From: Wu Fengguang <fengguang.wu@intel.com>
To: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: "linux-nfs@vger.kernel.org" <linux-nfs@vger.kernel.org>
Subject: NFS commit: sync or async?
Date: Thu, 22 Jul 2010 15:36:23 +0800 [thread overview]
Message-ID: <20100722073623.GA24462@localhost> (raw)
Hi Trond,
May I ask you an NFS question? I got a bit puzzled by this call trace. It
happens after stopping the nfsd at server side when the client side is
doing cp over NFSv3:
[49388.040091] cp D 0000000000000082 2968 2782 28204 0x00000000
[49388.040097] ffff8800b8587778 0000000000000002 ffff8800b85877f8 00000000001d4e40
[49388.040103] ffff8800b8587fd8 00000000001d4e40 ffff8800b8587fd8 ffff8800b8ec4700
[49388.040110] 00000000001d4e40 ffff8800b8587fd8 00000000001d4e40 00000000001d4e40
[49388.040116] Call Trace:
[49388.040121] [<ffffffff810de503>] ? prepare_to_wait+0x73/0xc0
[49388.040127] [<ffffffff81b32750>] ? rpc_wait_bit_killable+0x0/0x60
[49388.040132] [<ffffffff81b3277f>] rpc_wait_bit_killable+0x2f/0x60
[49388.040136] [<ffffffff81babded>] __wait_on_bit+0x8d/0xe0
[49388.040140] [<ffffffff81b32750>] ? rpc_wait_bit_killable+0x0/0x60
[49388.040144] [<ffffffff81babec6>] out_of_line_wait_on_bit+0x86/0xa0
[49388.040149] [<ffffffff810de170>] ? wake_bit_function+0x0/0x70
[49388.040154] [<ffffffff81b333bf>] __rpc_execute+0x16f/0x3f0
[49388.040158] [<ffffffff81b3367b>] rpc_execute+0x3b/0x50
[49388.040162] [<ffffffff81b28d31>] rpc_run_task+0x51/0xc0
[49388.040167] [<ffffffff81366ad6>] nfs_commit_list+0x1f6/0x3e0
[49388.040172] [<ffffffff81366de9>] nfs_commit_inode+0x129/0x170
[49388.040176] [<ffffffff813677fa>] nfs_write_inode+0x7a/0xf0
[49388.040180] [<ffffffff81239a8b>] writeback_single_inode+0x28b/0x3f0
[49388.040186] [<ffffffff8123ac08>] writeback_inodes_wb+0x318/0x650
[49388.040191] [<ffffffff8123b1d2>] writeback_inodes_wbc+0x22/0x30
[49388.040196] [<ffffffff811a5a00>] balance_dirty_pages_ratelimited_nr+0x400/0x5d0
[49388.040202] [<ffffffff81196306>] ? iov_iter_copy_from_user_atomic+0xa6/0x1c0
[49388.040207] [<ffffffff81196898>] generic_file_buffered_write+0x258/0x370
[49388.040213] [<ffffffff81199b7a>] __generic_file_aio_write+0x2ea/0x5f0
[49388.040218] [<ffffffff81bad374>] ? mutex_lock_nested+0x394/0x530
[49388.040223] [<ffffffff81199edf>] ? generic_file_aio_write+0x5f/0x100
[49388.040229] [<ffffffff81199ef9>] generic_file_aio_write+0x79/0x100
[49388.040235] [<ffffffff81353f00>] nfs_file_write+0xe0/0x2a0
[49388.040240] [<ffffffff8120a138>] do_sync_write+0xe8/0x140
[49388.040246] [<ffffffff811bd7b6>] ? might_fault+0xd6/0xf0
[49388.040251] [<ffffffff8120b156>] vfs_write+0xb6/0x220
[49388.040255] [<ffffffff8120b406>] sys_write+0x66/0xb0
[49388.040260] [<ffffffff8104ab72>] system_call_fastpath+0x16/0x1b
>From simple code review I cannot explain why out_of_line_wait_on_bit()
is called inside __rpc_execute() for a commit request.
nfs_commit_rpcsetup() sets RPC_TASK_ASYNC for task_setup_data.flags,
which is transferred to task->tk_flags in rpc_init_task().
__rpc_execute() should then return on task_is_async=1 and skip the
out_of_line_wait_on_bit() call. However the trace shows that
out_of_line_wait_on_bit() is called. I'm a bit puzzled. I must have
missed something. Is this the expected behavior?
Thanks,
Fengguang
next reply other threads:[~2010-07-22 7:36 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-07-22 7:36 Wu Fengguang [this message]
2010-07-22 12:38 ` NFS commit: sync or async? Trond Myklebust
[not found] ` <1279802335.3621.8.camel-rJ7iovZKK19ZJLDQqaL3InhyD016LWXt@public.gmane.org>
2010-07-23 0:47 ` Wu Fengguang
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20100722073623.GA24462@localhost \
--to=fengguang.wu@intel.com \
--cc=Trond.Myklebust@netapp.com \
--cc=linux-nfs@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.