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author | INSUN PYO <insun.pyo@samsung.com> | 2020-06-09 09:55:24 +0900 |
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committer | INSUN PYO <insun.pyo@samsung.com> | 2020-06-17 17:36:51 +0900 |
commit | 95b09c530e12cf7a26fcdcd83dab485ccc13e92a (patch) | |
tree | 7037db31c7d0aff883db1cdc462855c5a5cf7c3e /src/shared | |
parent | 08e51ac44ca7dc6a343d121f6aca67c3d61afb56 (diff) | |
download | systemd-95b09c530e12cf7a26fcdcd83dab485ccc13e92a.tar.gz systemd-95b09c530e12cf7a26fcdcd83dab485ccc13e92a.tar.bz2 systemd-95b09c530e12cf7a26fcdcd83dab485ccc13e92a.zip |
Revert: Rework unit loading to take into account all aliases
Revert below patches due to increasing unit loading time (UnitsLoadFinishTimestamp - UnitsLoadStartTimestamp)
Refer: https://github.com/systemd/systemd/pull/13119/commits
- test-unit-file: allow printing of information about specific units
- pid1: drop unit caches only based on mtime
- analyze: add "unit-files" to dump the unit fragment map
- core: restore initialization of u->source_mtime
- pid1: use a cache for all unit aliases
- shared/unit-file: add a function to validate unit alias symlinks
- TEST-15-DROPIN: add test for details of unit aliasing
Change-Id: I1bff89f5851544cda7522bd3ceb398499dac57d4
Diffstat (limited to 'src/shared')
-rw-r--r-- | src/shared/unit-file.c | 491 | ||||
-rw-r--r-- | src/shared/unit-file.h | 19 |
2 files changed, 1 insertions, 509 deletions
diff --git a/src/shared/unit-file.c b/src/shared/unit-file.c index 28cd3c8600..e99d304d5f 100644 --- a/src/shared/unit-file.c +++ b/src/shared/unit-file.c @@ -1,15 +1,9 @@ /* SPDX-License-Identifier: LGPL-2.1+ */ -#include "dirent-util.h" -#include "fd-util.h" -#include "fs-util.h" +#include "util.h" #include "macro.h" -#include "path-lookup.h" -#include "set.h" #include "special.h" -#include "stat-util.h" #include "string-util.h" -#include "strv.h" #include "unit-file.h" bool unit_type_may_alias(UnitType type) { @@ -31,489 +25,6 @@ bool unit_type_may_template(UnitType type) { UNIT_PATH); } -int unit_validate_alias_symlink_and_warn(const char *filename, const char *target) { - const char *src, *dst; - _cleanup_free_ char *src_instance = NULL, *dst_instance = NULL; - UnitType src_unit_type, dst_unit_type; - int src_name_type, dst_name_type; - - /* Check if the *alias* symlink is valid. This applies to symlinks like - * /etc/systemd/system/dbus.service → dbus-broker.service, but not to .wants or .requires symlinks - * and such. Neither does this apply to symlinks which *link* units, i.e. symlinks to outside of the - * unit lookup path. - * - * -EINVAL is returned if the something is wrong with the source filename or the source unit type is - * not allowed to symlink, - * -EXDEV if the target filename is not a valid unit name or doesn't match the source. - */ - - src = basename(filename); - dst = basename(target); - - /* src checks */ - - src_name_type = unit_name_to_instance(src, &src_instance); - if (src_name_type < 0) - return log_notice_errno(src_name_type, - "%s: not a valid unit name \"%s\": %m", filename, src); - - src_unit_type = unit_name_to_type(src); - assert(src_unit_type >= 0); /* unit_name_to_instance() checked the suffix already */ - - if (!unit_type_may_alias(src_unit_type)) - return log_notice_errno(SYNTHETIC_ERRNO(EINVAL), - "%s: symlinks are not allowed for units of this type, rejecting.", - filename); - - if (src_name_type != UNIT_NAME_PLAIN && - !unit_type_may_template(src_unit_type)) - return log_notice_errno(SYNTHETIC_ERRNO(EINVAL), - "%s: templates not allowed for %s units, rejecting.", - filename, unit_type_to_string(src_unit_type)); - - /* dst checks */ - - dst_name_type = unit_name_to_instance(dst, &dst_instance); - if (dst_name_type < 0) - return log_notice_errno(dst_name_type == -EINVAL ? SYNTHETIC_ERRNO(EXDEV) : dst_name_type, - "%s points to \"%s\" which is not a valid unit name: %m", - filename, dst); - - if (!