On Wed, Dec 14, 2011 at 9:33 AM, Bryan Schumaker <bjschuma@xxxxxxxxxx> wrote: > On Wed Dec 14 09:07:44 2011, J. Bruce Fields wrote: >> On Wed, Dec 14, 2011 at 08:42:18AM -0500, Bryan Schumaker wrote: >>> On Tue Dec 13 17:12:09 2011, J. Bruce Fields wrote: >>>> On Tue, Dec 13, 2011 at 04:35:58PM -0500, bjschuma@xxxxxxxxxx wrote: >>>>> From: Bryan Schumaker <bjschuma@xxxxxxxxxx> >>>>> >>>>> unhash_delegation() will grab the recall lock before calling >>>>> list_del_init() in each of these places. This patch removes the >>>>> redundant calls. >>>> >>>> Looks right, thanks. (How did you happen across this?) >>> >>> I was looking over the fault injection stuff to see if I can figure out >>> where an occasional oops was coming from. It seems to happen when I >>> forget delegations, so I was looking at how other functions release >>> delegations to see if there was something I missed. The oops doesn't >>> happen often enough for me to know if this patch fixes it yet, though. >> >> Hm, OK. Could you post the oops? > > I don't see it in the logs on the server, but I'll keep looking. I'll > post it the next time I come across it. I'm not sure if this is the same oops, but I'm able to reproduce it consistently against Bruce's 3.2.0-rc1 tree with fault injection enabled. I use the windows client to read a file, then 'echo 0 > /sys/kernel/debug/nfsd/forget_delegations'. I just tested with the patch above, and was able to reproduce the same oops: [ 1200.251735] NFSD Fault Injection: forget_delegations (all) [ 1200.251830] general protection fault: 0000 [#1] SMP [ 1200.252450] CPU 1 [ 1200.252597] Modules linked in: [ 1200.253062] [ 1200.253256] Pid: 2004, comm: bash Not tainted 3.2.0-rc1+ #9 VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform [ 1200.254102] RIP: 0010:[<ffffffff811ae7f5>] [<ffffffff811ae7f5>] nfsd_process_n_delegations+0x3e/0xbe [ 1200.254746] RSP: 0018:ffff88003b579e08 EFLAGS: 00010287 [ 1200.255067] RAX: dead000000100100 RBX: 0000000000000000 RCX: 00000001802c002b [ 1200.255458] RDX: ffff88003d2d3328 RSI: ffffffff811aa49e RDI: ffff88003d2d3308 [ 1200.255842] RBP: ffff88003b579e58 R08: ffff88003b558000 R09: ffff88003d2d3480 [ 1200.256226] R10: ffff88003b68b750 R11: 0000000000000040 R12: dead0000001000f8 [ 1200.256610] R13: 0000000000000001 R14: 000000000000002b R15: 00000000000000d5 [ 1200.257029] FS: 00007fbad1d44700(0000) GS:ffff88003fa20000(0000) knlGS:0000000000000000 [ 1200.257512] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1200.257850] CR2: 00007fbad1d49000 CR3: 000000003b593000 CR4: 00000000000006e0 [ 1200.258272] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 1200.258693] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 1200.259083] Process bash (pid: 2004, threadinfo ffff88003b578000, task ffff88003cc3dfe0) [ 1200.259561] Stack: [ 1200.259768] ffffffff811aa49e ffff88003d2d3308 ffffffff81be1560 ffff88003d2d3328 [ 1200.260553] ffff88003b579e88 ffffffff81a2b6a0 0000000000000000 0000000000000002 [ 1200.261337] ffff88003d8c1550 ffff88003d8c1528 ffff88003b579e88 ffffffff811ae897 [ 1200.262121] Call Trace: [ 1200.262346] [<ffffffff811aa49e>] ? nfs4_put_delegation+0x55/0x55 [ 1200.262701] [<ffffffff811ae897>] nfsd_forget_delegations+0x22/0x40 [ 1200.263119] [<ffffffff8119d3e7>] nfsd_inject_set+0x3f/0x46 [ 1200.263470] [<ffffffff810fb878>] simple_attr_write+0x8a/0xb2 [ 1200.263818] [<ffffffff810e0949>] vfs_write+0xa7/0xfa [ 1200.264136] [<ffffffff810e0b41>] sys_write+0x45/0x69 [ 1200.264483] [<ffffffff81450f3b>] system_call_fastpath+0x16/0x1b [ 1200.264832] Code: 45 31 ed 41 54 53 48 89 fb 48 83 ec 28 49 63 c6 48 c1 e0 04 4c 8b a0 b0 12 be 81 48 05 b0 12 be 81 48 89 45 c0 49 83 ec 08 eb 57 [ 1200.270209] 8b 7c 24 28 49 8d 54 24 28 48 89 55 c8 48 83 ef 20 48 8b 47 [ 1200.272534] RIP [<ffffffff811ae7f5>] nfsd_process_n_delegations+0x3e/0xbe [ 1200.273007] RSP <ffff88003b579e08> [ 1200.273331] ---[ end trace 0071bb3837d120e2 ]--- > > - Bryan >> >> --b. > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
