From: Greg Kurz <groug@kaod.org>
To: qemu-devel@nongnu.org
Cc: "Daniel P . Berrangé" <berrange@redhat.com>,
"Michael S. Tsirkin" <mst@redhat.com>,
"Dr. David Alan Gilbert" <dgilbert@redhat.com>,
"Greg Kurz" <groug@kaod.org>,
virtio-fs@redhat.com, "Stefan Hajnoczi" <stefanha@redhat.com>,
"Vivek Goyal" <vgoyal@redhat.com>
Subject: [PATCH v2 1/7] vhost-user: Drop misleading EAGAIN checks in slave_read()
Date: Fri, 12 Mar 2021 10:22:06 +0100 [thread overview]
Message-ID: <20210312092212.782255-2-groug@kaod.org> (raw)
In-Reply-To: <20210312092212.782255-1-groug@kaod.org>
slave_read() checks EAGAIN when reading or writing to the socket
fails. This gives the impression that the slave channel is in
non-blocking mode, which is certainly not the case with the current
code base. And the rest of the code isn't actually ready to cope
with non-blocking I/O.
Just drop the checks everywhere in this function for the sake of
clarity.
Signed-off-by: Greg Kurz <groug@kaod.org>
---
hw/virtio/vhost-user.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index 2fdd5daf74bb..6af9b43a7232 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -1420,7 +1420,7 @@ static void slave_read(void *opaque)
do {
size = recvmsg(u->slave_fd, &msgh, 0);
- } while (size < 0 && (errno == EINTR || errno == EAGAIN));
+ } while (size < 0 && errno == EINTR);
if (size != VHOST_USER_HDR_SIZE) {
error_report("Failed to read from slave.");
@@ -1452,7 +1452,7 @@ static void slave_read(void *opaque)
/* Read payload */
do {
size = read(u->slave_fd, &payload, hdr.size);
- } while (size < 0 && (errno == EINTR || errno == EAGAIN));
+ } while (size < 0 && errno == EINTR);
if (size != hdr.size) {
error_report("Failed to read payload from slave.");
@@ -1503,7 +1503,7 @@ static void slave_read(void *opaque)
do {
size = writev(u->slave_fd, iovec, ARRAY_SIZE(iovec));
- } while (size < 0 && (errno == EINTR || errno == EAGAIN));
+ } while (size < 0 && errno == EINTR);
if (size != VHOST_USER_HDR_SIZE + hdr.size) {
error_report("Failed to send msg reply to slave.");
--
2.26.2
next prev parent reply other threads:[~2021-03-12 9:25 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-12 9:22 [PATCH v2 0/7] virtiofsd: Avoid potential deadlocks Greg Kurz
2021-03-12 9:22 ` Greg Kurz [this message]
2021-03-15 10:34 ` [PATCH v2 1/7] vhost-user: Drop misleading EAGAIN checks in slave_read() Stefan Hajnoczi
2021-03-12 9:22 ` [PATCH v2 2/7] vhost-user: Fix double-close on slave_read() error path Greg Kurz
2021-03-15 10:36 ` Stefan Hajnoczi
2021-03-12 9:22 ` [PATCH v2 3/7] vhost-user: Factor out duplicated slave_fd teardown code Greg Kurz
2021-03-15 10:36 ` Stefan Hajnoczi
2021-03-12 9:22 ` [PATCH v2 4/7] vhost-user: Convert slave channel to QIOChannelSocket Greg Kurz
2021-03-15 10:37 ` Stefan Hajnoczi
2021-03-12 9:22 ` [PATCH v2 5/7] vhost-user: Introduce nested event loop in vhost_user_read() Greg Kurz
2021-03-15 10:38 ` Stefan Hajnoczi
2021-03-12 9:22 ` [PATCH v2 6/7] vhost-user: Monitor slave channel " Greg Kurz
2021-03-15 12:20 ` Stefan Hajnoczi
2021-03-12 9:22 ` [PATCH v2 7/7] virtiofsd: Release vu_dispatch_lock when stopping queue Greg Kurz
2021-03-15 14:57 ` Dr. David Alan Gilbert
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=20210312092212.782255-2-groug@kaod.org \
--to=groug@kaod.org \
--cc=berrange@redhat.com \
--cc=dgilbert@redhat.com \
--cc=mst@redhat.com \
--cc=qemu-devel@nongnu.org \
--cc=stefanha@redhat.com \
--cc=vgoyal@redhat.com \
--cc=virtio-fs@redhat.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).