TWIMC: this mail is primarily send for documentation purposes and for regzbot, my Linux kernel regression tracking bot. These mails usually contain '#forregzbot' in the subject, to make them easy to spot and filter. [TLDR: I'm adding this regression report to the list of tracked regressions; all text from me you find below is based on a few templates paragraphs you might have encountered already already in similar form.] Hi, this is your Linux kernel regression tracker. CCing the regression mailing list, as it should be in the loop for all regressions, as explained here: https://www.kernel.org/doc/html/latest/admin-guide/reporting-issues.html On 04.09.22 20:28, Mateusz Jończyk wrote: > Hello, > > On Linux 6.0.0-rc3, disconnecting a mounted pendrive with opened files causes these symptoms: > > - "task kworker/X blocked for more than Y seconds" warnings (see below) are repeatedly printed in dmesg, > - after reconnecting the pendrive (or possibly other USB devices), it is not detected, > - the login screen (Gnome on Ubuntu 20.04) freezes for some time (around 20s), due to a hang in colord-sane. > > These symptoms disappear after closing the opened files (and perhaps also directories) on the pendrive. > > I am aware that disconnecting a pendrive with a mounted filesystem is unwise, but many people do so > nonetheless. > > I have bisected this down to > commit 16728aaba62e ("scsi: core: Make sure that hosts outlive targets") > > With the previous > commit fe442604199e ("scsi: core: Make sure that targets outlive devices") > the problem does not happen. > > To reproduce: > > 1. Plug a pendrive into a USB port (checked with a pendrive formatted with a FAT32 filesystem). > 2. Mount it, open a file on this pendrive with the "less" command-line program. > 3. Optionally suspend the system to RAM. > 4. Disconnect the pendrive. > 5. Resume the system, if it was suspended. > > Warnings from dmesg: > > [ 76.212690] usb 1-3.4.3: USB disconnect, device number 6 > [ 76.219765] device offline error, dev sdc, sector 2049 op 0x1:(WRITE) flags 0x100000 phys_seg 1 prio class 2 > [ 76.219791] Buffer I/O error on dev sdc1, logical block 1, lost async page write > [ 242.764446] INFO: task kworker/0:7:1701 blocked for more than 120 seconds. > [ 242.764463] Tainted: G E 6.0.0-rc3mj6 #239 > [ 242.764470] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > [ 242.764474] task:kworker/0:7 state:D stack: 0 pid: 1701 ppid: 2 flags:0x00004000 > [ 242.764488] Workqueue: usb_hub_wq hub_event > [ 242.764504] Call Trace: > [ 242.764507] <TASK> > [ 242.764514] __schedule+0x2c5/0xcd0 > [ 242.764527] schedule+0x5d/0xf0 > [ 242.764535] scsi_remove_host+0x163/0x1b0 > [ 242.764547] ? var_wake_function+0x60/0x60 > [ 242.764559] usb_stor_disconnect+0x50/0xd0 [usb_storage] > [ 242.764571] usb_unbind_interface+0x8c/0x240 > [ 242.764581] device_remove+0x64/0x70 > [ 242.764590] device_release_driver_internal+0xd1/0x160 > [ 242.764599] device_release_driver+0x12/0x20 > [ 242.764608] bus_remove_device+0xde/0x150 > [ 242.764616] device_del+0x192/0x3e0 > [ 242.764621] ? usb_remove_ep_devs+0x1f/0x30 > [ 242.764632] usb_disable_device+0xab/0x240 > [ 242.764639] usb_disconnect+0xc7/0x260 > [ 242.764647] ? set_port_feature+0x37/0x40 > [ 242.764656] hub_event+0xeb0/0x17c0 > [ 242.764668] ? __schedule+0x2cd/0xcd0 > [ 242.764675] ? queue_rcu_work+0x2c/0x40 > [ 242.764684] process_one_work+0x21c/0x3c0 > [ 242.764693] worker_thread+0x4a/0x3b0 > [ 242.764703] ? process_one_work+0x3c0/0x3c0 > [ 242.764711] kthread+0xcf/0xf0 > [ 242.764719] ? kthread_complete_and_exit+0x20/0x20 > [ 242.764728] ret_from_fork+0x22/0x30 > [ 242.764737] </TASK> > > The kernel is tainted AFAIK because of the following: > > [ 0.442486] backlight: module verification failed: signature and/or required key missing - tainting kernel > [...] > [ 0.446462] Loading compiled-in X.509 certificates > [ 0.447431] Loaded X.509 cert 'Build time autogenerated kernel key: cbf6b5d58385db4124f3ddd5fa0457b112415dcb' > > The module was loaded before the signing keys were processed - which is an unrelated bug, present since a long time. > > > System information: > - Ubuntu 20.04 amd64, > - HP 17-by0001nw laptop, > - problem happens also when using an external USB 3.0 UNITEK hub. > > Greetings, > > Mateusz Jończyk > Thanks for the report. To be sure below issue doesn't fall through the cracks unnoticed, I'm adding it to regzbot, my Linux kernel regression tracking bot: #regzbot ^introduced 16728aaba62e #regzbot title scsi: core: Disconnecting pendrive with opened files suddenly causes trouble #regzbot ignore-activity This isn't a regression? This issue or a fix for it are already discussed somewhere else? It was fixed already? You want to clarify when the regression started to happen? Or point out I got the title or something else totally wrong? Then just reply -- ideally with also telling regzbot about it, as explained here: https://linux-regtracking.leemhuis.info/tracked-regression/ Reminder for developers: When fixing the issue, add 'Link:' tags pointing to the report (the mail this one replies to), as explained for in the Linux kernel's documentation; above webpage explains why this is important for tracked regressions. Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat) P.S.: As the Linux kernel's regression tracker I deal with a lot of reports and sometimes miss something important when writing mails like this. If that's the case here, don't hesitate to tell me in a public reply, it's in everyone's interest to set the public record straight.
