bin/53515: [PATCH] libufs/getino() calculates inode offset wrong

[Lukas Ertl]

>Number:         53515
>Category:       bin
>Synopsis:       [PATCH] libufs/getino() calculates inode offset wrong
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Thu Jun 19 14:20:14 PDT 2003
>Closed-Date:
>Last-Modified:
>Originator:     Lukas Ertl
>Release:        FreeBSD 5.1-CURRENT i386
>Organization:
Vienna University Computer Center
>Environment:
System: FreeBSD leelou 5.1-CURRENT FreeBSD 5.1-CURRENT #0: Mon Jun 16 13:00:21 CEST 2003 le at leelou:/usr/obj/usr/src/sys/LEELOU i386


	
>Description:

I just spent a couple of hours debugging an app that uses libufs/getino()
until I recognized that the bug was not in the app but in libufs.

The problem arises as soon as you're trying to get inode number 128 (UFS1) 
or 64 (UFS2).

>How-To-Repeat:

Use getino() from libufs and try to get inode 128 from an UFS1 fs or inode 64
from an UFS2 fs.

>Fix:

I looked at the dump(8) sources which has a function getino() in 
src/sbin/dump/traverse.c. getino() from libufs is almost a verbatim copy
of that function, but has a typo: '&' instead of '%'.

--- inode.c.diff begins here ---
Index: lib/libufs/inode.c
===================================================================
RCS file: /hugo/bsdcvs/src/lib/libufs/inode.c,v
retrieving revision 1.5
diff -u -r1.5 inode.c
--- lib/libufs/inode.c	9 Jun 2003 09:32:29 -0000	1.5
+++ lib/libufs/inode.c	19 Jun 2003 20:54:28 -0000
@@ -74,7 +74,7 @@
 		goto gotit;
 	bread(disk, fsbtodb(fs, ino_to_fsba(fs, inode)), inoblock,
 	    fs->fs_bsize);
-	disk->d_inomin = min = inode - (inode & INOPB(fs));
+	disk->d_inomin = min = inode - (inode % INOPB(fs));
 	disk->d_inomax = max = min + INOPB(fs);
 gotit:	switch (disk->d_ufs) {
 	case 1:
--- inode.c.diff ends here ---


>Release-Note:
>Audit-Trail:
>Unformatted: