Anton Nefedov b0a335e351 qemu-char: socket backend: disconnect on write error ... Socket backend read handler should normally perform a disconnect, however the read handler may not get a chance to run if the frontend is not ready (qemu_chr_be_can_write() == 0). This means that in virtio-serial frontend case if - the host has disconnected (giving EPIPE on socket write) - and the guest has disconnected (-> frontend not ready -> backend will not read) - and there is still data (frontend->backend) to flush (has to be a really tricky timing but nevertheless, we have observed the case in production) This results in virtio-serial trying to flush this data continiously forming a busy loop. Solution: react on write error in the socket write handler. errno is not reliable after qio_channel_writev_full(), so we may not get the exact EPIPE, so disconnect on any error but QIO_CHANNEL_ERR_BLOCK which io_channel_send_full() converts to errno EAGAIN. We must not disconnect right away though, there still may be data to read (see 4bf1cb0). Signed-off-by: Anton Nefedov <anton.nefedov@virtuozzo.com> Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Paolo Bonzini <pbonzini@redhat.com> CC: Daniel P. Berrange <berrange@redhat.com> CC: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <1486045589-8074-1-git-send-email-den@openvz.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>		2017-02-16 14:06:55 +01:00
..
char-console.c	char: move console in its own file	2017-01-31 23:31:21 +04:00
char-fd.c	char: move fd chardev in its own file	2017-01-31 23:31:21 +04:00
char-fd.h	char: move fd chardev in its own file	2017-01-31 23:31:21 +04:00
char-file.c	char: move file chardev in its own file	2017-01-31 23:31:21 +04:00
char-io.c
char-io.h
char-mux.c
char-mux.h
char-null.c
char-parallel.c	char: move parallel chardev in its own file	2017-01-31 23:31:21 +04:00
char-parallel.h	char: move parallel chardev in its own file	2017-01-31 23:31:21 +04:00
char-pipe.c	char: move pipe chardev in its own file	2017-01-31 23:31:21 +04:00
char-pty.c	char: move pty chardev in its own file	2017-01-31 23:31:21 +04:00
char-ringbuf.c
char-serial.c	char: move serial chardev to its own file	2017-01-31 23:31:21 +04:00
char-serial.h	char: move serial chardev to its own file	2017-01-31 23:31:21 +04:00
char-socket.c	qemu-char: socket backend: disconnect on write error	2017-02-16 14:06:55 +01:00
char-stdio.c	char: move stdio in its own file	2017-01-31 23:31:21 +04:00
char-udp.c	char: move udp chardev in its own file	2017-01-31 23:31:21 +04:00
char-win-stdio.c	char: move win-stdio into its own file	2017-01-31 23:31:21 +04:00
char-win-stdio.h	char: move win-stdio into its own file	2017-01-31 23:31:21 +04:00
char-win.c	char: move win chardev base class in its own file	2017-01-31 23:31:21 +04:00
char-win.h	char: move win chardev base class in its own file	2017-01-31 23:31:21 +04:00
char.c	char: headers clean-up	2017-01-31 23:31:22 +04:00
Makefile.objs	char: move parallel chardev in its own file	2017-01-31 23:31:21 +04:00