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Message-Id: <7EA40233-6820-4F0E-A2B7-687DC01BDD78@primarydata.com>
Date: Mon, 11 Aug 2014 22:52:38 -0400
From: Weston Andros Adamson <dros@...marydata.com>
To: Nick Krause <xerofoify@...il.com>
Cc: Fengguang Wu <fengguang.wu@...el.com>,
Peter Zijlstra <peterz@...radead.org>,
linux-nfs list <linux-nfs@...r.kernel.org>,
Jet Chen <jet.chen@...el.com>, Su Tao <tao.su@...el.com>,
Yuanhan Liu <yuanhan.liu@...el.com>, LKP <lkp@...org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [nfs] BUG: sleeping function called from invalid context at include/linux/wait.h:976
Hi,
I posted a 5 patch series to the nfs list last week with the cover letter titled
"nfs_page_group_lock cleanup”, but neglected to mail the wider list.
The might_sleep check was being hit because nfs_page_group_lock with wait=False called
wait_on_bit_lock (which might sleep). I also had to be careful to ignore the nonblock argument
in nfs_lock_and_join_requests and always call nonblocking, because the inode lock is held.
Blocking is handled by dropping the inode lock, calling wait_on_bit(), then trying again.
The cover letter for the patchset is below.
Thanks!
-dros
These patches clean up some issues surrouding nfs_page_group_lock:
- normalize wait/nonblock argument
- make nonblocking calls really nonblocking
- handle errors
- ensure that we don't call blocking nfs_page_group_lock when holding the
inode spinlock
This cleanup was inspired by Fengguang Wu's report that we were sleeping with
locks held in nfs_lock_and_join_requests.
Weston Andros Adamson (5):
nfs: change nfs_page_group_lock argument
nfs: fix nonblocking calls to nfs_page_group_lock
nfs: use blocking page_group_lock in add_request
nfs: fix error handling in lock_and_join_requests
nfs: don't sleep with inode lock in lock_and_join_requests
fs/nfs/pagelist.c | 59 ++++++++++++++++++++++++++++++------------------
fs/nfs/write.c | 21 +++++++++++++----
include/linux/nfs_page.h | 1 +
3 files changed, 55 insertions(+), 26 deletions(-)
On Aug 9, 2014, at 12:11 AM, Nick Krause <xerofoify@...il.com> wrote:
> On Tue, Aug 5, 2014 at 11:08 AM, Weston Andros Adamson
> <dros@...marydata.com> wrote:
>> Thanks, I’ll investigate.
>>
>> -dros
>>
>>
>> On Aug 5, 2014, at 10:03 AM, Fengguang Wu <fengguang.wu@...el.com> wrote:
>>
>>> Greetings,
>>>
>>> Here is an NFS error triggered by this debug check.
>>>
>>> git://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git sched/wait
>>> commit b87699e5fa31f451987a992b9cbda22d29ebcb46
>>> Author: Peter Zijlstra <peterz@...radead.org>
>>> AuthorDate: Mon Aug 4 11:12:21 2014 +0200
>>> Commit: Peter Zijlstra <a.p.zijlstra@...llo.nl>
>>> CommitDate: Mon Aug 4 13:29:57 2014 +0200
>>>
>>> wait: Add might_sleep()
>>>
>>> Add more might_sleep() checks, suppose someone put a wait_event() like
>>> thing in a wait loop..
>>>
>>> Can't put might_sleep() in ___wait_event() because there's the locked
>>> primitives which call ___wait_event() with locks held.
>>>
>>> Signed-off-by: Peter Zijlstra <peterz@...radead.org>
>>> Link: http://lkml.kernel.org/n/tip-amr894sd1j012khd3fgyh9m8@git.kernel.org
>>>
>>>
>>> [ 13.363454] BUG: sleeping function called from invalid context at include/linux/wait.h:976
>>> [ 13.365679] in_atomic(): 1, irqs_disabled(): 0, pid: 2715, name: dmesg
>>> [ 13.367109] CPU: 1 PID: 2715 Comm: dmesg Not tainted 3.16.0-00048-gb87699e #1
>>> [ 13.368385] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
>>> [ 13.369544] 0000000000000000 ffff88003e3efad0 ffffffff819c6bad ffff880035e9e480
>>> [ 13.371838] ffff88003e3efae0 ffffffff81106e96 ffff88003e3efb00 ffffffff81306a2e
>>> [ 13.373822] ffff880035e9e480 ffff88001b8a1a40 ffff88003e3efb48 ffffffff8130975a
>>> [ 13.376165] Call Trace:
>>> [ 13.376890] [<ffffffff819c6bad>] dump_stack+0x4d/0x66
>>> [ 13.377903] [<ffffffff81106e96>] __might_sleep+0x10a/0x10c
>>> [ 13.379247] [<ffffffff81306a2e>] nfs_page_group_lock+0x4e/0x7b
>>> [ 13.380739] [<ffffffff8130975a>] nfs_lock_and_join_requests+0x83/0x334
>>> [ 13.381884] [<ffffffff81309a9f>] nfs_do_writepage+0x94/0x191
>>> [ 13.383078] [<ffffffff81309baf>] nfs_writepages_callback+0x13/0x25
>>> [ 13.384592] [<ffffffff81309b9c>] ? nfs_do_writepage+0x191/0x191
>>> [ 13.385745] [<ffffffff811963d0>] write_cache_pages+0x281/0x3a9
>>> [ 13.386829] [<ffffffff81309b9c>] ? nfs_do_writepage+0x191/0x191
>>> [ 13.388524] [<ffffffff8130a1fd>] nfs_writepages+0xa9/0x10f
>>> [ 13.389903] [<ffffffff811994e1>] ? release_pages+0x1a2/0x20b
>>> [ 13.391087] [<ffffffff81194835>] ? free_pcppages_bulk+0x298/0x33c
>>> [ 13.392198] [<ffffffff81197c8b>] do_writepages+0x1e/0x2c
>>> [ 13.393202] [<ffffffff8118e3f4>] __filemap_fdatawrite_range+0x55/0x57
>>> [ 13.394313] [<ffffffff8118e4b4>] filemap_write_and_wait_range+0x2a/0x58
>>> [ 13.395448] [<ffffffff812ff101>] nfs_file_fsync+0x4e/0x10c
>>> [ 13.396546] [<ffffffff81211395>] vfs_fsync_range+0x1b/0x23
>>> [ 13.397567] [<ffffffff812113b9>] vfs_fsync+0x1c/0x1e
>>> [ 13.398517] [<ffffffff812ff679>] nfs_file_flush+0x6c/0x6f
>>> [ 13.399513] [<ffffffff811e918b>] filp_close+0x3c/0x72
>>> [ 13.400646] [<ffffffff8120295a>] put_files_struct+0x67/0xb3
>>> [ 13.401759] [<ffffffff81202a43>] exit_files+0x4a/0x4f
>>> [ 13.402756] [<ffffffff810e4073>] do_exit+0x3c9/0x985
>>> [ 13.403740] [<ffffffff8106e605>] ? trace_do_page_fault+0x52/0xb7
>>> [ 13.404875] [<ffffffff810e46a9>] do_group_exit+0x44/0xac
>>> [ 13.405878] [<ffffffff810e4725>] SyS_exit_group+0x14/0x14
>>> [ 13.406892] [<ffffffff819ce6a9>] system_call_fastpath+0x16/0x1b
>>> [ 15.733276] BUG: sleeping function called from invalid context at include/linux/wait.h:976
>>> [ 15.735154] in_atomic(): 1, irqs_disabled(): 0, pid: 2716, name: cat
>>> [ 15.736263] CPU: 1 PID: 2716 Comm: cat Not tainted 3.16.0-00048-gb87699e #1
>>> [ 15.737414] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
>>> [ 15.738754] 0000000000000000 ffff88000068b910 ffffffff819c6bad ffff880035e9e080
>>> [ 15.746872] ffff88000068b920 ffffffff81106e96 ffff88000068b940 ffffffff81306a2e
>>> [ 15.748694] ffff880035e9e080 ffff88001b8a1a40 ffff88000068b988 ffffffff8130975a
>>> [ 15.750479] Call Trace:
>>> [ 15.751164] [<ffffffff819c6bad>] dump_stack+0x4d/0x66
>>> [ 15.752141] [<ffffffff81106e96>] __might_sleep+0x10a/0x10c
>>> [ 15.753148] [<ffffffff81306a2e>] nfs_page_group_lock+0x4e/0x7b
>>> [ 15.754183] [<ffffffff8130975a>] nfs_lock_and_join_requests+0x83/0x334
>>> [ 15.755294] [<ffffffff81309a9f>] nfs_do_writepage+0x94/0x191
>>> [ 15.756335] [<ffffffff81309baf>] nfs_writepages_callback+0x13/0x25
