[systemd-devel] [PATCH 04/11] tmpfiles: attach an array of items to each path

Zbigniew Jędrzejewski-Szmek zbyszek at in.waw.pl
Sun Jan 18 16:20:37 PST 2015


The data structure used by tmpfiles is changed: instead of hashmaps
mapping {path → Item*} we now have hashmaps containing
{path -> ItemArray}, where ItemArray contains a pointer
to an array of Items.

For current code it doesn't matter much, but when we add new types it
is easier to simply add a new Item for a given path, then to coalesce
multiple lines into one Item.

In the future, this change will also make it possible to remember the
file and line where each Item originates, and use that in reporting
errors. Currently this is not possible, since each Item can be created
from multiple lines.
---
 man/tmpfiles.d.xml      |  13 +-
 src/tmpfiles/tmpfiles.c | 308 ++++++++++++++++++++++++------------------------
 2 files changed, 160 insertions(+), 161 deletions(-)

diff --git a/man/tmpfiles.d.xml b/man/tmpfiles.d.xml
index 9fd5913d83..8d806a41ea 100644
--- a/man/tmpfiles.d.xml
+++ b/man/tmpfiles.d.xml
@@ -288,16 +288,9 @@
 
         <varlistentry>
           <term><varname>t</varname></term>
-          <listitem><para>Set extended attributes on item. It may be
-          used in conjunction with other types (only
-          <varname>d</varname>, <varname>D</varname>,
-          <varname>f</varname>, <varname>F</varname>,
-          <varname>L</varname>, <varname>p</varname>,
-          <varname>c</varname>, <varname>b</varname>, makes sense).
-          If used as a standalone line, then
-          <command>systemd-tmpfiles</command> will try to set extended
-          attributes on specified path.  This can be especially used
-          to set SMACK labels.  </para></listitem>
+          <listitem><para>Set extended attributes on the specified
+          path. This can be useful for setting SMACK labels.
+          </para></listitem>
         </varlistentry>
       </variablelist>
 
diff --git a/src/tmpfiles/tmpfiles.c b/src/tmpfiles/tmpfiles.c
index 84d778a08f..c44dfaf1d2 100644
--- a/src/tmpfiles/tmpfiles.c
+++ b/src/tmpfiles/tmpfiles.c
@@ -4,6 +4,7 @@
   This file is part of systemd.
 
   Copyright 2010 Lennart Poettering, Kay Sievers
+  Copyright 2015 Zbigniew Jędrzejewski-Szmek
 
   systemd is free software; you can redistribute it and/or modify it
   under the terms of the GNU Lesser General Public License as published by
@@ -113,6 +114,12 @@ typedef struct Item {
         bool done:1;
 } Item;
 
+typedef struct ItemArray {
+        Item *items;
+        size_t count;
+        size_t size;
+} ItemArray;
+
 static bool arg_create = false;
 static bool arg_clean = false;
 static bool arg_remove = false;
@@ -141,13 +148,40 @@ static bool needs_glob(ItemType t) {
                       RECURSIVE_RELABEL_PATH);
 }
 
+static bool takes_ownership(ItemType t) {
+        return IN_SET(t,
+                      CREATE_FILE,
+                      TRUNCATE_FILE,
+                      CREATE_DIRECTORY,
+                      TRUNCATE_DIRECTORY,
+                      CREATE_SUBVOLUME,
+                      CREATE_FIFO,
+                      CREATE_SYMLINK,
+                      CREATE_CHAR_DEVICE,
+                      CREATE_BLOCK_DEVICE,
+                      COPY_FILES,
+
+                      WRITE_FILE,
+                      IGNORE_PATH,
+                      IGNORE_DIRECTORY_PATH,
+                      REMOVE_PATH,
+                      RECURSIVE_REMOVE_PATH);
+}
+
 static struct Item* find_glob(Hashmap *h, const char *match) {
-        Item *j;
+        ItemArray *j;
         Iterator i;
 
-        HASHMAP_FOREACH(j, h, i)
-                if (fnmatch(j->path, match, FNM_PATHNAME|FNM_PERIOD) == 0)
-                        return j;
+        HASHMAP_FOREACH(j, h, i) {
+                unsigned n;
+
+                for (n = 0; n < j->count; n++) {
+                        Item *item = j->items + n;
+
+                        if (fnmatch(item->path, match, FNM_PATHNAME|FNM_PERIOD) == 0)
+                                return item;
+                }
+        }
 
         return NULL;
 }
@@ -604,10 +638,6 @@ static int write_one_file(Item *i, const char *path) {
         if (r < 0)
                 return r;
 
-        r = item_set_xattrs(i, i->path);
-        if (r < 0)
-                return r;
-
         return 0;
 }
 
@@ -790,10 +820,6 @@ static int create_item(Item *i) {
                 if (r < 0)
                         return r;
 
-                r = item_set_xattrs(i, i->path);
-                if (r < 0)
-                        return r;
-
                 break;
 
         case CREATE_FIFO:
@@ -834,10 +860,6 @@ static int create_item(Item *i) {
                 if (r < 0)
                         return r;
 
-                r = item_set_xattrs(i, i->path);
-                if (r < 0)
-                        return r;
-
                 break;
 
         case CREATE_SYMLINK:
@@ -869,10 +891,6 @@ static int create_item(Item *i) {
                         }
                 }
 
-                r = item_set_xattrs(i, i->path);
-                if (r < 0)
-                       return r;
-
                 break;
 
         case CREATE_BLOCK_DEVICE:
@@ -933,10 +951,6 @@ static int create_item(Item *i) {
                 if (r < 0)
                         return r;
 
-                r = item_set_xattrs(i, i->path);
-                if (r < 0)
-                        return r;
-
                 break;
         }
 
@@ -994,7 +1008,7 @@ static int remove_item_instance(Item *i, const char *instance) {
 
         case REMOVE_PATH:
                 if (remove(instance) < 0 && errno != ENOENT)
-                        return log_error_errno(errno, "remove(%s): %m", instance);
+                        return log_error_errno(errno, "rm(%s): %m", instance);
 
                 break;
 
@@ -1116,6 +1130,8 @@ static int clean_item(Item *i) {
         return r;
 }
 
+static int process_item_array(ItemArray *array);
+
 static int process_item(Item *i) {
         int r, q, p, t = 0;
         _cleanup_free_ char *prefix = NULL;
@@ -1132,13 +1148,13 @@ static int process_item(Item *i) {
                 return log_oom();
 
         PATH_FOREACH_PREFIX(prefix, i->path) {
-                Item *j;
+                ItemArray *j;
 
                 j = hashmap_get(items, prefix);
                 if (j) {
                         int s;
 
-                        s = process_item(j);
+                        s = process_item_array(j);
                         if (s < 0 && t == 0)
                                 t = s;
                 }
@@ -1154,57 +1170,66 @@ static int process_item(Item *i) {
                 p;
 }
 
-static void item_free(Item *i) {
+static int process_item_array(ItemArray *array) {
+        unsigned n;
+        int r = 0, k;
 
-        if (!i)
-                return;
+        assert(array);
+
+        for (n = 0; n < array->count; n++) {
+                k = process_item(array->items + n);
+                if (k < 0 && r == 0)
+                        r = k;
+        }
+
+        return r;
+}
 
+static void item_free_contents(Item *i) {
+        assert(i);
         free(i->path);
         free(i->argument);
         strv_free(i->xattrs);
-        free(i);
 }
 
-DEFINE_TRIVIAL_CLEANUP_FUNC(Item*, item_free);
+static void item_array_free(ItemArray *a) {
+        unsigned n;
+
+        if (!a)
+                return;
+
+        for (n = 0; n < a->count; n++)
+                item_free_contents(a->items + n);
+        free(a->items);
+        free(a);
+}
 
-static bool item_equal(Item *a, Item *b) {
+static bool item_compatible(Item *a, Item *b) {
         assert(a);
         assert(b);
+        assert(streq(a->path, b->path));
 
-        if (!streq_ptr(a->path, b->path))
-                return false;
+        if (takes_ownership(a->type) && takes_ownership(b->type))
+                /* check if the items are the same */
+                return  streq_ptr(a->argument, b->argument) &&
 
-        if (a->type != b->type)
-                return false;
+                        a->uid_set == b->uid_set &&
+                        a->uid == b->uid &&
 
-        if (a->uid_set != b->uid_set ||
-            (a->uid_set && a->uid != b->uid))
-            return false;
+                        a->gid_set == b->gid_set &&
+                        a->gid == b->gid &&
 
-        if (a->gid_set != b->gid_set ||
-            (a->gid_set && a->gid != b->gid))
-            return false;
+                        a->mode_set == b->mode_set &&
+                        a->mode == b->mode &&
 
-        if (a->mode_set != b->mode_set ||
-            (a->mode_set && a->mode != b->mode))
-            return false;
+                        a->age_set == b->age_set &&
+                        a->age == b->age &&
 
-        if (a->age_set != b->age_set ||
-            (a->age_set && a->age != b->age))
-            return false;
+                        a->mask_perms == b->mask_perms &&
 
-        if ((a->type == CREATE_FILE ||
-             a->type == TRUNCATE_FILE ||
-             a->type == WRITE_FILE ||
-             a->type == CREATE_SYMLINK ||
-             a->type == COPY_FILES) &&
-            !streq_ptr(a->argument, b->argument))
-                return false;
+                        a->keep_first_level == b->keep_first_level &&
 
-        if ((a->type == CREATE_CHAR_DEVICE ||
-             a->type == CREATE_BLOCK_DEVICE) &&
-            a->major_minor != b->major_minor)
-                return false;
+                        a->major_minor == b->major_minor;
 
         return true;
 }
@@ -1236,10 +1261,10 @@ static int parse_line(const char *fname, unsigned line, const char *buffer) {
         };
 
         _cleanup_free_ char *action = NULL, *mode = NULL, *user = NULL, *group = NULL, *age = NULL, *path = NULL;
-        _cleanup_(item_freep) Item *i = NULL;
-        Item *existing;
+        _cleanup_(item_free_contents) Item i = {};
+        ItemArray *existing;
         Hashmap *h;
-        int r, n = -1, pos;
+        int r, c = -1, pos;
         bool force = false, boot = false;
 
         assert(fname);
@@ -1254,7 +1279,7 @@ static int parse_line(const char *fname, unsigned line, const char *buffer) {
                    &user,
                    &group,
                    &age,
-                   &n);
+                   &c);
         if (r < 2) {
                 log_error("[%s:%u] Syntax error.", fname, line);
                 return -EIO;
@@ -1280,29 +1305,25 @@ static int parse_line(const char *fname, unsigned line, const char *buffer) {
         if (boot && !arg_boot)
                 return 0;
 
-        i = new0(Item, 1);
-        if (!i)
-                return log_oom();
-
-        i->type = action[0];
-        i->force = force;
+        i.type = action[0];
+        i.force = force;
 
-        r = specifier_printf(path, specifier_table, NULL, &i->path);
+        r = specifier_printf(path, specifier_table, NULL, &i.path);
         if (r < 0) {
                 log_error("[%s:%u] Failed to replace specifiers: %s", fname, line, path);
                 return r;
         }
 
-        if (n >= 0)  {
-                n += strspn(buffer+n, WHITESPACE);
-                if (buffer[n] != 0 && (buffer[n] != '-' || buffer[n+1] != 0)) {
-                        i->argument = unquote(buffer+n, "\"");
-                        if (!i->argument)
+        if (c >= 0)  {
+                c += strspn(buffer+c, WHITESPACE);
+                if (buffer[c] != 0 && (buffer[c] != '-' || buffer[c+1] != 0)) {
+                        i.argument = unquote(buffer+c, "\"");
+                        if (!i.argument)
                                 return log_oom();
                 }
         }
 
-        switch (i->type) {
+        switch (i.type) {
 
         case CREATE_FILE:
         case TRUNCATE_FILE:
@@ -1320,109 +1341,109 @@ static int parse_line(const char *fname, unsigned line, const char *buffer) {
                 break;
 
         case CREATE_SYMLINK:
-                if (!i->argument) {
-                        i->argument = strappend("/usr/share/factory/", i->path);
-                        if (!i->argument)
+                if (!i.argument) {
+                        i.argument = strappend("/usr/share/factory/", i.path);
+                        if (!i.argument)
                                 return log_oom();
                 }
                 break;
 
         case WRITE_FILE:
-                if (!i->argument) {
+                if (!i.argument) {
                         log_error("[%s:%u] Write file requires argument.", fname, line);
                         return -EBADMSG;
                 }
                 break;
 
         case COPY_FILES:
-                if (!i->argument) {
-                        i->argument = strappend("/usr/share/factory/", i->path);
-                        if (!i->argument)
+                if (!i.argument) {
+                        i.argument = strappend("/usr/share/factory/", i.path);
+                        if (!i.argument)
                                 return log_oom();
-                } else if (!path_is_absolute(i->argument)) {
+                } else if (!path_is_absolute(i.argument)) {
                         log_error("[%s:%u] Source path is not absolute.", fname, line);
                         return -EBADMSG;
                 }
 
-                path_kill_slashes(i->argument);
+                path_kill_slashes(i.argument);
                 break;
 
         case CREATE_CHAR_DEVICE:
         case CREATE_BLOCK_DEVICE: {
                 unsigned major, minor;
 
-                if (!i->argument) {
+                if (!i.argument) {
                         log_error("[%s:%u] Device file requires argument.", fname, line);
                         return -EBADMSG;
                 }
 
-                if (sscanf(i->argument, "%u:%u", &major, &minor) != 2) {
-                        log_error("[%s:%u] Can't parse device file major/minor '%s'.", fname, line, i->argument);
+                if (sscanf(i.argument, "%u:%u", &major, &minor) != 2) {
+                        log_error("[%s:%u] Can't parse device file major/minor '%s'.", fname, line, i.argument);
                         return -EBADMSG;
                 }
 
-                i->major_minor = makedev(major, minor);
+                i.major_minor = makedev(major, minor);
                 break;
         }
 
         case SET_XATTR:
-                if (!i->argument) {
+                if (!i.argument) {
                         log_error("[%s:%u] Set extended attribute requires argument.", fname, line);
                         return -EBADMSG;
                 }
-                r = get_xattrs_from_arg(i);
+                r = get_xattrs_from_arg(&i);
                 if (r < 0)
                         return r;
                 break;
 
         default:
-                log_error("[%s:%u] Unknown command type '%c'.", fname, line, i->type);
+                log_error("[%s:%u] Unknown command type '%c'.", fname, line, i.type);
                 return -EBADMSG;
         }
 
-        if (!path_is_absolute(i->path)) {
-                log_error("[%s:%u] Path '%s' not absolute.", fname, line, i->path);
+        if (!path_is_absolute(i.path)) {
+                log_error("[%s:%u] Path '%s' not absolute.", fname, line, i.path);
                 return -EBADMSG;
         }
 
-        path_kill_slashes(i->path);
+        path_kill_slashes(i.path);
 
-        if (!should_include_path(i->path))
+        if (!should_include_path(i.path))
                 return 0;
 
         if (arg_root) {
                 char *p;
 
-                p = strappend(arg_root, i->path);
+                p = strappend(arg_root, i.path);
                 if (!p)
                         return log_oom();
 
-                free(i->path);
-                i->path = p;
+                free(i.path);
+                i.path = p;
         }
 
         if (user && !streq(user, "-")) {
                 const char *u = user;
 
-                r = get_user_creds(&u, &i->uid, NULL, NULL, NULL);
+                r = get_user_creds(&u, &i.uid, NULL, NULL, NULL);
                 if (r < 0) {
                         log_error("[%s:%u] Unknown user '%s'.", fname, line, user);
                         return r;
                 }
 
-                i->uid_set = true;
+                i.uid_set = true;
         }
 
         if (group && !streq(group, "-")) {
                 const char *g = group;
 
-                r = get_group_creds(&g, &i->gid);
+                r = get_group_creds(&g, &i.gid);
                 if (r < 0) {
                         log_error("[%s:%u] Unknown group '%s'.", fname, line, group);
                         return r;
                 }
 
-                i->gid_set = true;
+                i.gid_set = true;
         }
 
         if (mode && !streq(mode, "-")) {
@@ -1430,7 +1451,7 @@ static int parse_line(const char *fname, unsigned line, const char *buffer) {
                 unsigned m;
 
                 if (*mm == '~') {
-                        i->mask_perms = true;
+                        i.mask_perms = true;
                         mm++;
                 }
 
@@ -1439,66 +1460,51 @@ static int parse_line(const char *fname, unsigned line, const char *buffer) {
                         return -ENOENT;
                 }
 
