From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
To: Vivek Goyal <vgoyal@redhat.com>
Cc: virtio-fs@redhat.com, qemu-devel@nongnu.org
Subject: Re: [PATCH 6/7] virtiofsd: Check EOF before short read
Date: Tue, 18 May 2021 13:31:02 +0100 [thread overview]
Message-ID: <YKOzhol+5jCuZBKn@work-vm> (raw)
In-Reply-To: <20210511213736.281016-7-vgoyal@redhat.com>
* Vivek Goyal (vgoyal@redhat.com) wrote:
> 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>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@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
>
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
next prev parent reply other threads:[~2021-05-18 12:38 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 ` [PATCH 6/7] virtiofsd: Check EOF before short read Vivek Goyal
2021-05-18 12:31 ` Dr. David Alan Gilbert [this message]
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
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