[PATCH 13/21] ceph: monitor client

Sage Weil
2009-09-22T17:44:00Z

The monitor cluster is responsible for managing cluster membership
and state. The monitor client handles what minimal interaction
the Ceph client has with it: checking for updated versions of the
MDS and OSD maps, getting statfs() information, and unmounting.

Signed-off-by: Sage Weil <sage@newdream.net>
---
fs/ceph/mon_client.c | 694 ++++++++++++++++++++++++++++++++++++++++++++++++++
fs/ceph/mon_client.h | 109 ++++++++
2 files changed, 803 insertions(+), 0 deletions(-)
create mode 100644 fs/ceph/mon_client.c
create mode 100644 fs/ceph/mon_client.h

diff --git a/fs/ceph/mon_client.c b/fs/ceph/mon_client.c
new file mode 100644
index 0000000..2558986
--- /dev/null
+++ b/fs/ceph/mon_client.c
@@ -0,0 +1,694 @@
+
+#include <linux/types.h>
+#include <linux/random.h>
+#include <linux/sched.h>
+#include "mon_client.h"
+
+#include "ceph_debug.h"
+#include "super.h"
+#include "decode.h"
+
+/*
+ * Interact with Ceph monitor cluster. Handle requests for new map
+ * versions, and periodically resend as needed. Also implement
+ * statfs() and umount().
+ *
+ * A small cluster of Ceph "monitors" are responsible for managing critical
+ * cluster configuration and state information. An odd number (e.g., 3, 5)
+ * of cmon daemons use a modified version of the Paxos part-time parliament
+ * algorithm to manage the MDS map (mds cluster membership), OSD map, and
+ * list of clients who have mounted the file system.
+ *
+ * We maintain an open, active session with a monitor at all times in order to
+ * receive timely MDSMap updates. We periodically send a keepalive byte on the
+ * TCP socket to ensure we detect a failure. If the connection does break, we
+ * randomly hunt for a new monitor. Once the connection is reestablished, we
+ * resend any outstanding requests.
+ */
+
+const static struct ceph_connection_operations mon_con_ops;
+
+/*
+ * Decode a monmap blob (e.g., during mount).
+ */
+struct ceph_monmap *ceph_monmap_decode(void *p, void *end)
+{
+ struct ceph_monmap *m = NULL;
+ int i, err = -EINVAL;
+ struct ceph_fsid fsid;
+ u32 epoch, num_mon;
+ u16 version;
+
+ dout("monmap_decode %p %p len %d\n", p, end, (int)(end-p));
+
+ ceph_decode_16_safe(&p, end, version, bad);
+
+ ceph_decode_need(&p, end, sizeof(fsid) + 2*sizeof(u32), bad);
+ ceph_decode_copy(&p, &fsid, sizeof(fsid));
+ ceph_decode_32(&p, epoch);
+
+ ceph_decode_32(&p, num_mon);
+ ceph_decode_need(&p, end, num_mon*sizeof(m->mon_inst[0]), bad);
+
+ if (num_mon >= CEPH_MAX_MON)
+ goto bad;
+ m = kmalloc(sizeof(*m) + sizeof(m->mon_inst[0])*num_mon, GFP_NOFS);
+ if (m == NULL)
+ return ERR_PTR(-ENOMEM);
+ m->fsid = fsid;
+ m->epoch = epoch;
+ m->num_mon = num_mon;
+ ceph_decode_copy(&p, m->mon_inst, num_mon*sizeof(m->mon_inst[0]));
+
+ if (p != end)
+ goto bad;
+
+ dout("monmap_decode epoch %d, num_mon %d\n", m->epoch,
+ m->num_mon);
+ for (i = 0; i < m->num_mon; i++)
+ dout("monmap_decode mon%d is %u.%u.%u.%u:%u\n", i,
+ IPQUADPORT(m->mon_inst[i].addr.ipaddr));
+ return m;
+
+bad:
+ dout("monmap_decode failed with %d\n", err);
+ kfree(m);
+ return ERR_PTR(err);
+}
+
+/*
+ * return true if *addr is included in the monmap.
+ */
+int ceph_monmap_contains(struct ceph_monmap *m, struct ceph_entity_addr *addr)
+{
+ int i;
+
+ for (i = 0; i < m->num_mon; i++)
+ if (ceph_entity_addr_equal(addr, &m->mon_inst[i].addr))
+ return 1;
+ return 0;
+}
+
+/*
+ * Close monitor session, if any.
+ */
+static void __close_session(struct ceph_mon_client *monc)
+{
+ if (monc->con) {
+ dout("__close_session closing mon%d\n", monc->cur_mon);
+ ceph_con_close(monc->con);
+ monc->cur_mon = -1;
+ }
+}
+
+/*
+ * Open a session with a (new) monitor.
+ */
+static int __open_session(struct ceph_mon_client *monc)
+{
+ char r;
+
+ if (monc->cur_mon < 0) {
+ get_random_bytes(&r, 1);
+ monc->cur_mon = r % monc->monmap->num_mon;
+ dout("open_session num=%d r=%d -> mon%d\n",
+ monc->monmap->num_mon, r, monc->cur_mon);
+ monc->sub_sent = 0;
+ monc->sub_renew_after = jiffies; /* i.e., expired */
+ monc->want_next_osdmap = !!monc->want_next_osdmap;
+
+ dout("open_session mon%d opening\n", monc->cur_mon);
+ monc->con->peer_name.type = CEPH_ENTITY_TYPE_MON;
+ monc->con->peer_name.num = cpu_to_le64(monc->cur_mon);
+ ceph_con_open(monc->con,
+ &monc->monmap->mon_inst[monc->cur_mon].addr);
+ } else {
+ dout("open_session mon%d already open\n", monc->cur_mon);
+ }
+ return 0;
+}
+
+static bool __sub_expired(struct ceph_mon_client *monc)
+{
+ return time_after_eq(jiffies, monc->sub_renew_after);
+}
+
+/*
+ * Reschedule delayed work timer.
+ */
+static void __schedule_delayed(struct ceph_mon_client *monc)
+{
+ unsigned delay;
+
+ if (monc->cur_mon < 0 || monc->want_mount || __sub_expired(monc))
+ delay = 10 * HZ;
+ else
+ delay = 20 * HZ;
+ dout("__schedule_delayed after %u\n", delay);
+ schedule_delayed_work(&monc->delayed_work, delay);
+}
+
+/*
+ * Send subscribe request for mdsmap and/or osdmap.
+ */
+static void __send_subscribe(struct ceph_mon_client *monc)
+{
+ dout("__send_subscribe sub_sent=%u exp=%u want_osd=%d\n",
+ (unsigned)monc->sub_sent, __sub_expired(monc),
+ monc->want_next_osdmap);
+ if ((__sub_expired(monc) && !monc->sub_sent) ||
+ monc->want_next_osdmap == 1) {
+ struct ceph_msg *msg;
+ struct ceph_mon_subscribe_item *i;
+ void *p, *end;
+
+ msg = ceph_msg_new(CEPH_MSG_MON_SUBSCRIBE, 64, 0, 0, NULL);
+ if (!msg)
+ return;
+
+ p = msg->front.iov_base;
+ end = p + msg->front.iov_len;
+
+ dout("__send_subscribe to 'mdsmap' %u+\n",
+ (unsigned)monc->have_mdsmap);
+ if (monc->want_next_osdmap) {
+ dout("__send_subscribe to 'osdmap' %u\n",
+ (unsigned)monc->have_osdmap);
+ ceph_encode_32(&p, 2);
+ ceph_encode_string(&p, end, "osdmap", 6);
+ i = p;
+ i->have = cpu_to_le64(monc->have_osdmap);
+ i->onetime = 1;
+ p += sizeof(*i);
+ monc->want_next_osdmap = 2; /* requested */
+ } else {
+ ceph_encode_32(&p, 1);
+ }
+ ceph_encode_string(&p, end, "mdsmap", 6);
+ i = p;
+ i->have = cpu_to_le64(monc->have_mdsmap);
+ i->onetime = 0;
+ p += sizeof(*i);
+
+ msg->front.iov_len = p - msg->front.iov_base;
+ msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
+ ceph_con_send(monc->con, msg);
+
+ monc->sub_sent = jiffies | 1; /* never 0 */
+ }
+}
+
+static void handle_subscribe_ack(struct ceph_mon_client *monc,
+ struct ceph_msg *msg)
+{
+ unsigned seconds;
+ void *p = msg->front.iov_base;
+ void *end = p + msg->front.iov_len;
+
+ ceph_decode_32_safe(&p, end, seconds, bad);
+ mutex_lock(&monc->mutex);
+ if (monc->hunting) {
+ pr_info("ceph mon%d %u.%u.%u.%u:%u session established\n",
+ monc->cur_mon, IPQUADPORT(monc->con->peer_addr.ipaddr));
+ monc->hunting = false;
+ }
+ dout("handle_subscribe_ack after %d seconds\n", seconds);
+ monc->sub_renew_after = monc->sub_sent + seconds*HZ - 1;
+ monc->sub_sent = 0;
+ mutex_unlock(&monc->mutex);
+ return;
+bad:
+ pr_err("ceph got corrupt subscribe-ack msg\n");
+}
+
+/*
+ * Keep track of which maps we have
+ */
+int ceph_monc_got_mdsmap(struct ceph_mon_client *monc, u32 got)
+{
+ mutex_lock(&monc->mutex);
+ monc->have_mdsmap = got;
+ mutex_unlock(&monc->mutex);
+ return 0;
+}
+
+int ceph_monc_got_osdmap(struct ceph_mon_client *monc, u32 got)
+{
+ mutex_lock(&monc->mutex);
+ monc->have_osdmap = got;
+ monc->want_next_osdmap = 0;
+ mutex_unlock(&monc->mutex);
+ return 0;
+}
+
+/*
+ * Register interest in the next osdmap
+ */
+void ceph_monc_request_next_osdmap(struct ceph_mon_client *monc)
+{
+ dout("request_next_osdmap have %u\n", monc->have_osdmap);
+ mutex_lock(&monc->mutex);
+ if (!monc->want_next_osdmap)
+ monc->want_next_osdmap = 1;
+ if (monc->want_next_osdmap < 2)
+ __send_subscribe(monc);
+ mutex_unlock(&monc->mutex);
+}
+
+
+/*
+ * mount
+ */
+static void __request_mount(struct ceph_mon_client *monc)
+{
+ struct ceph_msg *msg;
+ struct ceph_client_mount *h;
+ int err;
+
+ dout("__request_mount\n");
+ err = __open_session(monc);
+ if (err)
+ return;
+ msg = ceph_msg_new(CEPH_MSG_CLIENT_MOUNT, sizeof(*h), 0, 0, NULL);
+ if (IS_ERR(msg))
+ return;
+ h = msg->front.iov_base;
+ h->have_version = 0;
+ ceph_con_send(monc->con, msg);
+}
+
+int ceph_monc_request_mount(struct ceph_mon_client *monc)
+{
+ if (!monc->con) {
+ monc->con = kmalloc(sizeof(*monc->con), GFP_KERNEL);
+ if (!monc->con)
+ return -ENOMEM;
+ ceph_con_init(monc->client->msgr, monc->con);
+ monc->con->private = monc;
+ monc->con->ops = &mon_con_ops;
+ }
+
+ mutex_lock(&monc->mutex);
+ __request_mount(monc);
+ __schedule_delayed(monc);
+ mutex_unlock(&monc->mutex);
+ return 0;
+}
+
+/*
+ * The monitor responds with mount ack indicate mount success. The
+ * included client ticket allows the client to talk to MDSs and OSDs.
+ */
+static void handle_mount_ack(struct ceph_mon_client *monc, struct ceph_msg *msg)
+{
+ struct ceph_client *client = monc->client;
+ struct ceph_monmap *monmap = NULL, *old = monc->monmap;
+ void *p, *end;
+ s32 result;
+ u32 len;
+ s64 cnum;
+ int err = -EINVAL;
+
+ if (client->whoami >= 0) {
+ dout("handle_mount_ack - already mounted\n");
+ return;
+ }
+
+ mutex_lock(&monc->mutex);
+
+ dout("handle_mount_ack\n");
+ p = msg->front.iov_base;
+ end = p + msg->front.iov_len;
+
+ ceph_decode_64_safe(&p, end, cnum, bad);
+ ceph_decode_32_safe(&p, end, result, bad);
+ ceph_decode_32_safe(&p, end, len, bad);
+ if (result) {
+ pr_err("ceph mount denied: %.*s (%d)\n", len, (char *)p,
+ result);
+ err = result;
+ goto out;
+ }
+ p += len;
+
+ ceph_decode_32_safe(&p, end, len, bad);
+ ceph_decode_need(&p, end, len, bad);
+ monmap = ceph_monmap_decode(p, p + len);
+ if (IS_ERR(monmap)) {
+ pr_err("ceph problem decoding monmap, %d\n",
+ (int)PTR_ERR(monmap));
+ err = -EINVAL;
+ goto out;
+ }
+ p += len;
+
+ client->monc.monmap = monmap;
+ kfree(old);
+
+ client->signed_ticket = NULL;
+ client->signed_ticket_len = 0;
+
+ monc->want_mount = false;
+
+ client->whoami = cnum;
+ client->msgr->inst.name.type = CEPH_ENTITY_TYPE_CLIENT;
+ client->msgr->inst.name.num = cpu_to_le64(cnum);
+ pr_info("ceph client%lld fsid " FSID_FORMAT "\n",