(dst_name_type == src_name_type || - (src_name_type == UNIT_NAME_INSTANCE && dst_name_type == UNIT_NAME_TEMPLATE))) - return log_notice_errno(SYNTHETIC_ERRNO(EXDEV), - "%s: symlink target name type \"%s\" does not match source, rejecting.", - filename, dst); - - if (dst_name_type == UNIT_NAME_INSTANCE) { - assert(src_instance); - assert(dst_instance); - if (!streq(src_instance, dst_instance)) - return log_notice_errno(SYNTHETIC_ERRNO(EXDEV), - "%s: unit symlink target \"%s\" instance name doesn't match, rejecting.", - filename, dst); - } - - dst_unit_type = unit_name_to_type(dst); - if (dst_unit_type != src_unit_type) - return log_notice_errno(SYNTHETIC_ERRNO(EXDEV), - "%s: symlink target \"%s\" has incompatible suffix, rejecting.", - filename, dst); - - return 0; -} - -#define FOLLOW_MAX 8 - -static int unit_ids_map_get( - Hashmap *unit_ids_map, - const char *unit_name, - const char **ret_fragment_path) { - - /* Resolve recursively until we hit an absolute path, i.e. a non-aliased unit. - * - * We distinguish the case where unit_name was not found in the hashmap at all, and the case where - * some symlink was broken. - * - * If a symlink target points to an instance name, then we also check for the template. */ - - const char *id = NULL; - int r; - - for (unsigned n = 0; n < FOLLOW_MAX; n++) { - const char *t = hashmap_get(unit_ids_map, id ?: unit_name); - if (!t) { - _cleanup_free_ char *template = NULL; - - if (!id) - return -ENOENT; - - r = unit_name_template(id, &template); - if (r == -EINVAL) - return -ENXIO; /* we failed to find the symlink target */ - if (r < 0) - return log_error_errno(r, "Failed to determine template name for %s: %m", id); - - t = hashmap_get(unit_ids_map, template); - if (!t) - return -ENXIO; - - /* We successfully switched from instanced name to a template, let's continue */ - } - - if (path_is_absolute(t)) { - if (ret_fragment_path) - *ret_fragment_path = t; - return 0; - } - - id = t; - } - - return -ELOOP; -} - -static bool lookup_paths_mtime_exclude(const LookupPaths *lp, const char *path) { - /* Paths that are under our exclusive control. Users shall not alter those directly. */ - - return streq_ptr(path, lp->generator) || - streq_ptr(path, lp->generator_early) || - streq_ptr(path, lp->generator_late) || - streq_ptr(path, lp->transient) || - streq_ptr(path, lp->persistent_control) || - streq_ptr(path, lp->runtime_control); -} - -static bool lookup_paths_mtime_good(const LookupPaths *lp, usec_t mtime) { - char **dir; - - STRV_FOREACH(dir, (char**) lp->search_path) { - struct stat st; - - if (lookup_paths_mtime_exclude(lp, *dir)) - continue; - - /* Determine the latest lookup path modification time */ - if (stat(*dir, &st) < 0) { - if (errno == ENOENT) - continue; - - log_debug_errno(errno, "Failed to stat %s, ignoring: %m", *dir); - continue; - } - - if (timespec_load(&st.st_mtim) > mtime) { - log_debug_errno(errno, "Unit dir %s has changed, need to update cache.", *dir); - return false; - } - } - - return true; -} - -int unit_file_build_name_map( - const LookupPaths *lp, - usec_t *cache_mtime, - Hashmap **ret_unit_ids_map, - Hashmap **ret_unit_names_map, - Set **ret_path_cache) { - - /* Build two mappings: any name → main unit (i.e. the end result of symlink resolution), unit name → - * all aliases (i.e. the entry for a