https://bugzilla.redhat.com/show_bug.cgi?id=1061339 It seems to happen when mke2fs issues an ioctl, looks like it might be related to TRIM/discard. This is under virtualization. The disk is backed by virtio-scsi. mke2fs -t ext2 -F -b 4096 /dev/VG/LV1 mke2fs 1.42.9 (28-Dec-2013) [ 44.142483] BUG: unable to handle kernel NULL pointer dereference at 0000000000000028 [ 44.142483] IP: [<ffffffff8122040a>] bio_trim+0x1a/0x40 [ 44.142483] PGD 1d193067 PUD 1d1c1067 PMD 0 [ 44.142483] Oops: 0000 [#1] SMP [ 44.142483] Modules linked in: raid1 kvm_amd snd_pcsp snd_pcm kvm snd_timer snd soundcore serio_raw ata_generic pata_acpi virtio_balloon virtio_pci virtio_mmio virtio_net virtio_scsi virtio_blk virtio_console virtio_rng virtio_ring virtio ideapad_laptop sparse_keymap rfkill sym53c8xx scsi_transport_spi crc8 crc_ccitt crc32 crc_itu_t libcrc32c megaraid megaraid_sas megaraid_mbox megaraid_mm [ 44.142483] CPU: 0 PID: 229 Comm: mke2fs Tainted: G W 3.14.0-0.rc1.git0.1.fc21.x86_64 #1 [ 44.142483] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 44.142483] task: ffff88001c100000 ti: ffff88001c0e4000 task.ti: ffff88001c0e4000 [ 44.142483] RIP: 0010:[<ffffffff8122040a>] [<ffffffff8122040a>] bio_trim+0x1a/0x40 [ 44.142483] RSP: 0018:ffff88001c0e5b88 EFLAGS: 00000246 [ 44.142483] RAX: ffff88001d13f020 RBX: 0000000000000000 RCX: 000000000000b690 [ 44.142483] RDX: 0000000000008000 RSI: 0000000000000000 RDI: 0000000000000000 [ 44.142483] RBP: ffff88001c0e5b98 R08: 00000000000174a0 R09: ffff88001f0174a0 [ 44.142483] R10: 0000000000000000 R11: ffffea0000744fc0 R12: 0000000001000000 [ 44.142483] R13: 0000000000000000 R14: ffff88001c0bfe80 R15: ffff88001d16df00 [ 44.142483] FS: 00007fe89c7817c0(0000) GS:ffff88001f000000(0000) knlGS:0000000000000000 [ 44.142483] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 44.142483] CR2: 0000000000000028 CR3: 000000001c0e7000 CR4: 00000000000006f0 [ 44.142483] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 44.142483] DR3: 0000000000000000 DR6: 0000000000000000 DR7: 0000000000000000 [ 44.142483] Stack: [ 44.142483] 0000000000000001 0000000000000000 ffff88001c0e5c80 ffffffffa01923f3 [ 44.142483] ffff88001c0e5c50 ffffc90000125040 0000000000008000 ffff88001d16df60 [ 44.142483] 0000000000003000 ffff88001c0e5c18 ffffffff00008000 0000000000000001 [ 44.142483] Call Trace: [ 44.142483] [<ffffffffa01923f3>] make_request+0x4c3/0xcd0 [raid1] [ 44.142483] [<ffffffff810c8ec6>] ? check_preempt_wakeup+0x166/0x250 [ 44.142483] [<ffffffff81555e85>] md_make_request+0xe5/0x230 [ 44.142483] [<ffffffff81326c20>] generic_make_request+0xe0/0x130 [ 44.142483] [<ffffffff81326ce8>] submit_bio+0x78/0x160 [ 44.142483] [<ffffffff81220bfe>] ? bio_alloc_bioset+0x1ce/0x2f0 [ 44.142483] [<ffffffff811fcc73>] ? pollwake+0x73/0x90 [ 44.142483] [<ffffffff8133243b>] blkdev_issue_discard+0x1fb/0x2c0 [ 44.142483] [<ffffffff81336da5>] blkdev_ioctl+0x635/0x7d0 [ 44.142483] [<ffffffff811e83a7>] ? do_sync_write+0x67/0xa0 [ 44.142483] [<ffffffff81222d11>] block_ioctl+0x41/0x50 [ 44.142483] [<ffffffff811fbf90>] do_vfs_ioctl+0x2e0/0x4a0 [ 44.142483] [<ffffffff811fc1f1>] SyS_ioctl+0xa1/0xc0 [ 44.142483] [<ffffffff816fbbe9>] system_call_fastpath+0x16/0x1b [ 44.142483] Code: 01 e9 75 ff ff ff 66 66 2e 0f 1f 84 00 00 00 00 00 66 66 66 66 90 55 48 89 e5 41 54 41 89 d4 41 c1 e4 09 85 f6 53 48 89 fb 75 06 <44> 3b 67 28 74 14 3e 80 63 10 f7 c1 e6 09 48 89 df e8 f0 fe ff [ 44.142483] RIP [<ffffffff8122040a>] bio_trim+0x1a/0x40 [ 44.142483] RSP <ffff88001c0e5b88> [ 44.142483] CR2: 0000000000000028 [ 44.144483] ---[ end trace f318ded04f590341 ]--- Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming blog: http://rwmj.wordpress.com Fedora now supports 80 OCaml packages (the OPEN alternative to F#) -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
