Fix cgroup configuration format

From: Daniel Lezcano <dlezcano@fr.ibm.com>

This modification change the configuration format. Instead of creating
a 'cgroup' directory with a file per controller, a single file is used
to store the different value for the control groups. That allows to assign
several values to the same controller like "devices.allow" and keep the same
assignation order as defined in the configuration.

In order to keep compatibility, when the old cgroup format is detected, it
is automatically converted to the new format.

Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>

diff --git a/src/lxc/lxc_conf.c b/src/lxc/lxc_conf.c
index f8e1d0cd63fed964e5716861d0d94047b4ba0e17..523dc7b629accd95f37b5afa0698c567f21d8d34 100644 (file)
--- a/src/lxc/lxc_conf.c
+++ b/src/lxc/lxc_conf.c
@@ -42,6 +42,7 @@
 #include <fcntl.h>
 #include <netinet/in.h>
 #include <net/if.h>
+#include <libgen.h>
 
 #include <lxc/lxc.h>
 #include <network.h>
@@ -50,10 +51,10 @@
 #define MAXINDEXLEN 20
 #define MAXLINELEN  128
 
-typedef int (*instanciate_cb)(const char *dirname, 
+typedef int (*instanciate_cb)(const char *directory, 
                              const char *file, pid_t pid);
 
-typedef int (*dir_cb)(const char *name, const char *dirname, 
+typedef int (*dir_cb)(const char *name, const char *directory, 
                      const char *file, void *data);
 
 typedef int (*file_cb)(void* buffer, void *data);
@@ -68,6 +69,7 @@ static int instanciate_veth(const char *, const char *, pid_t);
 static int instanciate_macvlan(const char *, const char *, pid_t);
 static int instanciate_phys(const char *, const char *, pid_t);
 static int instanciate_empty(const char *, const char *, pid_t);
+static int unconfigure_cgroup(const char *name);
 
 static struct netdev_conf netdev_conf[MAXCONFTYPE + 1] = {
        [VETH]    = { "veth",    instanciate_veth,    0  },
@@ -84,20 +86,20 @@ static int dir_filter(const struct dirent *dirent)
         return 1;
 }
 
-static int dir_for_each(const char *name, const char *dirname, 
+static int dir_for_each(const char *name, const char *directory, 
                        dir_cb callback, void *data)
 {
        struct dirent **namelist;
        int n;
        
-       n = scandir(dirname, &namelist, dir_filter, alphasort);
+       n = scandir(directory, &namelist, dir_filter, alphasort);
        if (n < 0) {
-               lxc_log_syserror("failed to scan %s directory", dirname);
+               lxc_log_syserror("failed to scan %s directory", directory);
                return -1;
        }
        
        while (n--) {
-               if (callback(name, dirname, namelist[n]->d_name, data)) {
+               if (callback(name, directory, namelist[n]->d_name, data)) {
                        lxc_log_error("callback failed");
                        free(namelist[n]);
                        return -1;
@@ -399,23 +401,26 @@ static int configure_cgroup(const char *name, struct lxc_list *cgroup)
        char path[MAXPATHLEN];
        struct lxc_list *iterator;
        struct lxc_cgroup *cg;
-       int ret = -1;
+       FILE *file;
 
        if (lxc_list_empty(cgroup))
                return 0;
 
        snprintf(path, MAXPATHLEN, LXCPATH "/%s/cgroup", name);
 
-       if (mkdir(path, 0755)) {
-               lxc_log_syserror("failed to create '%s' directory", path);
+       file = fopen(path, "w+");
+       if (!file) {
+               lxc_log_syserror("failed to open '%s'", path);
                return -1;
        }
 
        lxc_list_for_each(iterator, cgroup) {
                cg = iterator->elem;
-               write_info(path, cg->subsystem, cg->value);
+               fprintf(file, "%s=%s\n", cg->subsystem, cg->value);
        }
        
