xen/tapdisk-ioemu-shutdown-fix.patch

From 9062564d79cb45029403cc998b48410e42ead924 Mon Sep 17 00:00:00 2001
From: Kevin Wolf <kwolf@suse.de>
Date: Tue, 10 Mar 2009 16:45:44 +0100
Subject: [PATCH 6/6] tapdisk-ioemu: Fix shutdown condition

Even when opening the only image a tapdisk-ioemu instance is
responsible for fails, it can't immediately shut down. blktapctrl
still wants to communicate with tapdisk-ioemu and close the disk.

This patch changes tapdisk-ioemu to count the connections to
blktapctrl rather than the number of opened disk images.

Signed-off-by: Kevin Wolf <kwolf@suse.de>
---
 hw/xen_blktap.c |    5 ++++-
 tapdisk-ioemu.c |   13 ++++++++++---
 2 files changed, 14 insertions(+), 4 deletions(-)

Index: xen-4.0.0-testing/tools/ioemu-remote/hw/xen_blktap.c
===================================================================
--- xen-4.0.0-testing.orig/tools/ioemu-remote/hw/xen_blktap.c
+++ xen-4.0.0-testing/tools/ioemu-remote/hw/xen_blktap.c
@@ -65,6 +65,7 @@ int read_fd;
 int write_fd;
 
 static pid_t process;
+int connected_disks = 0;
 fd_list_entry_t *fd_start = NULL;
 
 extern char* get_snapshot_name(int devid);
@@ -547,6 +548,7 @@ static void handle_blktap_ctrlmsg(void*
 
 			/* Allocate the disk structs */
 			s = state_init();
+			connected_disks++;
 
 			/*Open file*/
 			if (s == NULL || open_disk(s, path, msg->drivertype, msg->readonly)) {
@@ -629,7 +631,8 @@ static void handle_blktap_ctrlmsg(void*
 		case CTLMSG_CLOSE:
 			s = get_state(msg->cookie);
 			if (s) unmap_disk(s);
-			break;			
+			connected_disks--;
+			break;
 
 		case CTLMSG_PID:
 			memset(buf, 0x00, MSG_SIZE);
Index: xen-4.0.0-testing/tools/ioemu-remote/tapdisk-ioemu.c
===================================================================
--- xen-4.0.0-testing.orig/tools/ioemu-remote/tapdisk-ioemu.c
+++ xen-4.0.0-testing/tools/ioemu-remote/tapdisk-ioemu.c
@@ -14,6 +14,7 @@ extern void qemu_aio_init(void);
 extern void qemu_aio_poll(void);
 
 extern void *fd_start;
+extern int connected_disks;
 
 int domid = 0;
 FILE* logfile;
@@ -76,7 +77,7 @@ int main(void)
     int max_fd;
     fd_set rfds;
     struct timeval tv;
-    void *old_fd_start = NULL;
+    int old_connected_disks = 0;
 
     /* Daemonize */
     if (fork() != 0)
@@ -128,11 +129,17 @@ int main(void)
                 pioh = &ioh->next;
         }
 
+	if (old_connected_disks != connected_disks)
+            fprintf(stderr, "connected disks: %d => %d\n",
+	        old_connected_disks, connected_disks);
+
         /* Exit when the last image has been closed */
-        if (old_fd_start != NULL && fd_start == NULL)
+        if (old_connected_disks != 0 && connected_disks == 0) {
+	    fprintf(stderr, "Last image is closed, exiting.\n");
             exit(0);
+	}
 
-        old_fd_start = fd_start;
+        old_connected_disks = connected_disks;
     }
     return 0;
 }