Re: 4.2 kernel trace when hot unplug a mounted USB/SATA/MMC devices with ext2/ext3/ext4 file system

2015-08-25 Thread Christoph Hellwig
On Mon, Aug 24, 2015 at 02:20:07PM -0700, Duc Dang wrote:
 For more information. We tested kernel at commit 5f80f62ada ext4:
 remove useless condition in if statement.
 (right before your commit) and still saw the issue.
 
 df3305156f989339529b3d6744b898d498fb1f7b [media] v4l: xilinx: Add
 Xilinx Video IP core
 08439fec266c3cc5702953b4f54bdf5649357de0 ext4: remove block_device_ejected
 5f80f62adae2a2920781a847805d34b36b323f7d ext4: remove useless
 condition in if statement.
 c9bca8b33118573da9b7ac2ea21947a8e4d287dd [media] v4l: of: Add
 v4l2_of_parse_link() function
 
 Further more, the issue does not happen with 3.19-rc7 but happens with 
 4.00-rc1

Thanks for the report.  Does it happen with commit aad653
block: discard bdi_unregister() in favour of bdi_destroy(), either
cherry picked or the whole tree at that version?

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Re: 4.2 kernel trace when hot unplug a mounted USB/SATA/MMC devices with ext2/ext3/ext4 file system

2015-08-24 Thread Duc Dang
On Sat, Aug 15, 2015 at 1:58 AM, Christoph Hellwig h...@lst.de wrote:
 On Fri, Aug 14, 2015 at 05:52:44PM -0700, Duc Dang wrote:
 The commit 08439fec26 ext4: remove block_device_ejected only causes
 issue with ext4 and
 trying reverting it helps our test passes with ext4.

 But how about the same issue with ext2/ext3?

 I tried to fix the underlying issue, but I either failed to fully
 fixed it or someone regressed it.

 Can you if rev 08439fec26 on it's own works to see if I missed
 a case or it was regressed later?

For more information. We tested kernel at commit 5f80f62ada ext4:
remove useless condition in if statement.
(right before your commit) and still saw the issue.

df3305156f989339529b3d6744b898d498fb1f7b [media] v4l: xilinx: Add
Xilinx Video IP core
08439fec266c3cc5702953b4f54bdf5649357de0 ext4: remove block_device_ejected
5f80f62adae2a2920781a847805d34b36b323f7d ext4: remove useless
condition in if statement.
c9bca8b33118573da9b7ac2ea21947a8e4d287dd [media] v4l: of: Add
v4l2_of_parse_link() function

Further more, the issue does not happen with 3.19-rc7 but happens with 4.00-rc1

-- 
Regards,
Duc Dang.
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Re: 4.2 kernel trace when hot unplug a mounted USB/SATA/MMC devices with ext2/ext3/ext4 file system

2015-08-15 Thread Christoph Hellwig
On Fri, Aug 14, 2015 at 05:52:44PM -0700, Duc Dang wrote:
 The commit 08439fec26 ext4: remove block_device_ejected only causes
 issue with ext4 and
 trying reverting it helps our test passes with ext4.
 
 But how about the same issue with ext2/ext3?

I tried to fix the underlying issue, but I either failed to fully
fixed it or someone regressed it.

Can you if rev 08439fec26 on it's own works to see if I missed
a case or it was regressed later?
--
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Re: 4.2 kernel trace when hot unplug a mounted USB/SATA/MMC devices with ext2/ext3/ext4 file system

2015-08-14 Thread Jan Kara
On Thu 13-08-15 09:01:28, Darrick J. Wong wrote:
 On Wed, Aug 12, 2015 at 08:17:28PM -0700, Duc Dang wrote:
  Hi Theodore, Andreas, Jan, Andrew and All,
  
  We are seeing kernel trace when we disconnect an USB/SATA/MMC devices
  that has its ext2/ext3/ext4 partition currently mounted. These traces
  are seen with kernel 4.2-rc5 on APM Arm64 X-Gene platforms. Similar
  issue also happens on an x86 machine (Lenovo T420s running Fedora Core
  22 (Linux 4.1.x))
 
 Sounds like this issue:
 https://bugzilla.kernel.org/show_bug.cgi?id=101011

Hum, the above bug mentions that at least for ext4 this is a regression
caused by commit 08439fec26 ext4: remove block_device_ejected from
Christoph, let's add him to CC. The assumption of the commit is that
bdi-dev never goes away so there's no point in checking it but these guys
are apparently able to make bdi go away before fs is done with it... Any
idea Christoph?

Honza

  We also tested with xfs kernel and kernel complains with some error
  message but there is no trace:
  
  usb 1-1: USB disconnect, device number 3
  XFS (sda1): Unmounting Filesystem
  XFS (sda1): metadata I/O error: block 0x1ddc12 (xlog_iodone) error 19 
  numblks
  64
  XFS (sda1): xfs_do_force_shutdown(0x2) called from line 1180 of file
  /projects/svdc/P4wsIPCSW/buildsw_shadowcat_2_03/shadowcat/linux/fs/xfs/xfs_log.c.
   Return address = 0xffc0003aa8d8
  XFS (sda1): Log I/O Error Detected.  Shutting down filesystem
  XFS (sda1): Unable to update superblock counters. Freespace may not be 
  correct
  on next mount.
  XFS (sda1): xfs_log_force: error -5 returned.
  XFS (sda1): Please umount the filesystem and rectify the problem(s)
  
  Below are traces for each case. Do you aware of this issue and is
  there a fix for it?
  
  CASE 1: SATA with ext2 partition:
  
  EXT2-fs (sda1): previous I/O error to superblock detected
  
  Unable to handle kernel paging request at virtual address 1ff256000
  pgd = ffc0e784b000
  [1ff256000] *pgd=, *pud=
  Internal error: Oops: 9605 [#1] PREEMPT SMP
  Modules linked in:
  CPU: 4 PID: 1484 Comm: umount Not tainted 4.1.0-xgene_sw_2.03.05-beta_rc_pm 
  #1
  Hardware name: APM X-Gene Mustang board (DT)
  task: ffc1ed5d3840 ti: ffc0e79dc000 task.ti: ffc0e79dc000
  PC is at __percpu_counter_add+0x2c/0x10c
  LR is at account_page_dirtied+0x78/0x12c
  pc : [ffc00043666c] lr : [ffc000147180] pstate: 81c5
  sp : ffc0e79dfc40
  x29: ffc0e79dfc40 x28: ffc0e79dc000
  x27: ffc000927000 x26: 0027
  x25: 011a x24: 0015
  x23: 8000 x22: 0140
  x21: ffc000d33000 x20: ffc1f6440fb8
  x19: ffbec7b3e500 x18: 
  x17: 007f8d95bfd0 x16: ffc0001dfad0
  x15: 003b9aca x14: 0ffe
  x13: 0020 x12: 0101010101010101
  x11: 0174 x10: 0006
  x9 : ffc1fff1e35c x8 : 746564206b636f6c
  x7 : ffc000d33618 x6 : 0001ff256000
  x5 : ffc0e79dfc40 x4 : ffc0e79dc000
  x3 :  x2 : 0020
  x1 : 0001 x0 : 0001ff256000
  
  Process umount (pid: 1484, stack limit = 0xffc0e79dc020)
  Stack: (0xffc0e79dfc40 to 0xffc0e79e)
  fc40: e79dfc70 ffc0 00147180 ffc0 c7b3e500 ffbe f6440f78 
  ffc1
  fc60: e79dfc70 ffc0 0014716c ffc0 e79dfcb0 ffc0 001ccd7c 
  ffc0
  fc80: c7b3e500 ffbe f6b28f48 ffc1 f6b28f60 ffc1 e79dfca0 
  ffc0
  fca0:   f6b28f48 ffc1 e79dfd00 ffc0 001cdfd4 
  ffc0
  fcc0: c7b3e500 ffbe ecf94400 ffc1 ee6022d8 ffc0  
  