+       fclose(file);
+
        return 0;
 }
 
@@ -512,27 +517,27 @@ out_open:
        goto out;
 }
 
-static int unconfigure_ip_addresses(const char *dirname)
+static int unconfigure_ip_addresses(const char *directory)
 {
        char path[MAXPATHLEN];
 
-       snprintf(path, MAXPATHLEN, "%s/ipv4", dirname);
+       snprintf(path, MAXPATHLEN, "%s/ipv4", directory);
        delete_info(path, "addresses");
        rmdir(path);
 
-       snprintf(path, MAXPATHLEN, "%s/ipv6", dirname);
+       snprintf(path, MAXPATHLEN, "%s/ipv6", directory);
        delete_info(path, "addresses");
        rmdir(path);
 
        return 0;
 }
 
-static int unconfigure_network_cb(const char *name, const char *dirname, 
+static int unconfigure_network_cb(const char *name, const char *directory, 
                                  const char *file, void *data)
 {
        char path[MAXPATHLEN];
 
-       snprintf(path, MAXPATHLEN, "%s/%s", dirname, file);
+       snprintf(path, MAXPATHLEN, "%s/%s", directory, file);
        delete_info(path, "ifindex");
        delete_info(path, "name");
        delete_info(path, "addr");
@@ -547,29 +552,40 @@ static int unconfigure_network_cb(const char *name, const char *dirname,
 
 static int unconfigure_network(const char *name)
 {
-       char dirname[MAXPATHLEN];
+       char directory[MAXPATHLEN];
 
-       snprintf(dirname, MAXPATHLEN, LXCPATH "/%s/network", name);
-       dir_for_each(name, dirname, unconfigure_network_cb, NULL);
-       rmdir(dirname);
+       snprintf(directory, MAXPATHLEN, LXCPATH "/%s/network", name);
+       dir_for_each(name, directory, unconfigure_network_cb, NULL);
+       rmdir(directory);
 
        return 0;
 }
 
-static int unconfigure_cgroup_cb(const char *name, const char *dirname, 
+static int unconfigure_cgroup_cb(const char *name, const char *directory, 
                                  const char *file, void *data)
 {
-       return delete_info(dirname, file);
+       return delete_info(directory, file);
 }
 
 static int unconfigure_cgroup(const char *name)
 {
-       char dirname[MAXPATHLEN];
+       char filename[MAXPATHLEN];
+       struct stat s;
 
-       lxc_unlink_nsgroup(name);
-       snprintf(dirname, MAXPATHLEN, LXCPATH "/%s/cgroup", name);
-       dir_for_each(name, dirname, unconfigure_cgroup_cb, NULL);
-       rmdir(dirname);
+       snprintf(filename, MAXPATHLEN, LXCPATH "/%s/cgroup", name);
+
+       if (stat(filename, &s)) {
+               lxc_log_syserror("failed to stat '%s'", filename);
+               return -1;
+       }
+
+       if (S_ISDIR(s.st_mode)) {
+               /* old cgroup configuration */
+               dir_for_each(name, filename, unconfigure_cgroup_cb, NULL);
+               rmdir(filename);
+       } else {
+               unlink(filename);
+       }
 
        return 0;
 }
@@ -647,19 +663,93 @@ static int setup_rootfs(const char *name)
        return 0;
 }
 
-static int setup_cgroup_cb(const char *name, const char *dirname, 
-                          const char *file, void *data)
+static int setup_cgroup_cb(void* buffer, void *data)
 {
-       if (lxc_cgroup_copy(name, file))
-               lxc_log_warning("failed to setup '%s'", name);
+       char *key = buffer, *value;
+
+       value = strchr(key, '=');
+       if (!value)
+               return -1;
+
+       *value = '\0';
+       value += 1;
+
+       printf("key: %s\n", key);
+       printf("value: %s\n", value);
+
        return 0;
 }
 
+static int setup_convert_cgroup_cb(const char *name, const char *directory, 
+                                  const char *file, void *data)
+{
+       FILE *f = data;
+       char line[MAXPATHLEN];
+       
+       if (read_info(directory, file, line, MAXPATHLEN)) {
+               lxc_log_error("failed to read %s", file);
+               return -1;
+       }
+
+       fprintf(f, "%s=%s\n", file, line);
+
+       return 0;
+}
+
+static int setup_convert_cgroup(const char *name, char *directory)
+{
+       char filename[MAXPATHLEN];
+       FILE *file;
+       int ret;
+
+       snprintf(filename, MAXPATHLEN, LXCPATH "/%s/cgroup.new", name);
+
+       file = fopen(filename, "w+");
+       if (!file)
+               return -1;
+
+       ret = dir_for_each(name, directory, setup_convert_cgroup_cb, file);
+       if (ret)
+               goto out_error;
+
+       ret = unconfigure_cgroup(name);
+       if (ret)
+               goto out_error;
+
+       ret = rename(filename, directory);
+       if (ret)
+               goto out_error;
+out:
+       fclose(file);
+       return ret;
+
+out_error:
+       unlink(filename);
+       goto out;
+}
+
 static int setup_cgroup(const char *name)
 {
-       char dirname[MAXPATHLEN];
-       snprintf(dirname, MAXPATHLEN, LXCPATH "/%s/cgroup", name);
-       return dir_for_each(name, dirname, setup_cgroup_cb, NULL);
+       char filename[MAXPATHLEN];
+       char line[MAXPATHLEN];
+       struct stat s;
+       
+       snprintf(filename, MAXPATHLEN, LXCPATH "/%s/cgroup", name);
+
+       if (stat(filename, &s)) {
+               lxc_log_syserror("failed to stat '%s'", filename);
+               return -1;
+       }
+
+       if (S_ISDIR(s.st_mode)) {
+               if (setup_convert_cgroup(name, filename)) {
+                       lxc_log_error("failed to convert old cgroup configuration");
+                       return -1;
+               }
+       }
+       
+       return file_for_each_line(filename, setup_cgroup_cb, 
+                                 line, MAXPATHLEN, filename);
 }
 
 static int setup_mount(const char *name)
@@ -794,33 +884,33 @@ static int setup_hw_addr(char *hwaddr, const char *ifname)
        return ret;
 }
 
-static int setup_ip_addr(const char *dirname, const char *ifname)
+static int setup_ip_addr(const char *directory, const char *ifname)
 {
        char path[MAXPATHLEN], line[MAXLINELEN];
        struct stat s;
        int ret = 0;
 
-       snprintf(path, MAXPATHLEN, "%s/ipv4/addresses", dirname);
+       snprintf(path, MAXPATHLEN, "%s/ipv4/addresses", directory);
        if (!stat(path, &s))
                ret = file_for_each_line(path, setup_ipv4_addr_cb, 
                                         line, MAXPATHLEN, (void*)ifname);
        return ret;
 }
 
-static int setup_ip6_addr(const char *dirname, const char *ifname)
+static int setup_ip6_addr(const char *directory, const char *ifname)
 {
        char path[MAXPATHLEN], line[MAXLINELEN];
        struct stat s;
        int ret = 0;
 
-       snprintf(path, MAXLINELEN, "%s/ipv6/addresses", dirname);
+       snprintf(path, MAXLINELEN, "%s/ipv6/addresses", directory);
        if (!stat(path, &s))
                ret = file_for_each_line(path, setup_ipv6_addr_cb, 
                                         line, MAXPATHLEN, (void*)ifname);      
        return ret;
 }
 
-static int setup_network_cb(const char *name, const char *dirname, 
+static int setup_network_cb(const char *name, const char *directory, 
                            const char *file, void *data)
 {
        char path[MAXPATHLEN];
@@ -831,7 +921,7 @@ static int setup_network_cb(const char *name, const char *dirname,
        char *current_ifname = ifname;
        int ifindex;
 
