char: move backends' io watch tag to CharDriverState

All the backends implement an io watcher tag for callbacks.  Move it to
CharDriverState from each backend's struct to make accessing the tag from
backend-neutral functions easier.

This will be used later to cancel a callback on chardev detach from a
frontend.

CC: <qemu-stable@nongnu.org>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
(cherry picked from commit 7ba9addc165b37b764baa08c02518b15b2361707)

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

2 files changed, 40 insertions, 38 deletions

diff --git a/include/sysemu/char.h b/include/sysemu/char.h
index 8053130a97..ad101d9258 100644
--- a/include/sysemu/char.h
+++ b/include/sysemu/char.h
@@ -78,6 +78,7 @@ struct CharDriverState {
     int explicit_be_open;
     int avail_connections;
     int is_mux;
+    guint fd_in_tag;
     QemuOpts *opts;
     QTAILQ_ENTRY(CharDriverState) next;
 };
diff --git a/qemu-char.c b/qemu-char.c
index 1621fbd30f..1dc1646c96 100644
--- a/qemu-char.c
+++ b/qemu-char.c
@@ -798,7 +798,6 @@ static int io_channel_send(GIOChannel *fd, const void *buf, size_t len)
 typedef struct FDCharDriver {
     CharDriverState *chr;
     GIOChannel *fd_in, *fd_out;
-    guint fd_in_tag;
     int max_size;
     QTAILQ_ENTRY(FDCharDriver) node;
 } FDCharDriver;
@@ -830,9 +829,9 @@ static gboolean fd_chr_read(GIOChannel *chan, GIOCondition cond, void *opaque)
     status = g_io_channel_read_chars(chan, (gchar *)buf,
                                      len, &bytes_read, NULL);
     if (status == G_IO_STATUS_EOF) {
-        if (s->fd_in_tag) {
-            io_remove_watch_poll(s->fd_in_tag);
-            s->fd_in_tag = 0;
+        if (chr->fd_in_tag) {
+            io_remove_watch_poll(chr->fd_in_tag);
+            chr->fd_in_tag = 0;
         }
         qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
         return FALSE;
@@ -863,13 +862,14 @@ static void fd_chr_update_read_handler(CharDriverState *chr)
 {
     FDCharDriver *s = chr->opaque;
 
-    if (s->fd_in_tag) {
-        io_remove_watch_poll(s->fd_in_tag);
-        s->fd_in_tag = 0;
+    if (chr->fd_in_tag) {
+        io_remove_watch_poll(chr->fd_in_tag);
+        chr->fd_in_tag = 0;
     }
 
     if (s->fd_in) {
-        s->fd_in_tag = io_add_watch_poll(s->fd_in, fd_chr_read_poll, fd_chr_read, chr);
+        chr->fd_in_tag = io_add_watch_poll(s->fd_in, fd_chr_read_poll,
+                                           fd_chr_read, chr);
     }
 }
 
@@ -877,9 +877,9 @@ static void fd_chr_close(struct CharDriverState *chr)
 {
     FDCharDriver *s = chr->opaque;
 
-    if (s->fd_in_tag) {
-        io_remove_watch_poll(s->fd_in_tag);
-        s->fd_in_tag = 0;
+    if (chr->fd_in_tag) {
+        io_remove_watch_poll(chr->fd_in_tag);
+        chr->fd_in_tag = 0;
     }
 
     if (s->fd_in) {
@@ -1012,7 +1012,6 @@ static CharDriverState *qemu_chr_open_stdio(ChardevStdio *opts)
 
 typedef struct {
     GIOChannel *fd;
-    guint fd_tag;
     int connected;
     int read_bytes;
     guint timer_tag;
@@ -1123,9 +1122,9 @@ static void pty_chr_state(CharDriverState *chr, int connected)
     PtyCharDriver *s = chr->opaque;
 
     if (!connected) {
-        if (s->fd_tag) {
-            io_remove_watch_poll(s->fd_tag);
-            s->fd_tag = 0;
+        if (chr->fd_in_tag) {
+            io_remove_watch_poll(chr->fd_in_tag);
+            chr->fd_in_tag = 0;
         }
         s->connected = 0;
         /* (re-)connect poll interval for idle guests: once per second.
@@ -1140,7 +1139,8 @@ static void pty_chr_state(CharDriverState *chr, int connected)
         if (!s->connected) {
             s->connected = 1;
             qemu_chr_be_generic_open(chr);
-            s->fd_tag = io_add_watch_poll(s->fd, pty_chr_read_poll, pty_chr_read, chr);
+            chr->fd_in_tag = io_add_watch_poll(s->fd, pty_chr_read_poll,
+                                               pty_chr_read, chr);
         }
     }
 }
@@ -1151,9 +1151,9 @@ static void pty_chr_close(struct CharDriverState *chr)
     PtyCharDriver *s = chr->opaque;
     int fd;
 
