tools: hv: use getmntent in hv_vss_daemon

As suggested by Paolo Bonzini, use getmntent instead of parsing output
of mount(1).

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/tools/hv/hv_vss_daemon.c b/tools/hv/hv_vss_daemon.c
index 921c1be..a5da91d 100644 (file)
--- a/tools/hv/hv_vss_daemon.c
+++ b/tools/hv/hv_vss_daemon.c
@@ -23,6 +23,7 @@
 #include <sys/poll.h>
 #include <linux/types.h>
 #include <stdio.h>
+#include <mntent.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <string.h>
@@ -47,11 +48,10 @@ static int vss_operate(int operation)
 {
        char *fs_op;
        char cmd[512];
-       char buf[512];
-       FILE *file;
-       char *p;
-       char *x;
-       int error = 0;
+       char match[] = "/dev/";
+       FILE *mounts;
+       struct mntent *ent;
+       int error = 0, root_seen = 0;
 
        switch (operation) {
        case VSS_OP_FREEZE:
@@ -64,25 +64,28 @@ static int vss_operate(int operation)
                return -1;
        }
 
-       file = popen("mount | awk '/^\\/dev\\// { print $3}'", "r");
-       if (file == NULL)
+       mounts = setmntent("/proc/mounts", "r");
+       if (mounts == NULL)
                return -1;
 
-       while ((p = fgets(buf, sizeof(buf), file)) != NULL) {
-               x = strchr(p, '\n');
-               *x = '\0';
-               if (!strncmp(p, "/", sizeof("/")))
+       while((ent = getmntent(mounts))) {
+               if (strncmp(ent->mnt_fsname, match, strlen(match)))
                        continue;
-
-               sprintf(cmd, "%s %s %s", "fsfreeze ", fs_op, p);
+               if (strcmp(ent->mnt_dir, "/") == 0) {
+                       root_seen = 1;
+                       continue;
+               }
+               snprintf(cmd, sizeof(cmd), "fsfreeze %s '%s'", fs_op, ent->mnt_dir);
                syslog(LOG_INFO, "VSS cmd is %s\n", cmd);
-               error = system(cmd);
+               error |= system(cmd);
        }
-       pclose(file);
+       endmntent(mounts);
 
-       sprintf(cmd, "%s %s %s", "fsfreeze ", fs_op, "/");
-       syslog(LOG_INFO, "VSS cmd is %s\n", cmd);
-       error = system(cmd);
+       if (root_seen) {
+               sprintf(cmd, "fsfreeze %s /", fs_op);
+               syslog(LOG_INFO, "VSS cmd is %s\n", cmd);
+               error |= system(cmd);
+       }
 
        return error;
 }