Merge tag 'juno-fix-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep...

[linux.git] / tools / hv / hv_kvp_daemon.c

diff --git a/tools/hv/hv_kvp_daemon.c b/tools/hv/hv_kvp_daemon.c
index e9ef4ca6a6557e11f809f17a93103d42af7a0e39..ee9c1bb2293eb322da794c7cf37e5bba7790aa4c 100644 (file)
--- a/tools/hv/hv_kvp_daemon.c
+++ b/tools/hv/hv_kvp_daemon.c
@@ -76,7 +76,7 @@ enum {
        DNS
 };
 
-static int in_hand_shake = 1;
+static int in_hand_shake;
 
 static char *os_name = "";
 static char *os_major = "";
@@ -1360,7 +1360,7 @@ void print_usage(char *argv[])
 
 int main(int argc, char *argv[])
 {
-       int kvp_fd, len;
+       int kvp_fd = -1, len;
        int error;
        struct pollfd pfd;
        char    *p;
@@ -1400,14 +1400,6 @@ int main(int argc, char *argv[])
        openlog("KVP", 0, LOG_USER);
        syslog(LOG_INFO, "KVP starting; pid is:%d", getpid());
 
-       kvp_fd = open("/dev/vmbus/hv_kvp", O_RDWR | O_CLOEXEC);
-
-       if (kvp_fd < 0) {
-               syslog(LOG_ERR, "open /dev/vmbus/hv_kvp failed; error: %d %s",
-                       errno, strerror(errno));
-               exit(EXIT_FAILURE);
-       }
-
        /*
         * Retrieve OS release information.
         */
@@ -1423,6 +1415,18 @@ int main(int argc, char *argv[])
                exit(EXIT_FAILURE);
        }
 
+reopen_kvp_fd:
+       if (kvp_fd != -1)
+               close(kvp_fd);
+       in_hand_shake = 1;
+       kvp_fd = open("/dev/vmbus/hv_kvp", O_RDWR | O_CLOEXEC);
+
+       if (kvp_fd < 0) {
+               syslog(LOG_ERR, "open /dev/vmbus/hv_kvp failed; error: %d %s",
+                      errno, strerror(errno));
+               exit(EXIT_FAILURE);
+       }
+
        /*
         * Register ourselves with the kernel.
         */
@@ -1456,9 +1460,7 @@ int main(int argc, char *argv[])
                if (len != sizeof(struct hv_kvp_msg)) {
                        syslog(LOG_ERR, "read failed; error:%d %s",
                               errno, strerror(errno));
-
-                       close(kvp_fd);
-                       return EXIT_FAILURE;
+                       goto reopen_kvp_fd;
                }
 
                /*
@@ -1617,13 +1619,17 @@ int main(int argc, char *argv[])
                        break;
                }
 
-               /* Send the value back to the kernel. */
+               /*
+                * Send the value back to the kernel. Note: the write() may
+                * return an error due to hibernation; we can ignore the error
+                * by resetting the dev file, i.e. closing and re-opening it.
+                */
 kvp_done:
                len = write(kvp_fd, hv_msg, sizeof(struct hv_kvp_msg));
                if (len != sizeof(struct hv_kvp_msg)) {
                        syslog(LOG_ERR, "write failed; error: %d %s", errno,
                               strerror(errno));
-                       exit(EXIT_FAILURE);
+                       goto reopen_kvp_fd;
                }
        }