+ client->whoami, PR_FSID(&client->monc.monmap->fsid));
+
+ ceph_debugfs_client_init(client);
+ __send_subscribe(monc);
+
+ err = 0;
+ goto out;
+
+bad:
+ pr_err("ceph error decoding mount_ack message\n");
+out:
+ client->mount_err = err;
+ mutex_unlock(&monc->mutex);
+ wake_up(&client->mount_wq);
+}
+
+
+
+
+/*
+ * statfs
+ */
+static void handle_statfs_reply(struct ceph_mon_client *monc,
+ struct ceph_msg *msg)
+{
+ struct ceph_mon_statfs_request *req;
+ struct ceph_mon_statfs_reply *reply = msg->front.iov_base;
+ u64 tid;
+
+ if (msg->front.iov_len != sizeof(*reply))
+ goto bad;
+ tid = le64_to_cpu(reply->tid);
+ dout("handle_statfs_reply %p tid %llu\n", msg, tid);
+
+ mutex_lock(&monc->mutex);
+ req = radix_tree_lookup(&monc->statfs_request_tree, tid);
+ if (req) {
+ *req->buf = reply->st;
+ req->result = 0;
+ }
+ mutex_unlock(&monc->mutex);
+ if (req)
+ complete(&req->completion);
+ return;
+
+bad:
+ pr_err("ceph corrupt statfs reply, no tid\n");
+}
+
+/*
+ * (re)send a statfs request
+ */
+static int send_statfs(struct ceph_mon_client *monc,
+ struct ceph_mon_statfs_request *req)
+{
+ struct ceph_msg *msg;
+ struct ceph_mon_statfs *h;
+ int err;
+
+ dout("send_statfs tid %llu\n", req->tid);
+ err = __open_session(monc);
+ if (err)
+ return err;
+ msg = ceph_msg_new(CEPH_MSG_STATFS, sizeof(*h), 0, 0, NULL);
+ if (IS_ERR(msg))
+ return PTR_ERR(msg);
+ req->request = msg;
+ h = msg->front.iov_base;
+ h->have_version = 0;
+ h->fsid = monc->monmap->fsid;
+ h->tid = cpu_to_le64(req->tid);
+ ceph_con_send(monc->con, msg);
+ return 0;
+}
+
+/*
+ * Do a synchronous statfs().
+ */
+int ceph_monc_do_statfs(struct ceph_mon_client *monc, struct ceph_statfs *buf)
+{
+ struct ceph_mon_statfs_request req;
+ int err;
+
+ req.buf = buf;
+ init_completion(&req.completion);
+
+ /* allocate memory for reply */
+ err = ceph_msgpool_resv(&monc->msgpool_statfs_reply, 1);
+ if (err)
+ return err;
+
+ /* register request */
+ mutex_lock(&monc->mutex);
+ req.tid = ++monc->last_tid;
+ req.last_attempt = jiffies;
+ req.delay = BASE_DELAY_INTERVAL;
+ if (radix_tree_insert(&monc->statfs_request_tree, req.tid, &req) < 0) {
+ mutex_unlock(&monc->mutex);
+ pr_err("ceph ENOMEM in do_statfs\n");
+ return -ENOMEM;
+ }
+ monc->num_statfs_requests++;
+ mutex_unlock(&monc->mutex);
+
+ /* send request and wait */
+ err = send_statfs(monc, &req);
+ if (!err)
+ err = wait_for_completion_interruptible(&req.completion);
+
+ mutex_lock(&monc->mutex);
+ radix_tree_delete(&monc->statfs_request_tree, req.tid);
+ monc->num_statfs_requests--;
+ ceph_msgpool_resv(&monc->msgpool_statfs_reply, -1);
+ mutex_unlock(&monc->mutex);
+
+ if (!err)
+ err = req.result;
+ return err;
+}
+
+/*
+ * Resend pending statfs requests.
+ */
+static void __resend_statfs(struct ceph_mon_client *monc)
+{
+ u64 next_tid = 0;
+ int got;
+ int did = 0;
+ struct ceph_mon_statfs_request *req;
+
+ while (1) {
+ got = radix_tree_gang_lookup(&monc->statfs_request_tree,
+ (void **)&req,
+ next_tid, 1);
+ if (got == 0)
+ break;
+ did++;
+ next_tid = req->tid + 1;
+
+ send_statfs(monc, req);
+ }
+}
+
+/*
+ * Delayed work. If we haven't mounted yet, retry. Otherwise,
+ * renew/retry subscription as needed (in case it is timing out, or we
+ * got an ENOMEM). And keep the monitor connection alive.
