Handle any path supplied to dm_task_set_name() by looking up in /dev/mapper.

diff --git a/WHATS_NEW_DM b/WHATS_NEW_DM
index 252670f2d59761ccb5a8da379bf520b3757ba736..7dc931d4542ee1358731f7b6bf0df1c9f146dfa0 100644 (file)
--- a/WHATS_NEW_DM
+++ b/WHATS_NEW_DM
@@ -1,5 +1,6 @@
 Version 1.02.38 - 
 =====================================
+  Handle any path supplied to dm_task_set_name() by looking up in /dev/mapper.
 
 Version 1.02.37 - 15th September 2009
 =====================================

diff --git a/libdm/libdm-common.c b/libdm/libdm-common.c
index fd913e1a935dc5cb55ff469144b72017648f16f0..826efd36634e41d82c04bcec4ea3654651d848a9 100644 (file)
--- a/libdm/libdm-common.c
+++ b/libdm/libdm-common.c
@@ -23,6 +23,7 @@
 #include <sys/param.h>
 #include <sys/ioctl.h>
 #include <fcntl.h>
+#include <dirent.h>
 
 #ifdef UDEV_SYNC_SUPPORT
 #  include <sys/types.h>
@@ -183,9 +184,54 @@ struct dm_task *dm_task_create(int type)
        return dmt;
 }
 
+/*
+ * Find the name associated with a given device number by scanning _dm_dir.
+ */
+static char *_translate_name(dev_t st_rdev, const char *devname)
+{
+       const char *name;
+       char path[PATH_MAX];
+       struct dirent *dirent;
+       DIR *d;
+       struct stat buf;
+       char *new_name = NULL;
+
+       if (!(d = opendir(_dm_dir))) {
+               log_sys_error("opendir", _dm_dir);
+               return NULL;
+       }
+
+       while ((dirent = readdir(d))) {
+               name = dirent->d_name;
+
+               if (!strcmp(name, ".") || !strcmp(name, ".."))
+                       continue;
+
+               if (dm_snprintf(path, sizeof(path), "%s/%s", _dm_dir,
+                               name) == -1) {
+                       log_error("Couldn't create path for %s", name);
+                       continue;
+               }
+
+               if (stat(path, &buf))
+                       continue;
+
+               if (buf.st_rdev == st_rdev) {
+                       new_name = dm_strdup(name);
+                       break;
+               }
+       }
+
+       if (closedir(d))
+               log_sys_error("closedir", _dm_dir);
+
+       return new_name;
+}
+
 int dm_task_set_name(struct dm_task *dmt, const char *name)
 {
        char *pos;
+       char *new_name = NULL;
        char path[PATH_MAX];
        struct stat st1, st2;
 
@@ -194,8 +240,8 @@ int dm_task_set_name(struct dm_task *dmt, const char *name)
                dmt->dev_name = NULL;
        }
 
-       /* If path was supplied, remove it if it points to the same device
-        * as its last component.
+       /*
+        * Path supplied for existing device?
         */
        if ((pos = strrchr(name, '/'))) {
                if (dmt->type == DM_DEVICE_CREATE) {
@@ -203,23 +249,38 @@ int dm_task_set_name(struct dm_task *dmt, const char *name)
                        return 0;
                }
 
+               if (stat(name, &st1)) {
+                       log_error("Device %s not found", name);
+                       return 0;
+               }
+
+               /*
+                * If supplied path points to same device as last component
+                * under /dev/mapper, use that name directly.  Otherwise call
+                * _translate_name() to scan _dm_dir for a match.
+                */
                snprintf(path, sizeof(path), "%s/%s", _dm_dir, pos + 1);
 
-               if (stat(name, &st1) || stat(path, &st2) ||
-                   !(st1.st_dev == st2.st_dev)) {
+               if (!stat(path, &st2) && (st1.st_rdev == st2.st_rdev))
+                       name = pos + 1;
+               else if ((new_name = _translate_name(st1.st_rdev, pos + 1)))
+                       name = new_name;
+               else {
                        log_error("Device %s not found", name);
                        return 0;
                }
-
-               name = pos + 1;
        }
 
        if (strlen(name) >= DM_NAME_LEN) {
                log_error("Name \"%s\" too long", name);
+               if (new_name)
+                       dm_free(new_name);
                return 0;
        }
 
-       if (!(dmt->dev_name = dm_strdup(name))) {
+       if (new_name)
+               dmt->dev_name = new_name;
+       else if (!(dmt->dev_name = dm_strdup(name))) {
                log_error("dm_task_set_name: strdup(%s) failed", name);
                return 0;
        }