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From: Paolo Bonzini <pbonzini@redhat.com>
To: pyssling@ludd.ltu.se, batuzovk@ispras.ru, qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH v3] qemu-char: Fix missed data on unix socket
Date: Fri, 17 Jul 2015 19:28:43 +0200	[thread overview]
Message-ID: <55A93B4B.4060408@redhat.com> (raw)
In-Reply-To: <1437153114-19074-1-git-send-email-pyssling@ludd.ltu.se>



On 17/07/2015 19:11, pyssling@ludd.ltu.se wrote:
> From: Nils Carlson <pyssling@ludd.ltu.se>
> 
> Commit 812c1057 introduced HUP detection on unix and tcp sockets prior
> to a read in tcp_chr_read. This unfortunately broke CloudStack 4.2
> which relied on the old behaviour where data on a socket was readable
> even if a HUP was present.
> 
> A working solution seems to be to simply check for a HUP after
> reading all available data, i.e. recv returns a negative value.
> 
> Signed-off-by: Nils Carlson <pyssling@ludd.ltu.se>
> ---
>  qemu-char.c |    8 +-------
>  1 file changed, 1 insertion(+), 7 deletions(-)
> 
> diff --git a/qemu-char.c b/qemu-char.c
> index 617e034..f92fcee 100644
> --- a/qemu-char.c
> +++ b/qemu-char.c
> @@ -2847,12 +2847,6 @@ static gboolean tcp_chr_read(GIOChannel *chan, GIOCondition cond, void *opaque)
>      uint8_t buf[READ_BUF_LEN];
>      int len, size;
>  
> -    if (cond & G_IO_HUP) {
> -        /* connection closed */
> -        tcp_chr_disconnect(chr);
> -        return TRUE;
> -    }
> -
>      if (!s->connected || s->max_size <= 0) {
>          return TRUE;
>      }
> @@ -2860,7 +2854,7 @@ static gboolean tcp_chr_read(GIOChannel *chan, GIOCondition cond, void *opaque)
>      if (len > s->max_size)
>          len = s->max_size;
>      size = tcp_chr_recv(chr, (void *)buf, len);
> -    if (size == 0) {
> +    if (size == 0 || (size < 0 && (cond & G_IO_HUP))) {
>          /* connection closed */
>          tcp_chr_disconnect(chr);
>      } else if (size > 0) {
> 

This looks good, but I'll also wait for your report on testing the patch
that uses the recv return value.

Paolo

      reply	other threads:[~2015-07-17 17:28 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-07-17 17:11 [Qemu-devel] [PATCH v3] qemu-char: Fix missed data on unix socket pyssling
2015-07-17 17:28 ` Paolo Bonzini [this message]

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