[lxc-devel] [PATCH 1/1] snapshots: move snapshot directory
Stéphane Graber
stgraber at ubuntu.com
Wed Apr 30 19:21:10 UTC 2014
On Wed, Apr 16, 2014 at 02:04:45PM -0500, Serge Hallyn wrote:
> Originally we kept snapshots under /var/lib/lxcsnaps. If a
> separate btrfs is mounted at /var/lib/lxc, then we can't
> make btrfs snapshots under /var/lib/lxcsnaps.
>
> This patch moves the default directory to /var/lib/lxc/lxcsnaps.
> If /var/lib/lxcsnaps already exists, then use that. Don't allow
> any container to be used with the name 'lxcsnaps'.
Just to follow up on thoughts I shared on IRC.
I wonder why we shouldn't move those to
/var/lib/lxc/<container>/snapshots/ instead. Regardless of where they
go, the testcase should also be updated to match.
>
> Signed-off-by: Serge Hallyn <serge.hallyn at ubuntu.com>
> ---
> src/lxc/lxccontainer.c | 49 +++++++++++++++++++++++++++++++++++++++----------
> src/lxc/lxccontainer.h | 4 ++--
> 2 files changed, 41 insertions(+), 12 deletions(-)
>
> diff --git a/src/lxc/lxccontainer.c b/src/lxc/lxccontainer.c
> index c90b564..1059961 100644
> --- a/src/lxc/lxccontainer.c
> +++ b/src/lxc/lxccontainer.c
> @@ -2823,16 +2823,42 @@ static int get_next_index(const char *lxcpath, char *cname)
> }
> }
>
> +static bool get_snappath_dir(struct lxc_container *c, char *snappath)
> +{
> + int ret;
> + /*
> + * If the old style snapshot path exists, use it
> + * /var/lib/lxc -> /var/lib/lxcsnaps
> + */
> + ret = snprintf(snappath, MAXPATHLEN, "%ssnaps", c->config_path);
> + if (ret < 0 || ret >= MAXPATHLEN)
> + return false;
> + if (dir_exists(snappath)) {
> + ret = snprintf(snappath, MAXPATHLEN, "%ssnaps/%s", c->config_path, c->name);
> + if (ret < 0 || ret >= MAXPATHLEN)
> + return false;
> + return true;
> + }
> +
> + /*
> + * Use the new style path
> + * /var/lib/lxc -> /var/lib/lxc + /lxcsnaps/ + c->name + \0
> + */
> + ret = snprintf(snappath, MAXPATHLEN, "%s/lxcsnaps/%s", c->config_path, c->name);
> + if (ret < 0 || ret >= MAXPATHLEN)
> + return false;
> + return true;
> +}
> +
> static int lxcapi_snapshot(struct lxc_container *c, const char *commentfile)
> {
> int i, flags, ret;
> struct lxc_container *c2;
> char snappath[MAXPATHLEN], newname[20];
>
> - // /var/lib/lxc -> /var/lib/lxcsnaps \0
> - ret = snprintf(snappath, MAXPATHLEN, "%ssnaps/%s", c->config_path, c->name);
> - if (ret < 0 || ret >= MAXPATHLEN)
> + if (!get_snappath_dir(c, snappath)) {
> return -1;
> + }
> i = get_next_index(snappath, c->name);
>
> if (mkdir_p(snappath, 0755) < 0) {
> @@ -2966,7 +2992,7 @@ static char *get_timestamp(char* snappath, char *name)
> static int lxcapi_snapshot_list(struct lxc_container *c, struct lxc_snapshot **ret_snaps)
> {
> char snappath[MAXPATHLEN], path2[MAXPATHLEN];
> - int dirlen, count = 0, ret;
> + int count = 0, ret;
> struct dirent dirent, *direntp;
> struct lxc_snapshot *snaps =NULL, *nsnaps;
> DIR *dir;
> @@ -2974,9 +3000,7 @@ static int lxcapi_snapshot_list(struct lxc_container *c, struct lxc_snapshot **r
> if (!c || !lxcapi_is_defined(c))
> return -1;
>
> - // snappath is ${lxcpath}snaps/${lxcname}/
> - dirlen = snprintf(snappath, MAXPATHLEN, "%ssnaps/%s", c->config_path, c->name);
> - if (dirlen < 0 || dirlen >= MAXPATHLEN) {
> + if (!get_snappath_dir(c, snappath)) {
> ERROR("path name too long");
> return -1;
> }
> @@ -3044,7 +3068,7 @@ out_free:
> static bool lxcapi_snapshot_restore(struct lxc_container *c, const char *snapname, const char *newname)
> {
> char clonelxcpath[MAXPATHLEN];
> - int flags = 0,ret;
> + int flags = 0;
> struct lxc_container *snap, *rest;
> struct bdev *bdev;
> bool b = false;
> @@ -3067,8 +3091,7 @@ static bool lxcapi_snapshot_restore(struct lxc_container *c, const char *snapnam
> return false;
> }
> }
> - ret = snprintf(clonelxcpath, MAXPATHLEN, "%ssnaps/%s", c->config_path, c->name);
> - if (ret < 0 || ret >= MAXPATHLEN) {
> + if (!get_snappath_dir(c, clonelxcpath)) {
> bdev_put(bdev);
> return false;
> }
> @@ -3284,6 +3307,12 @@ struct lxc_container *lxc_container_new(const char *name, const char *configpath
> {
> struct lxc_container *c;
>
> + if (!name)
> + return NULL;
> +
> + if (strcmp(name, "lxcsnaps") == 0)
> + return NULL;
> +
> c = malloc(sizeof(*c));
> if (!c) {
> fprintf(stderr, "failed to malloc lxc_container\n");
> diff --git a/src/lxc/lxccontainer.h b/src/lxc/lxccontainer.h
> index ba15ab7..946a662 100644
> --- a/src/lxc/lxccontainer.h
> +++ b/src/lxc/lxccontainer.h
> @@ -649,7 +649,7 @@ struct lxc_container {
> * \brief Create a container snapshot.
> *
> * Assuming default paths, snapshots will be created as
> - * \c /var/lib/lxcsnaps/\<c\>/snap\<n\>
> + * \c /var/lib/lxc/lxcsnaps/\<c\>/snap\<n\>
> * where \c \<c\> represents the container name and \c \<n\>
> * represents the zero-based snapshot number.
> *
> @@ -691,7 +691,7 @@ struct lxc_container {
> * fail if the snapshot is overlay-based, since the snapshots
> * will pin the original container.
> * \note As an example, if the container exists as \c /var/lib/lxc/c1, snapname might be \c 'snap0'
> - * (representing \c /var/lib/lxcsnaps/c1/snap0). If \p newname is \p c2,
> + * (representing \c /var/lib/lxc/lxcsnaps/c1/snap0). If \p newname is \p c2,
> * then \c snap0 will be copied to \c /var/lib/lxc/c2.
> */
> bool (*snapshot_restore)(struct lxc_container *c, const char *snapname, const char *newname);
> --
> 1.8.3.2
>
> _______________________________________________
> lxc-devel mailing list
> lxc-devel at lists.linuxcontainers.org
> http://lists.linuxcontainers.org/listinfo/lxc-devel
--
Stéphane Graber
Ubuntu developer
http://www.ubuntu.com
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 819 bytes
Desc: Digital signature
URL: <http://lists.linuxcontainers.org/pipermail/lxc-devel/attachments/20140430/70beedc1/attachment-0001.sig>
More information about the lxc-devel
mailing list