Re: kern/40163: mv(1) cause WAPBL panic

[David Holland <dholland-bugs%netbsd.org@localhost>]

The following reply was made to PR kern/40163; it has been noted by GNATS.

From: David Holland <dholland-bugs%netbsd.org@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: kern-bug-people%netbsd.org@localhost, gnats-admin%netbsd.org@localhost,
        netbsd-bugs%netbsd.org@localhost, 
lloyd%must-have-coffee.gen.nz@localhost
Subject: Re: kern/40163: mv(1) cause WAPBL panic
Date: Sat, 13 Dec 2008 03:52:09 +0000

 On Sat, Dec 13, 2008 at 02:55:02AM +0000, Greg Oster wrote:
  >>> Typing "mv foo/foo ." causes a panic if the filesystem in question has log
  >> ging enabled.
  >>  
  >>  I am able to reproduce this on 5.0 also, note that foo/foo must be a 
  >>  directory and not a regular file.
  >  
  >  Ah! That is the key..
  > [...]
  >  345             if (newparent) {
  >  346                     vn_lock(fdvp, LK_EXCLUSIVE | LK_RETRY);
 
 Untested (I don't have any wapbl volumes on hand) patch:
 
 Index: ufs_wapbl.c
 ===================================================================
 RCS file: /cvsroot/src/sys/ufs/ufs/ufs_wapbl.c,v
 retrieving revision 1.3
 diff -u -p -r1.3 ufs_wapbl.c
 --- ufs_wapbl.c        8 Dec 2008 11:37:37 -0000       1.3
 +++ ufs_wapbl.c        13 Dec 2008 03:49:29 -0000
 @@ -343,6 +343,11 @@ wapbl_ufs_rename(void *v)
        fcnp->cn_flags &= ~(MODMASK | SAVESTART);
        fcnp->cn_flags |= LOCKPARENT | LOCKLEAF;
        if (newparent) {
 +              /* Check for the rename("foo/foo", "foo") case. */
 +              if (fdvp == tvp) {
 +                      error = doingdirectory ? ENOTEMPTY : ENOTDIR;
 +                      goto out;
 +              }
                vn_lock(fdvp, LK_EXCLUSIVE | LK_RETRY);
                if ((error = relookup(fdvp, &fvp, fcnp))) {
                        vput(fdvp);
 
 
 Also, someone should squint at this to make sure "out" is the right
 error exit path here.
 
 -- 
 David A. Holland
 dholland%netbsd.org@localhost