>>> [ 15.757405] [<ffffffff81309b9c>] ? nfs_do_writepage+0x191/0x191
>>> [ 15.758452] [<ffffffff811963d0>] write_cache_pages+0x281/0x3a9
>>> [ 15.759483] [<ffffffff81309b9c>] ? nfs_do_writepage+0x191/0x191
>>> [ 15.760547] [<ffffffff8130a1fd>] nfs_writepages+0xa9/0x10f
>>> [ 15.761541] [<ffffffff81197c8b>] do_writepages+0x1e/0x2c
>>> [ 15.762514] [<ffffffff8118e3f4>] __filemap_fdatawrite_range+0x55/0x57
>>> [ 15.763612] [<ffffffff8118e4b4>] filemap_write_and_wait_range+0x2a/0x58
>>> [ 15.764746] [<ffffffff812ff101>] nfs_file_fsync+0x4e/0x10c
>>> [ 15.765748] [<ffffffff81211395>] vfs_fsync_range+0x1b/0x23
>>> [ 15.766745] [<ffffffff812113b9>] vfs_fsync+0x1c/0x1e
>>> [ 15.767681] [<ffffffff812ff679>] nfs_file_flush+0x6c/0x6f
>>> [ 15.768690] [<ffffffff811e918b>] filp_close+0x3c/0x72
>>> [ 15.769638] [<ffffffff8120295a>] put_files_struct+0x67/0xb3
>>> [ 15.770635] [<ffffffff81202a43>] exit_files+0x4a/0x4f
>>> [ 15.771581] [<ffffffff810e4073>] do_exit+0x3c9/0x985
>>> [ 15.772537] [<ffffffff819caf04>] ? __schedule+0x4cb/0x734
>>> [ 15.773522] [<ffffffff810e46a9>] do_group_exit+0x44/0xac
>>> [ 15.774493] [<ffffffff810f0c03>] get_signal_to_deliver+0x53b/0x5cb
>>> [ 15.775575] [<ffffffff810392b9>] do_signal+0x49/0x511
>>> [ 15.776561] [<ffffffff81127334>] ? do_syslog+0x141/0x4a8
>>> [ 15.777564] [<ffffffff8124915d>] ? kmsg_read+0x2d/0x54
>>> [ 15.778513] [<ffffffff8123d924>] ? proc_reg_read+0x56/0x69
>>> [ 15.779504] [<ffffffff810397b6>] do_notify_resume+0x35/0x72
>>> [ 15.780521] [<ffffffff819ce908>] int_signal+0x12/0x17
>>>
>>> This script may reproduce the error.
>>>
>>> ----------------------------------------------------------------------------
>>> #!/bin/bash
>>>
>>> kernel=$1
>>> initrd=debian-x86_64.cgz
>>>
>>> wget --no-clobber https://github.com/fengguang/reproduce-kernel-bug/raw/master/initrd/$initrd
>>>
>>> kvm=(
>>> qemu-system-x86_64
>>> -enable-kvm
>>> -cpu Nehalem
>>> -kernel $kernel
>>> -initrd $initrd
>>> -m 1024
>>> -smp 2
>>> -net nic,vlan=1,model=e1000
>>> -net user,vlan=1
>>> -boot order=nc
>>> -no-reboot
>>> -watchdog i6300esb
>>> -rtc base=localtime
>>> -serial stdio
>>> -display none
>>> -monitor null
>>> )
>>>
>>> append=(
>>> root=/dev/ram0
>>> ip=::::vm-vp-1G-5::dhcp
>>> oops=panic
>>> earlyprintk=ttyS0,115200
>>> debug
>>> apic=debug
>>> sysrq_always_enabled
>>> rcupdate.rcu_cpu_stall_timeout=100
>>> panic=10
>>> softlockup_panic=1
>>> nmi_watchdog=panic
>>> load_ramdisk=2
>>> prompt_ramdisk=0
>>> console=ttyS0,115200
>>> console=tty0
>>> vga=normal
>>> )
>>>
>>> "${kvm[@]}" --append "${append[*]}"
>>> ----------------------------------------------------------------------------
>>>
>>> Thanks,
>>> Fengguang
>>> _______________________________________________
>>> LKP mailing list
>>> LKP@...ux.intel.com
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
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>> Please read the FAQ at http://www.tux.org/lkml/
> Hey Weston,
> After doing the trace for you . seems the issue is in ,nfs_page_group_lock.
> As due to the head not being equal to head be are hitiing a warn on.
>
> 152 nfs_page_group_lock(struct nfs_page *req)
> 153 {
> 154 struct nfs_page *head = req->wb_head;
> 155
> 156 WARN_ON_ONCE(head != head->wb_head);
> 157
> 158 wait_on_bit_lock(&head->wb_flags, PG_HEADLOCK,
> 159 nfs_wait_bit_uninterruptible,
> 160 TASK_UNINTERRUPTIBLE);
> 161 }
>
> I am pasting the function for your convenience.
> Please CC me to let me known how this goes.
> Cheers Nick
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