  fce0: 8000  00226674 ffc0 e79dfd20 ffc0  
  
  fd00: e79dfd20 ffc0 0022ac84 ffc0 f6ff7000 ffc1 ecf94400 
  ffc1
  fd20: e79dfd50 ffc0 0022ad0c ffc0 f677e380 ffc1 ecf94400 
  ffc1
  fd40: f6ff7000 ffc1 ed5d3840 ffc1 e79dfd90 ffc0 001cb0c4 
  ffc0
  fd60: f6ff7000 ffc1 f6ff70a8 ffc1 00946080 ffc0 001b5ff0 
  ffc0
  fd80: f6ff7000 ffc1   e79dfdb0 ffc0 001a05e0 
  ffc0
  fda0: f6ff7000 ffc1 0083  e79dfde0 ffc0 001a0958 
  ffc0
  fdc0: f6b28d00 ffc1 0083  00db9000 ffc0 0015 
  
  fde0: e79dfe10 ffc0 001a0c68 ffc0 f6ff7000 ffc1 00d511e8 
  ffc0
  fe00: 00db9000 ffc0 00d511e8 ffc0 e79dfe30 ffc0 001a1168 
  ffc0
  fe20: f6ff7000 ffc1   e79dfe50 ffc0 001bcef0 
  ffc0
  fe40: f6c8b080 ffc1 0015  e79dfe70 ffc0 001bcf94 
  ffc0
  fe60: ed5d4190 ffc1 90a791c8 007f e79dfe80 ffc0 000ce47c 
  ffc0
  fe80: e79dfeb0 ffc0 00089800 ffc0 000c  79a5e4f0 
  0055
  fea0:   90a791c8 007f dc5d82a0 007f 00085b54 
  

Re: 4.2 kernel trace when hot unplug a mounted USB/SATA/MMC devices with ext2/ext3/ext4 file system

2015-08-14 Thread Duc Dang
On Fri, Aug 14, 2015 at 1:09 AM, Jan Kara j...@suse.cz wrote:
 On Thu 13-08-15 09:01:28, Darrick J. Wong wrote:
 On Wed, Aug 12, 2015 at 08:17:28PM -0700, Duc Dang wrote:
  Hi Theodore, Andreas, Jan, Andrew and All,
 
  We are seeing kernel trace when we disconnect an USB/SATA/MMC devices
  that has its ext2/ext3/ext4 partition currently mounted. These traces
  are seen with kernel 4.2-rc5 on APM Arm64 X-Gene platforms. Similar
  issue also happens on an x86 machine (Lenovo T420s running Fedora Core
  22 (Linux 4.1.x))

 Sounds like this issue:
 https://bugzilla.kernel.org/show_bug.cgi?id=101011

 Hum, the above bug mentions that at least for ext4 this is a regression
 caused by commit 08439fec26 ext4: remove block_device_ejected from
 Christoph, let's add him to CC. The assumption of the commit is that
 bdi-dev never goes away so there's no point in checking it but these guys
 are apparently able to make bdi go away before fs is done with it... Any
 idea Christoph?

The commit 08439fec26 ext4: remove block_device_ejected only causes
issue with ext4 and
trying reverting it helps our test passes with ext4.

But how about the same issue with ext2/ext3?


 Honza

  We also tested with xfs kernel and kernel complains with some error
  message but there is no trace:
 
  usb 1-1: USB disconnect, device number 3
  XFS (sda1): Unmounting Filesystem
  XFS (sda1): metadata I/O error: block 0x1ddc12 (xlog_iodone) error 19 
  numblks
  64
  XFS (sda1): xfs_do_force_shutdown(0x2) called from line 1180 of file
  /projects/svdc/P4wsIPCSW/buildsw_shadowcat_2_03/shadowcat/linux/fs/xfs/xfs_log.c.
   Return address = 0xffc0003aa8d8
  XFS (sda1): Log I/O Error Detected.  Shutting down filesystem
  XFS (sda1): Unable to update superblock counters. Freespace may not be 
  correct
  on next mount.
  XFS (sda1): xfs_log_force: error -5 returned.
  XFS (sda1): Please umount the filesystem and rectify the problem(s)
 
  Below are traces for each case. Do you aware of this issue and is
  there a fix for it?
 
