Public bug reported: Steps to reproduce: 1. Create RAID array (example for IMSM): mdadm -CR imsm -e imsm -n2 /dev/nvme[01]n1 mdadm -CR vol1 -l1 -n2 /dev/nvme[01]n1
2. Hot-remove one of the drive. 3. Insert drive back - recovery should start. 4. Reboot platform Expected: reboot is performed successfully. Recovery is continued. Actual: reboot hanged and call trace appeared. [ 776.416504] (sd-umoun[3359]: Failed to unmount /run/shutdown/mounts/bd36b757b23bbc6f: Device or resource busy [ 776.445568] shutdown[1]: Could not stop MD /dev/md126: Device or resource busy mdadm: Cannot get exclusive access to /dev/md126:Perhaps a running process, mounted filesystem or active volume group? mdadm: Cannot stop container /dev/md127: member md126 still active mdadm: Cannot get exclusive access to /dev/md126:Perhaps a running process, mounted filesystem or active volume group? mdadm: Cannot st[ 784.636276] (sd-exec-[3360]: /usr/lib/systemd/system- shutdown/mdadm.finalrd failed with exit status 1. op container /dev/md127: member [ 784.647309] shutdown[1]: Unable to finalize remaining file systems, MD devices, ignoring. md126 still active [ 986.549746] INFO: task shutdown:1 blocked for more than 122 seconds. [ 986.556158] Not tainted 6.8.0-31-generic #31-Ubuntu [ 986.561586] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 986.569440] task:shutdown state:D stack:0 pid:1 tgid:1 ppid:0 flags:0x00004002 [ 986.578769] Call Trace: [ 986.581236] <TASK> [ 986.583352] __schedule+0x27c/0x6b0 [ 986.586864] schedule+0x33/0x110 [ 986.590111] stop_sync_thread+0x135/0x1b0 [ 986.594143] ? __pfx_autoremove_wake_function+0x10/0x10 [ 986.599388] __md_stop_writes+0x19/0xf0 [ 986.603240] md_notify_reboot+0x93/0x160 [ 986.607186] notifier_call_chain+0x5e/0xe0 [ 986.611301] blocking_notifier_call_chain+0x41/0x70 [ 986.616201] kernel_restart+0x21/0xa0 [ 986.619881] __do_sys_reboot+0x156/0x250 [ 986.623824] __x64_sys_reboot+0x1b/0x30 [ 986.627680] x64_sys_call+0x223c/0x25c0 [ 986.631535] do_syscall_64+0x7f/0x180 [ 986.635218] ? irqentry_exit+0x43/0x50 [ 986.638990] ? exc_page_fault+0x94/0x1b0 [ 986.642932] entry_SYSCALL_64_after_hwframe+0x73/0x7b [ 986.648003] RIP: 0033:0x7da6531dea07 [ 986.651623] RSP: 002b:00007fff2babce18 EFLAGS: 00000246 ORIG_RAX: 00000000000000a9 [ 986.659211] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007da6531dea07 [ 986.666362] RDX: 0000000001234567 RSI: 0000000028121969 RDI: 00000000fee1dead [ 986.673509] RBP: 00007fff2babd050 R08: 0000000000000069 R09: 0000000000000000 [ 986.680662] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 986.687808] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000001234567 [ 986.694956] </TASK> [ 986.697665] Kernel panic - not syncing: hung_task: blocked tasks [ 986.703732] CPU: 0 PID: 982 Comm: khungtaskd Not tainted 6.8.0-31-generic #31-Ubuntu [ 986.711510] Hardware name: Intel Corporation WilsonCity/WilsonCity, BIOS WLYDCRB1.SYS.0020.P84.2103030140 03/03/2021 [ 986.722061] Call Trace: [ 986.724529] <TASK> [ 986.726639] dump_stack_lvl+0x48/0x70 [ 986.730326] dump_stack+0x10/0x20 [ 986.733661] panic+0x35f/0x3c0 [ 986.736738] check_hung_uninterruptible_tasks+0x279/0x320 [ 986.742157] ? __pfx_watchdog+0x10/0x10 [ 986.746011] watchdog+0xad/0xb0 [ 986.749164] kthread+0xef/0x120 [ 986.752317] ? __pfx_kthread+0x10/0x10 [ 986.756080] ret_from_fork+0x44/0x70 [ 986.760081] ? __pfx_kthread+0x10/0x10 [ 986.764201] ret_from_fork_asm+0x1b/0x30 [ 986.768473] </TASK> [ 986.771197] Kernel Offset: 0x1c00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) [ 986.913304] ---[ end Kernel panic - not syncing: hung_task: blocked tasks ]--- This issue is fixed in md. Please apply patch: https://github.com/torvalds/linux/commit/1ddeeb2a058d7b2a58ed9e820396b4ceb715d529 But customer also see other issue and reboot is delayed with this patch (not hanged). I cannot reproduce it on my platform, but I know that newer kernel (6.11-rc4) fixes his all issues. If possible rebase to the 6.11-rc4 (https://kernel.ubuntu.com/mainline/v6.11-rc4/ ) because there all of the customers issues are fixed. ** Affects: linux (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2079038 Title: [VROC] [Ub 24.04.0/1] Kernel bug and reboot hang during recovery - missing patch To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2079038/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs