From 1e75cda3454d08ff880600f86d296a23bfa1f996 Mon Sep 17 00:00:00 2001 From: Kay Sievers Date: Mon, 6 Oct 2008 13:52:43 +0200 Subject: [PATCH] store node name and symlinks into db symlink target if they are small enough --- udev/lib/libudev-device.c | 22 +++++++ udev/udev_db.c | 118 +++++++++++++++++++++++--------------- 2 files changed, 95 insertions(+), 45 deletions(-) diff --git a/udev/lib/libudev-device.c b/udev/lib/libudev-device.c index 8e4360a7..2113ebd4 100644 --- a/udev/lib/libudev-device.c +++ b/udev/lib/libudev-device.c @@ -83,6 +83,7 @@ static int device_read_db(struct udev_device *udev_device) if ((stats.st_mode & S_IFMT) == S_IFLNK) { char target[UTIL_PATH_SIZE]; int target_len; + char *next; target_len = readlink(filename, target, sizeof(target)); if (target_len > 0) @@ -91,8 +92,29 @@ static int device_read_db(struct udev_device *udev_device) info(udev_device->udev, "error reading db link %s: %m\n", filename); return -1; } + + next = strchr(target, ' '); + if (next != NULL) { + next[0] = '\0'; + next = &next[1]; + } if (asprintf(&udev_device->devnode, "%s/%s", udev_get_dev_path(udev_device->udev), target) < 0) return -ENOMEM; + while (next != NULL) { + char linkname[UTIL_PATH_SIZE]; + const char *lnk; + + lnk = next; + next = strchr(next, ' '); + if (next != NULL) { + next[0] = '\0'; + next = &next[1]; + } + util_strlcpy(linkname, udev_get_dev_path(udev_device->udev), sizeof(linkname)); + util_strlcat(linkname, "/", sizeof(linkname)); + util_strlcat(linkname, next, sizeof(linkname)); + device_add_devlink(udev_device, linkname); + } info(udev_device->udev, "device %p filled with db symlink data '%s'\n", udev_device, udev_device->devnode); return 0; } diff --git a/udev/udev_db.c b/udev/udev_db.c index 34bdef37..e03c2782 100644 --- a/udev/udev_db.c +++ b/udev/udev_db.c @@ -127,6 +127,10 @@ int udev_db_rename(struct udev *udev, const char *devpath_old, const char *devpa int udev_db_add_device(struct udevice *udevice) { char filename[UTIL_PATH_SIZE]; + FILE *f; + struct name_entry *name_loop; + char target[232]; /* on 64bit, tmpfs inlines up to 239 bytes */ + int ret; if (udevice->test_run) return 0; @@ -135,55 +139,61 @@ int udev_db_add_device(struct udevice *udevice) create_path(udevice->udev, filename); unlink(filename); - /* - * don't waste tmpfs memory pages, if we don't have any data to store - * create fake db-file; store the node-name in a symlink target - */ - if (list_empty(&udevice->symlink_list) && list_empty(&udevice->env_list) && - !udevice->partitions && !udevice->ignore_remove) { - int ret; - dbg(udevice->udev, "nothing interesting to store, create symlink\n"); - udev_selinux_setfscreatecon(udevice->udev, filename, S_IFLNK); - ret = symlink(udevice->name, filename); - udev_selinux_resetfscreatecon(udevice->udev); - if (ret != 0) { - err(udevice->udev, "unable to create db link '%s': %m\n", filename); - return -1; + if (!list_empty(&udevice->env_list)) + goto file; + if (udevice->partitions || udevice->ignore_remove) + goto file; + /* try not to waste tmpfs memory, store values, if they fit, in a symlink target */ + util_strlcpy(target, udevice->name, sizeof(target)); + list_for_each_entry(name_loop, &udevice->symlink_list, node) { + size_t len; + + util_strlcat(target, " ", sizeof(target)); + len = util_strlcat(target, name_loop->name, sizeof(target)); + if (len >= sizeof(target)) { + info(udevice->udev, "size of links too large, create file\n"); + goto file; } - } else { - FILE *f; - struct name_entry *name_loop; - - f = fopen(filename, "w"); - if (f == NULL) { - err(udevice->udev, "unable