  CASE 1: SATA with ext2 partition:
 
  EXT2-fs (sda1): previous I/O error to superblock detected
 
  Unable to handle kernel paging request at virtual address 1ff256000
  pgd = ffc0e784b000
  [1ff256000] *pgd=, *pud=
  Internal error: Oops: 9605 [#1] PREEMPT SMP
  Modules linked in:
  CPU: 4 PID: 1484 Comm: umount Not tainted 
  4.1.0-xgene_sw_2.03.05-beta_rc_pm #1
  Hardware name: APM X-Gene Mustang board (DT)
  task: ffc1ed5d3840 ti: ffc0e79dc000 task.ti: ffc0e79dc000
  PC is at __percpu_counter_add+0x2c/0x10c
  LR is at account_page_dirtied+0x78/0x12c
  pc : [ffc00043666c] lr : [ffc000147180] pstate: 81c5
  sp : ffc0e79dfc40
  x29: ffc0e79dfc40 x28: ffc0e79dc000
  x27: ffc000927000 x26: 0027
  x25: 011a x24: 0015
  x23: 8000 x22: 0140
  x21: ffc000d33000 x20: ffc1f6440fb8
  x19: ffbec7b3e500 x18: 
  x17: 007f8d95bfd0 x16: ffc0001dfad0
  x15: 003b9aca x14: 0ffe
  x13: 0020 x12: 0101010101010101
  x11: 0174 x10: 0006
  x9 : ffc1fff1e35c x8 : 746564206b636f6c
  x7 : ffc000d33618 x6 : 0001ff256000
  x5 : ffc0e79dfc40 x4 : ffc0e79dc000
  x3 :  x2 : 0020
  x1 : 0001 x0 : 0001ff256000
 
  Process umount (pid: 1484, stack limit = 0xffc0e79dc020)
  Stack: (0xffc0e79dfc40 to 0xffc0e79e)
  fc40: e79dfc70 ffc0 00147180 ffc0 c7b3e500 ffbe f6440f78 
  ffc1
  fc60: e79dfc70 ffc0 0014716c ffc0 e79dfcb0 ffc0 001ccd7c 
  ffc0
  fc80: c7b3e500 ffbe f6b28f48 ffc1 f6b28f60 ffc1 e79dfca0 
  ffc0
  fca0:   f6b28f48 ffc1 e79dfd00 ffc0 001cdfd4 
  ffc0
  fcc0: c7b3e500 ffbe ecf94400 ffc1 ee6022d8 ffc0  
  
  fce0: 8000  00226674 ffc0 e79dfd20 ffc0  
  
  fd00: e79dfd20 ffc0 0022ac84 ffc0 f6ff7000 ffc1 ecf94400 
  ffc1
  fd20: e79dfd50 ffc0 0022ad0c ffc0 f677e380 ffc1 ecf94400 
  ffc1
  fd40: f6ff7000 ffc1 ed5d3840 ffc1 e79dfd90 ffc0 001cb0c4 
  ffc0
  fd60: f6ff7000 ffc1 f6ff70a8 ffc1 00946080 ffc0 001b5ff0 
  ffc0
  fd80: f6ff7000 ffc1   e79dfdb0 ffc0 001a05e0 
  ffc0
  fda0: f6ff7000 ffc1 0083  e79dfde0 ffc0 001a0958 
  ffc0
  fdc0: f6b28d00 ffc1 0083  00db9000 ffc0 0015 
  
  fde0: e79dfe10 ffc0 001a0c68 ffc0 f6ff7000 ffc1 00d511e8 
  ffc0
  fe00: 00db9000 ffc0 00d511e8 ffc0 e79dfe30 ffc0 001a1168 
  ffc0
  fe20: f6ff7000 ffc1   e79dfe50 ffc0 001bcef0 
  ffc0
  fe40: f6c8b080 ffc1 0015  e79dfe70 ffc0 001bcf94 
 

Re: 4.2 kernel trace when hot unplug a mounted USB/SATA/MMC devices with ext2/ext3/ext4 file system

2015-08-13 Thread Darrick J. Wong
On Wed, Aug 12, 2015 at 08:17:28PM -0700, Duc Dang wrote:
 Hi Theodore, Andreas, Jan, Andrew and All,
 
 We are seeing kernel trace when we disconnect an USB/SATA/MMC devices
 that has its ext2/ext3/ext4 partition currently mounted. These traces
 are seen with kernel 4.2-rc5 on APM Arm64 X-Gene platforms. Similar
 issue also happens on an x86 machine (Lenovo T420s running Fedora Core
 22 (Linux 4.1.x))

Sounds like this issue:
https://bugzilla.kernel.org/show_bug.cgi?id=101011

--D

 
 We also tested with xfs kernel and kernel complains with some error
 message but there is no trace:
 
 usb 1-1: USB disconnect, device number 3
 XFS (sda1): Unmounting Filesystem
 XFS (sda1): metadata I/O error: block 0x1ddc12 (xlog_iodone) error 19 
 numblks
 64
 XFS (sda1): xfs_do_force_shutdown(0x2) called from line 1180 of file
 /projects/svdc/P4wsIPCSW/buildsw_shadowcat_2_03/shadowcat/linux/fs/xfs/xfs_log.c.
  Return address = 0xffc0003aa8d8
 XFS (sda1): Log I/O Error Detected.  Shutting down filesystem
 XFS (sda1): Unable to update superblock counters. Freespace may not be correct
 on next mount.
 XFS (sda1): xfs_log_force: error -5 returned.
 XFS (sda1): Please umount the filesystem and rectify the problem(s)
 
 Below are traces for each case. Do you aware of this issue and is
 there a fix for it?
 
 CASE 1: SATA with ext2 partition:
 
 EXT2-fs (sda1): previous I/O error to superblock detected
 
 Unable to handle kernel paging request at virtual address 1ff256000
 pgd = ffc0e784b000
 [1ff256000] *pgd=, *pud=
 Internal error: Oops: 9605 [#1] PREEMPT SMP
 Modules linked in:
 CPU: 4 PID: 1484 Comm: umount Not tainted 4.1.0-xgene_sw_2.03.05-beta_rc_pm #1
 Hardware name: APM X-Gene Mustang board (DT)
 task: ffc1ed5d3840 ti: ffc0e79dc000 task.ti: ffc0e79dc000
 PC is at __percpu_counter_add+0x2c/0x10c
 LR is at account_page_dirtied+0x78/0x12c
 pc : [ffc00043666c] lr : [ffc000147180] pstate: 81c5
 sp : ffc0e79dfc40
 x29: ffc0e79dfc40 x28: ffc0e79dc000
 x27: ffc000927000 x26: 0027
 x25: 011a x24: 0015
 x23: 8000 x22: 0140
 x21: ffc000d33000 x20: ffc1f6440fb8
 x19: ffbec7b3e500 x18: 
 x17: 007f8d95bfd0 x16: ffc0001dfad0
 x15: 003b9aca x14: 0ffe
 x13: 0020 x12: 0101010101010101
 x11: 0174 x10: 0006
 x9 : ffc1fff1e35c x8 : 746564206b636f6c
 x7 : ffc000d33618 x6 : 0001ff256000
 x5 : ffc0e79dfc40 x4 : ffc0e79dc000
 x3 :  x2 : 0020
 x1 : 0001 x0 : 0001ff256000
 
