_device *lo;
+ struct loop_device *lo = loop_init_one(dev & MINORMASK);
+ struct kobject *kobj;
- mutex_lock(&loop_devices_mutex);
- lo = loop_find_dev(number);
- if (lo == NULL)
- lo = loop_init_one(number);
+ kobj = lo ? get_disk(lo->lo_disk) : ERR_PTR(-ENOMEM);
mutex_unlock(&loop_devices_mutex);
*part = 0;
- if (IS_ERR(lo))
- return (void *)lo;
- else
- return &lo->lo_disk->kobj;
+ return kobj;
}
static int __init loop_init(void)
{
- struct loop_device *lo;
-
if (register_blkdev(LOOP_MAJOR, "loop"))
return -EIO;
blk_register_region(MKDEV(LOOP_MAJOR, 0), 1UL << MINORBITS,
- THIS_MODULE, loop_probe, NULL, NULL);
-
- lo = loop_init_one(0);
- if (IS_ERR(lo))
- goto out;
+ THIS_MODULE, loop_probe, loop_lock, NULL);
if (max_loop) {
printk(KERN_INFO "loop: the max_loop option is obsolete "
@@ -1498,11 +1475,6 @@
}
printk(KERN_INFO "loop: module loaded\n");
return 0;
-
-out:
- unregister_blkdev(LOOP_MAJOR, "loop");
- printk(KERN_ERR "loop: ran out of memory\n");
- return -ENOMEM;
}
static void __exit loop_exit(void)