[Qemu-devel] [PATCH 1/2] migration: Allow the migrate command to work on file: urls

[Benoît Canet]

Usage:
(qemu) migrate file:/path/to/vm_statefile

Signed-off-by: Benoit Canet <ben...@irqsave.net>
---
 migration-fd.c |    4 ++--
 migration.c    |   20 +++++++++++++++++++-
 migration.h    |    2 +-
 3 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/migration-fd.c b/migration-fd.c
index 50138ed..d39e44a 100644
--- a/migration-fd.c
+++ b/migration-fd.c
@@ -73,9 +73,9 @@ static int fd_close(MigrationState *s)
     return 0;
 }
 
-int fd_start_outgoing_migration(MigrationState *s, const char *fdname)
+int fd_start_outgoing_migration(MigrationState *s, const char *fdname, int fd)
 {
-    s->fd = monitor_get_fd(cur_mon, fdname);
+    s->fd = fd ? fd : monitor_get_fd(cur_mon, fdname);
     if (s->fd == -1) {
         DPRINTF("fd_migration: invalid file descriptor identifier\n");
         goto err_after_get_fd;
diff --git a/migration.c b/migration.c
index 1edeec5..679847d 100644
--- a/migration.c
+++ b/migration.c
@@ -239,9 +239,14 @@ void 
qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params,
 static int migrate_fd_cleanup(MigrationState *s)
 {
     int ret = 0;
+    struct stat st;
 
     qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
 
+    if (!fstat(s->fd, &st) && S_ISREG(st.st_mode)) {
+        fsync(s->fd);
+    }
+
     if (s->file) {
         DPRINTF("closing file\n");
         ret = qemu_fclose(s->file);
@@ -475,6 +480,17 @@ void migrate_del_blocker(Error *reason)
     migration_blockers = g_slist_remove(migration_blockers, reason);
 }
 
+static int file_start_outgoing_migration(MigrationState *s,
+                                         const char *filename)
+{
+    int fd;
+    fd = open(filename, O_CREAT|O_TRUNC|O_WRONLY, S_IRUSR|S_IWUSR);
+    if (fd < 0) {
+        return -errno;
+    }
+    return fd_start_outgoing_migration(s, NULL, fd);
+}
+
 void qmp_migrate(const char *uri, bool has_blk, bool blk,
                  bool has_inc, bool inc, bool has_detach, bool detach,
                  Error **errp)
@@ -511,7 +527,9 @@ void qmp_migrate(const char *uri, bool has_blk, bool blk,
     } else if (strstart(uri, "unix:", &p)) {
         ret = unix_start_outgoing_migration(s, p);
     } else if (strstart(uri, "fd:", &p)) {
-        ret = fd_start_outgoing_migration(s, p);
+        ret = fd_start_outgoing_migration(s, p, 0);
+    } else if (strstart(uri, "file:", &p)) {
+        ret = file_start_outgoing_migration(s, p);
 #endif
     } else {
         error_set(errp, QERR_INVALID_PARAMETER_VALUE, "uri", "a valid 
migration protocol");
diff --git a/migration.h b/migration.h
index a9852fc..d431284 100644
--- a/migration.h
+++ b/migration.h
@@ -69,7 +69,7 @@ int unix_start_outgoing_migration(MigrationState *s, const 
char *path);
 
 int fd_start_incoming_migration(const char *path);
 
-int fd_start_outgoing_migration(MigrationState *s, const char *fdname);
+int fd_start_outgoing_migration(MigrationState *s, const char *fdname, int fd);
 
 void migrate_fd_error(MigrationState *s);
 
-- 
1.7.9.5