From: "Will Manley" <will@williammanley.net>
To: linux-man@vger.kernel.org,
"Alejandro Colomar" <alx.manpages@gmail.com>,
"Michael Kerrisk" <mtk.manpages@gmail.com>
Subject: [PATCH] preadv2: Note preadv2(..., RWF_NOWAIT) bug in BUGS section
Date: Tue, 01 Jun 2021 15:15:35 +0100 [thread overview]
Message-ID: <3f280647-143d-4c52-822a-79338a1b76f7@www.fastmail.com> (raw)
From 4116851719f068bd4117f5d37ead700e88219de4 Mon Sep 17 00:00:00 2001
From: William Manley <will@williammanley.net>
Date: Tue, 1 Jun 2021 15:10:22 +0100
Subject: [PATCH] preadv2: Note preadv2(..., RWF_NOWAIT) bug in BUGS section
To save the next person before they fall foul of it. See
https://lore.kernel.org/linux-fsdevel/fea8b16d-5a69-40f9-b123-e84dcd6e8f2e@www.fastmail.com/T/#u
and https://github.com/tokio-rs/tokio/issues/3803 for more information.
---
man2/readv.2 | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/man2/readv.2 b/man2/readv.2
index df42cf830..3355fa9d7 100644
--- a/man2/readv.2
+++ b/man2/readv.2
@@ -243,7 +243,9 @@ If some data was successfully read, it will return the number of bytes read.
If no bytes were read, it will return \-1 and set
.IR errno
to
-.BR EAGAIN .
+.BR EAGAIN
+(but see
+.BR BUGS ")."
Currently, this flag is meaningful only for
.BR preadv2 ().
.TP
@@ -425,6 +427,13 @@ iov[1].iov_len = strlen(str1);
nwritten = writev(STDOUT_FILENO, iov, 2);
.EE
.in
+.SH BUGS
+Linux v5.9 and v5.10 have a bug where
+.BR preadv2()
+with the
+.BR RWF_NOWAIT
+flag may return 0 even when not at end of file. See
+https://lore.kernel.org/linux-fsdevel/fea8b16d-5a69-40f9-b123-e84dcd6e8f2e@www.fastmail.com/T/#u
.SH SEE ALSO
.BR pread (2),
.BR read (2),
--
2.17.1
next reply other threads:[~2021-06-01 14:15 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-01 14:15 Will Manley [this message]
2021-06-28 20:19 ` [PATCH] preadv2: Note preadv2(..., RWF_NOWAIT) bug in BUGS section Alejandro Colomar (man-pages)
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=3f280647-143d-4c52-822a-79338a1b76f7@www.fastmail.com \
--to=will@williammanley.net \
--cc=alx.manpages@gmail.com \
--cc=linux-man@vger.kernel.org \
--cc=mtk.manpages@gmail.com \
/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.