given key is a a list of all names which point to this key). The - * key is included in the value iff we saw a file or symlink with that name. In other words, if we - * have a key, but it is not present in the value for itself, there was an alias pointing to it, but - * the unit itself is not loadable. - * - * At the same, build a cache of paths where to find units. - */ - - _cleanup_hashmap_free_ Hashmap *ids = NULL, *names = NULL; - _cleanup_set_free_free_ Set *paths = NULL; - char **dir; - int r; - usec_t mtime = 0; - - /* Before doing anything, check if the mtime that was passed is still valid. If - * yes, do nothing. If *cache_time == 0, always build the cache. */ - if (cache_mtime && *cache_mtime > 0 && lookup_paths_mtime_good(lp, *cache_mtime)) - return 0; - - if (ret_path_cache) { - paths = set_new(&path_hash_ops); - if (!paths) - return log_oom(); - } - - STRV_FOREACH(dir, (char**) lp->search_path) { - struct dirent *de; - _cleanup_closedir_ DIR *d = NULL; - struct stat st; - - d = opendir(*dir); - if (!d) { - if (errno != ENOENT) - log_warning_errno(errno, "Failed to open \"%s\", ignoring: %m", *dir); - continue; - } - - /* Determine the latest lookup path modification time */ - if (fstat(dirfd(d), &st) < 0) - return log_error_errno(errno, "Failed to fstat %s: %m", *dir); - - if (!lookup_paths_mtime_exclude(lp, *dir)) - mtime = MAX(mtime, timespec_load(&st.st_mtim)); - - FOREACH_DIRENT_ALL(de, d, log_warning_errno(errno, "Failed to read \"%s\", ignoring: %m", *dir)) { - char *filename; - _cleanup_free_ char *_filename_free = NULL, *simplified = NULL; - const char *suffix, *dst = NULL; - bool valid_unit_name; - - valid_unit_name = unit_name_is_valid(de->d_name, UNIT_NAME_ANY); - - /* We only care about valid units and dirs with certain suffixes, let's ignore the - * rest. */ - if (!valid_unit_name && - !ENDSWITH_SET(de->d_name, ".wants", ".requires", ".d")) - continue; - - filename = path_join(*dir, de->d_name); - if (!filename) - return log_oom(); - - if (ret_path_cache) { - r = set_consume(paths, filename); - if (r < 0) - return log_oom(); - /* We will still use filename below. This is safe because we know the set - * holds a reference. */ - } else - _filename_free = filename; /* Make sure we free the filename. */ - - if (!valid_unit_name) - continue; - assert_se(suffix = strrchr(de->d_name, '.')); - - /* search_path is ordered by priority (highest first). If the name is already mapped - * to something (incl. itself), it means that we have already seen it, and we should - * ignore it here. */ - if (hashmap_contains(ids, de->d_name)) - continue; - - dirent_ensure_type(d, de); - if (de->d_type == DT_LNK) { - /* We don't explicitly check for alias loops here. unit_ids_map_get() which - * limits the number of hops should be used to access the map. */ - - _cleanup_free_ char *target = NULL, *target_abs = NULL; - - r = readlinkat_malloc(dirfd(d), de->d_name, &target); - if (r < 0) { - log_warning_errno(r, "Failed to read symlink %s/%s, ignoring: %m", - *dir, de->d_name); - continue; - } - - if (!path_is_absolute(target)) { - target_abs = path_join(*dir, target); - if (!target_abs) - return log_oom(); - - free_and_replace(target, target_abs); - } - - /* Get rid of "." and ".." components in target path */ - r = chase_symlinks(target, lp->root_dir, CHASE_NOFOLLOW | CHASE_NONEXISTENT, &simplified, NULL); - if (r < 0) { - log_warning_errno(r, "Failed to resolve symlink %s pointing to %s, ignoring: %m", - filename, target); - continue; - } - - /* Check if the symlink goes outside of our search path. - * If yes, it's a linked unit file or mask, and we don't care about