-       snprintf(path, MAXPATHLEN, "%s/%s", dirname, file);
+       snprintf(path, MAXPATHLEN, "%s/%s", directory, file);
 
        if (read_info(path, "ifindex", strindex, sizeof(strindex))) {
                lxc_log_error("failed to read ifindex info");
@@ -901,10 +991,10 @@ static int setup_network_cb(const char *name, const char *dirname,
 
 static int setup_network(const char *name)
 {
-       char dirname[MAXPATHLEN];
+       char directory[MAXPATHLEN];
 
-       snprintf(dirname, MAXPATHLEN, LXCPATH "/%s/network", name);
-       return dir_for_each(name, dirname, setup_network_cb, NULL);
+       snprintf(directory, MAXPATHLEN, LXCPATH "/%s/network", name);
+       return dir_for_each(name, directory, setup_network_cb, NULL);
 }
 
 int conf_has(const char *name, const char *info)
@@ -983,7 +1073,7 @@ int lxc_unconfigure(const char *name)
        return 0;
 }
 
-static int instanciate_veth(const char *dirname, const char *file, pid_t pid)
+static int instanciate_veth(const char *directory, const char *file, pid_t pid)
 {
        char *path = NULL, *strindex = NULL, *veth1 = NULL, *veth2 = NULL;
        char bridge[IFNAMSIZ];
@@ -991,7 +1081,7 @@ static int instanciate_veth(const char *dirname, const char *file, pid_t pid)
                        
        if (!asprintf(&veth1, "%s_%d", file, pid) ||
            !asprintf(&veth2, "%s~%d", file, pid) ||
-           !asprintf(&path, "%s/%s", dirname, file)) {
+           !asprintf(&path, "%s/%s", directory, file)) {
                lxc_log_syserror("failed to allocate memory");
                goto out;
        }
@@ -1037,7 +1127,7 @@ out:
        free(veth2);
        return ret;
 } 
-static int instanciate_macvlan(const char *dirname, const char *file, pid_t pid)
+static int instanciate_macvlan(const char *directory, const char *file, pid_t pid)
 {
        char path[MAXPATHLEN], *strindex = NULL, *peer = NULL;
        char link[IFNAMSIZ]; 
@@ -1048,7 +1138,7 @@ static int instanciate_macvlan(const char *dirname, const char *file, pid_t pid)
                return -1;
        }
 
-       snprintf(path, MAXPATHLEN, "%s/%s", dirname, file);
+       snprintf(path, MAXPATHLEN, "%s/%s", directory, file);
        if (read_info(path, "link", link, IFNAMSIZ)) {
                lxc_log_error("failed to read bridge info");
                goto out;
@@ -1082,13 +1172,13 @@ out:
        return ret;
 }
 
-static int instanciate_phys(const char *dirname, const char *file, pid_t pid)
+static int instanciate_phys(const char *directory, const char *file, pid_t pid)
 {
        char path[MAXPATHLEN], *strindex = NULL;
        char link[IFNAMSIZ];
        int ifindex, ret = -1;
 
-       snprintf(path, MAXPATHLEN, "%s/%s", dirname, file);
+       snprintf(path, MAXPATHLEN, "%s/%s", directory, file);
        if (read_info(path, "link", link, IFNAMSIZ)) {
                lxc_log_error("failed to read link info");
                goto out;
@@ -1116,12 +1206,12 @@ out:
        return ret;
 }
 
-static int instanciate_empty(const char *dirname, const char *file, pid_t pid)
+static int instanciate_empty(const char *directory, const char *file, pid_t pid)
 {
        char path[MAXPATHLEN], *strindex = NULL;
        int ret = -1;
 
-       snprintf(path, MAXPATHLEN, "%s/%s", dirname, file);
+       snprintf(path, MAXPATHLEN, "%s/%s", directory, file);
        if (!asprintf(&strindex, "%d", 0)) {
                lxc_log_error("not enough memory");
                return -1;
@@ -1138,39 +1228,39 @@ out:
        return ret;
 }
 
-static int instanciate_netdev_cb(const char *name, const char *dirname, 
+static int instanciate_netdev_cb(const char *name, const char *directory, 
                                 const char *file, void *data)
 {
        pid_t *pid = data;
 
        if (!strncmp("veth", file, strlen("veth")))
-               return instanciate_veth(dirname, file, *pid);
+               return instanciate_veth(directory, file, *pid);
        else if (!strncmp("macvlan", file, strlen("macvlan")))
-               return instanciate_macvlan(dirname, file, *pid);
+               return instanciate_macvlan(directory, file, *pid);
        else if (!strncmp("phys", file, strlen("phys")))
-               return instanciate_phys(dirname, file, *pid);
+               return instanciate_phys(directory, file, *pid);
        else if (!strncmp("empty", file, strlen("empty")))
-                return instanciate_empty(dirname, file, *pid);
+                return instanciate_empty(directory, file, *pid);
 
        return -1;
 }
 
 static int instanciate_netdev(const char *name, pid_t pid)
 {
-       char dirname[MAXPATHLEN];
+       char directory[MAXPATHLEN];
 
-       snprintf(dirname, MAXPATHLEN, LXCPATH "/%s/network", name);
-       return dir_for_each(name, dirname, instanciate_netdev_cb, &pid);
+       snprintf(directory, MAXPATHLEN, LXCPATH "/%s/network", name);
+       return dir_for_each(name, directory, instanciate_netdev_cb, &pid);
 }
 
-static int move_netdev_cb(const char *name, const char *dirname, 
+static int move_netdev_cb(const char *name, const char *directory, 
                          const char *file, void *data)
 {
        char path[MAXPATHLEN], ifname[IFNAMSIZ], strindex[MAXINDEXLEN];
        pid_t *pid = data;
        int ifindex;
 
-       snprintf(path, MAXPATHLEN, "%s/%s", dirname, file);
+       snprintf(path, MAXPATHLEN, "%s/%s", directory, file);
        if (read_info(path, "ifindex", strindex, MAXINDEXLEN) < 0) {
                lxc_log_error("failed to read index to from %s", path);
                return -1;
@@ -1196,9 +1286,9 @@ static int move_netdev_cb(const char *name, const char *dirname,
 
 static int move_netdev(const char *name, pid_t pid)
 {
-       char dirname[MAXPATHLEN];
-       snprintf(dirname, MAXPATHLEN, LXCPATH "/%s/network", name);
-       return dir_for_each(name, dirname, move_netdev_cb, &pid);
+       char directory[MAXPATHLEN];
+       snprintf(directory, MAXPATHLEN, LXCPATH "/%s/network", name);
+       return dir_for_each(name, directory, move_netdev_cb, &pid);
 }
 
 int conf_create_network(const char *name, pid_t pid)
@@ -1216,7 +1306,7 @@ int conf_create_network(const char *name, pid_t pid)
        return 0;
 }
 
-static int delete_netdev_cb(const char *name, const char *dirname, 
+static int delete_netdev_cb(const char *name, const char *directory, 
                            const char *file, void *data)
 {
        char strindex[MAXINDEXLEN];
@@ -1224,7 +1314,7 @@ static int delete_netdev_cb(const char *name, const char *dirname,
        char ifname[IFNAMSIZ];
        int i, ifindex;
        
-       snprintf(path, MAXPATHLEN, "%s/%s", dirname, file);
+       snprintf(path, MAXPATHLEN, "%s/%s", directory, file);
        
        if (read_info(path, "ifindex", strindex, MAXINDEXLEN)) {
                lxc_log_error("failed to read ifindex info");
@@ -1259,10 +1349,10 @@ static int delete_netdev_cb(const char *name, const char *dirname,
 
 static int delete_netdev(const char *name)
 {
-       char dirname[MAXPATHLEN];
+       char directory[MAXPATHLEN];
 
-       snprintf(dirname, MAXPATHLEN, LXCPATH "/%s/network", name);
-       return dir_for_each(name, dirname, delete_netdev_cb, NULL);
+       snprintf(directory, MAXPATHLEN, LXCPATH "/%s/network", name);
+       return dir_for_each(name, directory, delete_netdev_cb, NULL);
 }
 
 int conf_destroy_network(const char *name)