From: Olga Krishtal <okrish...@parallels.com>
Set fd non-blocking to avoid common use cases (like reading from a
named pipe) from hanging the agent. This was missed in the original
code.
The patch introduces analog of qemu_set_non/block for HANDLES.
The usage of handles in qemu_set_non/block is impossible, because for
win32 there is a difference between file discriptors and file handles,
and all file ops are made via Win32 api.
Signed-off-by: Olga Krishtal <okrish...@parallels.com>
Signed-off-by: Denis V. Lunev <d...@openvz.org>
CC: Michael Roth <mdr...@linux.vnet.ibm.com>
CC: Stefan Weil <s...@weilnetz.de>
---
include/qemu/sockets.h | 2 ++
qga/commands-win32.c | 6 ++++++
util/oslib-win32.c | 41 +++++++++++++++++++++++++++++++++++++++++
3 files changed, 49 insertions(+)
diff --git a/include/qemu/sockets.h b/include/qemu/sockets.h
index 5a183c5..e2323f4 100644
--- a/include/qemu/sockets.h
+++ b/include/qemu/sockets.h
@@ -39,6 +39,8 @@ int socket_set_cork(int fd, int v);
int socket_set_nodelay(int fd);
void qemu_set_block(int fd);
void qemu_set_nonblock(int fd);
+void qemu_set_nonblock_by_handle(int64_t fh);
+void qemu_set_block_by_handle(int64_t fh);
int socket_set_fast_reuse(int fd);
int send_all(int fd, const void *buf, int len1);
int recv_all(int fd, void *buf, int len1, bool single_read);
diff --git a/qga/commands-win32.c b/qga/commands-win32.c
index 97f19d5..f959d75 100644
--- a/qga/commands-win32.c
+++ b/qga/commands-win32.c
@@ -34,6 +34,7 @@
#include "qapi/qmp/qerror.h"
#include "qemu/queue.h"
#include "qemu/host-utils.h"
+#include "qemu/sockets.h"
#ifndef SHTDN_REASON_FLAG_PLANNED
#define SHTDN_REASON_FLAG_PLANNED 0x80000000
@@ -158,6 +159,11 @@ int64_t qmp_guest_file_open(const char *path, bool
has_mode,
return -1;
}
+ /* set fd non-blocking to avoid common use cases (like reading from a
+ * named pipe) from hanging the agent
+ */
+ qemu_set_nonblock_by_handle((int64_t)fh);
+
fd = guest_file_handle_add(fh, errp);
if (fd < 0) {
CloseHandle(fh);
diff --git a/util/oslib-win32.c b/util/oslib-win32.c
index 09f9e98..4a9fd8e 100644
--- a/util/oslib-win32.c
+++ b/util/oslib-win32.c
@@ -121,6 +121,37 @@ struct tm *localtime_r(const time_t *timep, struct tm
*result)
}
#endif /* CONFIG_LOCALTIME_R */
+static void qemu_set_handle_nonblocking(int64_t fh, bool nonblocking)
+{
+ DWORD file_type, pipe_state;
+ HANDLE handle = (HANDLE)fh;
+ file_type = GetFileType(handle);
+ if (file_type != FILE_TYPE_PIPE) {
+ return;
+ }
+ /* If file_type == FILE_TYPE_PIPE, according to msdn
+ * the specified file is socket or named pipe */
+ if (!GetNamedPipeHandleState(handle, &pipe_state, NULL,
+ NULL, NULL, NULL, 0)) {
+ return;
+ }
+ /* The fd is named pipe fd */
+ if (!nonblocking == !(pipe_state & PIPE_NOWAIT)) {
+ /* In this case we do not need perform any operation, because
+ * nonblocking = true and PIPE_NOWAIT is already set or
+ * nonblocking = false and PIPE_NOWAIT is not set */
+ return;
+ }
+
+ if (nonblocking) {
+ pipe_state |= PIPE_NOWAIT;
+ } else {
+ pipe_state &= ~PIPE_NOWAIT;
+ }
+
+ SetNamedPipeHandleState(handle, &pipe_state, NULL, NULL);
+}
+
void qemu_set_block(int fd)
{
unsigned long opt = 0;
@@ -135,6 +166,16 @@ void qemu_set_nonblock(int fd)
qemu_fd_register(fd);
}
+void qemu_set_block_by_handle(int64_t fh)
+{
+ qemu_set_handle_nonblocking(fh, false);
+}
+
+void qemu_set_nonblock_by_handle(int64_t fh)
+{
+ qemu_set_handle_nonblocking(fh, true);
+}
+
int socket_set_fast_reuse(int fd)
{
/* Enabling the reuse of an endpoint that was used by a socket still in
--
2.1.4