the target name. - * Let's just store the link destination directly. - * If not, let's verify that it's a good symlink. */ - char *tail = path_startswith_strv(simplified, lp->search_path); - if (tail) { - bool self_alias; - - dst = basename(simplified); - self_alias = streq(dst, de->d_name); - - if (is_path(tail)) - log_full(self_alias ? LOG_DEBUG : LOG_WARNING, - "Suspicious symlink %s→%s, treating as alias.", - filename, simplified); - - r = unit_validate_alias_symlink_and_warn(filename, simplified); - if (r < 0) - continue; - - if (self_alias) { - /* A self-alias that has no effect */ - log_debug("%s: self-alias: %s/%s → %s, ignoring.", - __func__, *dir, de->d_name, dst); - continue; - } - - log_debug("%s: alias: %s/%s → %s", __func__, *dir, de->d_name, dst); - } else { - dst = simplified; - - log_debug("%s: linked unit file: %s/%s → %s", __func__, *dir, de->d_name, dst); - } - - } else { - dst = filename; - log_debug("%s: normal unit file: %s", __func__, dst); - } - - r = hashmap_put_strdup(&ids, de->d_name, dst); - if (r < 0) - return log_warning_errno(r, "Failed to add entry to hashmap (%s→%s): %m", - de->d_name, dst); - } - } - - /* Let's also put the names in the reverse db. */ - Iterator it; - const char *dummy, *src; - HASHMAP_FOREACH_KEY(dummy, src, ids, it) { - const char *dst; - - r = unit_ids_map_get(ids, src, &dst); - if (r < 0) - continue; - - if (null_or_empty_path(dst) != 0) - continue; - - /* Do not treat instance symlinks that point to the template as aliases */ - if (unit_name_is_valid(basename(dst), UNIT_NAME_TEMPLATE) && - unit_name_is_valid(src, UNIT_NAME_INSTANCE)) - continue; - - r = string_strv_hashmap_put(&names, basename(dst), src); - if (r < 0) - return log_warning_errno(r, "Failed to add entry to hashmap (%s→%s): %m", - basename(dst), src); - } - - if (cache_mtime) - *cache_mtime = mtime; - *ret_unit_ids_map = TAKE_PTR(ids); - *ret_unit_names_map = TAKE_PTR(names); - if (ret_path_cache) - *ret_path_cache = TAKE_PTR(paths); - - return 1; -} - -int unit_file_find_fragment( - Hashmap *unit_ids_map, - Hashmap *unit_name_map, - const char *unit_name, - const char **ret_fragment_path, - Set **ret_names) { - - const char *fragment = NULL; - _cleanup_free_ char *template = NULL, *instance = NULL; - _cleanup_set_free_free_ Set *names = NULL; - char **t, **nnn; - int r, name_type; - - /* Finds a fragment path, and returns the set of names: - * if we have …/foo.service and …/foo-alias.service→foo.service, - * and …/foo@.service and …/foo-alias@.service→foo@.service, - * and …/foo@inst.service, - * this should return: - * foo.service → …/foo.service, {foo.service, foo-alias.service}, - * foo-alias.service → …/foo.service, {foo.service, foo-alias.service}, - * foo@.service → …/foo@.service, {foo@.service, foo-alias@.service}, - * foo-alias@.service → …/foo@.service, {foo@.service, foo-alias@.service}, - * foo@bar.service → …/foo@.service, {foo@bar.service, foo-alias@bar.service}, - * foo-alias@bar.service → …/foo@.service, {foo@bar.service, foo-alias@bar.service}, - * foo-alias@inst.service → …/foo@inst.service, {foo@inst.service, foo-alias@inst.service}. - */ - - name_type = unit_name_to_instance(unit_name, &instance); - if (name_type < 0) - return name_type; - - names = set_new(&string_hash_ops); - if (!names) - return -ENOMEM; - - /* The unit always has its own name if it's not a template. */ - if (IN_SET(name_type, UNIT_NAME_PLAIN, UNIT_NAME_INSTANCE)) { - r = set_put_strdup(names, unit_name); - if (r < 0) - return r; - } - - /* First try to load fragment under the original name */ - r = unit_ids_map_get(unit_ids_map, unit_name, &fragment); - if (r < 0 && !IN_SET(r, -ENOENT, -ENXIO)) - return log_debug_errno(r, "Cannot load unit %s: %m", unit_name); - - if (fragment) { - /* Add any aliases of the original name to the set of names */ - nnn = hashmap_get(unit_name_map, basename(fragment)); - STRV_FOREACH(t, nnn) { - if (name_type == UNIT_NAME_INSTANCE && unit_name_is_valid(*t, UNIT_NAME_TEMPLATE)) { - char *inst; - - r = unit_name_replace_instance(*t, instance, &inst); - if (r < 0) - return log_debug_errno(r, "Cannot build instance name %s+%s: %m", *t, instance); - - if (!streq(unit_name, inst)) - log_debug("%s: %s has alias %s", __func__, unit_name, inst); - - log_info("%s: %s+%s → %s", __func__, *t, instance, inst); - r = set_consume(names, inst); - } else { - if (!streq(unit_name, *t)) - log_debug("%s: %s has alias %s", __func__, unit_name, *t); - - r = set_put_strdup(names, *t); - } - if (r < 0) - return r; - } - } - - if (!fragment && name_type == UNIT_NAME_INSTANCE) { - /* Look for a fragment under the template name */ - - r = unit_name_template(unit_name, &template); - if (r < 0) - return log_error_errno(r, "Failed to determine template name: %m"); - - r = unit_ids_map_get(unit_ids_map, template, &fragment); - if (r < 0 && !IN_SET(r, -ENOENT, -ENXIO)) - return log_debug_errno(r, "Cannot load template %s: %m", template); - - if (fragment) { - /* Add any aliases of the original name to the set of names */ - nnn = hashmap_get(unit_name_map, basename(fragment)); - STRV_FOREACH(t, nnn) { - _cleanup_free_ char *inst = NULL; - const char *inst_fragment = NULL; - - r = unit_name_replace_instance(*t, instance, &inst); - if (r < 0) - return log_debug_errno(r, "Cannot build instance name %s+%s: %m", template, instance); - - /* Exclude any aliases that point in some other direction. */ - r = unit_ids_map_get(unit_ids_map, inst, &inst_fragment); - if (r < 0 && !IN_SET(r, -ENOENT, -ENXIO)) - return log_debug_errno(r, "Cannot find instance fragment %s: %m", inst); - - if (inst_fragment && - !streq(basename(inst_fragment), basename(fragment))) { - log_debug("Instance %s has fragment %s and is not an alias of %s.", - inst, inst_fragment, unit_name); - continue; - } - - if (!streq(unit_name, inst)) - log_debug("%s: %s has alias %s", __func__, unit_name, inst); - r = set_consume(names, TAKE_PTR(inst)); - if (r < 0) - return r; - } - } - } - - *ret_fragment_path = fragment; - *ret_names = TAKE_PTR(names); - - // FIXME: if instance, consider any unit names with different template name - return 0; -} - static const char * const rlmap[] = { "emergency", SPECIAL_EMERGENCY_TARGET, "-b", SPECIAL_EMERGENCY_TARGET, diff --git a/src/shared/unit-file.h b/src/shared/unit-file.h index 98ba677f3f..6925daefd5 100644 --- a/src/shared/unit-file.h +++ b/src/shared/unit-file.h @@ -3,13 +3,10 @@ #include <stdbool.h> -#include "hashmap.h" -#include "time-util.h" #include "unit-name.h" typedef enum UnitFileState UnitFileState; typedef enum UnitFileScope UnitFileScope; -typedef struct LookupPaths LookupPaths; enum UnitFileState { UNIT_FILE_ENABLED, @@ -39,20 +36,4 @@ enum UnitFileScope { bool unit_type_may_alias(UnitType type) _const_; bool unit_type_may_template(UnitType type) _const_; -int unit_validate_alias_symlink_and_warn(const char *filename, const char *target); - -int unit_file_build_name_map( - const LookupPaths *lp, - usec_t *ret_time, - Hashmap **ret_unit_ids_map, - Hashmap **ret_unit_names_map, - Set **ret_path_cache); - -int unit_file_find_fragment( - Hashmap *unit_ids_map, - Hashmap *unit_name_map, - const char *unit_name, - const char **ret_fragment_path, - Set **names); - const char* runlevel_to_target(const char *rl); |