loop: Push loop_ctl_mutex down to loop_set_status()

Push loop_ctl_mutex down to loop_set_status(). We will need this to be
able to call loop_reread_partitions() without loop_ctl_mutex.

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 2e814f8..af79a59 100644 (file)
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1141,46 +1141,55 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info)
        struct loop_func_table *xfer;
        kuid_t uid = current_uid();
 
+       err = mutex_lock_killable_nested(&loop_ctl_mutex, 1);
+       if (err)
+               return err;
        if (lo->lo_encrypt_key_size &&
            !uid_eq(lo->lo_key_owner, uid) &&
-           !capable(CAP_SYS_ADMIN))
-               return -EPERM;
-       if (lo->lo_state != Lo_bound)
-               return -ENXIO;
-       if ((unsigned int) info->lo_encrypt_key_size > LO_KEY_SIZE)
-               return -EINVAL;
+           !capable(CAP_SYS_ADMIN)) {
+               err = -EPERM;
+               goto out_unlock;
+       }
+       if (lo->lo_state != Lo_bound) {
+               err = -ENXIO;
+               goto out_unlock;
+       }
+       if ((unsigned int) info->lo_encrypt_key_size > LO_KEY_SIZE) {
+               err = -EINVAL;
+               goto out_unlock;
+       }
 
        /* I/O need to be drained during transfer transition */
        blk_mq_freeze_queue(lo->lo_queue);
 
        err = loop_release_xfer(lo);
        if (err)
-               goto exit;
+               goto out_unfreeze;
 
        if (info->lo_encrypt_type) {
                unsigned int type = info->lo_encrypt_type;
 
                if (type >= MAX_LO_CRYPT) {
                        err = -EINVAL;
-                       goto exit;
+                       goto out_unfreeze;
                }
                xfer = xfer_funcs[type];
                if (xfer == NULL) {
                        err = -EINVAL;
-                       goto exit;
+                       goto out_unfreeze;
                }
        } else
                xfer = NULL;
 
        err = loop_init_xfer(lo, xfer, info);
        if (err)
-               goto exit;
+               goto out_unfreeze;
 
        if (lo->lo_offset != info->lo_offset ||
            lo->lo_sizelimit != info->lo_sizelimit) {
                if (figure_loop_size(lo, info->lo_offset, info->lo_sizelimit)) {
                        err = -EFBIG;
-                       goto exit;
+                       goto out_unfreeze;
                }
        }
 
@@ -1212,7 +1221,7 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info)
        /* update dio if lo_offset or transfer is changed */
        __loop_update_dio(lo, lo->use_dio);
 
- exit:
+out_unfreeze:
        blk_mq_unfreeze_queue(lo->lo_queue);
 
        if (!err && (info->lo_flags & LO_FLAGS_PARTSCAN) &&
@@ -1221,6 +1230,8 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info)
                lo->lo_disk->flags &= ~GENHD_FL_NO_PART_SCAN;
                loop_reread_partitions(lo, lo->lo_device);
        }
+out_unlock:
+       mutex_unlock(&loop_ctl_mutex);
 
        return err;
 }
@@ -1467,12 +1478,8 @@ static int lo_ioctl(struct block_device *bdev, fmode_t mode,
        case LOOP_SET_STATUS:
                err = -EPERM;
                if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) {
-                       err = mutex_lock_killable_nested(&loop_ctl_mutex, 1);
-                       if (err)
-                               return err;
                        err = loop_set_status_old(lo,
                                        (struct loop_info __user *)arg);
-                       mutex_unlock(&loop_ctl_mutex);
                }
                break;
        case LOOP_GET_STATUS:
@@ -1480,12 +1487,8 @@ static int lo_ioctl(struct block_device *bdev, fmode_t mode,
        case LOOP_SET_STATUS64:
                err = -EPERM;
                if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) {
-                       err = mutex_lock_killable_nested(&loop_ctl_mutex, 1);
-                       if (err)
-                               return err;
                        err = loop_set_status64(lo,
                                        (struct loop_info64 __user *) arg);
-                       mutex_unlock(&loop_ctl_mutex);
                }
                break;
        case LOOP_GET_STATUS64:
@@ -1630,12 +1633,8 @@ static int lo_compat_ioctl(struct block_device *bdev, fmode_t mode,
 
        switch(cmd) {
        case LOOP_SET_STATUS:
-               err = mutex_lock_killable(&loop_ctl_mutex);
-               if (!err) {
-                       err = loop_set_status_compat(lo,
-                                                    (const struct compat_loop_info __user *)arg);
-                       mutex_unlock(&loop_ctl_mutex);
-               }
+               err = loop_set_status_compat(lo,
+                            (const struct compat_loop_info __user *)arg);
                break;
        case LOOP_GET_STATUS:
                err = loop_get_status_compat(lo,