loop: Push loop_ctl_mutex down to loop_set_fd()

Push lo_ctl_mutex down to loop_set_fd(). We will need this to be able to
call loop_reread_partitions() without lo_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 af79a59732b7997816f670c57b15dd835d9aed9b..161e2a08f2e8dd59f70e4595017e0aae221eed17 100644 (file)
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -918,13 +918,17 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode,
        if (!file)
                goto out;
 
+       error = mutex_lock_killable_nested(&loop_ctl_mutex, 1);
+       if (error)
+               goto out_putf;
+
        error = -EBUSY;
        if (lo->lo_state != Lo_unbound)
-               goto out_putf;
+               goto out_unlock;
 
        error = loop_validate_file(file, bdev);
        if (error)
-               goto out_putf;
+               goto out_unlock;
 
        mapping = file->f_mapping;
        inode = mapping->host;
@@ -936,10 +940,10 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode,
        error = -EFBIG;
        size = get_loop_size(lo, file);
        if ((loff_t)(sector_t)size != size)
-               goto out_putf;
+               goto out_unlock;
        error = loop_prepare_queue(lo);
        if (error)
-               goto out_putf;
+               goto out_unlock;
 
        error = 0;
 
@@ -978,11 +982,14 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode,
         * put /dev/loopXX inode. Later in __loop_clr_fd() we bdput(bdev).
         */
        bdgrab(bdev);
+       mutex_unlock(&loop_ctl_mutex);
        return 0;
 
- out_putf:
+out_unlock:
+       mutex_unlock(&loop_ctl_mutex);
+out_putf:
        fput(file);
- out:
+out:
        /* This is safe: open() is still holding a reference. */
        module_put(THIS_MODULE);
        return error;
@@ -1460,12 +1467,7 @@ static int lo_ioctl(struct block_device *bdev, fmode_t mode,
 
        switch (cmd) {
        case LOOP_SET_FD:
-               err = mutex_lock_killable_nested(&loop_ctl_mutex, 1);
-               if (err)
-                       return err;
-               err = loop_set_fd(lo, mode, bdev, arg);
-               mutex_unlock(&loop_ctl_mutex);
-               break;
+               return loop_set_fd(lo, mode, bdev, arg);
        case LOOP_CHANGE_FD:
                err = mutex_lock_killable_nested(&loop_ctl_mutex, 1);
                if (err)