lxc-copy: cleanup

- make free_mnts() work directly on the globals mnt_table and mnt_table_size
- have free_mnts() set mnt_table = NULL and mnt_table_size = 0 when its done to
  avoid double frees
- simplify error-handling in do_clone_ephemeral()
- do_clone_ephemeral(): when chmod() falls to set permissions on the temporary
  folder we created for mkdtemp() remove the folder
- simplify error handling in main()

Signed-off-by: Christian Brauner <christian.brauner@mailbox.org>

diff --git a/src/lxc/lxc_copy.c b/src/lxc/lxc_copy.c
index 98121764e3bb51503ba4394a8efd996b652b55a7..dbda1824a7763c13bd90afbfcf5ccd5c5808f788 100644 (file)
--- a/src/lxc/lxc_copy.c
+++ b/src/lxc/lxc_copy.c
@@ -144,7 +144,7 @@ static int do_clone_ephemeral(struct lxc_container *c,
 static int do_clone_rename(struct lxc_container *c, char *newname);
 static int do_clone_task(struct lxc_container *c, enum task task, int flags,
                         char **args);
-static void free_mnts(struct mnts *m, unsigned int num);
+static void free_mnts(void);
 static uint64_t get_fssize(char *s);
 static int parse_mntsubopts(char *subopts, char *const *keys,
                            char *mntparameters);
@@ -156,29 +156,29 @@ int main(int argc, char *argv[])
 {
        struct lxc_container *c;
        int flags = 0;
-       int ret;
+       int ret = EXIT_FAILURE;
 
        if (lxc_arguments_parse(&my_args, argc, argv))
-               exit(EXIT_FAILURE);
+               exit(ret);
 
        if (!my_args.log_file)
                my_args.log_file = "none";
 
        if (lxc_log_init(my_args.name, my_args.log_file, my_args.log_priority,
                         my_args.progname, my_args.quiet, my_args.lxcpath[0]))
-               exit(EXIT_FAILURE);
+               exit(ret);
        lxc_log_options_no_override();
 
        if (geteuid()) {
                if (access(my_args.lxcpath[0], O_RDWR) < 0) {
                        fprintf(stderr, "You lack access to %s\n", my_args.lxcpath[0]);
-                       exit(EXIT_FAILURE);
+                       exit(ret);
                }
        }
 
        if (!my_args.newname && !(my_args.task == DESTROY)) {
                printf("Error: You must provide a NEWNAME for the clone.\n");
-               exit(EXIT_FAILURE);
+               exit(ret);
        }
 
        if (my_args.task == SNAP || my_args.task == DESTROY)
@@ -193,24 +193,21 @@ int main(int argc, char *argv[])
 
        c = lxc_container_new(my_args.name, my_args.lxcpath[0]);
        if (!c)
-               exit(EXIT_FAILURE);
+               exit(ret);
 
        if (!c->may_control(c)) {
-               fprintf(stderr, "Insufficent privileges to control %s\n",
-                       c->name);
-               lxc_container_put(c);
-               exit(EXIT_FAILURE);
+               fprintf(stderr, "Insufficent privileges to control %s\n", c->name);
+               goto out;
        }
 
        if (!c->is_defined(c)) {
-               fprintf(stderr, "Error: container %s is not defined\n",
-                       c->name);
-               lxc_container_put(c);
-               exit(EXIT_FAILURE);
+               fprintf(stderr, "Error: container %s is not defined\n", c->name);
+               goto out;
        }
 
        ret = do_clone_task(c, my_args.task, flags, &argv[optind]);
 
+out:
        lxc_container_put(c);
 
        if (ret == 0)
@@ -240,41 +237,36 @@ static int mk_rand_ovl_dirs(struct mnts *mnts, unsigned int num, struct lxc_argu
        char upperdir[MAXPATHLEN];
        char workdir[MAXPATHLEN];
        unsigned int i;
-       int ret = 0;
-       struct mnts *m;
+       int ret;
+       struct mnts *m = NULL;
 
-       for (i = 0; i < num; i++) {
-               m = mnts + i;
+       for (i = 0, m = mnts; i < num; i++, m++) {
                if ((m->mnt_type == LXC_MNT_OVL) || (m->mnt_type == LXC_MNT_AUFS)) {
                        ret = snprintf(upperdir, MAXPATHLEN, "%s/%s/delta#XXXXXX",
                                        arg->newpath, arg->newname);
                        if (ret < 0 || ret >= MAXPATHLEN)
-                               goto err;
+                               return -1;
                        if (!mkdtemp(upperdir))
-                               goto err;
+                               return -1;
                        m->upper = strdup(upperdir);
                        if (!m->upper)
-                               goto err;
+                               return -1;
                }
 
                if (m->mnt_type == LXC_MNT_OVL) {
                        ret = snprintf(workdir, MAXPATHLEN, "%s/%s/work#XXXXXX",
                                        arg->newpath, arg->newname);
                        if (ret < 0 || ret >= MAXPATHLEN)
-                               goto err;
+                               return -1;
                        if (!mkdtemp(workdir))
-                               goto err;
+                               return -1;
                        m->workdir = strdup(workdir);
                        if (!m->workdir)
-                               goto err;
+                               return -1;
                }
        }
 
        return 0;
-
-err:
-       free_mnts(mnt_table, mnt_table_size);
-       return -1;
 }
 
 static char *construct_path(char *path, bool as_prefix)
@@ -343,7 +335,6 @@ static char *set_mnt_entry(struct mnts *m)
        return mntentry;
 
 err:
-       free_mnts(mnt_table, mnt_table_size);
        free(mntentry);
        return NULL;
 }
@@ -370,15 +361,13 @@ static int do_clone(struct lxc_container *c, char *newname, char *newpath,
 }
 
 static int do_clone_ephemeral(struct lxc_container *c,
-                             struct lxc_arguments *arg, char **args,
-                             int flags)
+               struct lxc_arguments *arg, char **args, int flags)
 {
        char randname[MAXPATHLEN];
        unsigned int i;
        int ret = 0;
-       bool bret = true;
+       bool bret = true, started = false;
        struct lxc_container *clone;
-       struct mnts *n;
 
        lxc_attach_options_t attach_options = LXC_ATTACH_OPTIONS_DEFAULT;
        attach_options.env_policy = LXC_ATTACH_CLEAR_ENV;
@@ -389,8 +378,10 @@ static int do_clone_ephemeral(struct lxc_container *c,
                        return -1;
                if (!mkdtemp(randname))
                        return -1;
-               if (chmod(randname, 0770) < 0)
+               if (chmod(randname, 0770) < 0) {
+                       remove(randname);
                        return -1;
+               }
                arg->newname = randname + strlen(arg->newpath) + 1;
        }
 
@@ -401,26 +392,27 @@ static int do_clone_ephemeral(struct lxc_container *c,
 
        if (!arg->keepdata)
                if (!clone->set_config_item(clone, "lxc.ephemeral", "1"))
-                       goto err;
+                       goto destroy_and_put;
 
        /* allocate and create random upper- and workdirs for overlay mounts */
        if (mk_rand_ovl_dirs(mnt_table, mnt_table_size, arg) < 0)
-               goto err;
+               goto destroy_and_put;
 
        /* allocate and set mount entries */
-       for (i = 0; i < mnt_table_size; i++) {
+       struct mnts *n = NULL;
+       for (i = 0, n = mnt_table; i < mnt_table_size; i++, n++) {
                char *mntentry = NULL;
-               n = mnt_table + i;
-               if ((mntentry = set_mnt_entry(n))) {
-                       bret = clone->set_config_item(clone, "lxc.mount.entry", mntentry);
-                       free(mntentry);
-               }
-               if (!mntentry || !bret)
-                       goto err;
+               mntentry = set_mnt_entry(n);
+               if (!mntentry)
+                       goto destroy_and_put;
+               bret = clone->set_config_item(clone, "lxc.mount.entry", mntentry);
+               free(mntentry);
+               if (!bret)
+                       goto destroy_and_put;
        }
 
        if (!clone->save_config(clone, NULL))
-               goto err;
+               goto destroy_and_put;
 
        printf("Created %s as %s of %s\n", arg->name, "clone", arg->newname);
 
@@ -431,26 +423,27 @@ static int do_clone_ephemeral(struct lxc_container *c,
                clone->want_daemonize(clone, false);
        }
 
-       if (!clone->start(clone, 0, NULL)) {
-               if (!(clone->lxc_conf->ephemeral == 1))
-                       goto err;
-               goto put;
-       }
+       started = clone->start(clone, 0, NULL);
+       if (!started)
+               goto destroy_and_put;
 
        if (arg->daemonize && arg->argc) {
                ret = clone->attach_run_wait(clone, &attach_options, arg->argv[0], (const char *const *)arg->argv);
                if (ret < 0)
-                       goto put;
-               clone->shutdown(clone, true);
+                       goto destroy_and_put;
+               clone->shutdown(clone, -1);
        }
 
+       free_mnts();
        lxc_container_put(clone);
        return 0;
 
-err:
-       clone->destroy(clone);
-put:
-       free_mnts(mnt_table, mnt_table_size);
+destroy_and_put:
+       if (started)
+               clone->shutdown(clone, -1);
+       if (!started || clone->lxc_conf->ephemeral != 1)
+               clone->destroy(clone);
+       free_mnts();
        lxc_container_put(clone);
        return -1;
 }
@@ -489,20 +482,21 @@ static int do_clone_task(struct lxc_container *c, enum task task, int flags,
        return ret;
 }
 
-static void free_mnts(struct mnts *m, unsigned int num)
+static void free_mnts()
 {
        unsigned int i;
-       struct mnts *n;
+       struct mnts *n = NULL;
 
-       for (i = 0; i < num; i++) {
-               n = m + i;
+       for (i = 0, n = mnt_table; i < mnt_table_size; i++, n++) {
                free(n->src);
                free(n->dest);
                free(n->options);
                free(n->upper);
                free(n->workdir);
        }
-       free(m);
+       free(mnt_table);
+       mnt_table = NULL;
+       mnt_table_size = 0;
 }
 
 /* we pass fssize in bytes */
@@ -627,7 +621,7 @@ static int parse_aufs_mnt(char *mntstring, enum mnttype type)
        return 0;
 
 err:
-       free_mnts(mnt_table, mnt_table_size);
+       free_mnts();
        lxc_free_array((void **)mntarray, free);
        return -1;
 }
@@ -685,7 +679,7 @@ static int parse_bind_mnt(char *mntstring, enum mnttype type)
        return 0;
 
 err:
-       free_mnts(mnt_table, mnt_table_size);
+       free_mnts();
        lxc_free_array((void **)mntarray, free);
        return -1;
 }
@@ -746,8 +740,7 @@ static int parse_ovl_mnt(char *mntstring, enum mnttype type)
        return 0;
 
 err:
-       free_mnts(mnt_table, mnt_table_size);
+       free_mnts();
        lxc_free_array((void **)mntarray, free);
        return -1;
 }
-