Bug 42823

Summary:	WARNING: at block/genhd.c:1465
Product:	IO/Storage	Reporter:	Maciej Rutecki (maciej.rutecki)
Component:	Block Layer	Assignee:	Jens Axboe (axboe)
Status:	CLOSED CODE_FIX
Severity:	normal	CC:	error27, florian, kernel, maciej.rutecki, rjw, stf_xl, tj
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:	3.3-rc4	Subsystem:
Regression:	Yes	Bisected commit-id:
Bug Depends on:
Bug Blocks:	42644

Description Maciej Rutecki 2012-02-26 10:31:33 UTC

Subject    : WARNING: at block/genhd.c:1465
Submitter  : Christian Kujau <lists@nerdbynature.de>
Date       : 2012-02-21 11:00
Message-ID : alpine.DEB.2.01.1202210246400.4930@trent.utfs.org
References : http://marc.info/?l=linux-kernel&m=132982259213941&w=2

This entry is being used for tracking a regression from 3.2. Please don't
close it until the problem is fixed in the mainline.

Comment 1 Christian Kujau 2012-03-04 21:12:44 UTC

The WARNING is still there with 3.3.0-rc5, see http://nerdbynature.de/bits/3.3.0-rc4/dmesg-rc5.txt. Full .config on: http://nerdbynature.de/bits/3.3.0-rc4/

Comment 2 Christian Kujau 2012-03-12 09:44:51 UTC

Still there with 3.3.0-rc7, see http://nerdbynature.de/bits/3.3.0-rc4/


[   12.943147] ------------[ cut here ]------------
[   12.944562] WARNING: at /usr/local/src/linux-2.6-git/block/genhd.c:1465
[   12.945927] Modules linked in: firewire_sbp2 i2c_powermac arc4 sd_mod b43 mac80211 cfg80211 usb_storage scsi_mod
[   12.947476] NIP: c02f97c4 LR: c02f9688 CTR: f20871f0
[   12.948891] REGS: ef9f3c60 TRAP: 0700   Not tainted  (3.3.0-rc7)
[   12.950296] MSR: 00021032 <ME,IR,DR,RI>  CR: 28042482  XER: 00000000
[   12.951774] TASK = ef937300[802] 'fsck' THREAD: ef9f2000
[   12.951821] GPR00: 00000001 ef9f3d10 ef937300 00009032 ffffffff c071ebb0 15300000 00000000 
[   12.953324] GPR08: 00000000 c0bf14ac c0976a34 0000000a 28042488 1001e828 00000000 00000830 
[   12.954856] GPR16: 0ffeb778 0ffeb760 0ffefeb4 0ffeb748 00000000 ffffffe9 0ffeb5e4 bf915fb0 
[   12.956413] GPR24: ef9f3d38 00000000 0000001d 00000000 eed5a000 eec06800 00009032 eec0680c 
[   12.959460] NIP [c02f97c4] __disk_unblock_events+0x174/0x18c
[   12.960938] LR [c02f9688] __disk_unblock_events+0x38/0x18c
[   12.962381] Call Trace:
[   12.963827] [ef9f3d10] [c02f9688] __disk_unblock_events+0x38/0x18c (unreliable)
[   12.965322] [ef9f3d30] [c010fc28] __blkdev_get+0x1e0/0x3dc
[   12.966778] [ef9f3d70] [c010fe88] blkdev_get+0x64/0x38c
[   12.968211] [ef9f3dd0] [c00d3220] __dentry_open+0x268/0x35c
[   12.969639] [ef9f3df0] [c00e62fc] do_last+0x140/0x78c
[   12.971068] [ef9f3e30] [c00e6a34] path_openat+0xec/0x410
[   12.972504] [ef9f3e90] [c00e6e78] do_filp_open+0x44/0xb0
[   12.973937] [ef9f3f10] [c00d2eac] do_sys_open+0x104/0x1e8
[   12.975379] [ef9f3f40] [c00127a0] ret_from_syscall+0x0/0x38
[   12.976802] --- Exception: c01 at 0xfef4d58
[   12.976805]     LR = 0xfef4d08
[   12.979612] Instruction dump:
[   12.981026] 8361000c 7c0803a6 83810010 83a10014 83c10018 83e1001c 38210020 4e800020 
[   12.982585] 3d20c0bf 392914ac 88090404 68000001 <0f000000> 2f800000 419eff10 38000001 
[   12.984162] ---[ end trace 9dd447525f1d4050 ]---

Comment 3 Dan Carpenter 2012-03-13 11:42:09 UTC

There is a patch for this:

http://marc.info/?l=linux-kernel&m=132993002617591&w=2
https://bugzilla.redhat.com/show_bug.cgi?id=752175

Comment 4 Christian Kujau 2012-03-17 03:58:42 UTC

Thanks, the patch from Stanislaw worked for me. With his patch applied, the WARNING during bootup is gone.

  Tested-by: Christian Kujau <lists@nerdbynature.de>

Comment 5 Florian Mickler 2012-03-20 20:47:12 UTC

Patch: http://marc.info/?l=linux-kernel&m=132993002617591&w=2

Comment 6 Stanislaw Gruszka 2012-03-21 14:44:56 UTC

Patch was already commited:

commit 9f53d2fe815b4011ff930a7b6db98385d45faa68
Author: Stanislaw Gruszka <sgruszka@redhat.com>
Date:   Fri Mar 2 10:43:28 2012 +0100

    block: fix __blkdev_get and add_disk race condition

Comment 7 Florian Mickler 2012-03-24 20:28:51 UTC

Which landed in Linux v3.3, nice.