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>

1 files changed, 21 insertions, 18 deletions

diff --git a/tools/hv/hv_vss_daemon.c b/tools/hv/hv_vss_daemon.c
index 921c1bec0305..a5da91df4f76 100644
--- 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;
 }