From: Kay Sievers Date: Sat, 11 Dec 2010 13:00:46 +0000 (+0100) Subject: udevd: simplify udev database and fix DEVNAME handling X-Git-Tag: 174~287 X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=commitdiff_plain;h=24d1076696ebe6696a8b8df414ab265aa6fc89c2 udevd: simplify udev database and fix DEVNAME handling --- diff --git a/libudev/libudev-device-private.c b/libudev/libudev-device-private.c index 63f947e16..bf93834c1 100644 --- a/libudev/libudev-device-private.c +++ b/libudev/libudev-device-private.c @@ -72,96 +72,83 @@ int udev_device_tag_index(struct udev_device *dev, struct udev_device *dev_old, return 0; } +static bool device_has_info(struct udev_device *udev_device) +{ + struct udev_list_entry *list_entry; + + if (udev_device_get_devlinks_list_entry(udev_device) != NULL) + return true; + if (udev_device_get_devlink_priority(udev_device) != 0) + return true; + udev_list_entry_foreach(list_entry, udev_device_get_properties_list_entry(udev_device)) + if (udev_list_entry_get_flags(list_entry)) + return true; + if (udev_device_get_tags_list_entry(udev_device) != NULL) + return true; + if (udev_device_get_watch_handle(udev_device) >= 0) + return true; + return false; +} + int udev_device_update_db(struct udev_device *udev_device) { + bool has_info; const char *id; struct udev *udev = udev_device_get_udev(udev_device); char filename[UTIL_PATH_SIZE]; char filename_tmp[UTIL_PATH_SIZE]; FILE *f; - char target[232]; /* on 64bit, tmpfs inlines up to 239 bytes */ size_t devlen = strlen(udev_get_dev_path(udev))+1; - char *s; - size_t l; - struct udev_list_entry *list_entry; - int ret; id = udev_device_get_id_filename(udev_device); if (id == NULL) return -1; + + has_info = device_has_info(udev_device); util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/.udev/db/", id, NULL); - util_strscpyl(filename_tmp, sizeof(filename_tmp), filename, ".tmp", NULL); - udev_list_entry_foreach(list_entry, udev_device_get_properties_list_entry(udev_device)) - if (udev_list_entry_get_flags(list_entry)) - goto file; - if (udev_device_get_tags_list_entry(udev_device) != NULL) - goto file; - if (udev_device_get_devlink_priority(udev_device) != 0) - goto file; - if (udev_device_get_event_timeout(udev_device) >= 0) - goto file; - if (udev_device_get_watch_handle(udev_device) >= 0) - goto file; - if (udev_device_get_devnode(udev_device) == NULL) - goto out; - - /* - * if we have only the node and symlinks to store, try not to waste - * tmpfs memory -- store values, if they fit, in a symlink target - */ - s = target; - l = util_strpcpy(&s, sizeof(target), &udev_device_get_devnode(udev_device)[devlen]); - udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(udev_device)) { - l = util_strpcpyl(&s, l, " ", &udev_list_entry_get_name(list_entry)[devlen], NULL); - if (l == 0) { - info(udev, "size of links too large, create file\n"); - goto file; - } + /* do not store anything for otherwise empty devices */ + if (!has_info && udev_device_get_devnode(udev_device) == NULL) { + unlink(filename); + return 0; } - udev_selinux_setfscreatecon(udev, filename_tmp, S_IFLNK); - util_create_path(udev, filename_tmp); - ret = symlink(target, filename_tmp); - udev_selinux_resetfscreatecon(udev); - if (ret != 0) - goto file; - ret = rename(filename_tmp, filename); - if (ret != 0) - goto file; - info(udev, "created db link (%s)\n", target); - goto out; -file: + + /* write a database file */ + util_strscpyl(filename_tmp, sizeof(filename_tmp), filename, ".tmp", NULL); util_create_path(udev, filename_tmp); - f = fopen(filename_tmp, "w"); + f = fopen(filename_tmp, "we"); if (f == NULL) { err(udev, "unable to create temporary db file '%s': %m\n", filename_tmp); return -1; } - if (udev_device_get_devnode(udev_device) != NULL) { - fprintf(f, "N:%s\n", &udev_device_get_devnode(udev_device)[devlen]); - udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(udev_device)) - fprintf(f, "S:%s\n", &udev_list_entry_get_name(list_entry)[devlen]); - } - if (udev_device_get_devlink_priority(udev_device) != 0) - fprintf(f, "L:%i\n", udev_device_get_devlink_priority(udev_device)); - if (udev_device_get_event_timeout(udev_device) >= 0) - fprintf(f, "T:%i\n", udev_device_get_event_timeout(udev_device)); - if (udev_device_get_watch_handle(udev_device) >= 0) - fprintf(f, "W:%i\n", udev_device_get_watch_handle(udev_device)); - udev_list_entry_foreach(list_entry, udev_device_get_properties_list_entry(udev_device)) { - if (!udev_list_entry_get_flags(list_entry)) - continue; - fprintf(f, "E:%s=%s\n", - udev_list_entry_get_name(list_entry), - udev_list_entry_get_value(list_entry)); + if (has_info) { + struct udev_list_entry *list_entry; + + if (udev_device_get_devnode(udev_device) != NULL) { + fprintf(f, "N:%s\n", &udev_device_get_devnode(udev_device)[devlen]); + udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(udev_device)) + fprintf(f, "S:%s\n", &udev_list_entry_get_name(list_entry)[devlen]); + } + if (udev_device_get_devlink_priority(udev_device) != 0) + fprintf(f, "L:%i\n", udev_device_get_devlink_priority(udev_device)); + if (udev_device_get_watch_handle(udev_device) >= 0) + fprintf(f, "W:%i\n", udev_device_get_watch_handle(udev_device)); + udev_list_entry_foreach(list_entry, udev_device_get_properties_list_entry(udev_device)) { + if (!udev_list_entry_get_flags(list_entry)) + continue; + fprintf(f, "E:%s=%s\n", + udev_list_entry_get_name(list_entry), + udev_list_entry_get_value(list_entry)); + } + udev_list_entry_foreach(list_entry, udev_device_get_tags_list_entry(udev_device)) + fprintf(f, "G:%s\n", udev_list_entry_get_name(list_entry)); } - udev_list_entry_foreach(list_entry, udev_device_get_tags_list_entry(udev_device)) - fprintf(f, "G:%s\n", udev_list_entry_get_name(list_entry)); + fclose(f); rename(filename_tmp, filename); - info(udev, "created db file for '%s' in '%s'\n", udev_device_get_devpath(udev_device), filename); -out: + info(udev, "created %s file '%s' for '%s'\n", has_info ? "db" : "empty", + filename, udev_device_get_devpath(udev_device)); return 0; } diff --git a/libudev/libudev-device.c b/libudev/libudev-device.c index d87b0c6c8..ac206a0e1 100644 --- a/libudev/libudev-device.c +++ b/libudev/libudev-device.c @@ -232,70 +232,28 @@ const char *udev_device_get_property_value(struct udev_device *udev_device, cons int udev_device_read_db(struct udev_device *udev_device) { const char *id; - struct stat stats; char filename[UTIL_PATH_SIZE]; char line[UTIL_LINE_SIZE]; FILE *f; if (udev_device->db_loaded) return 0; + udev_device->db_loaded = true; id = udev_device_get_id_filename(udev_device); if (id == NULL) return -1; util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev_device->udev), "/.udev/db/", id, NULL); - - if (lstat(filename, &stats) != 0) { - dbg(udev_device->udev, "no db file to read %s: %m\n", filename); - return -1; - } - if ((stats.st_mode & S_IFMT) == S_IFLNK) { - char target[UTIL_PATH_SIZE]; - char devnode[UTIL_PATH_SIZE]; - int target_len; - char *next; - - target_len = readlink(filename, target, sizeof(target)); - if (target_len <= 0 || target_len == sizeof(target)) { - info(udev_device->udev, "error reading db link %s: %m\n", filename); - return -1; - } - target[target_len] = '\0'; - - next = strchr(target, ' '); - if (next != NULL) { - next[0] = '\0'; - next = &next[1]; - } - util_strscpyl(devnode, sizeof(devnode), udev_get_dev_path(udev_device->udev), "/", target, NULL); - udev_device_set_devnode(udev_device, devnode); - while (next != NULL) { - char devlink[UTIL_PATH_SIZE]; - const char *lnk; - - lnk = next; - next = strchr(next, ' '); - if (next != NULL) { - next[0] = '\0'; - next = &next[1]; - } - util_strscpyl(devlink, sizeof(devlink), udev_get_dev_path(udev_device->udev), "/", lnk, NULL); - udev_device_add_devlink(udev_device, devlink, 0); - } - info(udev_device->udev, "device %p filled with db symlink data '%s'\n", udev_device, udev_device->devnode); - return 0; - } - f = fopen(filename, "re"); if (f == NULL) { - dbg(udev_device->udev, "error reading db file %s: %m\n", filename); + info(udev_device->udev, "no db file to read %s: %m\n", filename); return -1; } - udev_device->db_loaded = true; while (fgets(line, sizeof(line), f)) { ssize_t len; const char *val; + struct udev_list_entry *entry; len = strlen(line); if (len < 4) @@ -314,11 +272,9 @@ int udev_device_read_db(struct udev_device *udev_device) case 'L': udev_device_set_devlink_priority(udev_device, atoi(val)); break; - case 'T': - udev_device_set_event_timeout(udev_device, atoi(val)); - break; case 'E': - udev_device_add_property_from_string(udev_device, val); + entry = udev_device_add_property_from_string(udev_device, val); + udev_list_entry_set_flags(entry, 1); break; case 'G': udev_device_add_tag(udev_device, val); @@ -888,9 +844,11 @@ const char *udev_device_get_devnode(struct udev_device *udev_device) /* we might get called before we handled an event and have a db, use the kernel-provided name */ if (udev_device->devnode == NULL && udev_device_get_knodename(udev_device) != NULL) { - if (asprintf(&udev_device->devnode, "%s/%s", - udev_get_dev_path(udev_device->udev), udev_device_get_knodename(udev_device)) < 0) - return NULL; + char filename[UTIL_NAME_SIZE]; + + util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev_device->udev), "/", + udev_device_get_knodename(udev_device), NULL); + udev_device_set_devnode(udev_device, filename); return udev_device->devnode; } @@ -1271,8 +1229,6 @@ int udev_device_set_devnode(struct udev_device *udev_device, const char *devnode { free(udev_device->devnode); udev_device->devnode = strdup(devnode); - if (devnode == NULL) - return 0; if (udev_device->devnode == NULL) return -ENOMEM; udev_device_add_property(udev_device, "DEVNAME", udev_device->devnode); @@ -1516,7 +1472,9 @@ int udev_device_set_knodename(struct udev_device *udev_device, const char *knode udev_device->knodename = strdup(knodename); if (udev_device->knodename == NULL) return -ENOMEM; - udev_device_add_property(udev_device, "DEVNAME", udev_device->knodename); + /* do not overwrite the udev property with the kernel property */ + if (udev_device->devnode == NULL) + udev_device_add_property(udev_device, "DEVNAME", udev_device->knodename); return 0; } diff --git a/udev/udev-node.c b/udev/udev-node.c index 70488c420..a9ffa988b 100644 --- a/udev/udev-node.c +++ b/udev/udev-node.c @@ -327,7 +327,7 @@ static void link_update(struct udev_device *dev, const char *slink, bool add) err = util_create_path(udev, filename); if (err != 0 && err != -ENOENT) break; - fd = open(filename, O_WRONLY|O_CREAT|O_NOFOLLOW, 0444); + fd = open(filename, O_WRONLY|O_CREAT|O_CLOEXEC|O_TRUNC|O_NOFOLLOW, 0444); if (fd >= 0) close(fd); else diff --git a/udev/udevadm-info.c b/udev/udevadm-info.c index 7206f4fcf..4510f4aa9 100644 --- a/udev/udevadm-info.c +++ b/udev/udevadm-info.c @@ -210,38 +210,44 @@ static int convert_db(struct udev *udev) device = udev_device_new_from_syspath(udev, udev_list_entry_get_name(list_entry)); if (device != NULL) { const char *id; - struct stat statbuf; + struct stat stats; char to[UTIL_PATH_SIZE]; char devpath[UTIL_PATH_SIZE]; char from[UTIL_PATH_SIZE]; id = udev_device_get_id_filename(device); - if (id == NULL) - goto next; + if (id == NULL) { + udev_device_unref(device); + continue; + } util_strscpyl(to, sizeof(to), udev_get_dev_path(udev), "/.udev/db/", id, NULL); - /* do not overwrite a new database file */ - if (lstat(to, &statbuf) == 0) - goto next; - /* find old database with $subsys:$sysname */ util_strscpyl(from, sizeof(from), udev_get_dev_path(udev), "/.udev/db/", udev_device_get_subsystem(device), ":", udev_device_get_sysname(device), NULL); - if (lstat(from, &statbuf) == 0) { - rename(from, to); - goto next; + if (lstat(from, &stats) == 0) { + if (lstat(to, &stats) == 0) + unlink(from); + else + rename(from, to); } /* find old database with the encoded devpath */ util_path_encode(udev_device_get_devpath(device), devpath, sizeof(devpath)); util_strscpyl(from, sizeof(from), udev_get_dev_path(udev), "/.udev/db/", devpath, NULL); - if (lstat(from, &statbuf) == 0) { - rename(from, to); - goto next; + if (lstat(from, &stats) == 0) { + if (lstat(to, &stats) == 0) + unlink(from); + else + rename(from, to); } -next: + + /* read the old database, and write out a new one */ + udev_device_read_db(device); + udev_device_update_db(device); + udev_device_unref(device); } }