 Process umount (pid: 1484, stack limit = 0xffc0e79dc020)
 Stack: (0xffc0e79dfc40 to 0xffc0e79e)
 fc40: e79dfc70 ffc0 00147180 ffc0 c7b3e500 ffbe f6440f78 ffc1
 fc60: e79dfc70 ffc0 0014716c ffc0 e79dfcb0 ffc0 001ccd7c ffc0
 fc80: c7b3e500 ffbe f6b28f48 ffc1 f6b28f60 ffc1 e79dfca0 ffc0
 fca0:   f6b28f48 ffc1 e79dfd00 ffc0 001cdfd4 ffc0
 fcc0: c7b3e500 ffbe ecf94400 ffc1 ee6022d8 ffc0  
 fce0: 8000  00226674 ffc0 e79dfd20 ffc0  
 fd00: e79dfd20 ffc0 0022ac84 ffc0 f6ff7000 ffc1 ecf94400 ffc1
 fd20: e79dfd50 ffc0 0022ad0c ffc0 f677e380 ffc1 ecf94400 ffc1
 fd40: f6ff7000 ffc1 ed5d3840 ffc1 e79dfd90 ffc0 001cb0c4 ffc0
 fd60: f6ff7000 ffc1 f6ff70a8 ffc1 00946080 ffc0 001b5ff0 ffc0
 fd80: f6ff7000 ffc1   e79dfdb0 ffc0 001a05e0 ffc0
 fda0: f6ff7000 ffc1 0083  e79dfde0 ffc0 001a0958 ffc0
 fdc0: f6b28d00 ffc1 0083  00db9000 ffc0 0015 
 fde0: e79dfe10 ffc0 001a0c68 ffc0 f6ff7000 ffc1 00d511e8 ffc0
 fe00: 00db9000 ffc0 00d511e8 ffc0 e79dfe30 ffc0 001a1168 ffc0
 fe20: f6ff7000 ffc1   e79dfe50 ffc0 001bcef0 ffc0
 fe40: f6c8b080 ffc1 0015  e79dfe70 ffc0 001bcf94 ffc0
 fe60: ed5d4190 ffc1 90a791c8 007f e79dfe80 ffc0 000ce47c ffc0
 fe80: e79dfeb0 ffc0 00089800 ffc0 000c  79a5e4f0 0055
 fea0:   90a791c8 007f dc5d82a0 007f 00085b54 ffc0
 fec0:   e79dfec0 ffc0    
 fee0:     8000 80808080  
 ff00: 80808080 0080 ff2f6172 fefefefe 0027  0004 
 ff20: 01010101 01010101 0030  0006  6974616f 6e2c656d
 ff40:   578b  90a79180 007f 756f8ed0 0055
 ff60:   79a5e4f0 0055 79a5e4f0 0055 0002 
 ff80: 0002  79a5e550 0055   dc5d8410 007f
 ffa0: 79a5e530 0055 756f5df1 0055   dc5d82a0 

4.2 kernel trace when hot unplug a mounted USB/SATA/MMC devices with ext2/ext3/ext4 file system

2015-08-12 Thread Duc Dang
Hi Theodore, Andreas, Jan, Andrew and All,

We are seeing kernel trace when we disconnect an USB/SATA/MMC devices
that has its ext2/ext3/ext4 partition currently mounted. These traces
are seen with kernel 4.2-rc5 on APM Arm64 X-Gene platforms. Similar
issue also happens on an x86 machine (Lenovo T420s running Fedora Core
22 (Linux 4.1.x))

We also tested with xfs kernel and kernel complains with some error
message but there is no trace:

usb 1-1: USB disconnect, device number 3
XFS (sda1): Unmounting Filesystem
XFS (sda1): metadata I/O error: block 0x1ddc12 (xlog_iodone) error 19 numblks
64
XFS (sda1): xfs_do_force_shutdown(0x2) called from line 1180 of file
/projects/svdc/P4wsIPCSW/buildsw_shadowcat_2_03/shadowcat/linux/fs/xfs/xfs_log.c.
 Return address = 0xffc0003aa8d8
XFS (sda1): Log I/O Error Detected.  Shutting down filesystem
XFS (sda1): Unable to update superblock counters. Freespace may not be correct
on next mount.
XFS (sda1): xfs_log_force: error -5 returned.
XFS (sda1): Please umount the filesystem and rectify the problem(s)

Below are traces for each case. Do you aware of this issue and is
there a fix for it?

