On Fri, Jul 02, 2021 at 12:18:19PM +0530, Venky Shankar wrote:
> The new device syntax requires the cluster FSID as part
> of the device string. Use this FSID to verify if it matches
> the cluster FSID we get back from the monitor, failing the
> mount on mismatch.
>
> Also, rename parse_fsid() to ceph_parse_fsid() as it is too
> generic.
>
> Signed-off-by: Venky Shankar <vshankar@xxxxxxxxxx>
> ---
> fs/ceph/super.c | 9 +++++++++
> fs/ceph/super.h | 1 +
> include/linux/ceph/libceph.h | 1 +
> net/ceph/ceph_common.c | 5 +++--
> 4 files changed, 14 insertions(+), 2 deletions(-)
>
> diff --git a/fs/ceph/super.c b/fs/ceph/super.c
> index 0b324e43c9f4..03e5f4bb2b6f 100644
> --- a/fs/ceph/super.c
> +++ b/fs/ceph/super.c
> @@ -268,6 +268,9 @@ static int ceph_parse_new_source(const char *dev_name, const char *dev_name_end,
> if (!fs_name_start)
> return invalfc(fc, "missing file system name");
>
> + if (ceph_parse_fsid(fsid_start, &fsopt->fsid))
> + return invalfc(fc, "invalid fsid format");
> +
> ++fs_name_start; /* start of file system name */
> fsopt->mds_namespace = kstrndup(fs_name_start,
> dev_name_end - fs_name_start, GFP_KERNEL);
> @@ -750,6 +753,12 @@ static struct ceph_fs_client *create_fs_client(struct ceph_mount_options *fsopt,
> }
> opt = NULL; /* fsc->client now owns this */
>
> + /* help learn fsid */
> + if (fsopt->new_dev_syntax) {
> + ceph_check_fsid(fsc->client, &fsopt->fsid);
This call to ceph_check_fsid() made me wonder what would happen if I use
the wrong fsid with the new syntax. And the result is:
[ 41.882334] libceph: mon0 (1)192.168.155.1:40594 session established
[ 41.884537] libceph: bad fsid, had d52783e6-efc2-4dce-ad01-aa3272fa5f66 got 90bdb539-9d95-402e-8f23-b0e26cba8b1b
[ 41.885955] libceph: bad fsid, had d52783e6-efc2-4dce-ad01-aa3272fa5f66 got 90bdb539-9d95-402e-8f23-b0e26cba8b1b
[ 41.889313] libceph: bad fsid, had d52783e6-efc2-4dce-ad01-aa3272fa5f66 got 90bdb539-9d95-402e-8f23-b0e26cba8b1b
[ 41.892578] libceph: osdc handle_map corrupt msg
... followed by a msg dump.
I guess this means that manually setting the fsid requires changes to the
messenger (I've only tested with v1) so that it gracefully handles this
scenario.
Cheers,
--
Luís
> + fsc->client->have_fsid = true;
> + }
> +
> fsc->client->extra_mon_dispatch = extra_mon_dispatch;
> ceph_set_opt(fsc->client, ABORT_ON_FULL);
>
> diff --git a/fs/ceph/super.h b/fs/ceph/super.h
> index 8f71184b7c85..ce5fb90a01a4 100644
> --- a/fs/ceph/super.h
> +++ b/fs/ceph/super.h
> @@ -99,6 +99,7 @@ struct ceph_mount_options {
> char *server_path; /* default NULL (means "/") */
> char *fscache_uniq; /* default NULL */
> char *mon_addr;
> + struct ceph_fsid fsid;
> };
>
> struct ceph_fs_client {
> diff --git a/include/linux/ceph/libceph.h b/include/linux/ceph/libceph.h
> index 409d8c29bc4f..75d059b79d90 100644
> --- a/include/linux/ceph/libceph.h
> +++ b/include/linux/ceph/libceph.h
> @@ -296,6 +296,7 @@ extern bool libceph_compatible(void *data);
> extern const char *ceph_msg_type_name(int type);
> extern int ceph_check_fsid(struct ceph_client *client, struct ceph_fsid *fsid);
> extern void *ceph_kvmalloc(size_t size, gfp_t flags);
> +extern int ceph_parse_fsid(const char *str, struct ceph_fsid *fsid);
>
> struct fs_parameter;
> struct fc_log;
> diff --git a/net/ceph/ceph_common.c b/net/ceph/ceph_common.c
> index 97d6ea763e32..da480757fcca 100644
> --- a/net/ceph/ceph_common.c
> +++ b/net/ceph/ceph_common.c
> @@ -217,7 +217,7 @@ void *ceph_kvmalloc(size_t size, gfp_t flags)
> return p;
> }
>
> -static int parse_fsid(const char *str, struct ceph_fsid *fsid)
> +int ceph_parse_fsid(const char *str, struct ceph_fsid *fsid)
> {
> int i = 0;
> char tmp[3];
> @@ -247,6 +247,7 @@ static int parse_fsid(const char *str, struct ceph_fsid *fsid)
> dout("parse_fsid ret %d got fsid %pU\n", err, fsid);
> return err;
> }
> +EXPORT_SYMBOL(ceph_parse_fsid);
>
> /*
> * ceph options
> @@ -465,7 +466,7 @@ int ceph_parse_param(struct fs_parameter *param, struct ceph_options *opt,
> break;
>
> case Opt_fsid:
> - err = parse_fsid(param->string, &opt->fsid);
> + err = ceph_parse_fsid(param->string, &opt->fsid);
> if (err) {
> error_plog(&log, "Failed to parse fsid: %d", err);
> return err;
> --
> 2.27.0
>
