On 06/09/2016 15:56, Daniel P. Berrange wrote:
> The mux chardev was not checking the return value of any
> qemu_chr_fe_write() call so would silently loose data
> on EAGAIN.
>
> Similarly the qemu_chr_fe_printf method would not check
> errors and was not in a position to retry even if it
> could check.
>
> Signed-off-by: Daniel P. Berrange <berra...@redhat.com>
> ---
> qemu-char.c | 18 ++++++++++++------
> 1 file changed, 12 insertions(+), 6 deletions(-)
>
> diff --git a/qemu-char.c b/qemu-char.c
> index 5f82ebb..6104f24 100644
> --- a/qemu-char.c
> +++ b/qemu-char.c
> @@ -440,7 +440,9 @@ void qemu_chr_fe_printf(CharDriverState *s, const char
> *fmt, ...)
> va_list ap;
> va_start(ap, fmt);
> vsnprintf(buf, sizeof(buf), fmt, ap);
> - qemu_chr_fe_write(s, (uint8_t *)buf, strlen(buf));
> + /* XXX this blocks entire thread. Rewrite to use
> + * qemu_chr_fe_write and background I/O callbacks */
> + qemu_chr_fe_write_all(s, (uint8_t *)buf, strlen(buf));
> va_end(ap);
> }
>
> @@ -556,7 +558,9 @@ static int mux_chr_write(CharDriverState *chr, const
> uint8_t *buf, int len)
> (secs / 60) % 60,
> secs % 60,
> (int)(ti % 1000));
> - qemu_chr_fe_write(d->drv, (uint8_t *)buf1, strlen(buf1));
> + /* XXX this blocks entire thread. Rewrite to use
> + * qemu_chr_fe_write and background I/O callbacks */
> + qemu_chr_fe_write_all(d->drv, (uint8_t *)buf1, strlen(buf1));
> d->linestart = 0;
> }
> ret += qemu_chr_fe_write(d->drv, buf+i, 1);
> @@ -594,13 +598,15 @@ static void mux_print_help(CharDriverState *chr)
> "\n\rEscape-Char set to Ascii: 0x%02x\n\r\n\r",
> term_escape_char);
> }
> - qemu_chr_fe_write(chr, (uint8_t *)cbuf, strlen(cbuf));
> + /* XXX this blocks entire thread. Rewrite to use
> + * qemu_chr_fe_write and background I/O callbacks */
> + qemu_chr_fe_write_all(chr, (uint8_t *)cbuf, strlen(cbuf));
> for (i = 0; mux_help[i] != NULL; i++) {
> for (j=0; mux_help[i][j] != '\0'; j++) {
> if (mux_help[i][j] == '%')
> - qemu_chr_fe_write(chr, (uint8_t *)ebuf, strlen(ebuf));
> + qemu_chr_fe_write_all(chr, (uint8_t *)ebuf, strlen(ebuf));
> else
> - qemu_chr_fe_write(chr, (uint8_t *)&mux_help[i][j], 1);
> + qemu_chr_fe_write_all(chr, (uint8_t *)&mux_help[i][j], 1);
> }
> }
> }
> @@ -625,7 +631,7 @@ static int mux_proc_byte(CharDriverState *chr, MuxDriver
> *d, int ch)
> case 'x':
> {
> const char *term = "QEMU: Terminated\n\r";
> - qemu_chr_fe_write(chr, (uint8_t *)term, strlen(term));
> + qemu_chr_fe_write_all(chr, (uint8_t *)term, strlen(term));
> exit(0);
> break;
> }
>
Queued for 2.8, thanks.
Paolo
