OpenZFS 7900 - zdb shouldn't print the path of a znode at verbosity < 5

Authored by: Alan Somers <[email protected]>
Approved by: Dan McDonald <[email protected]>
Reviewed by: Paul Dagnelie <[email protected]>
Reviewed by: Matt Ahrens <[email protected]>
Reviewed-by: Brian Behlendorf <[email protected]>
Ported-by: Giuseppe Di Natale <[email protected]>

There are two reasons:
1) Finding a znode's path is slower than printing any other znode
   information at verbosity < 5.
2) On a corrupted pool like the one mentioned below, zdb will crash when it
   tries to determine the znode's path. But with this patch, zdb can still
   extract useful information from such pools.

OpenZFS-issue: https://www.illumos.org/issues/7900
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/2b0dee1
Closes #6016

1 files changed, 8 insertions, 12 deletions

diff --git a/cmd/zdb/zdb.c b/cmd/zdb/zdb.c
index 13d0bcf0e..e8672c836 100644
--- a/cmd/zdb/zdb.c
+++ b/cmd/zdb/zdb.c
@@ -1824,23 +1824,19 @@ dump_znode(objset_t *os, uint64_t object, void *data, size_t size)
 		return;
 	}
 
-	error = zfs_obj_to_path(os, object, path, sizeof (path));
-	if (error != 0) {
-		(void) snprintf(path, sizeof (path), "\?\?\?<object#%llu>",
-		    (u_longlong_t)object);
-	}
-	if (dump_opt['d'] < 3) {
-		(void) printf("\t%s\n", path);
-		(void) sa_handle_destroy(hdl);
-		return;
-	}
-
 	z_crtime = (time_t)crtm[0];
 	z_atime = (time_t)acctm[0];
 	z_mtime = (time_t)modtm[0];
 	z_ctime = (time_t)chgtm[0];
 
-	(void) printf("\tpath	%s\n", path);
+	if (dump_opt['d'] > 4) {
+		error = zfs_obj_to_path(os, object, path, sizeof (path));
+		if (error != 0) {
+			(void) snprintf(path, sizeof (path),
+			    "\?\?\?<object#%llu>", (u_longlong_t)object);
+		}
+		(void) printf("\tpath	%s\n", path);
+	}
 	dump_uidgid(os, uid, gid);
 	(void) printf("\tatime	%s", ctime(&z_atime));
 	(void) printf("\tmtime	%s", ctime(&z_mtime));