htree rename bug

<title>htree bug</title>
<h1>htree rename bug</h1>

<h2>Summary</h2>

<p>rename seems broken.  Under some circumstances, it seems that rename
within a directory doesn't complete properly, and leaves both the from
and to names in the directory (but leaves the inode with a refcount of 1).

<h2>Reproducing the bug</h2>

<p>You'll need these:
<ul>
<li><a href="genfs">genfs</a>
<li><a href="tickle.c.gz">tickle.c.gz</a>
</ul>

as well as e2fsprogs-1.30(-WIP).

<p> To do this:
<pre>
$ sh genfs

# mkdir m
# mount -o loop htree-bug.fs m

$ gcc -o tickle tickle.c
$ ./tickle m/test
*** rename("drivers/scsi/psi240i.h", "drivers/scsi/psi240i.h.orig") failure:
stating drivers/scsi/psi240i.h
  ino=294
  nlink=1
stating drivers/scsi/psi240i.h.orig
  ino=294
  nlink=1
*** rename("drivers/scsi/sun3_scsi.h", "drivers/scsi/sun3_scsi.h.orig") failure:
stating drivers/scsi/sun3_scsi.h
  ino=350
  nlink=1
stating drivers/scsi/sun3_scsi.h.orig
  ino=350
  nlink=1

# umount m

$ e2fsck -f htree-bug.fs
e2fsck 1.30-WIP (30-Sep-2002)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Inode 294 ref count is 1, should be 2.  Fix<y>? yes

Inode 350 ref count is 1, should be 2.  Fix<y>? yes

Pass 5: Checking group summary information

htree-bug.fs: ***** FILE SYSTEM WAS MODIFIED *****
htree-bug.fs: 541/10240 files (0.2% non-contiguous), 1369/10240 blocks
exit status 1
$ debugfs htree-bug.fs 
debugfs 1.30-WIP (30-Sep-2002)
debugfs:  ncheck 294
Inode   Pathname
294     /test/drivers/scsi/psi240i.h
debugfs:  ncheck 350
Inode   Pathname
350     /test/drivers/scsi/sun3_scsi.h

</pre>