chiark / gitweb /
maintain index over device-names to devpath relation
authorKay Sievers <kay.sievers@vrfy.org>
Thu, 15 Mar 2007 01:09:39 +0000 (02:09 +0100)
committerKay Sievers <kay.sievers@vrfy.org>
Thu, 15 Mar 2007 01:09:39 +0000 (02:09 +0100)
udev.h
udev_db.c

diff --git a/udev.h b/udev.h
index 200d7e8..7fc7fd3 100644 (file)
--- a/udev.h
+++ b/udev.h
@@ -44,6 +44,7 @@
 #define WRITE_END                              1
 
 #define DB_DIR                                 ".udev/db"
+#define DB_NAME_INDEX_DIR                      ".udev/names"
 
 struct udev_rules;
 
index 9032eef..c07588d 100644 (file)
--- a/udev_db.c
+++ b/udev_db.c
@@ -44,13 +44,46 @@ static size_t devpath_to_db_path(const char *devpath, char *filename, size_t len
        return path_encode(&filename[start+1], len - (start+1));
 }
 
-static int db_file_to_devpath(const char *filename, char *devpath, size_t len)
+static size_t db_file_to_devpath(const char *filename, char *devpath, size_t len)
 {
        strlcpy(devpath, "/", len);
        strlcat(devpath, filename, len);
        return path_decode(devpath);
 }
 
+
+/* reverse mapping from the device file name to the devpath */
+static int name_index(const char *devpath, const char *name, int add)
+{
+       char device[PATH_SIZE];
+       char filename[PATH_SIZE * 2];
+       size_t start;
+       int fd;
+
+       /* directory with device name */
+       strlcpy(filename, udev_root, sizeof(filename));
+       start = strlcat(filename, "/"DB_NAME_INDEX_DIR"/", sizeof(filename));
+       strlcat(filename, name, sizeof(filename));
+       path_encode(&filename[start+1], sizeof(filename) - (start+1));
+       /* entry with the devpath */
+       strlcpy(device, devpath, sizeof(device));
+       path_encode(&device[1], sizeof(device)-1);
+       strlcat(filename, device, sizeof(filename));
+
+       if (add) {
+               dbg("creating: '%s'", filename);
+               create_path(filename);
+               fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
+               if (fd > 0)
+                       close(fd);
+       } else {
+               dbg("removing: '%s'", filename);
+               unlink(filename);
+               delete_path(filename);
+       }
+       return 0;
+}
+
 int udev_db_add_device(struct udevice *udev)
 {
        char filename[PATH_SIZE];
@@ -60,6 +93,7 @@ int udev_db_add_device(struct udevice *udev)
 
        devpath_to_db_path(udev->dev->devpath, filename, sizeof(filename));
        create_path(filename);
+       name_index(udev->dev->devpath, udev->name, 1);
 
        /*
         * create only a symlink with the name as the target
@@ -86,8 +120,10 @@ int udev_db_add_device(struct udevice *udev)
                dbg("storing data for device '%s' in '%s'", udev->dev->devpath, filename);
 
                fprintf(f, "N:%s\n", udev->name);
-               list_for_each_entry(name_loop, &udev->symlink_list, node)
+               list_for_each_entry(name_loop, &udev->symlink_list, node) {
                        fprintf(f, "S:%s\n", name_loop->name);
+                       name_index(udev->dev->devpath, name_loop->name, 1);
+               }
                fprintf(f, "M:%u:%u\n", major(udev->devt), minor(udev->devt));
                if (udev->partitions)
                        fprintf(f, "A:%u\n", udev->partitions);
@@ -203,37 +239,42 @@ int udev_db_get_device(struct udevice *udev, const char *devpath)
 int udev_db_delete_device(struct udevice *udev)
 {
        char filename[PATH_SIZE];
+       struct name_entry *name_loop;
 
        devpath_to_db_path(udev->dev->devpath, filename, sizeof(filename));
        unlink(filename);
 
+       name_index(udev->dev->devpath, udev->name, 0);
+       list_for_each_entry(name_loop, &udev->symlink_list, node)
+               name_index(udev->dev->devpath, name_loop->name, 0);
+
        return 0;
 }
 
 int udev_db_lookup_name(const char *name, char *devpath, size_t len)
 {
-       char dbpath[PATH_MAX];
+       char dirname[PATH_MAX];
+       size_t start;
        DIR *dir;
        int found = 0;
 
-       strlcpy(dbpath, udev_root, sizeof(dbpath));
-       strlcat(dbpath, "/"DB_DIR, sizeof(dbpath));
-       dir = opendir(dbpath);
+       strlcpy(dirname, udev_root, sizeof(dirname));
+       start = strlcat(dirname, "/"DB_NAME_INDEX_DIR"/", sizeof(dirname));
+       strlcat(dirname, name, sizeof(dirname));
+       path_encode(&dirname[start+1], sizeof(dirname) - (start+1));
+
+       dir = opendir(dirname);
        if (dir == NULL) {
-               info("no udev_db available '%s': %s", dbpath, strerror(errno));
+               info("no index directory '%s': %s", dirname, strerror(errno));
                return -1;
        }
 
+       info("found index directory '%s'", dirname);
        while (!found) {
                struct dirent *ent;
+               char device[PATH_SIZE];
                char filename[PATH_SIZE];
-               char nodename[PATH_SIZE];
-               struct stat stats;
-               char *bufline;
-               char *buf;
-               size_t bufsize;
-               size_t cur;
-               size_t count;
+               struct stat statbuf;
 
                ent = readdir(dir);
                if (ent == NULL || ent->d_name[0] == '\0')
@@ -241,63 +282,18 @@ int udev_db_lookup_name(const char *name, char *devpath, size_t len)
                if (ent->d_name[0] == '.')
                        continue;
 
-               snprintf(filename, sizeof(filename), "%s/%s", dbpath, ent->d_name);
-               filename[sizeof(filename)-1] = '\0';
-               dbg("looking at '%s'", filename);
-
-               if (lstat(filename, &stats) != 0) {
-                       info("unable to read %s: %s", filename, strerror(errno));
-                       continue;
-               }
-               if ((stats.st_mode & S_IFMT) == S_IFLNK) {
-                       char target[NAME_SIZE];
-                       int target_len;
-
-                       info("found a symlink as db file");
-                       target_len = readlink(filename, target, sizeof(target));
-                       if (target_len > 0)
-                               target[target_len] = '\0';
-                       else {
-                               info("error reading db link %s: %s", filename, strerror(errno));
-                               return -1;
-                       }
-                       dbg("db link points to '%s'", target);
-                       if (strcmp(name, target) == 0) {
-                               db_file_to_devpath(ent->d_name, devpath, len);
-                               found =1;
-                       }
-                       continue;
-               }
-
-               if (file_map(filename, &buf, &bufsize) != 0) {
-                       info("unable to read db file '%s': %s", filename, strerror(errno));
-                       continue;
-               }
+               strlcpy(device, "/", len);
+               strlcat(device, ent->d_name, sizeof(device));
+               path_decode(device);
 
-               cur = 0;
-               while (cur < bufsize && !found) {
-                       count = buf_get_line(buf, bufsize, cur);
-                       bufline = &buf[cur];
-                       cur += count+1;
-
-                       switch(bufline[0]) {
-                       case 'N':
-                       case 'S':
-                               if (count > sizeof(nodename))
-                                       count = sizeof(nodename);
-                               memcpy(nodename, &bufline[2], count-2);
-                               nodename[count-2] = '\0';
-                               dbg("compare '%s' '%s'", nodename, name);
-                               if (strcmp(nodename, name) == 0) {
-                                       db_file_to_devpath(ent->d_name, devpath, len);
-                                       found = 1;
-                               }
-                               break;
-                       default:
-                               continue;
-                       }
+               dbg("looking at '%s'", device);
+               strlcpy(filename, sysfs_path, sizeof(filename));
+               strlcat(filename, device, sizeof(filename));
+               if (stat(filename, &statbuf) == 0) {
+                       strlcpy(devpath, device, len);
+                       found = 1;
+                       break;
                }
-               file_unmap(buf, bufsize);
        }
 
        closedir(dir);