qemu-devel.nongnu.org archive mirror
 help / color / mirror / Atom feed
From: Vivek Goyal <vgoyal@redhat.com>
To: qemu-devel@nongnu.org, virtio-fs@redhat.com
Cc: dgilbert@redhat.com, vgoyal@redhat.com
Subject: [PATCH 6/7] virtiofsd: Check EOF before short read
Date: Tue, 11 May 2021 17:37:35 -0400	[thread overview]
Message-ID: <20210511213736.281016-7-vgoyal@redhat.com> (raw)
In-Reply-To: <20210511213736.281016-1-vgoyal@redhat.com>

In virtio_send_data_iov() we are checking first for short read and then
EOF condition. Change the order. Basically check for error and EOF first
and last remaining piece is short ready which will lead to retry
automatically at the end of while loop.

Just that it is little simpler to read to the code. There is no need
to call "continue" and also one less call of "len-=ret".

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
---
 tools/virtiofsd/fuse_virtio.c | 21 ++++++++++-----------
 1 file changed, 10 insertions(+), 11 deletions(-)

diff --git a/tools/virtiofsd/fuse_virtio.c b/tools/virtiofsd/fuse_virtio.c
index 434fe401cf..aa53808ef9 100644
--- a/tools/virtiofsd/fuse_virtio.c
+++ b/tools/virtiofsd/fuse_virtio.c
@@ -410,25 +410,24 @@ int virtio_send_data_iov(struct fuse_session *se, struct fuse_chan *ch,
                      __func__, len);
             goto err;
         }
-        fuse_log(FUSE_LOG_DEBUG, "%s: preadv ret=%d len=%zd\n", __func__,
-                 ret, len);
-        if (ret < len && ret) {
-            fuse_log(FUSE_LOG_DEBUG, "%s: ret < len\n", __func__);
-            /* Skip over this much next time around */
-            iov_discard_front(&in_sg_ptr, &in_sg_cpy_count, ret);
-            buf->buf[0].pos += ret;
-            len -= ret;
 
-            /* Lets do another read */
-            continue;
-        }
         if (!ret) {
             /* EOF case? */
             fuse_log(FUSE_LOG_DEBUG, "%s: !ret len remaining=%zd\n", __func__,
                      len);
             break;
         }
+        fuse_log(FUSE_LOG_DEBUG, "%s: preadv ret=%d len=%zd\n", __func__,
+                 ret, len);
+
         len -= ret;
+        /* Short read. Retry reading remaining bytes */
+        if (len) {
+            fuse_log(FUSE_LOG_DEBUG, "%s: ret < len\n", __func__);
+            /* Skip over this much next time around */
+            iov_discard_front(&in_sg_ptr, &in_sg_cpy_count, ret);
+            buf->buf[0].pos += ret;
+        }
     } while (len);
 
     /* Need to fix out->len on EOF */
-- 
2.25.4



  parent reply	other threads:[~2021-05-11 21:39 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-11 21:37 [PATCH 0/7] virtiofsd: Few cleanups in virtio_send_data_iov() Vivek Goyal
2021-05-11 21:37 ` [PATCH 1/7] virtiofsd: Check for EINTR in preadv() and retry Vivek Goyal
2021-05-18 11:59   ` Dr. David Alan Gilbert
2021-05-11 21:37 ` [PATCH 2/7] virtiofsd: Get rid of unreachable code in read Vivek Goyal
2021-05-18 12:01   ` Dr. David Alan Gilbert
2021-05-11 21:37 ` [PATCH 3/7] virtiofsd: Use iov_discard_front() to skip bytes Vivek Goyal
2021-05-18 12:10   ` Dr. David Alan Gilbert
2021-05-11 21:37 ` [PATCH 4/7] virtiofsd: get rid of in_sg_left variable Vivek Goyal
2021-05-18 12:19   ` Dr. David Alan Gilbert
2021-05-11 21:37 ` [PATCH 5/7] virtiofsd: Simplify skip byte logic Vivek Goyal
2021-05-18 12:26   ` Dr. David Alan Gilbert
2021-05-11 21:37 ` Vivek Goyal [this message]
2021-05-18 12:31   ` [PATCH 6/7] virtiofsd: Check EOF before short read Dr. David Alan Gilbert
2021-05-11 21:37 ` [PATCH 7/7] virtiofsd: Set req->reply_sent right after sending reply Vivek Goyal
2021-05-13 20:50   ` [Virtio-fs] " Connor Kuehl
2021-05-17 13:08     ` Vivek Goyal
2021-05-18 12:34       ` Dr. David Alan Gilbert
2021-05-18 12:32   ` Dr. David Alan Gilbert
2021-05-11 21:48 ` [PATCH 0/7] virtiofsd: Few cleanups in virtio_send_data_iov() no-reply
2021-05-13 20:50 ` [Virtio-fs] " Connor Kuehl
2021-05-17 13:08   ` Vivek Goyal

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=20210511213736.281016-7-vgoyal@redhat.com \
    --to=vgoyal@redhat.com \
    --cc=dgilbert@redhat.com \
    --cc=qemu-devel@nongnu.org \
    --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).