> Il giorno 11 gen 2018, alle ore 16:40, Jens Axboe <ax...@kernel.dk> ha > scritto: > > On 1/11/18 2:41 AM, Paolo Valente wrote: >> >> >>> Il giorno 11 gen 2018, alle ore 10:30, Paolo Valente >>> <paolo.vale...@linaro.org> ha scritto: >>> >>> >>> >>>> Il giorno 10 gen 2018, alle ore 05:58, Ming Lei <ming....@redhat.com> ha >>>> scritto: >>>> >>>> Hi Paolo, >>>> >>>> Looks this one is introduced in recent merge, and it is triggered >>>> in test of IO vs. removing device on the latest for-next of block >>>> tree: >>>> >>>> [ 296.151615] BUG: unable to handle kernel NULL pointer dereference at >>>> 0000000000000436 >>>> [ 296.152302] IP: percpu_counter_add_batch+0x25/0x9d >>>> [ 296.152698] PGD 0 P4D 0 >>>> [ 296.152916] Oops: 0000 [#1] PREEMPT SMP >>>> [ 296.153233] Dumping ftrace buffer: >>>> [ 296.153517] (ftrace buffer empty) >>>> [ 296.153817] Modules linked in: scsi_debug(E) null_blk(E) isofs(E) >>>> iTCO_wdt(E) iTCO_vendor_support(E) i2c_i801(E) i2c_core(E) lpc_ich(E) >>>> mfd_core(E) ip_tables(E) sr_mod(E) cdrom(E) sd_mod(E) usb_storage(E) >>>> ahci(E) libahci(E) libata(E) crc32c_intel(E) virtio_scsi(E) qemu_fw_cfg(E) >>>> dm_mirror(E) dm_region_hash(E) dm_log(E) dm_mod(E) [last unloaded: >>>> scsi_debug] >>>> [ 296.156199] CPU: 2 PID: 2001 Comm: scsi_id Tainted: G E >>>> 4.15.0-rc7790529290ab3_my_v4.15-rc-block-for-next #4 >>>> [ 296.156961] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS >>>> 1.9.3-1.fc25 04/01/2014 >>>> [ 296.157546] RIP: 0010:percpu_counter_add_batch+0x25/0x9d >>>> [ 296.157920] RSP: 0018:ffffc90001133b28 EFLAGS: 00010002 >>>> [ 296.158285] RAX: 0000000000000002 RBX: ffffffffffffff6e RCX: >>>> 0000000000000001 >>>> [ 296.158779] RDX: 000000003fffffff RSI: ffffffff81e95429 RDI: >>>> ffffffff81e5e64c >>>> [ 296.159276] RBP: 0000000000000416 R08: 0000000000000001 R09: >>>> 0000000000000001 >>>> [ 296.159770] R10: ffffc90001133aa0 R11: ffff88007e96caf0 R12: >>>> 000000003fffffff >>>> [ 296.160273] R13: 0000000000000001 R14: 0000000000000001 R15: >>>> ffffe8ffffd0b180 >>>> [ 296.160780] FS: 00007f635988af80(0000) GS:ffff88007cf00000(0000) >>>> knlGS:0000000000000000 >>>> [ 296.161325] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >>>> [ 296.161744] CR2: 0000000000000436 CR3: 00000000717f1005 CR4: >>>> 00000000003606e0 >>>> [ 296.162258] DR0: 0000000000000000 DR1: 0000000000000000 DR2: >>>> 0000000000000000 >>>> [ 296.162764] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: >>>> 0000000000000400 >>>> [ 296.163246] Call Trace: >>>> [ 296.163445] bfqg_stats_update_io_add+0x35/0xdc >>>> [ 296.163754] bfq_insert_requests+0xbb9/0xbf2 >>>> [ 296.164049] ? blk_rq_bio_prep+0x51/0x5d >>>> [ 296.164353] ? blk_rq_append_bio+0x32/0x78 >>>> [ 296.164633] ? blk_rq_map_user_iov+0x11b/0x1a0 >>>> [ 296.164940] blk_mq_sched_insert_request+0xaf/0x12f >>>> [ 