| From ddc3793752ae726e761173ce214ab895b936d15a Mon Sep 17 00:00:00 2001 |
| From: Laszlo Ersek <lersek@redhat.com> |
| Date: Fri, 19 Jul 2013 13:05:22 +0200 |
| Subject: char: io_channel_send: don't lose written bytes |
| |
| RH-Author: Laszlo Ersek <lersek@redhat.com> |
| Message-id: <1374239123-4841-2-git-send-email-lersek@redhat.com> |
| Patchwork-id: 52615 |
| O-Subject: [RHEL-7 qemu-kvm PATCH 1/2] char: io_channel_send: don't lose written bytes |
| Bugzilla: 970047 |
| RH-Acked-by: Amit Shah <amit.shah@redhat.com> |
| RH-Acked-by: Markus Armbruster <armbru@redhat.com> |
| RH-Acked-by: Luiz Capitulino <lcapitulino@redhat.com> |
| |
| The g_io_channel_write_chars() documentation states, |
| |
| bytes_written: The number of bytes written. This can be nonzero even if |
| the return value is not G_IO_STATUS_NORMAL. [...] |
| |
| io_channel_send() could lose such bytes before. |
| |
| Furthermore, the (status == G_IO_STATUS_EOF) condition used to evaluate to |
| constant false whenever it was reached. When that condition actually held, |
| it always led to -1 / EINVAL. This patch (almost) distinguishes |
| G_IO_STATUS_EOF only when no bytes have been written, and then treats it |
| as an error. |
| |
| Signed-off-by: Laszlo Ersek <lersek@redhat.com> |
| Reviewed-by: Amit Shah <amit.shah@redhat.com> |
| Reviewed-by: Anthony Liguori <aliguori@us.ibm.com> |
| Message-id: 1373998781-29561-2-git-send-email-lersek@redhat.com |
| Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> |
| (cherry picked from commit ac8c26f633b01bb32cdf347f9dbd5a80c6712925) |
| |
| diff --git a/qemu-char.c b/qemu-char.c |
| index efe706d..c01deae 100644 |
| |
| |
| @@ -722,35 +722,32 @@ static GIOChannel *io_channel_from_socket(int fd) |
| |
| static int io_channel_send(GIOChannel *fd, const void *buf, size_t len) |
| { |
| - GIOStatus status; |
| - size_t offset; |
| + size_t offset = 0; |
| + GIOStatus status = G_IO_STATUS_NORMAL; |
| |
| - offset = 0; |
| - while (offset < len) { |
| - gsize bytes_written; |
| + while (offset < len && status == G_IO_STATUS_NORMAL) { |
| + gsize bytes_written = 0; |
| |
| status = g_io_channel_write_chars(fd, buf + offset, len - offset, |
| &bytes_written, NULL); |
| - if (status != G_IO_STATUS_NORMAL) { |
| - if (status == G_IO_STATUS_AGAIN) { |
| - /* If we've written any data, return a partial write. */ |
| - if (offset) { |
| - break; |
| - } |
| - errno = EAGAIN; |
| - } else { |
| - errno = EINVAL; |
| - } |
| - |
| - return -1; |
| - } else if (status == G_IO_STATUS_EOF) { |
| - break; |
| - } |
| - |
| offset += bytes_written; |
| } |
| |
| - return offset; |
| + if (offset > 0) { |
| + return offset; |
| + } |
| + switch (status) { |
| + case G_IO_STATUS_NORMAL: |
| + g_assert(len == 0); |
| + return 0; |
| + case G_IO_STATUS_AGAIN: |
| + errno = EAGAIN; |
| + return -1; |
| + default: |
| + break; |
| + } |
| + errno = EINVAL; |
| + return -1; |
| } |
| |
| #ifndef _WIN32 |