to create db file '%s': %m\n", filename); - return -1; + } + /* add symlink names to index */ + list_for_each_entry(name_loop, &udevice->symlink_list, node) { + name_index(udevice->udev, udevice->dev->devpath, name_loop->name, 1); + } + info(udevice->udev, "create db link (%s)\n", target); + udev_selinux_setfscreatecon(udevice->udev, filename, S_IFLNK); + ret = symlink(target, filename); + udev_selinux_resetfscreatecon(udevice->udev); + if (ret == 0) + goto out; +file: + f = fopen(filename, "w"); + if (f == NULL) { + err(udevice->udev, "unable to create db file '%s': %m\n", filename); + return -1; } - dbg(udevice->udev, "storing data for device '%s' in '%s'\n", udevice->dev->devpath, filename); + info(udevice->udev, "created db file for '%s' in '%s'\n", udevice->dev->devpath, filename); - fprintf(f, "N:%s\n", udevice->name); - list_for_each_entry(name_loop, &udevice->symlink_list, node) { - fprintf(f, "S:%s\n", name_loop->name); - /* add symlink-name to index */ - name_index(udevice->udev, udevice->dev->devpath, name_loop->name, 1); - } - fprintf(f, "M:%u:%u\n", major(udevice->devt), minor(udevice->devt)); - if (udevice->link_priority != 0) - fprintf(f, "L:%u\n", udevice->link_priority); - if (udevice->event_timeout >= 0) - fprintf(f, "T:%u\n", udevice->event_timeout); - if (udevice->partitions != 0) - fprintf(f, "A:%u\n", udevice->partitions); - if (udevice->ignore_remove) - fprintf(f, "R:%u\n", udevice->ignore_remove); - list_for_each_entry(name_loop, &udevice->env_list, node) - fprintf(f, "E:%s\n", name_loop->name); - fclose(f); + fprintf(f, "N:%s\n", udevice->name); + list_for_each_entry(name_loop, &udevice->symlink_list, node) { + fprintf(f, "S:%s\n", name_loop->name); + /* add symlink names to index */ + name_index(udevice->udev, udevice->dev->devpath, name_loop->name, 1); } - + fprintf(f, "M:%u:%u\n", major(udevice->devt), minor(udevice->devt)); + if (udevice->link_priority != 0) + fprintf(f, "L:%u\n", udevice->link_priority); + if (udevice->event_timeout >= 0) + fprintf(f, "T:%u\n", udevice->event_timeout); + if (udevice->partitions != 0) + fprintf(f, "A:%u\n", udevice->partitions); + if (udevice->ignore_remove) + fprintf(f, "R:%u\n", udevice->ignore_remove); + list_for_each_entry(name_loop, &udevice->env_list, node) + fprintf(f, "E:%s\n", name_loop->name); + fclose(f); +out: /* add name to index */ name_index(udevice->udev, udevice->dev->devpath, udevice->name, 1); - return 0; } @@ -209,8 +219,9 @@ int udev_db_get_device(struct udevice *udevice, const char *devpath) if ((stats.st_mode & S_IFMT) == S_IFLNK) { char target[UTIL_NAME_SIZE]; int target_len; + char *next; - info(udevice->udev, "found a symlink as db file\n"); + info(udevice->udev, "found db symlink\n"); target_len = readlink(filename, target, sizeof(target)); if (target_len > 0) target[target_len] = '\0'; @@ -218,8 +229,25 @@ int udev_db_get_device(struct udevice *udevice, const char *devpath) info(udevice->udev, "error reading db link %s: %m\n", filename); return -1; } - dbg(udevice->udev, "db link points to '%s'\n", target); + next = strchr(target, ' '); + if (next != NULL) { + next[0] = '\0'; + next = &next[1]; + } + info(udevice->udev, "got db link node: '%s'\n", target); util_strlcpy(udevice->name, target, sizeof(udevice->name)); + while (next != NULL) { + char *lnk; + + lnk = next; + next = strchr(next, ' '); + if (next != NULL) { + next[0] = '\0'; + next = &next[1]; + } + info(udevice->udev, "got db link link: '%s'\n", lnk); + name_list_add(udevice->udev, &udevice->symlink_list, lnk, 0); + } return 0; } -- 2.39.5