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>

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>
Olaf Hering · Greg Kroah-Hartman
1 parent 038336a5b4
Showing 1 changed file with 21 additions and 18 deletions Side-by-side Diff
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 @@
 {
 	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 @@
 		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;
 }
...	...	@@ -23,6 +23,7 @@
23	23	#include <sys/poll.h>
24	24	#include <linux/types.h>
25	25	#include <stdio.h>
	26	+#include <mntent.h>
26	27	#include <stdlib.h>
27	28	#include <unistd.h>
28	29	#include <string.h>
...	...	@@ -47,11 +48,10 @@
47	48	{
48	49	char *fs_op;
49	50	char cmd[512];
50		- char buf[512];
51		- FILE *file;
52		- char *p;
53		- char *x;
54		- int error = 0;
	51	+ char match[] = "/dev/";
	52	+ FILE *mounts;
	53	+ struct mntent *ent;
	54	+ int error = 0, root_seen = 0;
55	55
56	56	switch (operation) {
57	57	case VSS_OP_FREEZE:
58	58
59	59
60	60
61	61
62	62
...	...	@@ -64,25 +64,28 @@
64	64	return -1;
65	65	}
66	66
67		- file = popen("mount \| awk '/^\\/dev\\// { print $3}'", "r");
68		- if (file == NULL)
	67	+ mounts = setmntent("/proc/mounts", "r");
	68	+ if (mounts == NULL)
69	69	return -1;
70	70
71		- while ((p = fgets(buf, sizeof(buf), file)) != NULL) {
72		- x = strchr(p, '\n');
73		- *x = '\0';
74		- if (!strncmp(p, "/", sizeof("/")))
	71	+ while((ent = getmntent(mounts))) {
	72	+ if (strncmp(ent->mnt_fsname, match, strlen(match)))
75	73	continue;
76		-
77		- sprintf(cmd, "%s %s %s", "fsfreeze ", fs_op, p);
	74	+ if (strcmp(ent->mnt_dir, "/") == 0) {
	75	+ root_seen = 1;
	76	+ continue;
	77	+ }
	78	+ snprintf(cmd, sizeof(cmd), "fsfreeze %s '%s'", fs_op, ent->mnt_dir);
78	79	syslog(LOG_INFO, "VSS cmd is %s\n", cmd);
79		- error = system(cmd);
	80	+ error \|= system(cmd);
80	81	}
81		- pclose(file);
	82	+ endmntent(mounts);
82	83
83		- sprintf(cmd, "%s %s %s", "fsfreeze ", fs_op, "/");
84		- syslog(LOG_INFO, "VSS cmd is %s\n", cmd);
85		- error = system(cmd);
	84	+ if (root_seen) {
	85	+ sprintf(cmd, "fsfreeze %s /", fs_op);
	86	+ syslog(LOG_INFO, "VSS cmd is %s\n", cmd);
	87	+ error \|= system(cmd);
	88	+ }
86	89
87	90	return error;
88	91	}