Re: [czhong@xxxxxxxxxx: [bug report] WARNING: CPU: 121 PID: 93233 at fs/dcache.c:365 __dentry_kill+0x214/0x278]

[Ming Lei]

On Wed, Aug 23, 2023 at 4:47 PM Christian Brauner <brauner@xxxxxxxxxx> wrote:
>
> On Wed, Aug 23, 2023 at 12:06:14PM +0800, Ming Lei wrote:
> >
> > Looks the issue is more related with vfs, so forward to vfs list.
> >
> > ----- Forwarded message from Changhui Zhong <czhong@xxxxxxxxxx> -----
> >
> > Date: Wed, 23 Aug 2023 11:17:55 +0800
> > From: Changhui Zhong <czhong@xxxxxxxxxx>
> > To: linux-scsi@xxxxxxxxxxxxxxx
> > Cc: Ming Lei <ming.lei@xxxxxxxxxx>
> > Subject: [bug report] WARNING: CPU: 121 PID: 93233 at fs/dcache.c:365 __dentry_kill+0x214/0x278
> >
> > Hello,
> >
> > triggered below warning issue with branch
> > "
> > Tree: mainline.kernel.org-clang
> > Repository: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> > @ master
> > Commit Hash: 89bf6209cad66214d3774dac86b6bbf2aec6a30d
> > Commit Name: v6.5-rc7-18-g89bf6209cad6
> > Kernel information:
> > Commit message: Merge tag 'devicetree-fixes-for-6.5-2' of
> > git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux
> > "
> > for more detail，please check
> > https://datawarehouse.cki-project.org/kcidb/tests/9232643
> >
> > #modprobe scsi_debug virtual_gb=128
> > #echo none > /sys/block/sdb/queue/scheduler
> > #fio --bs=4k --ioengine=libaio --iodepth=1 --numjobs=4 --rw=randrw
> > --name=sdb-libaio-randrw-4k --filename=/dev/sdb --direct=1 --size=60G
> > --runtime=60
>
> Looking at this issue it seems unlikely that this is a vfs bug.
> We should see this all over the place and specifically not just on arm64.
>
> The sequence here seems to be:
>
> echo 4 > /proc/sys/vm/drop_caches
> rmmod scsi_debug > /dev/null 3>&1
>
> [ 3117.059778] WARNING: CPU: 121 PID: 93233 at fs/dcache.c:365 __dentry_kill+0x214/0x278
> [ 3117.067601] Modules linked in: scsi_debug nvme nvme_core nvme_common null_blk pktcdvd ipmi_watchdog ipmi_poweroff rfkill sunrpc vfat fat acpi_ipmi ipmi_ssif arm_spe_pmu igb ipmi_devintf ipmi_msghandler arm_cmn arm_dmc620_pmu cppc_cpufreq arm_dsu_pmu acpi_tad loop fuse zram xfs crct10dif_ce polyval_ce polyval_generic ghash_ce sbsa_gwdt ast onboard_usb_hub i2c_algo_bit xgene_hwmon [last unloaded: scsi_debug]
>
> So my money is on some device that gets removed still having an
> increased refcount and pinning the dentry. Immediate suspects would be:
>
> 7882541ca06d ("of/platform: increase refcount of fwnode")
>
> but that part is complete speculation on my part.

BTW, just saw another panic on 6.5-rc7, still scsi_debug test on arm64:

[  959.371726] sr 50:0:0:0: Attached scsi generic sg1 type 5
[  959.603145] scsi 48:0:0:0: CD-ROM            Linux    scsi_debug
   0191 PQ: 0 ANSI: 7
[  959.603155] scsi 50:0:0:0: CD-ROM            Linux    scsi_debug
   0191 PQ: 0 ANSI: 7
[  959.603950] scsi 49:0:0:0: CD-ROM            Linux    scsi_debug
   0191 PQ: 0 ANSI: 7
[  959.604052] scsi 49:0:0:0: Power-on or device reset occurred
[  959.609336] sr 49:0:0:0: [sr1] scsi-1 drive
[  959.611360] scsi 48:0:0:0: Power-on or device reset occurred
[  959.614540] Unable to handle kernel paging request at virtual
address 65888c2e6fe694d5
[  959.614544] Mem abort info:
[  959.614545]   ESR = 0x0000000096000004
[  959.614547]   EC = 0x25: DABT (current EL), IL = 32 bits
[  959.614550]   SET = 0, FnV = 0
[  959.614552]   EA = 0, S1PTW = 0
[  959.614553]   FSC = 0x04: level 0 translation fault
[  959.614555] Data abort info:
[  959.614556]   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
[  959.614559]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[  959.614561]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[  959.614563] [65888c2e6fe694d5] address between user and kernel address ranges
[  959.614566] Internal error: Oops: 0000000096000004 [#1] SMP
[  959.614570] Modules linked in: pktcdvd scsi_debug ipmi_watchdog
ipmi_poweroff rfkill sunrpc vfat fat acpi_ipmi ipmi_ssif arm_spe_pmu
igb ipmi_devintf arm_cmn ipmi_msghandler arm_dmc620_pmu arm_dsu_pmu
cppc_cpufreq acpi_tad loop fuse zram xfs nvme crct10dif_ce polyval_ce
nvme_core polyval_generic ghash_ce sbsa_gwdt nvme_common ast
onboard_usb_hub i2c_algo_bit xgene_hwmon [last unloaded: scsi_debug]
[  959.614620] CPU: 108 PID: 19529 Comm: check Not tainted 6.5.0-rc7 #1
[  959.614625] Hardware name: GIGABYTE R152-P31-00/MP32-AR1-00, BIOS
F31n (SCP: 2.10.20220810) 09/30/2022
[  959.614627] pstate: 80400009 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[  959.614632] pc : d_alloc_parallel+0x140/0x440
[  959.614641] lr : d_alloc_parallel+0xcc/0x440
[  959.614646] sp : ffff80008a7d3290
[  959.614647] x29: ffff80008a7d3290 x28: ffff07ff8230c530 x27: 65888c2e6fe69565
[  959.614654] x26: ffffcb72eac9e1d0 x25: ffff80008a7d33d8 x24: ffff07ffa0fd3800
[  959.614659] x23: 00000000000003c0 x22: 000000007a701548 x21: ffffcb72eac9ffd0
[  959.614664] x20: ffff07ffa0fd35c0 x19: ffffcb72ea6e9600 x18: ffffffffffffffff
[  959.614670] x17: 00000000440fd8e0 x16: 00000000b6431329 x15: ffff80008a7d3360
[  959.614675] x14: ffff80008a7d3508 x13: ffffcb72e94da6d0 x12: ffff80008a7d334c
[  959.614680] x11: 0000000c7a701548 x10: ffff3c8cb54590b8 x9 : ffffcb72e80832f4
[  959.614685] x8 : ffff07ffa0fd35c0 x7 : 7473696c5f71725f x6 : 0000000000200008
[  959.614690] x5 : ffffcb72ea6f4000 x4 : 00000000003d380a x3 : 0000000000000004
[  959.614696] x2 : ffff80008a7d331c x1 : ffff07ffe1760000 x0 : 0000000000005000
[  959.614701] Call trace:
[  959.614703]  d_alloc_parallel+0x140/0x440
[  959.614708]  __lookup_slow+0x64/0x158
[  959.614714]  lookup_one_len+0xac/0xc8
[  959.614719]  start_creating.part.0+0x88/0x198
[  959.614725]  __debugfs_create_file+0x70/0x230
[  959.614730]  debugfs_create_file+0x34/0x48
[  959.614734]  blk_mq_debugfs_register_hctx+0x154/0x1d0
[  959.614740]  blk_mq_debugfs_register+0xfc/0x1e0
[  959.614745]  blk_register_queue+0xc0/0x1f0
[  959.614750]  device_add_disk+0x1dc/0x3e0
[  959.614754]  sr_probe+0x2c0/0x368
[  959.614760]  really_probe+0x190/0x3d8
[  959.614766]  __driver_probe_device+0x84/0x180
[  959.614771]  driver_probe_device+0x44/0x120
[  959.614776]  __device_attach_driver+0xc4/0x168
[  959.614781]  bus_for_each_drv+0x8c/0xf0
[  959.614785]  __device_attach+0xa4/0x1c0
[  959.614790]  device_initial_probe+0x1c/0x30
[  959.614795]  bus_probe_device+0xb4/0xc0
[  959.614799]  device_add+0x508/0x6f8
[  959.614803]  scsi_sysfs_add_sdev+0x8c/0x250
[  959.614809]  scsi_add_lun+0x424/0x558
[  959.614813]  scsi_probe_and_add_lun+0x11c/0x430
[  959.614817]  __scsi_scan_target+0xb8/0x258
[  959.614821]  scsi_scan_channel+0xa0/0xb8
[  959.614825]  scsi_scan_host_selected+0x170/0x188
[  959.614830]  store_scan+0x194/0x1a8
[  959.614835]  dev_attr_store+0x20/0x40
[  959.614840]  sysfs_kf_write+0x4c/0x68
[  959.614845]  kernfs_fop_write_iter+0x13c/0x1d8
[  959.614849]  vfs_write+0x1c0/0x310
[  959.614855]  ksys_write+0x78/0x118
[  959.614859]  __arm64_sys_write+0x24/0x38
[  959.614864]  invoke_syscall+0x78/0x100
[  959.614868]  el0_svc_common.constprop.0+0x4c/0xf8
[  959.614871]  do_el0_svc+0x34/0x50
[  959.614874]  el0_svc+0x34/0x108
[  959.614879]  el0t_64_sync_handler+0x120/0x130
[  959.614884]  el0t_64_sync+0x194/0x198
[  959.614889] Code: 54000088 14000067 f940037b b4000cbb (b8570360)
[  959.614892] ---[ end trace 0000000000000000 ]---
[  959.614895] Kernel panic - not syncing: Oops: Fatal exception
[  959.614897] SMP: stopping secondary CPUs
[  959.619492] Kernel Offset: 0x4b7267c40000 from 0xffff800080000000
[  959.619494] PHYS_OFFSET: 0x80000000
[  959.619496] CPU features: 0x00000010,b80140a1,8841720b
[  959.619498] Memory Limit: none
[  960.040819] ---[ end Kernel panic - not syncing: Oops: Fatal exception ]---