fs/ntfs3: fix deadlock in mark_as_free_ex

Reported-by: syzbot+e94d98936a0ed08bde43@syzkaller.appspotmail.com
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>

fs/ntfs3/fsntfs.c

@@ -2454,10 +2454,12 @@ void mark_as_free_ex(struct ntfs_sb_info *sbi, CLST lcn, CLST len, bool trim)
 {
 	CLST end, i, zone_len, zlen;
 	struct wnd_bitmap *wnd = &sbi->used.bitmap;
+	bool dirty = false;
 
 	down_write_nested(&wnd->rw_lock, BITMAP_MUTEX_CLUSTERS);
 	if (!wnd_is_used(wnd, lcn, len)) {
-		ntfs_set_state(sbi, NTFS_DIRTY_ERROR);
+		/* mark volume as dirty out of wnd->rw_lock */
+		dirty = true;
 
 		end = lcn + len;
 		len = 0;
@@ -2511,6 +2513,8 @@ void mark_as_free_ex(struct ntfs_sb_info *sbi, CLST lcn, CLST len, bool trim)
 
 out:
 	up_write(&wnd->rw_lock);
+	if (dirty)
+		ntfs_set_state(sbi, NTFS_DIRTY_ERROR);
 }
 
 /*