loop: Push loop_ctl_mutex down to loop_get_status()

Push loop_ctl_mutex down to loop_get_status() to avoid the unusual
convention that the function gets called with loop_ctl_mutex held and
releases it.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index d8a7b5d..2e814f8 100644 (file)
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1232,6 +1232,9 @@ loop_get_status(struct loop_device *lo, struct loop_info64 *info)
        struct kstat stat;
        int ret;
 
+       ret = mutex_lock_killable_nested(&loop_ctl_mutex, 1);
+       if (ret)
+               return ret;
        if (lo->lo_state != Lo_bound) {
                mutex_unlock(&loop_ctl_mutex);
                return -ENXIO;
@@ -1346,10 +1349,8 @@ loop_get_status_old(struct loop_device *lo, struct loop_info __user *arg) {
        struct loop_info64 info64;
        int err;
 
-       if (!arg) {
-               mutex_unlock(&loop_ctl_mutex);
+       if (!arg)
                return -EINVAL;
-       }
        err = loop_get_status(lo, &info64);
        if (!err)
                err = loop_info64_to_old(&info64, &info);
@@ -1364,10 +1365,8 @@ loop_get_status64(struct loop_device *lo, struct loop_info64 __user *arg) {
        struct loop_info64 info64;
        int err;
 
-       if (!arg) {
-               mutex_unlock(&loop_ctl_mutex);
+       if (!arg)
                return -EINVAL;
-       }
        err = loop_get_status(lo, &info64);
        if (!err && copy_to_user(arg, &info64, sizeof(info64)))
                err = -EFAULT;
@@ -1477,12 +1476,7 @@ static int lo_ioctl(struct block_device *bdev, fmode_t mode,
                }
                break;
        case LOOP_GET_STATUS:
-               err = mutex_lock_killable_nested(&loop_ctl_mutex, 1);
-               if (err)
-                       return err;
-               err = loop_get_status_old(lo, (struct loop_info __user *) arg);
-               /* loop_get_status() unlocks loop_ctl_mutex */
-               break;
+               return loop_get_status_old(lo, (struct loop_info __user *) arg);
        case LOOP_SET_STATUS64:
                err = -EPERM;
                if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) {
@@ -1495,12 +1489,7 @@ static int lo_ioctl(struct block_device *bdev, fmode_t mode,
                }
                break;
        case LOOP_GET_STATUS64:
-               err = mutex_lock_killable_nested(&loop_ctl_mutex, 1);
-               if (err)
-                       return err;
-               err = loop_get_status64(lo, (struct loop_info64 __user *) arg);
-               /* loop_get_status() unlocks loop_ctl_mutex */
-               break;
+               return loop_get_status64(lo, (struct loop_info64 __user *) arg);
        case LOOP_SET_CAPACITY:
        case LOOP_SET_DIRECT_IO:
        case LOOP_SET_BLOCK_SIZE:
@@ -1625,10 +1614,8 @@ loop_get_status_compat(struct loop_device *lo,
        struct loop_info64 info64;
        int err;
 
-       if (!arg) {
-               mutex_unlock(&loop_ctl_mutex);
+       if (!arg)
                return -EINVAL;
-       }
        err = loop_get_status(lo, &info64);
        if (!err)
                err = loop_info64_to_compat(&info64, arg);
@@ -1651,12 +1638,8 @@ static int lo_compat_ioctl(struct block_device *bdev, fmode_t mode,
                }
                break;
        case LOOP_GET_STATUS:
-               err = mutex_lock_killable(&loop_ctl_mutex);
-               if (!err) {
-                       err = loop_get_status_compat(lo,
-                                                    (struct compat_loop_info __user *)arg);
-                       /* loop_get_status() unlocks loop_ctl_mutex */
-               }
+               err = loop_get_status_compat(lo,
+                                    (struct compat_loop_info __user *)arg);
                break;
        case LOOP_SET_CAPACITY:
        case LOOP_CLR_FD: