xfs: print buffer offsets when dumping corrupt buffers

djwong · djwong · commit bdec055bb9f2 · 2018-11-06T07:50:50.000-08:00
Use DUMP_PREFIX_OFFSET when printing hex dumps of corrupt buffers
because modern Linux now prints a 32-bit hash of our 64-bit pointer when
using DUMP_PREFIX_ADDRESS:

00000000b4bb4297: 00 00 00 00 00 00 00 00 3b ee 00 00 00 00 00 00  ........;.......
00000005ec77e26: 00 00 00 00 02 d0 5a 00 00 00 00 00 00 00 00 00  ......Z.........
000000015938018: 21 98 e8 b4 fd de 4c 07 bc ea 3c e5 ae b4 7c 48  !.....L...&lt;...|H

This is totally worthless for a sequential dump since we probably only
care about tracking the buffer offsets and afaik there's no way to
recover the actual pointer from the hashed value.

Signed-off-by: Darrick J. Wong &lt;darrick.wong@oracle.com&gt;
Reviewed-by: Dave Chinner &lt;dchinner@redhat.com&gt;
diff --git a/fs/xfs/xfs_message.c b/fs/xfs/xfs_message.c
@@ -107,5 +107,5 @@ assfail(char *expr, char *file, int line)
 void
 xfs_hex_dump(void *p, int length)
 {
-	print_hex_dump(KERN_ALERT, "", DUMP_PREFIX_ADDRESS, 16, 1, p, length, 1);
+	print_hex_dump(KERN_ALERT, "", DUMP_PREFIX_OFFSET, 16, 1, p, length, 1);
 }

Original file line number	Diff line number	Diff line change
`@@ -107,5 +107,5 @@ assfail(char expr, char file, int line)`
`107`	`107`	`void`
`108`	`108`	`xfs_hex_dump(void *p, int length)`
`109`	`109`	`{`
`110`		`- print_hex_dump(KERN_ALERT, "", DUMP_PREFIX_ADDRESS, 16, 1, p, length, 1);`
	`110`	`+ print_hex_dump(KERN_ALERT, "", DUMP_PREFIX_OFFSET, 16, 1, p, length, 1);`
`111`	`111`	`}`