296.165273] blk_execute_rq+0x4b/0x93 >>>> [ 296.165586] sg_io+0x236/0x38a >>>> [ 296.165800] scsi_cmd_ioctl+0x1d4/0x381 >>>> [ 296.166065] ? seccomp_run_filters+0xee/0x12d >>>> [ 296.166362] ? preempt_count_add+0x6d/0x8c >>>> [ 296.166643] sd_ioctl+0xbb/0xde [sd_mod] >>>> [ 296.166915] blkdev_ioctl+0x7f2/0x850 >>>> [ 296.167167] block_ioctl+0x39/0x3c >>>> [ 296.167401] vfs_ioctl+0x1b/0x28 >>>> [ 296.167622] do_vfs_ioctl+0x4bc/0x542 >>>> [ 296.167877] ? syscall_trace_enter+0x164/0x261 >>>> [ 296.168180] SyS_ioctl+0x3e/0x5a >>>> [ 296.168402] do_syscall_64+0x71/0x168 >>>> [ 296.168654] entry_SYSCALL64_slow_path+0x25/0x25 >>>> [ 296.168970] RIP: 0033:0x7f63593a1dc7 >>>> [ 296.169214] RSP: 002b:00007fff87210878 EFLAGS: 00000246 ORIG_RAX: >>>> 0000000000000010 >>>> [ 296.169823] RAX: ffffffffffffffda RBX: 00007fff872108b0 RCX: >>>> 00007f63593a1dc7 >>>> [ 296.170303] RDX: 00007fff872108b0 RSI: 0000000000002285 RDI: >>>> 0000000000000004 >>>> [ 296.170783] RBP: 00007fff87210f00 R08: 0000000000002006 R09: >>>> 00000000fffffe00 >>>> [ 296.171266] R10: 00007fff87210910 R11: 0000000000000246 R12: >>>> 00000000ffffffff >>>> [ 296.171745] R13: 00007fff872108b0 R14: 00007fff872108ba R15: >>>> 00007fff872112b0 >>>> [ 296.172228] Code: 5d 41 5c 41 5d c3 41 55 41 54 49 89 f5 55 53 48 89 fd >>>> bf 01 00 00 00 41 89 d4 e8 8c 19 d4 ff 48 c7 c7 29 54 e9 81 e8 fd 3d ff ff >>>> <48> 8b 45 20 49 63 d4 65 8b 18 48 63 db 4c 01 eb 48 39 d3 7d 0b >>>> [ 296.173594] RIP: percpu_counter_add_batch+0x25/0x9d RSP: >>>> ffffc90001133b28 >>>> [ 296.174054] CR2: 0000000000000436 >>>> [ 296.174283] ---[ end trace 87b58f9235daac7e ]--- >>>> [ 296.174673] Kernel panic - not syncing: Fatal exception >>>> [ 297.270432] Shutting down cpus with NMI >>>> [ 297.271020] Dumping ftrace buffer: >>>> [ 297.271262] (ftrace buffer empty) >>>> [ 297.271513] Kernel Offset: disabled >>>> [ 297.271760] ---[ end Kernel panic - not syncing: Fatal exception >>>> >>> >>> Well, then don't do it! :) >>> >>> Jokes aside, I've been trying to reproduce this failure, with a USB >>> drive, but at no avail. With a just-pulled for-next, after entering >>> >>> echo bfq | sudo tee /sys/block/sdc/queue/scheduler && sudo dd if=/dev/zero >>> of=/dev/sdc >>> >>> I've tried both a: >>> >>> echo 1 > /sys/block/sdc/device/delete >>> >>> and a physical unplug of the USB stick. >>> >> >> Just tried with reads from the USB drive too, and with an internal >> HDD. Same outcome: no failure. > > Are you regularly running blktests on bfq as part of your testing? If > not, you definitely should.
I will, thanks. I was using (only) xfstests. Paolo > There are some good torture removal tests > there. If that isn't what Ming is running, Ming should submit his > test to blktests so we can get better coverage. > > https://github.com/osandov/blktests > > -- > Jens Axboe
