Add gpt pseudo-metadata

[thirdparty/mdadm.git] / msg.c

diff --git a/msg.c b/msg.c
index 013bcb99e71fa7e4c2a6bb21f012444507478517..aabfa8f566072b64d900b91c8e50cfaf0fde0057 100644 (file)
--- a/msg.c
+++ b/msg.c
@@ -81,12 +81,12 @@ static int recv_buf(int fd, void* buf, int len, int tmo)
 
 int send_message(int fd, struct metadata_update *msg, int tmo)
 {
-       __u32 len = msg->len;
+       __s32 len = msg->len;
        int rv;
 
        rv = send_buf(fd, &start_magic, 4, tmo);
        rv = rv ?: send_buf(fd, &len, 4, tmo);
-       if (len)
+       if (len > 0)
                rv = rv ?: send_buf(fd, msg->buf, msg->len, tmo);
        rv = send_buf(fd, &end_magic, 4, tmo);
 
@@ -96,7 +96,7 @@ int send_message(int fd, struct metadata_update *msg, int tmo)
 int receive_message(int fd, struct metadata_update *msg, int tmo)
 {
        __u32 magic;
-       __u32 len;
+       __s32 len;
        int rv;
 
        rv = recv_buf(fd, &magic, 4, tmo);
@@ -105,7 +105,7 @@ int receive_message(int fd, struct metadata_update *msg, int tmo)
        rv = recv_buf(fd, &len, 4, tmo);
        if (rv < 0 || len > MSG_MAX_LEN)
                return -1;
-       if (len) {
+       if (len > 0) {
                msg->buf = malloc(len);
                if (msg->buf == NULL)
                        return -1;
@@ -147,7 +147,7 @@ int connect_monitor(char *devname)
        int pos;
        char *c;
 
-       pos = sprintf(path, "/var/run/mdadm/");
+       pos = sprintf(path, "%s/", MDMON_DIR);
        if (is_subarray(devname)) {
                devname++;
                c = strchr(devname, '/');
@@ -177,9 +177,8 @@ int connect_monitor(char *devname)
        return sfd;
 }
 
-int ping_monitor(char *devname)
+int fping_monitor(int sfd)
 {
-       int sfd = connect_monitor(devname);
        int err = 0;
 
        if (sfd < 0)
@@ -189,6 +188,40 @@ int ping_monitor(char *devname)
        if (ack(sfd, 20) != 0)
                err = -1;
 
+       /* check the reply */
+       if (!err && wait_reply(sfd, 20) != 0)
+               err = -1;
+
+       return err;
+}
+
+
+/* give the monitor a chance to update the metadata */
+int ping_monitor(char *devname)
+{
+       int sfd = connect_monitor(devname);
+       int err = fping_monitor(sfd);
+
+       close(sfd);
+       return err;
+}
+
+/* give the manager a chance to view the updated container state.  This
+ * would naturally happen due to the manager noticing a change in
+ * /proc/mdstat; however, pinging encourages this detection to happen
+ * while an exclusive open() on the container is active
+ */
+int ping_manager(char *devname)
+{
+       int sfd = connect_monitor(devname);
+       struct metadata_update msg = { .len = -1 };
+       int err = 0;
+
+       if (sfd < 0)
+               return sfd;
+
+       err = send_message(sfd, &msg, 20);
+
        /* check the reply */
        if (!err && wait_reply(sfd, 20) != 0)
                err = -1;