From: Linus Torvalds <torvalds@linux-foundation.org>
To: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Schwab <schwab@linux-m68k.org>,
Dave Chinner <david@fromorbit.com>, CAI Qian <caiqian@redhat.com>,
linux-xfs <linux-xfs@vger.kernel.org>,
xfs@oss.sgi.com, Jens Axboe <axboe@kernel.dk>,
Nick Piggin <npiggin@gmail.com>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>
Subject: Re: [PATCH 04/12] splice: lift pipe_lock out of splice_to_pipe()
Date: Sun, 18 Dec 2016 14:10:54 -0800 [thread overview]
Message-ID: <CA+55aFzPE6FbwX2NuiMkz9G+FzAoiNeb8jOSWwSoX3O7+KuH4Q@mail.gmail.com> (raw)
In-Reply-To: <20161218203003.GZ1555@ZenIV.linux.org.uk>
On Sun, Dec 18, 2016 at 12:30 PM, Al Viro <viro@zeniv.linux.org.uk> wrote:
>
> OK, I see what's going on - it's wait_for_space() lifted past the checks
> for lack of readers. The fix, AFAICS, is simply
Ugh. Does it have to be duplicated?
How about just making the wait_for_space() loop be a for-loop, and writing it as
for (;;) {
if (unlikely(!pipe->readers)) {
send_sig(SIGPIPE, current, 0);
return -EPIPE;
}
if (pipe->nrbufs == pipe->buffers)
return 0;
if (flags & SPLICE_F_NONBLOCK)
return -EAGAIN;
if (signal_pending(current))
return -ERESTARTSYS;
pipe->waiting_writers++;
pipe_wait(pipe);
pipe->waiting_writers--;
}
and just having it once?
Regardless - Andreas, can you verify that that fixes your issues? I'm
assuming you had some real load that made you notice this, not just he
dummy example..
Linus
next prev parent reply other threads:[~2016-12-18 22:10 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 [this message]
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
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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