[systemd-devel] [PATCH 1/2] core/cryptsetup: Add WantsMountFor option to enable fallback to password request for crypt mounts.

Przemek Rudy prudy1 at o2.pl
Tue Apr 29 13:09:26 PDT 2014


---
 src/core/dbus-unit.c                  |   1 +
 src/core/load-fragment-gperf.gperf.m4 |   1 +
 src/core/load-fragment.c              |  47 +++++++++++
 src/core/load-fragment.h              |   1 +
 src/core/manager.c                    |  15 ++++
 src/core/manager.h                    |   6 ++
 src/core/mount.c                      |  25 +++++-
 src/core/unit.c                       | 144 ++++++++++++++++++++++++++++++++++
 src/core/unit.h                       |   5 ++
 src/cryptsetup/cryptsetup-generator.c |   3 +-
 10 files changed, 246 insertions(+), 2 deletions(-)

diff --git a/src/core/dbus-unit.c b/src/core/dbus-unit.c
index 07e7f20..31a35e9 100644
--- a/src/core/dbus-unit.c
+++ b/src/core/dbus-unit.c
@@ -516,6 +516,7 @@ const sd_bus_vtable bus_unit_vtable[] = {
         SD_BUS_PROPERTY("ReloadPropagatedFrom", "as", property_get_dependencies, offsetof(Unit, dependencies[UNIT_RELOAD_PROPAGATED_FROM]), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("JoinsNamespaceOf", "as", property_get_dependencies, offsetof(Unit, dependencies[UNIT_JOINS_NAMESPACE_OF]), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("RequiresMountsFor", "as", NULL, offsetof(Unit, requires_mounts_for), SD_BUS_VTABLE_PROPERTY_CONST),
+        SD_BUS_PROPERTY("WantsMountsFor", "as", NULL, offsetof(Unit, wants_mounts_for), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("Documentation", "as", NULL, offsetof(Unit, documentation), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("Description", "s", property_get_description, 0, SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("LoadState", "s", property_get_load_state, offsetof(Unit, load_state), SD_BUS_VTABLE_PROPERTY_CONST),
diff --git a/src/core/load-fragment-gperf.gperf.m4 b/src/core/load-fragment-gperf.gperf.m4
index 21bccbb..4e51866 100644
--- a/src/core/load-fragment-gperf.gperf.m4
+++ b/src/core/load-fragment-gperf.gperf.m4
@@ -139,6 +139,7 @@ Unit.PropagateReloadFrom,        config_parse_unit_deps,             UNIT_RELOAD
 Unit.PartOf,                     config_parse_unit_deps,             UNIT_PART_OF,                  0
 Unit.JoinsNamespaceOf,           config_parse_unit_deps,             UNIT_JOINS_NAMESPACE_OF,       0
 Unit.RequiresMountsFor,          config_parse_unit_requires_mounts_for, 0,                          0
+Unit.WantsMountsFor,             config_parse_unit_wants_mounts_for, 0,                             0
 Unit.StopWhenUnneeded,           config_parse_bool,                  0,                             offsetof(Unit, stop_when_unneeded)
 Unit.RefuseManualStart,          config_parse_bool,                  0,                             offsetof(Unit, refuse_manual_start)
 Unit.RefuseManualStop,           config_parse_bool,                  0,                             offsetof(Unit, refuse_manual_stop)
diff --git a/src/core/load-fragment.c b/src/core/load-fragment.c
index 3b36d15..24c1849 100644
--- a/src/core/load-fragment.c
+++ b/src/core/load-fragment.c
@@ -2048,6 +2048,52 @@ int config_parse_unit_requires_mounts_for(
         return 0;
 }
 
