public inbox for [email protected]
 help / color / mirror / Atom feed
From: Pavel Begunkov <[email protected]>
To: Alexander Viro <[email protected]>,
	[email protected], Jens Axboe <[email protected]>,
	[email protected]
Cc: [email protected], [email protected]
Subject: [PATCH 1/2] iov_iter: mark truncated iters
Date: Mon,  9 Aug 2021 12:52:36 +0100	[thread overview]
Message-ID: <a2c762e46ede42470f4dd9aafb927466bd363943.1628509745.git.asml.silence@gmail.com> (raw)
In-Reply-To: <[email protected]>

Track if an iterator has ever been truncated. This will be used to
mitigate revert-truncate problems.

Signed-off-by: Pavel Begunkov <[email protected]>
---
 include/linux/uio.h | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/include/linux/uio.h b/include/linux/uio.h
index 82c3c3e819e0..61b8d312d13a 100644
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -30,6 +30,7 @@ enum iter_type {
 struct iov_iter {
 	u8 iter_type;
 	bool data_source;
+	bool truncated;
 	size_t iov_offset;
 	size_t count;
 	union {
@@ -254,8 +255,10 @@ static inline void iov_iter_truncate(struct iov_iter *i, u64 count)
 	 * conversion in assignement is by definition greater than all
 	 * values of size_t, including old i->count.
 	 */
-	if (i->count > count)
+	if (i->count > count) {
 		i->count = count;
+		i->truncated = true;
+	}
 }
 
 /*
-- 
2.32.0


  reply	other threads:[~2021-08-09 11:53 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-09 11:52 [PATCH 0/2] iter revert problems Pavel Begunkov
2021-08-09 11:52 ` Pavel Begunkov [this message]
2021-08-09 11:52 ` [PATCH 2/2] io_uring: don't retry with truncated iter Pavel Begunkov
2021-08-09 15:52 ` [PATCH 0/2] iter revert problems Al Viro
2021-08-09 18:56   ` Pavel Begunkov
2021-08-10  8:47   ` David Laight

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=a2c762e46ede42470f4dd9aafb927466bd363943.1628509745.git.asml.silence@gmail.com \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    /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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox