ddb: do not assume that ffs is mounted with softdep

Avoid a panic when debugging with "show ffs" in ddb.

Reviewed By:	kib, markj, mckusick
MFC after:	1 week
Sponsored by:	Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D31622

(cherry picked from commit 3b29c8b4bdb0e396d7bb5d0760f11d7fa4208c84)

diff --git a/sys/ufs/ffs/ffs_softdep.c b/sys/ufs/ffs/ffs_softdep.c
index 37709b605fbd365267b5c77a719e6b0698948064..d8b143d9d816002c99033e75fd6121e74b63a322 100644 (file)
--- a/sys/ufs/ffs/ffs_softdep.c
+++ b/sys/ufs/ffs/ffs_softdep.c
@@ -15006,9 +15006,15 @@ db_print_ffs(struct ufsmount *ump)
 {
        db_printf("mp %p (%s) devvp %p\n", ump->um_mountp,
            ump->um_mountp->mnt_stat.f_mntonname, ump->um_devvp);
-       db_printf("    fs %p su_wl %d su_deps %d su_req %d\n",
-           ump->um_fs, ump->softdep_on_worklist,
-           ump->softdep_deps, ump->softdep_req);
+       db_printf("    fs %p ", ump->um_fs);
+
+       if (ump->um_softdep != NULL) {
+               db_printf("su_wl %d su_deps %d su_req %d\n",
+                   ump->softdep_on_worklist, ump->softdep_deps,
+                   ump->softdep_req);
+       } else {
+               db_printf("su disabled\n");
+       }
 }
 
 static void