+int config_parse_unit_wants_mounts_for(
+                const char *unit,
+                const char *filename,
+                unsigned line,
+                const char *section,
+                unsigned section_line,
+                const char *lvalue,
+                int ltype,
+                const char *rvalue,
+                void *data,
+                void *userdata) {
+
+        Unit *u = userdata;
+        char *state;
+        size_t l;
+        char *w;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+        assert(data);
+
+        FOREACH_WORD_QUOTED(w, l, rvalue, state) {
+                int r;
+                _cleanup_free_ char *n;
+
+                n = strndup(w, l);
+                if (!n)
+                        return log_oom();
+
+                if (!utf8_is_valid(n)) {
+                        log_invalid_utf8(unit, LOG_ERR, filename, line, EINVAL, rvalue);
+                        continue;
+                }
+
+                r = unit_want_mounts_for(u, n);
+                if (r < 0) {
+                        log_syntax(unit, LOG_ERR, filename, line, r,
+                                   "Failed to add wanted mount for, ignoring: %s", rvalue);
+                        continue;
+                }
+        }
+
+        return 0;
+}
+
 int config_parse_documentation(const char *unit,
                                const char *filename,
                                unsigned line,
@@ -3422,6 +3468,7 @@ void unit_dump_config_items(FILE *f) {
                 { config_parse_nsec,                  "NANOSECONDS" },
                 { config_parse_namespace_path_strv,   "PATH [...]" },
                 { config_parse_unit_requires_mounts_for, "PATH [...]" },
+                { config_parse_unit_wants_mounts_for, "PATH [...]" },
                 { config_parse_exec_mount_flags,      "MOUNTFLAG [...]" },
                 { config_parse_unit_string_printf,    "STRING" },
                 { config_parse_trigger_unit,          "UNIT" },
diff --git a/src/core/load-fragment.h b/src/core/load-fragment.h
index 242fd27..761d936 100644
--- a/src/core/load-fragment.h
+++ b/src/core/load-fragment.h
@@ -74,6 +74,7 @@ int config_parse_kill_mode(const char *unit, const char *filename, unsigned line
 int config_parse_notify_access(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
 int config_parse_failure_action(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
 int config_parse_unit_requires_mounts_for(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+int config_parse_unit_wants_mounts_for(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
 int config_parse_syscall_filter(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
 int config_parse_syscall_archs(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
 int config_parse_syscall_errno(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
diff --git a/src/core/manager.c b/src/core/manager.c
index 5772f40..84ce11d 100644
--- a/src/core/manager.c
+++ b/src/core/manager.c
@@ -830,6 +830,9 @@ void manager_free(Manager *m) {
         assert(hashmap_isempty(m->units_requiring_mounts_for));
         hashmap_free(m->units_requiring_mounts_for);
 
+        assert(hashmap_isempty(m->units_want_mounts_for));
+        hashmap_free(m->units_want_mounts_for);
+
         free(m);
 }
 
@@ -2849,6 +2852,18 @@ Set *manager_get_units_requiring_mounts_for(Manager *m, const char *path) {
         return hashmap_get(m->units_requiring_mounts_for, streq(p, "/") ? "" : p);
 }
 
+Set *manager_get_units_want_mounts_for(Manager *m, const char *path) {
+        char p[strlen(path)+1];
+
+        assert(m);
+        assert(path);
+
+        strcpy(p, path);
+        path_kill_slashes(p);
+
+        return hashmap_get(m->units_want_mounts_for, streq(p, "/") ? "" : p);
+}
+
 const char *manager_get_runtime_prefix(Manager *m) {
         assert(m);
 
diff --git a/src/core/manager.h b/src/core/manager.h
index a3de351..ba5e688 100644
--- a/src/core/manager.h
+++ b/src/core/manager.h
@@ -269,6 +269,11 @@ struct Manager {
          * value where Unit objects are contained. */
         Hashmap *units_requiring_mounts_for;
 
+        /* This maps all possible path prefixes to the units want
+         * them. It's a hashmap with a path string as key and a Set as
+         * value where Unit objects are contained. */
+        Hashmap *units_want_mounts_for;
+
         /* Reference to the kdbus bus control fd */
         int kdbus_fd;
 };
@@ -335,6 +340,7 @@ void manager_status_printf(Manager *m, bool ephemeral, const char *status, const
 void manager_flip_auto_status(Manager *m, bool enable);
 
 Set *manager_get_units_requiring_mounts_for(Manager *m, const char *path);
+Set *manager_get_units_want_mounts_for(Manager *m, const char *path);
 
 const char *manager_get_runtime_prefix(Manager *m);
 
diff --git a/src/core/mount.c b/src/core/mount.c
index a979837..64d6914 100644
--- a/src/core/mount.c
+++ b/src/core/mount.c
@@ -264,7 +264,7 @@ static int mount_add_mount_links(Mount *m) {
                         return r;
         }
 
