libceph: support for subscribing to "mdsmap.<id>" maps

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

diff --git a/include/linux/ceph/ceph_fs.h b/include/linux/ceph/ceph_fs.h
index 3b911ff..bae833d 100644 (file)
--- a/include/linux/ceph/ceph_fs.h
+++ b/include/linux/ceph/ceph_fs.h
@@ -208,6 +208,8 @@ struct ceph_mon_subscribe_ack {
        struct ceph_fsid fsid;
 } __attribute__ ((packed));
 
+#define CEPH_FS_CLUSTER_ID_NONE  -1
+
 /*
  * mdsmap flags
  */

diff --git a/include/linux/ceph/mon_client.h b/include/linux/ceph/mon_client.h
index 1d73099..e2a92df 100644 (file)
--- a/include/linux/ceph/mon_client.h
+++ b/include/linux/ceph/mon_client.h
@@ -96,6 +96,7 @@ struct ceph_mon_client {
                bool want;
                u32 have; /* epoch */
        } subs[3];
+       int fs_cluster_id; /* "mdsmap.<id>" sub */
 
 #ifdef CONFIG_DEBUG_FS
        struct dentry *debugfs_file;

diff --git a/net/ceph/debugfs.c b/net/ceph/debugfs.c
index 6e434c7..e77b04c 100644 (file)
--- a/net/ceph/debugfs.c
+++ b/net/ceph/debugfs.c
@@ -128,6 +128,7 @@ static int monc_show(struct seq_file *s, void *p)
                                        CEPH_SUBSCRIBE_ONETIME ?  "" : "+"));
                seq_putc(s, '\n');
        }
+       seq_printf(s, "fs_cluster_id %d\n", monc->fs_cluster_id);
 
        for (rp = rb_first(&monc->generic_request_tree); rp; rp = rb_next(rp)) {
                __u16 op;

diff --git a/net/ceph/mon_client.c b/net/ceph/mon_client.c
index 72a910b..37c38a7 100644 (file)
--- a/net/ceph/mon_client.c
+++ b/net/ceph/mon_client.c
@@ -260,20 +260,26 @@ static void __send_subscribe(struct ceph_mon_client *monc)
        BUG_ON(num < 1); /* monmap sub is always there */
        ceph_encode_32(&p, num);
        for (i = 0; i < ARRAY_SIZE(monc->subs); i++) {
-               const char *s = ceph_sub_str[i];
+               char buf[32];
+               int len;
 
                if (!monc->subs[i].want)
                        continue;
 
-               dout("%s %s start %llu flags 0x%x\n", __func__, s,
+               len = sprintf(buf, "%s", ceph_sub_str[i]);
+               if (i == CEPH_SUB_MDSMAP &&
+                   monc->fs_cluster_id != CEPH_FS_CLUSTER_ID_NONE)
+                       len += sprintf(buf + len, ".%d", monc->fs_cluster_id);
+
+               dout("%s %s start %llu flags 0x%x\n", __func__, buf,
                     le64_to_cpu(monc->subs[i].item.start),
                     monc->subs[i].item.flags);
-               ceph_encode_string(&p, end, s, strlen(s));
+               ceph_encode_string(&p, end, buf, len);
                memcpy(p, &monc->subs[i].item, sizeof(monc->subs[i].item));
                p += sizeof(monc->subs[i].item);
        }
 
-       BUG_ON(p != (end - 35 - (ARRAY_SIZE(monc->subs) - num) * 19));
+       BUG_ON(p > end);
        msg->front.iov_len = p - msg->front.iov_base;
        msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
        ceph_msg_revoke(msg);
@@ -948,7 +954,7 @@ int ceph_monc_init(struct ceph_mon_client *monc, struct ceph_client *cl)
        if (!monc->m_subscribe_ack)
                goto out_auth;
 
-       monc->m_subscribe = ceph_msg_new(CEPH_MSG_MON_SUBSCRIBE, 96, GFP_NOFS,
+       monc->m_subscribe = ceph_msg_new(CEPH_MSG_MON_SUBSCRIBE, 128, GFP_NOFS,
                                         true);
        if (!monc->m_subscribe)
                goto out_subscribe_ack;
@@ -974,6 +980,8 @@ int ceph_monc_init(struct ceph_mon_client *monc, struct ceph_client *cl)
        monc->generic_request_tree = RB_ROOT;
        monc->last_tid = 0;
 
+       monc->fs_cluster_id = CEPH_FS_CLUSTER_ID_NONE;
+
        return 0;
 
 out_auth_reply: