[LU-7577] 'lfs migrate -m1 d0/..' oopses MDT

• Type: Bug
• Resolution: Fixed
• Priority: Critical
• Fix Version/s: Lustre 2.8.0
• Affects Version/s: Lustre 2.8.0
• Severity: 3
• Assignee: Di Wang
• Reporter: John Hammond

Description

# export MDSCOUNT=4
# llmount.sh
...
# cd /mnt/lusstre
# mkdir d0
# lfs migrate -m1 d0/..

[  196.573755] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
[  196.574465] IP: [<ffffffffa131eade>] mdd_links_write+0x2e/0x2e0 [mdd]
[  196.574465] PGD 42c9b067 PUD 42c9a067 PMD 0 
[  196.574465] Oops: 0000 [#1] SMP 
[  196.574465] last sysfs file: /sys/devices/system/cpu/possible
[  196.574465] CPU 1 
[  196.574465] Modules linked in: lustre(U) ofd(U) osp(U) lod(U) ost(U) mdt(U) mdd(U) mgs(U) osd_ldiskfs(U) ldiskfs(U) exportfs lquota(U) lfsck(U) jbd obdecho(U) mgc(U) lov(U) osc(U) mdc(U) lmv(U) fid(U) fld(U) ptlrpc_gss(U) ptlrpc(U) obdclass(U) ksocklnd(U) lnet(U) sha512_generic sha256_generic libcfs(U) autofs4 nfs lockd fscache auth_rpcgss nfs_acl sunrpc ipv6 zfs(U) zcommon(U) znvpair(U) spl(U) zlib_deflate zavl(U) zunicode(U) microcode virtio_balloon virtio_net i2c_piix4 i2c_core ext4 jbd2 mbcache virtio_blk virtio_pci virtio_ring virtio pata_acpi ata_generic ata_piix dm_mirror dm_region_hash dm_log dm_mod [last unloaded: speedstep_lib]
[  196.574465] 
[  196.574465] Pid: 4093, comm: mdt00_002 Tainted: G        W  ---------------    2.6.32-431.29.2.el6.lustre.x86_64 #1 Bochs Bochs
[  196.574465] RIP: 0010:[<ffffffffa131eade>]  [<ffffffffa131eade>] mdd_links_write+0x2e/0x2e0 [mdd]
[  196.574465] RSP: 0018:ffff880065ca7890  EFLAGS: 00010286
[  196.574465] RAX: 0000000000000000 RBX: ffff880051636d00 RCX: ffff8800515c7930
[  196.574465] RDX: ffff880065ca90f0 RSI: ffff880051636d00 RDI: ffff88006e348a30
[  196.574465] RBP: ffff880065ca78d0 R08: ffff8800515c7930 R09: 0000000000000000
[  196.574465] R10: 0000000000000060 R11: ffff880065ca7690 R12: ffff88006e348a30
[  196.574465] R13: ffff8800515c7930 R14: ffff88006e348a30 R15: ffff88005da9d928
[  196.574465] FS:  0000000000000000(0000) GS:ffff88000d400000(0000) knlGS:0000000000000000
[  196.574465] CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
[  196.574465] CR2: 0000000000000008 CR3: 00000000420ac000 CR4: 00000000000006e0
[  196.574465] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  196.574465] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[  196.574465] Process mdt00_002 (pid: 4093, threadinfo ffff880065ca6000, task ffff880065ca4380)
[  196.574465] Stack:
[  196.574465]  0000000000000000 ffff880065ca8e90 ffff88006e348a30 ffff880065ca8fc0
[  196.574465] <d> 0000000000000000 ffff880065ca8e90 ffff88006e348a30 ffff88005da9d928
[  196.574465] <d> ffff880065ca79a0 ffffffffa132ad51 0000000000000000 ffff880065ca90c8
[  196.574465] Call Trace:
[  196.574465]  [<ffffffffa132ad51>] mdd_migrate_create+0xa81/0xc00 [mdd]
[  196.574465]  [<ffffffffa131e428>] ? mdd_may_create+0x1f8/0x370 [mdd]
[  196.574465]  [<ffffffffa132c881>] mdd_migrate+0x6d1/0x15e0 [mdd]
[  196.574465]  [<ffffffffa12a6bcb>] ? osd_object_read_unlock+0x8b/0xd0 [osd_ldiskfs]
[  196.574465]  [<ffffffffa1432288>] ? lod_object_read_unlock+0x38/0xd0 [lod]
[  196.574465]  [<ffffffffa0ac9bf6>] ? lu_object_find+0x16/0x20 [obdclass]
[  196.574465]  [<ffffffffa1390542>] mdt_reint_migrate_internal+0x1e02/0x2370 [mdt]
[  196.574465]  [<ffffffffa0c9e51d>] ? ldlm_lock_enqueue+0x2cd/0x870 [ptlrpc]
[  196.574465]  [<ffffffffa0cbe810>] ? ldlm_completion_ast+0x0/0x9b0 [ptlrpc]
[  196.574465]  [<ffffffffa0cbcec0>] ? ldlm_blocking_ast+0x0/0x180 [ptlrpc]
[  196.574465]  [<ffffffffa13942b3>] mdt_reint_rename_or_migrate+0x253/0x7e0 [mdt]
[  196.574465]  [<ffffffffa0cbcec0>] ? ldlm_blocking_ast+0x0/0x180 [ptlrpc]
[  196.574465]  [<ffffffffa0cbe810>] ? ldlm_completion_ast+0x0/0x9b0 [ptlrpc]
[  196.574465]  [<ffffffffa1388cd2>] ? ucred_set_jobid+0x62/0x70 [mdt]
[  196.574465]  [<ffffffffa1394850>] mdt_reint_migrate+0x10/0x20 [mdt]
[  196.574465]  [<ffffffffa138c98d>] mdt_reint_rec+0x5d/0x200 [mdt]
[  196.574465]  [<ffffffffa1375cf3>] mdt_reint_internal+0x633/0xa50 [mdt]
[  196.574465]  [<ffffffffa13765ab>] mdt_reint+0x6b/0x120 [mdt]
[  196.574465]  [<ffffffffa0d538f7>] tgt_request_handle+0x907/0x14a0 [ptlrpc]
[  196.574465]  [<ffffffffa0cfdd7a>] ptlrpc_main+0xdaa/0x18b0 [ptlrpc]
[  196.574465]  [<ffffffffa0cfcfd0>] ? ptlrpc_main+0x0/0x18b0 [ptlrpc]
[  196.574465]  [<ffffffff8109e856>] kthread+0x96/0xa0
[  196.574465]  [<ffffffff8100c30a>] child_rip+0xa/0x20
[  196.574465]  [<ffffffff8100bb10>] ? restore_args+0x0/0x30
[  196.574465]  [<ffffffff8109e7c0>] ? kthread+0x0/0xa0
[  196.574465]  [<ffffffff8100c300>] ? child_rip+0x0/0x20