xfs_repair: print superblock offsets and denial reasons

Eric has pointed out that verify_set_primary_sb() will either return 1 or XR_INSUFF_SEC_SB. Move the check lower into verify_set_primary_sb() by checking the return value of verify_sb(). Example output:

found candidate secondary superblock... verifying sb at 31249334272: bad magic number (1) verifying sb at 62498668544: bad magic number (1) verifying sb at 93748002816: bad magic number (1) verifying sb at 124997337088: bad magic number (1) unable to verify superblock, continuing...

Signed-off-by KELEMEN Peter <[email protected]>

Index: xfsprogs/repair/sb.c
===================================================================
RCS file: /cvs/xfs-cmds/xfsprogs/repair/sb.c,v
retrieving revision 1.22
diff -u -u -r1.22 sb.c

repair/sb.c +5 -1

@@ -683,6 +683,7 @@
 	int		num_ok;
 	int		retval;
 	int		round;
+	int		reason;	/* why the sb check failed */
 
 	/*
 	 * select the number of secondaries to try for

@@ -727,7 +728,7 @@
 				goto out;
 			}
 
-			if (verify_sb(sb, 0) == XR_OK)  {
+			if ((reason = verify_sb(sb, 0)) == XR_OK)  {
 				/*
 				 * save away geometry info.
 				 * don't bother checking the sb

@@ -740,6 +741,9 @@
 				get_sb_geometry(&geo, sb);
 				list = add_geo(list, &geo, agno);
 				num_ok++;
+			} else {
+				do_warn("verifying sb at %Lu: %s (%d)\n",
+					off, err_string(reason), reason);
 			}
 		}
 	}

Quoted 5 lines · KELEMEN Peter

Eric has pointed out that verify_set_primary_sb() will either return 1 or XR_INSUFF_SEC_SB. Move the check lower into verify_set_primary_sb() by checking the return value of verify_sb(). Example output:

Quoted 7 lines

found candidate secondary superblock... verifying sb at 31249334272: bad magic number (1) verifying sb at 62498668544: bad magic number (1) verifying sb at 93748002816: bad magic number (1) verifying sb at 124997337088: bad magic number (1) unable to verify superblock, continuing...

This looks better :) You may want to add even more info...

while it's just searching block by block, if it finds a candidate, I'd print the sector offset for that candidate (your first output line).

And rather than "verifying sb at..." you might do something like "comparing to sb N at offset X":

Quoted 5 lines · KELEMEN Peter

Eric has pointed out that verify_set_primary_sb() will either return 1 or XR_INSUFF_SEC_SB. Move the check lower into verify_set_primary_sb() by checking the return value of verify_sb(). Example output:

Quoted 7 lines

found candidate secondary superblock... verifying sb at 31249334272: bad magic number (1) verifying sb at 62498668544: bad magic number (1) verifying sb at 93748002816: bad magic number (1) verifying sb at 124997337088: bad magic number (1) unable to verify superblock, continuing...

This looks better :) You may want to add even more info...

while it's just searching block by block, if it finds a candidate, I'd print the sector offset for that candidate (your first output line).

And rather than "verifying sb at..." you might do something like "comparing to sb N at offset X":

(quoted diff) +3 -0

+	} else {
+		do_warn("comparing with sb %d at sector %Lu failed: %s (%d)\n",
+			agno, off, err_string(reason), reason);

because at this point it's using the geometry of the candidate sb to see if it can be used to find enough other valid sb's....