ceph: mount non-default filesystem by name
To mount non-default filesytem, user currently needs to provide mds
namespace ID. This is inconvenience.
This patch makes user be able to mount filesystem by name. If user
wants to mount non-default filesystem. Client first subscribes to
fsmap.user. Subscribe to mdsmap.<ID> after getting ID of filesystem.
Signed-off-by: Yan, Zheng <zyan@redhat.com>
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 78a3495..e555745 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -2166,6 +2166,11 @@
mds = __choose_mds(mdsc, req);
if (mds < 0 ||
ceph_mdsmap_get_state(mdsc->mdsmap, mds) < CEPH_MDS_STATE_ACTIVE) {
+ if (mdsc->mdsmap_err) {
+ err = mdsc->mdsmap_err;
+ dout("do_request mdsmap err %d\n", err);
+ goto finish;
+ }
dout("do_request no mds or not active, waiting for map\n");
list_add(&req->r_wait, &mdsc->waiting_for_map);
goto out;
@@ -3683,11 +3688,86 @@
dout("mdsc_destroy %p done\n", mdsc);
}
+void ceph_mdsc_handle_fsmap(struct ceph_mds_client *mdsc, struct ceph_msg *msg)
+{
+ struct ceph_fs_client *fsc = mdsc->fsc;
+ const char *mds_namespace = fsc->mount_options->mds_namespace;
+ void *p = msg->front.iov_base;
+ void *end = p + msg->front.iov_len;
+ u32 epoch;
+ u32 map_len;
+ u32 num_fs;
+ u32 mount_fscid = (u32)-1;
+ u8 struct_v, struct_cv;
+ int err = -EINVAL;
+
+ ceph_decode_need(&p, end, sizeof(u32), bad);
+ epoch = ceph_decode_32(&p);
+
+ dout("handle_fsmap epoch %u\n", epoch);
+
+ ceph_decode_need(&p, end, 2 + sizeof(u32), bad);
+ struct_v = ceph_decode_8(&p);
+ struct_cv = ceph_decode_8(&p);
+ map_len = ceph_decode_32(&p);
+
+ ceph_decode_need(&p, end, sizeof(u32) * 3, bad);
+ p += sizeof(u32) * 2; /* skip epoch and legacy_client_fscid */
+
+ num_fs = ceph_decode_32(&p);
+ while (num_fs-- > 0) {
+ void *info_p, *info_end;
+ u32 info_len;
+ u8 info_v, info_cv;
+ u32 fscid, namelen;
+
+ ceph_decode_need(&p, end, 2 + sizeof(u32), bad);
+ info_v = ceph_decode_8(&p);
+ info_cv = ceph_decode_8(&p);
+ info_len = ceph_decode_32(&p);
+ ceph_decode_need(&p, end, info_len, bad);
+ info_p = p;
+ info_end = p + info_len;
+ p = info_end;
+
+ ceph_decode_need(&info_p, info_end, sizeof(u32) * 2, bad);
+ fscid = ceph_decode_32(&info_p);
+ namelen = ceph_decode_32(&info_p);
+ ceph_decode_need(&info_p, info_end, namelen, bad);
+
+ if (mds_namespace &&
+ strlen(mds_namespace) == namelen &&
+ !strncmp(mds_namespace, (char *)info_p, namelen)) {
+ mount_fscid = fscid;
+ break;
+ }
+ }
+
+ ceph_monc_got_map(&fsc->client->monc, CEPH_SUB_FSMAP, epoch);
+ if (mount_fscid != (u32)-1) {
+ fsc->client->monc.fs_cluster_id = mount_fscid;
+ ceph_monc_want_map(&fsc->client->monc, CEPH_SUB_MDSMAP,
+ 0, true);
+ ceph_monc_renew_subs(&fsc->client->monc);
+ } else {
+ err = -ENOENT;
+ goto err_out;
+ }
+ return;
+bad:
+ pr_err("error decoding fsmap\n");
+err_out:
+ mutex_lock(&mdsc->mutex);
+ mdsc->mdsmap_err = -ENOENT;
+ __wake_requests(mdsc, &mdsc->waiting_for_map);
+ mutex_unlock(&mdsc->mutex);
+ return;
+}
/*
* handle mds map update.
*/
-void ceph_mdsc_handle_map(struct ceph_mds_client *mdsc, struct ceph_msg *msg)
+void ceph_mdsc_handle_mdsmap(struct ceph_mds_client *mdsc, struct ceph_msg *msg)
{
u32 epoch;
u32 maplen;
@@ -3794,7 +3874,10 @@
switch (type) {
case CEPH_MSG_MDS_MAP:
- ceph_mdsc_handle_map(mdsc, msg);
+ ceph_mdsc_handle_mdsmap(mdsc, msg);
+ break;
+ case CEPH_MSG_FS_MAP_USER:
+ ceph_mdsc_handle_fsmap(mdsc, msg);
break;
case CEPH_MSG_CLIENT_SESSION:
handle_session(s, msg);