[ Copied. First sent to linux-hotplug ] Hi, I have a many identical looking USB drives in two btrfs multi-device configurations. I was unplugging and replugging a few devices to identify which physical device belonged to which btrfs filesystem. Running "btrfs fi show" during this unplugging/replugging business produced the BUG() stack trace shown below. "btrfs fi show" wouldn't return and neither would "fdisk -l". When I tried to reboot the computer, it panicked forcing me to do a hard reset. All hard disks are run-of-the-mill Seagate Expansion or Backup Plus drives. They all work fine (data and SMART) when kernel detects them at the start. I hit the BUG() twice during unplugging/replugging them randomly and I think it could've been when I swapped USB ports for identical drives (model/version etc.) If more lspci/lsusb information if needed, let me know. I should be able to reproduce it again and if needed insert printks and debug on mainline. # uname -a Linux godel 3.15.1-1-ARCH #1 SMP PREEMPT Tue Jun 17 09:32:20 CEST 2014 x86_64 GNU/Linux ------------[ cut here ]------------ kernel BUG at block/blk-tag.c:89! invalid opcode: 0000 [#1] PREEMPT SMP Modules linked in: bridge stp llc tun nct6775 hwmon_vid hid_microsoft uas usb_storage joydev hid_generic ir_lirc_codec mousedev lirc_dev ir_mce_kbd_decoder ir_sharp_decoder ir_sanyo_decoder ir_sony_decoder ir_jvc_decoder ir_rc6_decoder ir_rc5_decoder ir_nec_decoder rc_rc6_mce usbhid mceusb rc_core hid snd_hda_codec_hdmi coretemp hwmon x86_pkg_temp_thermal intel_powerclamp kvm_intel kvm iTCO_wdt iTCO_vendor_support ppdev mxm_wmi evdev mac_hid ext4 crc16 mbcache jbd2 crct10dif_pclmul crc32_pclmul ghash_clmulni_intel cryptd microcode snd_hda_codec_realtek i915 snd_hda_codec_generic psmouse serio_raw pcspkr snd_hda_intel snd_hda_controller drm_kms_helper drm snd_hda_codec snd_hwdep parport_pc i2c_i801 snd_pcm lpc_ich r8169 mii parport mei_me thermal fan wmi battery tpm_infineon tpm_tis tpm mei snd_timer video shpchp intel_gtt snd i2c_algo_bit button i2c_core soundcore processor btrfs xor atkbd libps2 c rc32c_intel ehci_pci ehci_hcd xhci_hcd usbcore usb_common raid6_pq i8042 serio sd_mod crc_t10dif crct10dif_common ahci libahci libata scsi_mod CPU: 0 PID: 821 Comm: systemd-udevd Not tainted 3.15.1-1-ARCH #1 Hardware name: MSI MS-7850/Z87-G41 PC Mate(MS-7850), BIOS V1.6 02/21/2014 task: ffff88020a369460 ti: ffff8801f4ff8000 task.ti: ffff8801f4ff8000 RIP: 0010:[<ffffffff8126b188>] [<ffffffff8126b188>] blk_free_tags+0x18/0x20 RSP: 0018:ffff8801f4ffbbb0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff8801f2845000 RCX: 0000000000340780 RDX: 0000000000000000 RSI: ffff880037d1a600 RDI: ffff8802112a3a00 RBP: ffff8801f4ffbbb0 R08: 000000000001b760 R09: ffff880214873800 R10: ffff88021fa1b760 R11: ffffea0000df4680 R12: ffff88020629f030 R13: ffff8800b65ca480 R14: ffff8801f28451a0 R15: ffff8800b65c4120 FS: 00007f4256c9f7c0(0000) GS:ffff88021fa00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2ba863e038 CR3: 00000001f4fe0000 CR4: 00000000000407f0 Stack: ffff8801f4ffbbd8 ffffffffa0003230 ffff8801f28451a0 ffff8801f2845190 ffff8800b65ca480 ffff8801f4ffbc00 ffffffff8138c552 ffff8801f28451d8 ffffffff8189e2c0 ffff8802106f8ac0 ffff8801f4ffbc30 ffffffff8129466a Call Trace: [<ffffffffa0003230>] scsi_host_dev_release+0xb0/0xf0 [scsi_mod] [<ffffffff8138c552>] device_release+0x32/0xa0 [<ffffffff8129466a>] kobject_release+0x7a/0x1c0 [<ffffffff812947dd>] kobject_put+0x2d/0x60 [<ffffffff8138c997>] put_device+0x17/0x20 [<ffffffffa000af7f>] scsi_target_dev_release+0x1f/0x30 [scsi_mod] [<ffffffff8138c552>] device_release+0x32/0xa0 [<ffffffff8129466a>] kobject_release+0x7a/0x1c0 [<ffffffff812947dd>] kobject_put+0x2d/0x60 [<ffffffff8138c997>] put_device+0x17/0x20 [<ffffffffa000e435>] scsi_device_dev_release_usercontext+0x195/0x1a0 [scsi_mod] [<ffffffff81085257>] execute_in_process_context+0x67/0x70 [<ffffffffa000e29c>] scsi_device_dev_release+0x1c/0x20 [scsi_mod] [<ffffffff8138c552>] device_release+0x32/0xa0 [<ffffffff8129466a>] kobject_release+0x7a/0x1c0 [<ffffffff812947dd>] kobject_put+0x2d/0x60 [<ffffffff8138c997>] put_device+0x17/0x20 [<ffffffffa000180a>] scsi_device_put+0x3a/0x50 [scsi_mod] [<ffffffffa00a4810>] scsi_disk_put+0x30/0x50 [sd_mod] [<ffffffffa00a5821>] sd_release+0x31/0x70 [sd_mod] [<ffffffff811ef642>] __blkdev_put+0x182/0x1c0 [<ffffffff811f000c>] blkdev_put+0x4c/0x150 [<ffffffff811f01c5>] blkdev_close+0x25/0x30 [<ffffffff811b609c>] __fput+0x9c/0x200 [<ffffffff811b624e>] ____fput+0xe/0x10 [<ffffffff8108a35f>] task_work_run+0x9f/0xe0 [<ffffffff81014c55>] do_notify_resume+0x95/0xa0 [<ffffffff81515be0>] int_signal+0x12/0x17 Code: c3 66 90 0f 0b 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 e8 82 ff ff ff 85 c0 74 0 6 5d c3 0f 1f 40 00 <0f> 0b 66 0f 1f 44 00 00 0f 1f 44 00 00 55 48 89 e5 53 48 89 fb RIP [<ffffffff8126b188>] blk_free_tags+0x18/0x20 RSP <ffff8801f4ffbbb0> ---[ end trace bc3cb23eb685d10a ]--- systemd-udevd[185]: worker [821] terminated by signal 11 (Segmentation fault) -- Saran -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
