From da3039bc7ec4fda6719be3bdd10f4b0fdaceb17a Mon Sep 17 00:00:00 2001

From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

Date: Fri, 16 Jan 2015 17:35:35 +0100

Subject: [PATCH 03/16] socket shutdown

Message-id: <1421429737-23581-2-git-send-email-dgilbert@redhat.com>

Patchwork-id: 63332

O-Subject: [RHEL-7.2 qemu-kvm PATCH 1/3] socket shutdown

Bugzilla: 1086168

RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>

RH-Acked-by: Amit Shah <amit.shah@redhat.com>

RH-Acked-by: Laszlo Ersek <lersek@redhat.com>

From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

Add QEMUFile interface to allow a socket to be 'shut down' - i.e. any

reads/writes will fail (and any blocking read/write will be woken).

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>

Reviewed-by: Amit Shah <amit.shah@redhat.com>

Signed-off-by: Amit Shah <amit.shah@redhat.com>

(cherry picked from commit e1a8c9b67fc97d293211773edcae9e8e2f3367ab)

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>

Conflicts:

	include/migration/qemu-file.h

	migration/qemu-file-unix.c

	migration/qemu-file.c

   Because we split qemu-file.c out of savevm and moved it

---

 include/migration/qemu-file.h | 10 ++++++++++

 include/qemu/sockets.h        |  7 +++++++

 savevm.c                      | 33 +++++++++++++++++++++++++++++----

 3 files changed, 46 insertions(+), 4 deletions(-)

diff --git a/include/migration/qemu-file.h b/include/migration/qemu-file.h

index 0f757fb..032de47 100644

--- a/include/migration/qemu-file.h

+++ b/include/migration/qemu-file.h

@@ -82,6 +82,14 @@ typedef size_t (QEMURamSaveFunc)(QEMUFile *f, void *opaque,

                                size_t size,

                                int *bytes_sent);

+/*

+ * Stop any read or write (depending on flags) on the underlying

+ * transport on the QEMUFile.

+ * Existing blocking reads/writes must be woken

+ * Returns 0 on success, -err on error

+ */

+typedef int (QEMUFileShutdownFunc)(void *opaque, bool rd, bool wr);

+

 typedef struct QEMUFileOps {

     QEMUFilePutBufferFunc *put_buffer;

     QEMUFileGetBufferFunc *get_buffer;

@@ -92,6 +100,7 @@ typedef struct QEMUFileOps {

     QEMURamHookFunc *after_ram_iterate;

     QEMURamHookFunc *hook_ram_load;

     QEMURamSaveFunc *save_page;

+    QEMUFileShutdownFunc *shut_down;

 } QEMUFileOps;

 QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops);

@@ -141,6 +150,7 @@ void qemu_file_reset_rate_limit(QEMUFile *f);

 void qemu_file_set_rate_limit(QEMUFile *f, int64_t new_rate);

 int64_t qemu_file_get_rate_limit(QEMUFile *f);

 int qemu_file_get_error(QEMUFile *f);

+int qemu_file_shutdown(QEMUFile *f);

 void qemu_fflush(QEMUFile *f);

 static inline void qemu_put_be64s(QEMUFile *f, const uint64_t *pv)

diff --git a/include/qemu/sockets.h b/include/qemu/sockets.h

index c5174d7..729ff52 100644

--- a/include/qemu/sockets.h

+++ b/include/qemu/sockets.h

@@ -42,6 +42,13 @@ void qemu_set_nonblock(int fd);

 int send_all(int fd, const void *buf, int len1);

 int recv_all(int fd, void *buf, int len1, bool single_read);

+#ifdef WIN32

+/* Windows has different names for the same constants with the same values */

+#define SHUT_RD   0

+#define SHUT_WR   1

+#define SHUT_RDWR 2

+#endif

+

 /* callback function for nonblocking connect

  * valid fd on success, negative error code on failure

  */

diff --git a/savevm.c b/savevm.c

index 963dc7d..731d5c0 100644

--- a/savevm.c

+++ b/savevm.c

@@ -204,6 +204,17 @@ static int socket_close(void *opaque)

     return 0;

 }

+static int socket_shutdown(void *opaque, bool rd, bool wr)

+{

+    QEMUFileSocket *s = opaque;

+

+    if (shutdown(s->fd, rd ? (wr ? SHUT_RDWR : SHUT_RD) : SHUT_WR)) {

+        return -errno;

+    } else {

+        return 0;

+    }

+}

+

 static int stdio_get_fd(void *opaque)

 {

     QEMUFileStdio *s = opaque;

@@ -448,17 +459,31 @@ QEMUFile *qemu_fdopen(int fd, const char *mode)

 }

 static const QEMUFileOps socket_read_ops = {

-    .get_fd =     socket_get_fd,

+    .get_fd     = socket_get_fd,

     .get_buffer = socket_get_buffer,

-    .close =      socket_close

+    .close      = socket_close,

+    .shut_down  = socket_shutdown

 };

 static const QEMUFileOps socket_write_ops = {

-    .get_fd =     socket_get_fd,

+    .get_fd        = socket_get_fd,

     .writev_buffer = socket_writev_buffer,

-    .close =      socket_close

+    .close         = socket_close,

+    .shut_down     = socket_shutdown

 };

+/*

+ * Stop a file from being read/written - not all backing files can do this

+ * typically only sockets can.

+ */

+int qemu_file_shutdown(QEMUFile *f)

+{

+    if (!f->ops->shut_down) {

+        return -ENOSYS;

+    }

+    return f->ops->shut_down(f->opaque, true, true);

+}

+

 bool qemu_file_mode_is_not_valid(const char *mode)

 {

     if (mode == NULL ||

-- 

1.8.3.1