clone_paths: use 'rootfs' for destination directory

We were trying to be smart and use whatever the last part of
the container's rootfs path was.  However for block devices
that doesn't make much sense.  I.e. if lxc.rootfs = /dev/md-1,
chances are that /var/lib/lxc/c1/md-1 does not exist.

So always use the $lxcpath/$lxcname/rootfs, and if it does
not exist, try to create it.

With this, 'lxc-clone -s -o c1 -n c2' where c1 has an lvm backend
is fixed.  See https://bugs.launchpad.net/ubuntu/+source/lxc/+bug/1414771

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>

diff --git a/src/lxc/bdev.c b/src/lxc/bdev.c
index 721a72b3713794cc881f2d9346acbf19cdcc9d3e..197ab55e9021f41bf2f392f406153827f05e8215 100644 (file)
--- a/src/lxc/bdev.c
+++ b/src/lxc/bdev.c
@@ -3340,7 +3340,6 @@ struct bdev *bdev_copy(struct lxc_container *c0, const char *cname,
        const char *oldname = c0->name;
        const char *oldpath = c0->config_path;
        struct rsync_data data;
-       char *rootfs;
 
        /* if the container name doesn't show up in the rootfs path, then
         * we don't know how to come up with a new name
@@ -3359,25 +3358,26 @@ struct bdev *bdev_copy(struct lxc_container *c0, const char *cname,
 
        if (!orig->dest) {
                int ret;
-               orig->dest = malloc(MAXPATHLEN);
+               size_t len;
+               struct stat sb;
+
+               len = strlen(oldpath) + strlen(oldname) + strlen("/rootfs") + 2;
+               orig->dest = malloc(len);
                if (!orig->dest) {
                        ERROR("out of memory");
                        bdev_put(orig);
                        return NULL;
                }
-               rootfs = strrchr(orig->src, '/');
-               if (!rootfs) {
-                       ERROR("invalid rootfs path");
-                       bdev_put(orig);
-                       return NULL;
-               }
-               rootfs++;
-               ret = snprintf(orig->dest, MAXPATHLEN, "%s/%s/%s", oldpath, oldname, rootfs);
-               if (ret < 0 || ret >= MAXPATHLEN) {
+               ret = snprintf(orig->dest, len, "%s/%s/rootfs", oldpath, oldname);
+               if (ret < 0 || ret >= len) {
                        ERROR("rootfs path too long");
                        bdev_put(orig);
                        return NULL;
                }
+               ret = stat(orig->dest, &sb);
+               if (ret < 0 && errno == ENOENT)
+                       if (mkdir_p(orig->dest, 0755) < 0)
+                               WARN("Error creating '%s', continuing.", orig->dest);
        }
 
        /*