Bug 720231

Summary:	kernel BUG at fs/ext4/extents.c:1919!
Product:	Red Hat Enterprise Linux 6	Reporter:	Botu Sun <bosun>
Component:	kernel	Assignee:	Red Hat Kernel Manager <kernel-mgr>
Status:	CLOSED DUPLICATE	QA Contact:	Red Hat Kernel QE team <kernel-qe>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	6.1	CC:	eguan, esandeen, lczerner, qcai, rwheeler
Target Milestone:	rc
Target Release:	---
Hardware:	i686
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2011-10-12 17:05:00 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:

Comment 4 Qian Cai 2011-07-12 00:58:58 UTC

The real problem is that you hit a panic during xfstests.

kernel BUG at fs/ext4/extents.c:1919! 
invalid opcode: 0000 [#1] SMP  
last sysfs file: /sys/devices/virtual/block/loop0/dev 
Modules linked in: ext4 jbd2 nfs fscache(T) nfsd lockd nfs_acl auth_rpcgss exportfs sunrpc cpufreq_ondemand powernow_k8 ipv6 dm_mirror dm_region_hash dm_log bnx2 sg microcode serio_raw k10temp i2c_piix4 ext3 jbd mbcache dm_round_robin scsi_dh_rdac sd_mod crc_t10dif mptsas mptscsih mptbase scsi_transport_sas qla2xxx scsi_transport_fc scsi_tgt radeon ttm drm_kms_helper drm hwmon i2c_algo_bit i2c_core dm_multipath dm_mod [last unloaded: scsi_wait_scan] 
 
Pid: 11886, comm: fiemap-tester Tainted: G           ---------------- T (2.6.32-131.6.1.el6.i686 #1) BladeCenter LS22 -[79013SG]- 
EIP: 0060:[<fe4f190b>] EFLAGS: 00210212 CPU: 0 
EIP is at ext4_ext_walk_space+0x29b/0x2f0 [ext4] 
EAX: 00000000 EBX: 00000119 ECX: 0000008a EDX: 00000085 
ESI: edfb96c0 EDI: 00000001 EBP: ea5201bc ESP: dc147e88 
 DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 
Process fiemap-tester (pid: 11886, ti=dc146000 task=ee19d570 task.ti=dc146000) 
Stack: 
 ea5201bc dc147f68 00001000 dc147ed8 00000004 000000e8 00000000 e731bd64 
<0> 00000201 e731bd54 00000004 e731bcdc 00048cca 00000000 00000000 00000118 
<0> 000000e8 00000001 e731bd64 dc147f68 fffffee8 00000119 fe4f1aca fe4efac0 
Call Trace: 
 [<fe4f1aca>] ? ext4_fiemap+0x16a/0x1e0 [ext4] 
 [<fe4efac0>] ? ext4_ext_fiemap_cb+0x0/0x210 [ext4] 
 [<c05a4f72>] ? file_has_perm+0xd2/0xe0 
 [<c05380b5>] ? do_vfs_ioctl+0x505/0x5c0 
 [<c05381e6>] ? sys_ioctl+0x76/0x90 
 [<c04ad970>] ? __audit_syscall_exit+0x220/0x250 
 [<c0409bdf>] ? sysenter_do_call+0x12/0x28 
Code: e9 eb fe ff ff 8b 4c 24 1c bd fb ff ff ff c7 44 24 08 54 be 50 fe c7 04 24 26 4d 50 fe 89 4c 24 04 e8 0a 71 ff ff e9 c5 fe ff ff <0f> 0b eb fe 0f 0b eb fe 0f 0b 8d 74 26 00 8d bc 27 00 00 00 00  
EIP: [<fe4f190b>] ext4_ext_walk_space+0x29b/0x2f0 [ext4] SS:ESP 0068:dc147e88 

The second problem is that your kdump is misconfigured.

Saving to the local filesystem /dev/sdc2 
e2fsck 1.41.12 (17-May-2010) 
fsck.ext3: No such device or address while trying to open /dev/sdc2 
Possibly non-existent or swap device? 
mount: mounting /dev/sdc2 on /mnt failed: No such device or address 
Attempting to enter user-space to capture vmcore 

So, it then tried to enter user-space to capture vmcore which your system was running out of free memory from reserved 128MB at that time, but unfortunately oom won't work in kdump kernel.

Comment 5 Eric Sandeen 2011-09-28 14:53:50 UTC

The bug is in:

ext4_ext_walk_space()
{
...
        while (block < last && block != EXT_MAX_BLOCK) {
...
                BUG_ON(end <= start);


Given that this function is ONLY used for fiemap, BUG_ON is quite a terrible result - we should at least just fail the fiemap call with a message I suppose rather than taking down the box...

Comment 6 Eryu Guan 2011-10-10 14:45:27 UTC

The xfstests 225 panic issue should be a dup of bug 692063

Comment 7 Eric Sandeen 2011-10-12 17:05:00 UTC

Duping because the bug summary is identical to 692063.

Please open a new bug explicitly for the memory-related issues you mentioned; I'm not quite sure what the actual issue is there.

Thanks,
-Eric

*** This bug has been marked as a duplicate of bug 692063 ***