-                i->mode = m;
-                i->mode_set = true;
+                i.mode = m;
+                i.mode_set = true;
         } else
-                i->mode =
-                        i->type == CREATE_DIRECTORY ||
-                        i->type == CREATE_SUBVOLUME ||
-                        i->type == TRUNCATE_DIRECTORY ? 0755 : 0644;
+                i.mode = IN_SET(i.type, CREATE_DIRECTORY, CREATE_SUBVOLUME, TRUNCATE_DIRECTORY)
+                        ? 0755 : 0644;
 
         if (age && !streq(age, "-")) {
                 const char *a = age;
 
                 if (*a == '~') {
-                        i->keep_first_level = true;
+                        i.keep_first_level = true;
                         a++;
                 }
 
-                if (parse_sec(a, &i->age) < 0) {
+                if (parse_sec(a, &i.age) < 0) {
                         log_error("[%s:%u] Invalid age '%s'.", fname, line, age);
                         return -EBADMSG;
                 }
 
-                i->age_set = true;
+                i.age_set = true;
         }
 
-        h = needs_glob(i->type) ? globs : items;
+        h = needs_glob(i.type) ? globs : items;
 
-        existing = hashmap_get(h, i->path);
+        existing = hashmap_get(h, i.path);
         if (existing) {
-                if (i->type == SET_XATTR) {
-                        r = strv_extend_strv(&existing->xattrs, i->xattrs);
-                        if (r < 0)
-                                return log_oom();
-                        return 0;
-                } else if (existing->type == SET_XATTR) {
-                        r = strv_extend_strv(&i->xattrs, existing->xattrs);
-                        if (r < 0)
-                                return log_oom();
-                        r = hashmap_replace(h, i->path, i);
-                        if (r < 0) {
-                                log_error("Failed to replace item for %s.", i->path);
-                                return r;
-                        }
-                        item_free(existing);
-                } else {
-                        /* Two identical items are fine */
-                        if (!item_equal(existing, i))
+                unsigned n;
+
+                for (n = 0; n < existing->count; n++) {
+                        if (!item_compatible(existing->items + n, &i))
                                 log_warning("[%s:%u] Duplicate line for path \"%s\", ignoring.",
-                                            fname, line, i->path);
-                        return 0;
+                                            fname, line, i.path);
                 }
         } else {
-                r = hashmap_put(h, i->path, i);
-                if (r < 0) {
-                        log_error("Failed to insert item %s: %s", i->path, strerror(-r));
-                        return r;
-                }
+                existing = new0(ItemArray, 1);
+                r = hashmap_put(h, i.path, existing);
+                if (r < 0)
+                        return log_oom();
         }
 
-        i = NULL; /* avoid cleanup */
+        if (!GREEDY_REALLOC(existing->items, existing->size, existing->count + 1))
+                return log_oom();
 
+        memcpy(existing->items + existing->count++, &i, sizeof(i));
+        zero(i);
         return 0;
 }
 
@@ -1683,7 +1689,7 @@ static int read_config_file(const char *fn, bool ignore_enoent) {
 
 int main(int argc, char *argv[]) {
         int r, k;
-        Item *i;
+        ItemArray *a;
         Iterator iterator;
 
         r = parse_argv(argc, argv);
@@ -1734,24 +1740,24 @@ int main(int argc, char *argv[]) {
                 }
         }
 
-        HASHMAP_FOREACH(i, globs, iterator) {
-                k = process_item(i);
+        HASHMAP_FOREACH(a, globs, iterator) {
+                k = process_item_array(a);
                 if (k < 0 && r == 0)
                         r = k;
         }
 
-        HASHMAP_FOREACH(i, items, iterator) {
-                k = process_item(i);
+        HASHMAP_FOREACH(a, items, iterator) {
+                k = process_item_array(a);
                 if (k < 0 && r == 0)
                         r = k;
         }
 
 finish:
-        while ((i = hashmap_steal_first(items)))
-                item_free(i);
+        while ((a = hashmap_steal_first(items)))
+                item_array_free(a);
 
-        while ((i = hashmap_steal_first(globs)))
-                item_free(i);
+        while ((a = hashmap_steal_first(globs)))
+                item_array_free(a);
 
         hashmap_free(items);
         hashmap_free(globs);
-- 
1.8.4.652.g0d6e0ce



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