[Ocfs2-tools-devel] [PATCH] adding code to mounted.c to translate /dev/dm-[N] names to /dev/mapper/xxx names.

[XiaoweiHu]

Signed-off-by: XiaoweiHu <xiaowei.hu at oracle.com>
---
 mounted.ocfs2/mounted.c |   76 +++++++++++++++++++++++++++++++++++++++++++++-
 1 files changed, 74 insertions(+), 2 deletions(-)

diff --git a/mounted.ocfs2/mounted.c b/mounted.ocfs2/mounted.c
index e4c5877..c691a3d 100644
--- a/mounted.ocfs2/mounted.c
+++ b/mounted.ocfs2/mounted.c
@@ -33,6 +33,7 @@
 #include <linux/fd.h>
 #include <string.h>
 #include <sys/stat.h>
+#include <dirent.h>
 
 #include <uuid/uuid.h>
 
@@ -155,12 +156,70 @@ static void ocfs2_print_quick_detect(struct list_head *dev_list)
 	}
 }
 
+char *devname_strndup(const char *s, int length)
+{
+        char *ret;
+
+        if (!s)
+                return NULL;
+
+        if (!length)
+                length = strlen(s);
+
+        ret = malloc(length + 1);
+        if (ret) {
+                strncpy(ret, s, length);
+                ret[length] = '\0';
+        }
+        return ret;
+}
+
+char *devname_strdup(const char *s)
+{
+        return devname_strndup(s, 0);
+}
+
+void scan_dir_for_dev(char *dirname, dev_t devno, char **devname)
+{
+        DIR     *dir;
+        struct dirent *dp;
+        char    path[1024];
+        int     dirlen;
+        struct stat st;
+
+        if ((dir = opendir(dirname)) == NULL)
+                return;
+        dirlen = strlen(dirname) + 2;
+        while ((dp = readdir(dir)) != 0) {
+                if (dirlen + strlen(dp->d_name) >= sizeof(path))
+                        continue;
+
+                if (dp->d_name[0] == '.' &&
+                    ((dp->d_name[1] == 0) ||
+                     ((dp->d_name[1] == '.') && (dp->d_name[2] == 0))))
+                        continue;
+
+                sprintf(path, "%s/%s", dirname, dp->d_name);
+                if (stat(path, &st) < 0)
+                        continue;
+
+                if (S_ISBLK(st.st_mode) && st.st_rdev == devno) {
+			*devname = devname_strdup(path);
+                        break;
+                }
+        }
+        closedir(dir);
+        return;
+}
+
 static errcode_t ocfs2_partition_list (struct list_head *dev_list)
 {
 	errcode_t ret = 0;
 	FILE *proc;
 	char line[256];
 	char name[256];
+	char *devname = NULL;
+	int major,minor;
 	ocfs2_devices *dev;
 
 	proc = fopen ("/proc/partitions", "r");
@@ -170,14 +229,27 @@ static errcode_t ocfs2_partition_list (struct list_head *dev_list)
 	}
 
 	while (fgets (line, sizeof(line), proc) != NULL) {
-		if (sscanf(line, "%*d %*d %*d %99[^ \t\n]", name) != 1)
+		if (sscanf(line, "%d %d %*d %99[^ \t\n]", &major, &minor, name) != 3)
 			continue;
 
 		ret = ocfs2_malloc0(sizeof(ocfs2_devices), &dev);
 		if (ret)
 			goto bail;
 
-		snprintf(dev->dev_name, sizeof(dev->dev_name), "/dev/%s", name);
+		/* Try to translate private device-mapper dm-<N> names
+         	 * to standard /dev/mapper/<name>.
+         	 */
+        	if (!strncmp(name, "dm-", 3) && isdigit(name[3])) {
+                        scan_dir_for_dev("/dev/mapper", makedev(major, minor), &devname);
+                	if (devname)
+				snprintf(dev->dev_name, sizeof(dev->dev_name), "%s", devname);
+			else
+				snprintf(dev->dev_name, sizeof(dev->dev_name), "/dev/%s", name);
+
+        	} else {
+			snprintf(dev->dev_name, sizeof(dev->dev_name), "/dev/%s", name);
+		}
+
 		list_add_tail(&(dev->list), dev_list);
 	}
 
-- 
1.6.3.3