Fix coverity defects

coverity scan CID:147504 Type: Explicit null dereferenced
Reason: passing null pointer dl to zfs_dirent_unlock

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: BearBabyLiu <liu.huang@zte.com.cn>
Closes #5131

diff --git a/module/zfs/zfs_vnops.c b/module/zfs/zfs_vnops.c
index 405b37c1925d6e555b9365ea9aa9794e199bf45d..796cd1e342c4788508c2502503074127392427fe 100644 (file)
--- a/module/zfs/zfs_vnops.c
+++ b/module/zfs/zfs_vnops.c
@@ -1470,8 +1470,10 @@ top:
                if (S_ISREG(ZTOI(zp)->i_mode) &&
                    (vap->va_mask & ATTR_SIZE) && (vap->va_size == 0)) {
                        /* we can't hold any locks when calling zfs_freesp() */
-                       zfs_dirent_unlock(dl);
-                       dl = NULL;
+                       if (dl) {
+                               zfs_dirent_unlock(dl);
+                               dl = NULL;
+                       }
                        error = zfs_freesp(zp, 0, 0, mode, TRUE);
                }
        }