CASE 1: SATA with ext2 partition:

EXT2-fs (sda1): previous I/O error to superblock detected

Unable to handle kernel paging request at virtual address 1ff256000
pgd = ffc0e784b000
[1ff256000] *pgd=, *pud=
Internal error: Oops: 9605 [#1] PREEMPT SMP
Modules linked in:
CPU: 4 PID: 1484 Comm: umount Not tainted 4.1.0-xgene_sw_2.03.05-beta_rc_pm #1
Hardware name: APM X-Gene Mustang board (DT)
task: ffc1ed5d3840 ti: ffc0e79dc000 task.ti: ffc0e79dc000
PC is at __percpu_counter_add+0x2c/0x10c
LR is at account_page_dirtied+0x78/0x12c
pc : [ffc00043666c] lr : [ffc000147180] pstate: 81c5
sp : ffc0e79dfc40
x29: ffc0e79dfc40 x28: ffc0e79dc000
x27: ffc000927000 x26: 0027
x25: 011a x24: 0015
x23: 8000 x22: 0140
x21: ffc000d33000 x20: ffc1f6440fb8
x19: ffbec7b3e500 x18: 
x17: 007f8d95bfd0 x16: ffc0001dfad0
x15: 003b9aca x14: 0ffe
x13: 0020 x12: 0101010101010101
x11: 0174 x10: 0006
x9 : ffc1fff1e35c x8 : 746564206b636f6c
x7 : ffc000d33618 x6 : 0001ff256000
x5 : ffc0e79dfc40 x4 : ffc0e79dc000
x3 :  x2 : 0020
x1 : 0001 x0 : 0001ff256000

Process umount (pid: 1484, stack limit = 0xffc0e79dc020)
Stack: (0xffc0e79dfc40 to 0xffc0e79e)
fc40: e79dfc70 ffc0 00147180 ffc0 c7b3e500 ffbe f6440f78 ffc1
fc60: e79dfc70 ffc0 0014716c ffc0 e79dfcb0 ffc0 001ccd7c ffc0
fc80: c7b3e500 ffbe f6b28f48 ffc1 f6b28f60 ffc1 e79dfca0 ffc0
fca0:   f6b28f48 ffc1 e79dfd00 ffc0 001cdfd4 ffc0
fcc0: c7b3e500 ffbe ecf94400 ffc1 ee6022d8 ffc0  
fce0: 8000  00226674 ffc0 e79dfd20 ffc0  
fd00: e79dfd20 ffc0 0022ac84 ffc0 f6ff7000 ffc1 ecf94400 ffc1
fd20: e79dfd50 ffc0 0022ad0c ffc0 f677e380 ffc1 ecf94400 ffc1
fd40: f6ff7000 ffc1 ed5d3840 ffc1 e79dfd90 ffc0 001cb0c4 ffc0
fd60: f6ff7000 ffc1 f6ff70a8 ffc1 00946080 ffc0 001b5ff0 ffc0
fd80: f6ff7000 ffc1   e79dfdb0 ffc0 001a05e0 ffc0
fda0: f6ff7000 ffc1 0083  e79dfde0 ffc0 001a0958 ffc0
fdc0: f6b28d00 ffc1 0083  00db9000 ffc0 0015 
fde0: e79dfe10 ffc0 001a0c68 ffc0 f6ff7000 ffc1 00d511e8 ffc0
fe00: 00db9000 ffc0 00d511e8 ffc0 e79dfe30 ffc0 001a1168 ffc0
fe20: f6ff7000 ffc1   e79dfe50 ffc0 001bcef0 ffc0
fe40: f6c8b080 ffc1 0015  e79dfe70 ffc0 001bcf94 ffc0
fe60: ed5d4190 ffc1 90a791c8 007f e79dfe80 ffc0 000ce47c ffc0
fe80: e79dfeb0 ffc0 00089800 ffc0 000c  79a5e4f0 0055
fea0:   90a791c8 007f dc5d82a0 007f 00085b54 ffc0
fec0:   e79dfec0 ffc0    
fee0:     8000 80808080  
ff00: 80808080 0080 ff2f6172 fefefefe 0027  0004 
ff20: 01010101 01010101 0030  0006  6974616f 6e2c656d
ff40:   578b  90a79180 007f 756f8ed0 0055
ff60:   79a5e4f0 0055 79a5e4f0 0055 0002 
ff80: 0002  79a5e550 0055   dc5d8410 007f
ffa0: 79a5e530 0055 756f5df1 0055   dc5d82a0 007f
ffc0: 756a2ae0 0055 dc5d8150 007f 90a791c8 007f 8000 
ffe0: 79a5e530 0055 0027     
Call trace:
[ffc00043666c] __percpu_counter_add+0x2c/0x10c