-        /* Adds in links to other units that use this path or paths
+        /* Adds in links to other units that use (require) this path or paths
          * further down in the hierarchy */
         s = manager_get_units_requiring_mounts_for(UNIT(m)->manager, m->where);
         SET_FOREACH(other, s, i) {
@@ -287,6 +287,29 @@ static int mount_add_mount_links(Mount *m) {
                 }
         }
 
+        /* Adds in links to other units that use (want) this path or paths
+         * further down in the hierarchy */
+        s = manager_get_units_want_mounts_for(UNIT(m)->manager, m->where);
+        SET_FOREACH(other, s, i) {
+
+                if (other->load_state != UNIT_LOADED)
+                        continue;
+
+                if (other == UNIT(m))
+                        continue;
+
+                r = unit_add_dependency(other, UNIT_AFTER, UNIT(m), true);
+                if (r < 0)
+                        return r;
+
+                if (UNIT(m)->fragment_path) {
+                        /* If we have fragment configuration, then make this dependency required */
+                        r = unit_add_dependency(other, UNIT_WANTS, UNIT(m), true);
+                        if (r < 0)
+                                return r;
+                }
+        }
+
         return 0;
 }
 
diff --git a/src/core/unit.c b/src/core/unit.c
index 6ac359e..f7c03f7 100644
--- a/src/core/unit.c
+++ b/src/core/unit.c
@@ -428,6 +428,34 @@ static void unit_free_requires_mounts_for(Unit *u) {
         u->requires_mounts_for = NULL;
 }
 
+static void unit_free_wants_mounts_for(Unit *u) {
+        char **j;
+
+        STRV_FOREACH(j, u->wants_mounts_for) {
+                char s[strlen(*j) + 1];
+
+                PATH_FOREACH_PREFIX_MORE(s, *j) {
+                        char *y;
+                        Set *x;
+
+                        x = hashmap_get2(u->manager->units_want_mounts_for, s, (void**) &y);
+                        if (!x)
+                                continue;
+
+                        set_remove(x, u);
+
+                        if (set_isempty(x)) {
+                                hashmap_remove(u->manager->units_want_mounts_for, y);
+                                free(y);
+                                set_free(x);
+                        }
+                }
+        }
+
+        strv_free(u->wants_mounts_for);
+        u->wants_mounts_for = NULL;
+}
+
 static void unit_done(Unit *u) {
         ExecContext *ec;
         CGroupContext *cc;
@@ -464,6 +492,7 @@ void unit_free(Unit *u) {
         unit_done(u);
 
         unit_free_requires_mounts_for(u);
+        unit_free_wants_mounts_for(u);
 
         SET_FOREACH(t, u->names, i)
                 hashmap_remove_value(u->manager->units, t, u);
@@ -885,6 +914,16 @@ void unit_dump(Unit *u, FILE *f, const char *prefix) {
                 fputs("\n", f);
         }
 
+        if (!strv_isempty(u->wants_mounts_for)) {
+                fprintf(f,
+                        "%s\tWantsMountsFor:", prefix);
+
+                STRV_FOREACH(j, u->wants_mounts_for)
+                        fprintf(f, " %s", *j);
+
+                fputs("\n", f);
+        }
+
         if (u->load_state == UNIT_LOADED) {
 
                 fprintf(f,
@@ -1068,6 +1107,35 @@ static int unit_add_mount_dependencies(Unit *u) {
                 }
         }
 
+        STRV_FOREACH(i, u->wants_mounts_for) {
+                char prefix[strlen(*i) + 1];
+
+                PATH_FOREACH_PREFIX_MORE(prefix, *i) {
+                        Unit *m;
+
+                        r = manager_get_unit_by_path(u->manager, prefix, ".mount", &m);
+                        if (r < 0)
+                                return r;
+                        if (r == 0)
+                                continue;
+                        if (m == u)
+                                continue;
+
+                        if (m->load_state != UNIT_LOADED)
+                                continue;
+
+                        r = unit_add_dependency(u, UNIT_AFTER, m, true);
+                        if (r < 0)
+                                return r;
+
+                        if (m->fragment_path) {
+                                r = unit_add_dependency(u, UNIT_WANTS, m, true);
+                                if (r < 0)
+                                        return r;
+                        }
+                }
+        }
+
         return 0;
 }
 
@@ -3289,6 +3357,82 @@ int unit_require_mounts_for(Unit *u, const char *path) {
         return 0;
 }
 
+int unit_want_mounts_for(Unit *u, const char *path) {
+        char prefix[strlen(path) + 1], *p;
+        int r;
+
+        assert(u);
+        assert(path);
+
+        /* Registers a unit for want a certain path and all its
+         * prefixes. We keep a simple array of these paths in the
+         * unit, since its usually short. However, we build a prefix
+         * table for all possible prefixes so that new appearing mount
+         * units can easily determine which units to make themselves a
+         * dependency of. */
+
+        if (!path_is_absolute(path))
+                return -EINVAL;
+
+        p = strdup(path);
+        if (!p)
+                return -ENOMEM;
+
+        path_kill_slashes(p);
+
+        if (!path_is_safe(p)) {
+                free(p);
+                return -EPERM;
+        }
+
+        if (strv_contains(u->wants_mounts_for, p)) {
+                free(p);
+                return 0;
+        }
+
+        r = strv_consume(&u->wants_mounts_for, p);
+        if (r < 0)
+                return r;
+
+        PATH_FOREACH_PREFIX_MORE(prefix, p) {
+                Set *x;
+
+                x = hashmap_get(u->manager->units_want_mounts_for, prefix);
+                if (!x) {
+                        char *q;
+
+                        if (!u->manager->units_want_mounts_for) {
+                                u->manager->units_want_mounts_for = hashmap_new(string_hash_func, string_compare_func);
+                                if (!u->manager->units_want_mounts_for)
+                                        return -ENOMEM;
+                        }
+
+                        q = strdup(prefix);
+                        if (!q)
+                                return -ENOMEM;
+
+                        x = set_new(NULL, NULL);
+                        if (!x) {
+                                free(q);
+                                return -ENOMEM;
+                        }
+
+                        r = hashmap_put(u->manager->units_want_mounts_for, q, x);
+                        if (r < 0) {
+                                free(q);
+                                set_free(x);
+                                return r;
+                        }
+                }
+
+                r = set_put(x, u);
+                if (r < 0)
+                        return r;
+        }
+
+        return 0;
+}
+
 int unit_setup_exec_runtime(Unit *u) {
         ExecRuntime **rt;
         size_t offset;
diff --git a/src/core/unit.h b/src/core/unit.h
index 3e61067..0db0b91 100644
--- a/src/core/unit.h
+++ b/src/core/unit.h
@@ -143,6 +143,7 @@ struct Unit {
         Set *dependencies[_UNIT_DEPENDENCY_MAX];
 
         char **requires_mounts_for;
+        char **wants_mounts_for;
 
         char *description;
         char **documentation;
@@ -189,6 +190,9 @@ struct Unit {
         /* All units which have requires_mounts_for set */
         LIST_FIELDS(Unit, has_requires_mounts_for);
 
+        /* All units which have wantss_mounts_for set */
+        LIST_FIELDS(Unit, has_wants_mounts_for);
+
         /* Load queue */
         LIST_FIELDS(Unit, load_queue);
 
@@ -625,6 +629,7 @@ int unit_kill_context(Unit *u, KillContext *c, bool sigkill, pid_t main_pid, pid
 int unit_make_transient(Unit *u);
 
 int unit_require_mounts_for(Unit *u, const char *path);
+int unit_want_mounts_for(Unit *u, const char *path);
 
 const char *unit_active_state_to_string(UnitActiveState i) _const_;
 UnitActiveState unit_active_state_from_string(const char *s) _pure_;
diff --git a/src/cryptsetup/cryptsetup-generator.c b/src/cryptsetup/cryptsetup-generator.c
index f4eeb2a..ce7ae92 100644
--- a/src/cryptsetup/cryptsetup-generator.c
+++ b/src/cryptsetup/cryptsetup-generator.c
@@ -153,7 +153,8 @@ static int create_disk(
 
                                 fprintf(f, "After=%1$s\nRequires=%1$s\n", dd);
                         } else
-                                fprintf(f, "RequiresMountsFor=%s\n", password);
+                                /* Do not use 'RequiresMountsFor=' here to allow fallback to password in case the key device is not available */
+                                fprintf(f, "WantsMountsFor=%s\n", password);
                 }
         }
 
-- 
1.9.0



More information about the systemd-devel mailing list