With kernel CURRENT from feb., 19 2018 kernel crashes (panic) and goes into debug, when 1. Always - A connected memory stick shall be mounted i.e mount_msdosfs is executed for a memory stick 2. Sometimes on boot, when the kernel shows the messages for an integrated USB umass device (in this case a SD card reader connected via USB without inserted SD-card) it crashes Because of point 2 i assume this is a problem in the USB system and not of mount.
What's the panic? I've been working on some lock issues that my assert uncovered. Please try https://reviews.freebsd.org/D14456 if you can repeat this panic reliably.
1. Installed the patch for scsi_da from below link (D14456) --> Same behaviour 2. messages when crashing (hope no typo): ----------------------- # // plug in usb stick umass1 on uhub0 . umass1: SCSI over bulk-only; quirks=0x4000 umass1:2:1: Attached to scbus2 da1 at umass-sim1 bus 1 scbus 2 target 0 lun 0 da1: < 1100> Removable Direct Access SPC-2 SCSI device . da1: 40.000MB/s transfers . da1: quirks=0x2<NO_6_BYTE> # # mount_msdosfs /dev/da1 /mnt/dos panic: bq_remove: Remove buffer 0xfffffe0000e3ec40 from wrong queue cpuid=1 time=1520878478 KBD: stack backtrace: db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe00004a07a0 vpanic() at vpanic+0x18d/frame 0xfffffe00004a0800 vpanic() at vpanic/frame 0xfffffe00004a0800 bq_remove() at bq_remove+0x151/frame 0xfffffe00004a08a0 buf_recycle() at buf_recycle+0x1a6/frame 0xfffffe00004a0910 bufspace_demon() at bufspace_demon+0x9a/frame 0xfffffe00004a0970 fork_exit() at fork_exit+0x84/frame 0xfffffe00004a09b0 fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe00004a09b0 --- trap 0, rip = 0, rsp = 0, rbp = 0 --- KBD: enter: panic [thread pid 22 tid 1000072 ] Stopped at kbd_enter+0x3b: movq $0,kdb_why db> ------------------------------ // Added some debug printfs at various functions at head and at end for entering and leaving (only at the end of function) some functions // Before panic: ENTER dastart, LEAVE dastart, ENTER dadone, ENTER dastart, LEAVE dastart panic: ----------------------------- Might be of interest: Machine has microcode patches (for Meltdown / Spectre) in BIOS.
Bug does not show up with 12.0-ALPHA1 --> Closed