conf: fix ephemeral copies

Don't rely on rootfs->bdev_type because that may be NULL. Use storage->type
instead which can't be NULL.

Co-Developed-by: Mathias Gibbens <gibmat@debian.org>
Signed-off-by: Mathias Gibbens <gibmat@debian.org>
Reported-by: Mathias Gibbens <gibmat@debian.org>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

diff --git a/src/lxc/conf.c b/src/lxc/conf.c
index 9c2d6b66a90f84a17355f481dd79296c0beca890..a7775059dfaa537bc8575cae86f81518df9f57a3 100644 (file)
--- a/src/lxc/conf.c
+++ b/src/lxc/conf.c
@@ -536,16 +536,21 @@ int lxc_rootfs_init(struct lxc_conf *conf, bool userns)
        struct stat st;
        struct statfs stfs;
        struct lxc_rootfs *rootfs = &conf->rootfs;
+       const char *type;
 
        ret = lxc_storage_prepare(conf);
        if (ret)
                return syserror_set(-EINVAL, "Failed to prepare rootfs storage");
+       type = rootfs->storage->type;
+
+       if (!type)
+               return syserror_set(-EINVAL, "Storage type neither set nor automatically detected");
 
        if (!is_empty_string(rootfs->mnt_opts.userns_path)) {
                if (!rootfs->path)
                        return syserror_set(-EINVAL, "Idmapped rootfs currently only supported with separate rootfs for container");
 
-               if (rootfs->bdev_type && !strequal(rootfs->bdev_type, "dir"))
+               if (type && !strequal(type, "dir"))
                        return syserror_set(-EINVAL, "Idmapped rootfs currently only supports the \"dir\" storage driver");
        }
 
@@ -555,14 +560,12 @@ int lxc_rootfs_init(struct lxc_conf *conf, bool userns)
        if (userns)
                return log_trace(0, "Not pinning because container runs in user namespace");
 
-       if (rootfs->bdev_type) {
-               if (strequal(rootfs->bdev_type, "overlay") ||
-                   strequal(rootfs->bdev_type, "overlayfs"))
-                       return log_trace_errno(0, EINVAL, "Not pinning on stacking filesystem");
+       if (strequal(type, "overlay") ||
+           strequal(type, "overlayfs"))
+               return log_trace_errno(0, EINVAL, "Not pinning on stacking filesystem");
 
-               if (strequal(rootfs->bdev_type, "zfs"))
-                       return log_trace_errno(0, EINVAL, "Not pinning on ZFS filesystem");
-       }
+       if (strequal(type, "zfs"))
+               return log_trace_errno(0, EINVAL, "Not pinning on ZFS filesystem");
 
        dfd_path = open_at(-EBADF, rootfs->path, PROTECT_OPATH_FILE, 0, 0);
        if (dfd_path < 0)
@@ -4831,8 +4834,8 @@ void lxc_conf_free(struct lxc_conf *conf)
        if (current_config == conf)
                current_config = NULL;
        lxc_terminal_conf_free(&conf->console);
+       free(conf->rootfs.__bdev_type);
        free(conf->rootfs.mount);
-       free(conf->rootfs.bdev_type);
        free(conf->rootfs.path);
        put_lxc_rootfs(&conf->rootfs, true);
        free(conf->logfile);

diff --git a/src/lxc/conf.h b/src/lxc/conf.h
index 185e0b35db20a9b200fc5564e45eef492e3125aa..4ad8970443913a6493bd0d388f76f2e68134fdd0 100644 (file)
--- a/src/lxc/conf.h
+++ b/src/lxc/conf.h
@@ -233,7 +233,7 @@ struct lxc_mount_options {
  * @path         : the rootfs source (directory or device)
  * @mount        : where it is mounted
  * @buf                 : static buffer to construct paths
- * @bdev_type     : optional backing store type
+ * @__bdev_type    : optional backing store type
  * @managed      : whether it is managed by LXC
  * @dfd_mnt     : fd for @mount
  * @dfd_dev : fd for /dev of the container
@@ -251,7 +251,7 @@ struct lxc_rootfs {
        int dfd_dev;
 
        char buf[PATH_MAX];
-       char *bdev_type;
+       char *__bdev_type;
        bool managed;
        struct lxc_mount_options mnt_opts;
        struct lxc_storage *storage;

diff --git a/src/lxc/confile.c b/src/lxc/confile.c
index 7a8a53418660fdbe59bc4d1481469619b255051d..89d50f35d3fe0a1afc7d221ad9802cacf63b982d 100644 (file)
--- a/src/lxc/confile.c
+++ b/src/lxc/confile.c
@@ -2795,14 +2795,14 @@ static int set_config_rootfs_path(const char *key, const char *value,
                return ret_errno(ENOMEM);
 
        /* Split <storage type>:<container path> into <storage type> and
-        * <container path>. Set "rootfs.bdev_type" to <storage type> and
+        * <container path>. Set "rootfs.__bdev_type" to <storage type> and
         * "rootfs.path" to <container path>.
         */
        tmp = strchr(dup, ':');
        if (tmp) {
                *tmp = '\0';
 
-               ret = set_config_path_item(&lxc_conf->rootfs.bdev_type, dup);
+               ret = set_config_path_item(&lxc_conf->rootfs.__bdev_type, dup);
                if (ret < 0)
                        return ret_errno(ENOMEM);
 

diff --git a/src/lxc/storage/storage.c b/src/lxc/storage/storage.c
index 1f48eac3e5b1cd792355a96638460edb662ab30d..497cad78826df590cb89830a98d7c932e2e0f302 100644 (file)
--- a/src/lxc/storage/storage.c
+++ b/src/lxc/storage/storage.c
@@ -215,7 +215,7 @@ static const struct lxc_storage_type *storage_query(struct lxc_conf *conf)
        size_t i;
        const struct lxc_storage_type *bdev;
        const char *path = conf->rootfs.path;
-       const char *type = conf->rootfs.bdev_type;
+       const char *type = conf->rootfs.__bdev_type;
 
        bdev = get_storage_by_name(path, type);
        if (bdev)
@@ -641,7 +641,7 @@ struct lxc_storage *storage_init(struct lxc_conf *conf)
 bool storage_lxc_is_dir(struct lxc_conf *conf)
 {
        struct lxc_storage *orig;
-       char *type = conf->rootfs.bdev_type;
+       const char *type = conf->rootfs.__bdev_type;
        bool bret = false;
 
        if (type)

diff --git a/src/lxc/storage/storage.h b/src/lxc/storage/storage.h
index a3873fa80e2b06a6b3557177997c6b427444676f..f8b0d1a87814db3e67e3d7a0277a2b9bafd5175d 100644 (file)
--- a/src/lxc/storage/storage.h
+++ b/src/lxc/storage/storage.h
@@ -98,7 +98,7 @@ struct lxc_storage {
  *                  trust the config file. If the config file key
  *                  lxc.rootfs.path is set to <storage type>:<container path>
  *                  the confile parser will have split this into <storage type>
- *                  and <container path> and set the <bdev_type> member in the
+ *                  and <container path> and set the <__bdev_type> member in the
  *                  lxc_rootfs struct to <storage type> and the <path> member
  *                  will be set to a clean <container path> without the <storage
  *                  type> prefix. This is the new, clean way of handling storage