-    if (s->fd_tag) {
-        io_remove_watch_poll(s->fd_tag);
-        s->fd_tag = 0;
+    if (chr->fd_in_tag) {
+        io_remove_watch_poll(chr->fd_in_tag);
+        chr->fd_in_tag = 0;
     }
     fd = g_io_channel_unix_get_fd(s->fd);
     g_io_channel_unref(s->fd);
@@ -2161,7 +2161,6 @@ static CharDriverState *qemu_chr_open_stdio(ChardevStdio *opts)
 typedef struct {
     int fd;
     GIOChannel *chan;
-    guint tag;
     uint8_t buf[READ_BUF_LEN];
     int bufcnt;
     int bufptr;
@@ -2217,9 +2216,9 @@ static gboolean udp_chr_read(GIOChannel *chan, GIOCondition cond, void *opaque)
     s->bufcnt = bytes_read;
     s->bufptr = s->bufcnt;
     if (status != G_IO_STATUS_NORMAL) {
-        if (s->tag) {
-            io_remove_watch_poll(s->tag);
-            s->tag = 0;
+        if (chr->fd_in_tag) {
+            io_remove_watch_poll(chr->fd_in_tag);
+            chr->fd_in_tag = 0;
         }
         return FALSE;
     }
@@ -2238,22 +2237,23 @@ static void udp_chr_update_read_handler(CharDriverState *chr)
 {
     NetCharDriver *s = chr->opaque;
 
-    if (s->tag) {
-        io_remove_watch_poll(s->tag);
-        s->tag = 0;
+    if (chr->fd_in_tag) {
+        io_remove_watch_poll(chr->fd_in_tag);
+        chr->fd_in_tag = 0;
     }
 
     if (s->chan) {
-        s->tag = io_add_watch_poll(s->chan, udp_chr_read_poll, udp_chr_read, chr);
+        chr->fd_in_tag = io_add_watch_poll(s->chan, udp_chr_read_poll,
+                                           udp_chr_read, chr);
     }
 }
 
 static void udp_chr_close(CharDriverState *chr)
 {
     NetCharDriver *s = chr->opaque;
-    if (s->tag) {
-        io_remove_watch_poll(s->tag);
-        s->tag = 0;
+    if (chr->fd_in_tag) {
+        io_remove_watch_poll(chr->fd_in_tag);
+        chr->fd_in_tag = 0;
     }
     if (s->chan) {
         g_io_channel_unref(s->chan);
@@ -2304,7 +2304,7 @@ static CharDriverState *qemu_chr_open_udp(QemuOpts *opts)
 typedef struct {
 
     GIOChannel *chan, *listen_chan;
-    guint tag, listen_tag;
+    guint listen_tag;
     int fd, listen_fd;
     int connected;
     int max_size;
@@ -2489,9 +2489,9 @@ static gboolean tcp_chr_read(GIOChannel *chan, GIOCondition cond, void *opaque)
         if (s->listen_chan) {
             s->listen_tag = g_io_add_watch(s->listen_chan, G_IO_IN, tcp_chr_accept, chr);
         }
-        if (s->tag) {
-            io_remove_watch_poll(s->tag);
-            s->tag = 0;
+        if (chr->fd_in_tag) {
+            io_remove_watch_poll(chr->fd_in_tag);
+            chr->fd_in_tag = 0;
         }
         g_io_channel_unref(s->chan);
         s->chan = NULL;
@@ -2522,7 +2522,8 @@ static void tcp_chr_connect(void *opaque)
 
     s->connected = 1;
     if (s->chan) {
-        s->tag = io_add_watch_poll(s->chan, tcp_chr_read_poll, tcp_chr_read, chr);
+        chr->fd_in_tag = io_add_watch_poll(s->chan, tcp_chr_read_poll,
+                                           tcp_chr_read, chr);
     }
     qemu_chr_be_generic_open(chr);
 }
@@ -2605,9 +2606,9 @@ static void tcp_chr_close(CharDriverState *chr)
 {
     TCPCharDriver *s = chr->opaque;
     if (s->fd >= 0) {
-        if (s->tag) {
-            io_remove_watch_poll(s->tag);
-            s->tag = 0;
+        if (chr->fd_in_tag) {
+            io_remove_watch_poll(chr->fd_in_tag);
+            chr->fd_in_tag = 0;
         }
         if (s->chan) {
             g_io_channel_unref(s->chan);