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Description of problem:
I have 6 small swap partitions and one larger, lower-priority and never-used
excess swap logical volume on top of raid 5 physical volumes.  I had it
accidentally enabled with the same priority as the other swap partitions, so a
bit of it was used.  After fixing /etc/fstab, I ran swapoff -a, immediately
followed by swapon -a.  swapoff crashed and logged an error message to
/var/log/messages, but the machine kept on running.  This was not the first time
this happened to me, but it doesn't always happen.  At this time, I had a lot of
disk activity going on: pvmoving unrelated physical volumes around, and
resyncing also unrelated raid5 volumes.  I don't know whether this is related,
or whether it just happened by chance.  It's not 100% reproducible, unfortunately.

Version-Release number of selected component (if applicable):
kernel-2.4.20-18.9

How reproducible:
Sometimes

Steps to Reproduce:
1.Create a few swap partitions, as well as one logical volume atop of raid5
physical volumes, and enable them all with the same priority
2.Wait until you've got about 1MB used in each of them, not because of excess
memory demand, but rather only due to inactivity
3.swapoff -a
    

Actual Results:  Segmentation fault.

/var/log/messages says:
Jul  5 20:06:08 free kernel: Unable to handle kernel paging request at virtual
address 00003a04
Jul  5 20:06:08 free kernel:  printing eip:
Jul  5 20:06:08 free kernel: c0158791
Jul  5 20:06:08 free kernel: *pde = 00000000
Jul  5 20:06:08 free kernel: Oops: 0002
Jul  5 20:06:08 free kernel: binfmt_misc parport_pc lp parport nfs nfsd lockd
sunrpc sd_mod cipcb 8139too mii ipt_TCPMSS ipt_REJECT ipt_LOG ipt_state
iptable_nat ip_conntrack iptable_mang
Jul  5 20:06:08 free kernel: CPU:    0
Jul  5 20:06:08 free kernel: EIP:    0060:[<c0158791>]    Not tainted
Jul  5 20:06:08 free kernel: EFLAGS: 00010202
Jul  5 20:06:08 free kernel:
Jul  5 20:06:08 free kernel: EIP is at dput [kernel] 0x11 (2.4.20-18.9)
Jul  5 20:06:08 free kernel: eax: 00003a04   ebx: 00003a04   ecx: ffffffff  
edx: ffffffff
Jul  5 20:06:08 free kernel: esi: ffffffea   edi: 0804976e   ebp: dba5edc0  
esp: da29df64
Jul  5 20:06:08 free kernel: ds: 0068   es: 0068   ss: 0068
Jul  5 20:06:08 free kernel: Process swapoff (pid: 4884, stackpage=da29d000)
Jul  5 20:06:08 free kernel: Stack: 00000000 da29df7c da29df90 ffffffea c014f6f5
00003a04 00000000 c013e06f
Jul  5 20:06:08 free kernel:        da29df90 00000002 00000000 00003a04 00000000
00000000 3f074568 3f074568
Jul  5 20:06:08 free kernel:        3f074568 00001000 00000000 da29c000 0804b5d5
0804976e bfffe278 c010939f
Jul  5 20:06:08 free kernel: Call Trace:   [<c014f6f5>] path_release [kernel]
0x15 (0xda29df74))
Jul  5 20:06:08 free kernel: [<c013e06f>] sys_swapoff [kernel] 0x17f (0xda29df80))
Jul  5 20:06:08 free kernel: [<c010939f>] system_call [kernel] 0x33 (0xda29dfc0))
Jul  5 20:06:08 free kernel:
Jul  5 20:06:09 free kernel:
Jul  5 20:06:09 free kernel: Code: ff 0b 0f 94 c0 84 c0 0f 84 c6 00 00 00 8d 73
18 39 73 18 74


Expected Results:  No oops, successful completion of swapoff.

Additional info: