From: Dave Chinner <david@fromorbit.com>
To: CAI Qian <caiqian@redhat.com>
Cc: Jan Kara <jack@suse.cz>, Al Viro <viro@ZenIV.linux.org.uk>,
tj <tj@kernel.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
linux-xfs <linux-xfs@vger.kernel.org>,
Jens Axboe <axboe@kernel.dk>, Nick Piggin <npiggin@gmail.com>,
linux-fsdevel@vger.kernel.org, Miklos Szeredi <miklos@szeredi.hu>,
Dave Jones <davej@codemonkey.org.uk>
Subject: Re: local DoS - systemd hang or timeout (WAS: Re: [RFC][CFT] splice_read reworked)
Date: Mon, 10 Oct 2016 08:51:46 +1100 [thread overview]
Message-ID: <20161009215146.GL9806@dastard> (raw)
In-Reply-To: <1720038662.1062048.1475851398433.JavaMail.zimbra@redhat.com>
On Fri, Oct 07, 2016 at 10:43:18AM -0400, CAI Qian wrote:
> Hmm, this round of trinity triggered a different hang.
>
> [ 2094.487964] [<ffffffff813e27b7>] call_rwsem_down_write_failed+0x17/0x30
> [ 2094.495450] [<ffffffff817d1bff>] down_write+0x5f/0x80
> [ 2094.508284] [<ffffffff8127e301>] chown_common.isra.12+0x131/0x1e0
> [ 2094.553784] 2 locks held by trinity-c0/3126:
> [ 2094.558552] #0: (sb_writers#14){.+.+.+}, at: [<ffffffff81284be1>] __sb_start_write+0xd1/0xf0
> [ 2094.568240] #1: (&sb->s_type->i_mutex_key#17){++++++}, at: [<ffffffff8127e301>] chown_common.isra.12+0x131/0x1e0
Waiting on i_mutex.
> [ 2094.643597] [<ffffffff817d24b7>] rwsem_down_read_failed+0x107/0x190
> [ 2094.665119] [<ffffffff810f8b0b>] down_read_nested+0x5b/0x80
> [ 2094.691133] [<ffffffff812bdbbd>] vfs_fsync_range+0x3d/0xb0
> [ 2094.721844] 1 lock held by trinity-c1/3127:
> [ 2094.726515] #0: (&xfs_nondir_ilock_class){++++..}, at: [<ffffffffa03335fa>] xfs_ilock+0xfa/0x260 [xfs]
Waiting on i_ilock.
> [ 2094.808078] [<ffffffff817cf4df>] mutex_lock_nested+0x19f/0x450
> [ 2094.820715] [<ffffffff812a5313>] __fdget_pos+0x43/0x50
> [ 2094.826544] [<ffffffff81297f53>] SyS_getdents+0x83/0x140
> [ 2094.856682] #0: (&f->f_pos_lock){+.+.+.}, at: [<ffffffff812a5313>] __fdget_pos+0x43/0x50
concurrent readdir on the same directory fd, blocked on fd.
> [ 2094.936885] [<ffffffff817cf4df>] mutex_lock_nested+0x19f/0x450
> [ 2094.956620] [<ffffffff812a5313>] __fdget_pos+0x43/0x50
> [ 2094.962454] [<ffffffff81298091>] SyS_getdents64+0x81/0x130
> [ 2094.988204] 1 lock held by trinity-c3/3129:
> [ 2094.992872] #0: (&f->f_pos_lock){+.+.+.}, at: [<ffffffff812a5313>] __fdget_pos+0x43/0x50
Same.
> [ 2095.073118] [<ffffffff817cf4df>] mutex_lock_nested+0x19f/0x450
> [ 2095.091589] [<ffffffff812811dd>] SyS_lseek+0x1d/0xb0
> [ 2095.097229] [<ffffffff81003c9c>] do_syscall_64+0x6c/0x1e0
> [ 2095.110547] 1 lock held by trinity-c4/3130:
> [ 2095.115216] #0: (&f->f_pos_lock){+.+.+.}, at: [<ffffffff812a5313>] __fdget_pos+0x43/0x50
Concurrent lseek on directory fd, blocked on fd.
> [ 2095.188230] [<ffffffff817d24b7>] rwsem_down_read_failed+0x107/0x190
> [ 2095.223558] [<ffffffffa03335fa>] xfs_ilock+0xfa/0x260 [xfs]
> [ 2095.229894] [<ffffffffa03337d4>] xfs_ilock_attr_map_shared+0x34/0x40 [xfs]
> [ 2095.237682] [<ffffffffa02ccfaf>] xfs_attr_get+0xdf/0x1b0 [xfs]
> [ 2095.244312] [<ffffffffa0341bfc>] xfs_xattr_get+0x4c/0x70 [xfs]
> [ 2095.250924] [<ffffffff812ad269>] generic_getxattr+0x59/0x70
> [ 2095.257244] [<ffffffff812acf9b>] vfs_getxattr+0x8b/0xb0
> [ 2095.263177] [<ffffffffa0435bd6>] ovl_xattr_get+0x46/0x60 [overlay]
> [ 2095.270176] [<ffffffffa04331aa>] ovl_other_xattr_get+0x1a/0x20 [overlay]
> [ 2095.277756] [<ffffffff812ad269>] generic_getxattr+0x59/0x70
> [ 2095.284079] [<ffffffff81345e9e>] cap_inode_need_killpriv+0x2e/0x40
> [ 2095.291078] [<ffffffff81349a33>] security_inode_need_killpriv+0x33/0x50
> [ 2095.298560] [<ffffffff812a2fb0>] dentry_needs_remove_privs+0x30/0x50
> [ 2095.305743] [<ffffffff8127ea21>] do_truncate+0x51/0xc0
> [ 2095.311581] [<ffffffff81284be1>] ? __sb_start_write+0xd1/0xf0
> [ 2095.318094] [<ffffffff81284be1>] ? __sb_start_write+0xd1/0xf0
> [ 2095.324609] [<ffffffff8127edde>] do_sys_ftruncate.constprop.15+0xfe/0x160
> [ 2095.332286] [<ffffffff8127ee7e>] SyS_ftruncate+0xe/0x10
> [ 2095.338225] [<ffffffff81003c9c>] do_syscall_64+0x6c/0x1e0
> [ 2095.344339] [<ffffffff817d4a3f>] entry_SYSCALL64_slow_path+0x25/0x25
> [ 2095.351531] 2 locks held by trinity-c5/3131:
> [ 2095.356297] #0: (sb_writers#14){.+.+.+}, at: [<ffffffff81284be1>] __sb_start_write+0xd1/0xf0
> [ 2095.365983] #1: (&xfs_nondir_ilock_class){++++..}, at: [<ffffffffa03335fa>] xfs_ilock+0xfa/0x260 [xfs]
truncate on overlay, removing xattrs from XFS file, blocked on
i_ilock.
> [ 2095.440372] [<ffffffff817d2782>] rwsem_down_write_failed+0x242/0x4b0
> [ 2095.474300] [<ffffffff8127e413>] chmod_common+0x63/0x150
> [ 2095.513452] 2 locks held by trinity-c6/3132:
> [ 2095.518217] #0: (sb_writers#14){.+.+.+}, at: [<ffffffff81284be1>] __sb_start_write+0xd1/0xf0
> [ 2095.527895] #1: (&sb->s_type->i_mutex_key#17){++++++}, at: [<ffffffff8127e413>] chmod_common+0x63/0x150
chmod, blocked on i_mutex.
> [ 2095.602379] [<ffffffff817d24b7>] rwsem_down_read_failed+0x107/0x190
> [ 2095.616490] [<ffffffff813e2788>] call_rwsem_down_read_failed+0x18/0x30
> [ 2095.623877] [<ffffffff810f8b0b>] down_read_nested+0x5b/0x80
> [ 2095.649889] [<ffffffff812bdbbd>] vfs_fsync_range+0x3d/0xb0
> [ 2095.680610] 1 lock held by trinity-c7/3133:
> [ 2095.685281] #0: (&xfs_nondir_ilock_class){++++..}, at: [<ffffffffa03335fa>] xfs_ilock+0xfa/0x260 [xfs]
fsync on file, blocked on i_ilock.
> [ 2095.759662] [<ffffffff817d24b7>] rwsem_down_read_failed+0x107/0x190
> [ 2095.807155] [<ffffffff812bdbbd>] vfs_fsync_range+0x3d/0xb0
> [ 2095.813377] [<ffffffff812bdc8d>] do_fsync+0x3d/0x70
> [ 2095.818921] [<ffffffff812bdf63>] SyS_fdatasync+0x13/0x20
> [ 2095.838261] 1 lock held by trinity-c8/3135:
> [ 2095.842930] #0: (&xfs_nondir_ilock_class){++++..}, at: [<ffffffffa03335fa>] xfs_ilock+0xfa/0x260 [xfs]
ditto.
> [ 2095.917305] [<ffffffff817d24b7>] rwsem_down_read_failed+0x107/0x190
> [ 2095.958968] [<ffffffffa0333790>] xfs_ilock_data_map_shared+0x30/0x40 [xfs]
> [ 2095.966752] [<ffffffffa03128c6>] __xfs_get_blocks+0x96/0x9d0 [xfs]
> [ 2095.989413] [<ffffffffa0313214>] xfs_get_blocks+0x14/0x20 [xfs]
> [ 2095.996122] [<ffffffff812cca44>] do_mpage_readpage+0x474/0x800
> [ 2096.029678] [<ffffffff812ccf0d>] mpage_readpages+0x13d/0x1b0
> [ 2096.050724] [<ffffffffa0311f14>] xfs_vm_readpages+0x54/0x170 [xfs]
> [ 2096.057724] [<ffffffff811f1a1d>] __do_page_cache_readahead+0x2ad/0x370
> [ 2096.079787] [<ffffffff811f2014>] force_page_cache_readahead+0x94/0xf0
> [ 2096.087077] [<ffffffff811f2168>] SyS_readahead+0xa8/0xc0
> [ 2096.106427] 1 lock held by trinity-c9/3136:
> [ 2096.111097] #0: (&xfs_nondir_ilock_class){++++..}, at: [<ffffffffa03335fa>] xfs_ilock+0xfa/0x260 [xfs]
readhead blocking in i_ilock before reading in extents.
Nothing here indicates a deadlock. Everything is waiting for locks,
but nothing is holding locks in a way that indicates that progress
is not being made. This sort of thing can happen when slow storage
is massively overloaded - sysrq-w is really the only way to get a
better picutre of what is happening here, but so far there's no
concrete evidence of a hang from this output.
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
next prev parent reply other threads:[~2016-10-09 21:52 UTC|newest]
Thread overview: 104+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20160908235521.GL2356@ZenIV.linux.org.uk>
[not found] ` <20160909015324.GD30056@dastard>
[not found] ` <CA+55aFzohsUXj_3BeFNr2t50Wm=G+7toRDEz=Tk7VJqP3n1hXQ@mail.gmail.com>
[not found] ` <CA+55aFxrqCng2Qxasc9pyMrKUGFjo==fEaFT1vkH9Lncte3RgQ@mail.gmail.com>
[not found] ` <20160909023452.GO2356@ZenIV.linux.org.uk>
[not found] ` <CA+55aFwHQMjO4-vtfB9-ytc=o+DRo-HXVGckvXLboUxgpwb7_g@mail.gmail.com>
[not found] ` <20160909221945.GQ2356@ZenIV.linux.org.uk>
[not found] ` <CA+55aFzTOOB6oEVaaGD0N7Uznk-W9+ULPwzsxS_L_oZqGVSeLA@mail.gmail.com>
[not found] ` <20160914031648.GB2356@ZenIV.linux.org.uk>
[not found] ` <20160914133925.2fba4629@roar.ozlabs.ibm.com>
2016-09-18 5:33 ` xfs_file_splice_read: possible circular locking dependency detected Al Viro
2016-09-19 3:08 ` Nicholas Piggin
2016-09-19 6:11 ` Al Viro
2016-09-19 7:26 ` Nicholas Piggin
[not found] ` <CA+55aFznQaOWoSMNphgGJJWZ=8-odrc0DAUMzfGPQe+_N4UgNA@mail.gmail.com>
[not found] ` <20160914042559.GC2356@ZenIV.linux.org.uk>
[not found] ` <20160917082007.GA6489@ZenIV.linux.org.uk>
[not found] ` <20160917190023.GA8039@ZenIV.linux.org.uk>
2016-09-18 19:31 ` skb_splice_bits() and large chunks in pipe (was " Al Viro
2016-09-18 20:12 ` Linus Torvalds
2016-09-18 22:31 ` Al Viro
2016-09-19 0:18 ` Linus Torvalds
2016-09-19 0:22 ` Al Viro
2016-09-20 9:51 ` Herbert Xu
2016-09-23 19:00 ` [RFC][CFT] splice_read reworked Al Viro
2016-09-23 19:01 ` [PATCH 01/11] fix memory leaks in tracing_buffers_splice_read() Al Viro
2016-09-23 19:02 ` [PATCH 02/11] splice_to_pipe(): don't open-code wakeup_pipe_readers() Al Viro
2016-09-23 19:02 ` [PATCH 03/11] splice: switch get_iovec_page_array() to iov_iter Al Viro
2016-09-23 19:03 ` [PATCH 04/11] splice: lift pipe_lock out of splice_to_pipe() Al Viro
2016-09-23 19:45 ` Linus Torvalds
2016-09-23 20:10 ` Al Viro
2016-09-23 20:36 ` Linus Torvalds
2016-09-24 3:59 ` Al Viro
2016-09-24 17:29 ` Al Viro
2016-09-27 15:38 ` Nicholas Piggin
2016-09-27 15:53 ` Chuck Lever
2016-09-24 3:59 ` [PATCH 04/12] " Al Viro
2016-09-26 13:35 ` Miklos Szeredi
2016-09-27 4:14 ` Al Viro
2016-12-17 19:54 ` Andreas Schwab
2016-12-18 19:28 ` Linus Torvalds
2016-12-18 19:57 ` Andreas Schwab
2016-12-18 20:12 ` Al Viro
2016-12-18 20:30 ` Al Viro
2016-12-18 22:10 ` Linus Torvalds
2016-12-18 22:18 ` Al Viro
2016-12-18 22:22 ` Linus Torvalds
2016-12-18 22:49 ` Andreas Schwab
2016-12-21 18:56 ` Andreas Schwab
2016-12-21 19:12 ` Linus Torvalds
2016-09-24 4:00 ` [PATCH 06/12] new helper: add_to_pipe() Al Viro
2016-09-26 13:49 ` Miklos Szeredi
2016-09-24 4:01 ` [PATCH 10/12] new iov_iter flavour: pipe-backed Al Viro
2016-09-29 20:53 ` Miklos Szeredi
2016-09-29 22:50 ` Al Viro
2016-09-30 7:30 ` Miklos Szeredi
2016-10-03 3:34 ` [RFC] O_DIRECT vs EFAULT (was Re: [PATCH 10/12] new iov_iter flavour: pipe-backed) Al Viro
2016-10-03 17:07 ` Linus Torvalds
2016-10-03 18:54 ` Al Viro
2016-09-24 4:01 ` [PATCH 11/12] switch generic_file_splice_read() to use of ->read_iter() Al Viro
2016-09-24 4:02 ` [PATCH 12/12] switch default_file_splice_read() to use of pipe-backed iov_iter Al Viro
2016-09-23 19:03 ` [PATCH 05/11] skb_splice_bits(): get rid of callback Al Viro
2016-09-23 19:04 ` [PATCH 06/11] new helper: add_to_pipe() Al Viro
2016-09-23 19:04 ` [PATCH 07/11] fuse_dev_splice_read(): switch to add_to_pipe() Al Viro
2016-09-23 19:06 ` [PATCH 08/11] cifs: don't use memcpy() to copy struct iov_iter Al Viro
2016-09-23 19:08 ` [PATCH 09/11] fuse_ioctl_copy_user(): don't open-code copy_page_{to,from}_iter() Al Viro
2016-09-26 9:31 ` Miklos Szeredi
2016-09-23 19:09 ` [PATCH 10/11] new iov_iter flavour: pipe-backed Al Viro
2016-09-23 19:10 ` [PATCH 11/11] switch generic_file_splice_read() to use of ->read_iter() Al Viro
2016-09-30 13:32 ` [RFC][CFT] splice_read reworked CAI Qian
2016-09-30 17:42 ` CAI Qian
2016-09-30 18:33 ` CAI Qian
2016-10-03 1:37 ` Al Viro
2016-10-03 17:49 ` CAI Qian
2016-10-04 17:39 ` local DoS - systemd hang or timeout (WAS: Re: [RFC][CFT] splice_read reworked) CAI Qian
2016-10-04 21:42 ` tj
2016-10-05 14:09 ` CAI Qian
2016-10-05 15:30 ` tj
2016-10-05 15:54 ` CAI Qian
2016-10-05 18:57 ` CAI Qian
2016-10-05 20:05 ` Al Viro
2016-10-06 12:20 ` CAI Qian
2016-10-06 12:25 ` CAI Qian
2016-10-06 16:11 ` CAI Qian
2016-10-06 17:00 ` Linus Torvalds
2016-10-06 18:12 ` CAI Qian
2016-10-07 9:57 ` Dave Chinner
2016-10-07 15:25 ` Linus Torvalds
2016-10-07 7:08 ` Jan Kara
2016-10-07 14:43 ` CAI Qian
2016-10-07 15:27 ` CAI Qian
2016-10-07 18:56 ` CAI Qian
2016-10-09 21:54 ` Dave Chinner
2016-10-10 14:10 ` CAI Qian
2016-10-10 20:14 ` CAI Qian
2016-10-10 21:57 ` Dave Chinner
2016-10-12 19:50 ` [bisected] " CAI Qian
2016-10-12 20:59 ` Dave Chinner
2016-10-13 16:25 ` CAI Qian
2016-10-13 20:49 ` Dave Chinner
2016-10-13 20:56 ` CAI Qian
2016-10-09 21:51 ` Dave Chinner [this message]
2016-10-21 15:38 ` [4.9-rc1+] overlayfs lockdep CAI Qian
2016-10-24 12:57 ` Miklos Szeredi
2016-10-07 9:27 ` local DoS - systemd hang or timeout (WAS: Re: [RFC][CFT] splice_read reworked) Dave Chinner
2016-10-03 1:42 ` [RFC][CFT] splice_read reworked Al Viro
2016-10-03 14:06 ` CAI Qian
2016-10-03 15:20 ` CAI Qian
2016-10-03 21:12 ` Dave Chinner
2016-10-04 13:57 ` CAI Qian
2016-10-03 20:32 ` CAI Qian
2016-10-03 20:35 ` Al Viro
2016-10-04 13:29 ` CAI Qian
2016-10-04 14:28 ` Al Viro
2016-10-04 16:21 ` CAI Qian
2016-10-04 20:12 ` Al Viro
2016-10-05 14:30 ` CAI Qian
2016-10-05 16:07 ` Al Viro
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