mdev: if device was moved at creation, at removal coreectly remove

 it from moved location and also remove symlinks to it

function                                             old     new   delta
build_alias                                            -      78     +78
mdev_main                                            505     503      -2
make_device                                         1300    1294      -6
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 0/2 up/down: 78/-8)              Total: 70 bytes

1 files changed, 37 insertions, 19 deletions

diff --git a/util-linux/mdev.c b/util-linux/mdev.c
index a4c0520ac..4ac5c430a 100644
--- a/util-linux/mdev.c
+++ b/util-linux/mdev.c
@@ -35,6 +35,30 @@ static char *next_field(char *s)
         return s;
 }
 
+/* Builds an alias path.
+ * This function potentionally reallocates the alias parameter.
+ */
+static char *build_alias(char *alias, const char *device_name)
+{
+        char *dest;
+
+        /* ">bar/": rename to bar/device_name */
+        /* ">bar[/]baz": rename to bar[/]baz */
+        dest = strrchr(alias, '/');
+        if (dest) { /* ">bar/[baz]" ? */
+                *dest = '\0'; /* mkdir bar */
+                bb_make_directory(alias, 0755, FILEUTILS_RECUR);
+                *dest = '/';
+                if (dest[1] == '\0') { /* ">bar/" => ">bar/device_name" */
+                        dest = alias;
+                        alias = concat_path_file(alias, device_name);
+                        free(dest);
+                }
+        }
+
+        return alias;
+}
+
 /* mknod in /dev based on a path like "/sys/block/hda/hda1" */
 /* NB: "mdev -s" may call us many times, do not leak memory/fds! */
 static void make_device(char *path, int delete)
@@ -257,21 +281,7 @@ static void make_device(char *path, int delete)
                         chown(device_name, uid, gid);
 
                         if (ENABLE_FEATURE_MDEV_RENAME && alias) {
-                                char *dest;
-
-                                /* ">bar/": rename to bar/device_name */
-                                /* ">bar[/]baz": rename to bar[/]baz */
-                                dest = strrchr(alias, '/');
-                                if (dest) { /* ">bar/[baz]" ? */
-                                        *dest = '\0'; /* mkdir bar */
-                                        bb_make_directory(alias, 0755, FILEUTILS_RECUR);
-                                        *dest = '/';
-                                        if (dest[1] == '\0') { /* ">bar/" => ">bar/device_name" */
-                                                dest = alias;
-                                                alias = concat_path_file(alias, device_name);
-                                                free(dest);
-                                        }
-                                }
+                                alias = build_alias(alias, device_name);
 
                                 /* move the device, and optionally
                                  * make a symlink to moved device node */
@@ -295,8 +305,16 @@ static void make_device(char *path, int delete)
                 free(command);
         }
 
-        if (delete)
+        if (delete) {
                 unlink(device_name);
+                /* At creation time, device might have been moved
+                 * and a symlink might have been created. Undo that. */
+                if (ENABLE_FEATURE_MDEV_RENAME && alias) {
+                        alias = build_alias(alias, device_name);
+                        unlink(alias);
+                        free(alias);
+                }
+        }
 }
 
 /* File callback for /sys/ traversal */
@@ -309,7 +327,7 @@ static int FAST_FUNC fileAction(const char *fileName,
         char *scratch = userData;
 
         /* len check is for paranoid reasons */
-        if (strcmp(fileName + len, "/dev") || len >= PATH_MAX)
+        if (strcmp(fileName + len, "/dev") != 0 || len >= PATH_MAX)
                 return FALSE;
 
         strcpy(scratch, fileName);
@@ -387,7 +405,7 @@ static void load_firmware(const char *const firmware, const char *const sysfs_pa
 }
 
 int mdev_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-int mdev_main(int argc, char **argv)
+int mdev_main(int argc UNUSED_PARAM, char **argv)
 {
         char *action;
         char *env_path;
@@ -410,7 +428,7 @@ int mdev_main(int argc, char **argv)
 
         xchdir("/dev");
 
-        if (argc == 2 && !strcmp(argv[1], "-s")) {
+        if (argv[1] && !strcmp(argv[1], "-s")) {
                 /* Scan:
                  * mdev -s
                  */