Btrfs: fix sync subvol/snapshot creation

We were incorrectly taking the async path even for the sync ioctls by
passing in &transid unconditionally.

There's ample room for further cleanup here, but this keeps the fix simple.

Signed-off-by: Sage Weil <sage@newdream.net>
Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 11 insertions, 9 deletions

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index f1c9bb4079ed..7cc2e8e075b4 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -964,6 +964,15 @@ static noinline int btrfs_ioctl_snap_create(struct file *file,
                 name = async_vol_args->name;
                 fd = async_vol_args->fd;
                 async_vol_args->name[BTRFS_SNAPSHOT_NAME_MAX] = '\0';
+
+                ret = btrfs_ioctl_snap_create_transid(file, name, fd,
+                                                      subvol, &transid);
+
+                if (ret == 0 &&
+                    copy_to_user(arg +
+                                 offsetof(struct btrfs_ioctl_async_vol_args,
+                                          transid), &transid, sizeof(transid)))
+                        ret = -EFAULT;
         } else {
                 vol_args = memdup_user(arg, sizeof(*vol_args));
                 if (IS_ERR(vol_args))
@@ -971,16 +980,9 @@ static noinline int btrfs_ioctl_snap_create(struct file *file,
                 name = vol_args->name;
                 fd = vol_args->fd;
                 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
-        }
 
-        ret = btrfs_ioctl_snap_create_transid(file, name, fd,
-                                              subvol, &transid);
-
-        if (!ret && async) {
-                if (copy_to_user(arg +
-                                offsetof(struct btrfs_ioctl_async_vol_args,
-                                transid), &transid, sizeof(transid)))
-                        return -EFAULT;
+                ret = btrfs_ioctl_snap_create_transid(file, name, fd,
+                                                      subvol, NULL);
         }
 
         kfree(vol_args);