+ */
+static void delayed_work(struct work_struct *work)
+{
+ struct ceph_mon_client *monc =
+ container_of(work, struct ceph_mon_client, delayed_work.work);
+
+ dout("monc delayed_work\n");
+ mutex_lock(&monc->mutex);
+ if (monc->want_mount) {
+ __request_mount(monc);
+ } else {
+ if (__sub_expired(monc)) {
+ __close_session(monc);
+ __open_session(monc); /* continue hunting */
+ } else {
+ ceph_con_keepalive(monc->con);
+ }
+ }
+ __send_subscribe(monc);
+ __schedule_delayed(monc);
+ mutex_unlock(&monc->mutex);
+}
+
+int ceph_monc_init(struct ceph_mon_client *monc, struct ceph_client *cl)
+{
+ int err = 0;
+
+ dout("init\n");
+ memset(monc, 0, sizeof(*monc));
+ monc->client = cl;
+ monc->monmap = NULL;
+ mutex_init(&monc->mutex);
+
+ monc->con = NULL;
+
+ /* msg pools */
+ err = ceph_msgpool_init(&monc->msgpool_mount_ack, 4096, 1, false);
+ if (err < 0)
+ goto out;
+ err = ceph_msgpool_init(&monc->msgpool_subscribe_ack, 8, 1, false);
+ if (err < 0)
+ goto out;
+ err = ceph_msgpool_init(&monc->msgpool_statfs_reply,
+ sizeof(struct ceph_mon_statfs_reply), 0, false);
+ if (err < 0)
+ goto out;
+
+ monc->cur_mon = -1;
+ monc->hunting = false; /* not really */
+ monc->sub_renew_after = jiffies;
+ monc->sub_sent = 0;
+
+ INIT_DELAYED_WORK(&monc->delayed_work, delayed_work);
+ INIT_RADIX_TREE(&monc->statfs_request_tree, GFP_NOFS);
+ monc->num_statfs_requests = 0;
+ monc->last_tid = 0;
+
+ monc->have_mdsmap = 0;
+ monc->have_osdmap = 0;
+ monc->want_next_osdmap = 1;
+ monc->want_mount = true;
+out:
+ return err;
+}
+
+void ceph_monc_stop(struct ceph_mon_client *monc)
+{
+ dout("stop\n");
+ cancel_delayed_work_sync(&monc->delayed_work);
+
+ mutex_lock(&monc->mutex);
+ __close_session(monc);
+ if (monc->con) {
+ monc->con->private = NULL;
+ monc->con->ops->put(monc->con);
+ monc->con = NULL;
+ }
+ mutex_unlock(&monc->mutex);
+
+ ceph_msgpool_destroy(&monc->msgpool_mount_ack);
+ ceph_msgpool_destroy(&monc->msgpool_subscribe_ack);
+ ceph_msgpool_destroy(&monc->msgpool_statfs_reply);
+
+ kfree(monc->monmap);
+}
+
+
+/*
+ * handle incoming message
+ */
+static void dispatch(struct ceph_connection *con, struct ceph_msg *msg)
+{
+ struct ceph_mon_client *monc = con->private;
+ int type = le16_to_cpu(msg->hdr.type);
+
+ if (!monc)
+ return;
+
+ switch (type) {
+ case CEPH_MSG_CLIENT_MOUNT_ACK:
+ handle_mount_ack(monc, msg);
+ break;
+
+ case CEPH_MSG_MON_SUBSCRIBE_ACK:
+ handle_subscribe_ack(monc, msg);
+ break;
+
+ case CEPH_MSG_STATFS_REPLY:
+ handle_statfs_reply(monc, msg);
+ break;
+
+ case CEPH_MSG_MDS_MAP:
+ ceph_mdsc_handle_map(&monc->client->mdsc, msg);
+ break;
+
+ case CEPH_MSG_OSD_MAP:
+ ceph_osdc_handle_map(&monc->client->osdc, msg);
+ break;
+
+ default:
+ pr_err("ceph received unknown message type %d %s\n", type,
+ ceph_msg_type_name(type));
+ }
+ ceph_msg_put(msg);
+}
+
+/*
+ * Allocate memory for incoming message
+ */
+static struct ceph_msg *mon_alloc_msg(struct ceph_connection *con,
+ struct ceph_msg_header *hdr)
+{
+ struct ceph_mon_client *monc = con->private;
+ int type = le16_to_cpu(hdr->type);
+
+ switch (type) {
+ case CEPH_MSG_CLIENT_MOUNT_ACK:
+ return ceph_msgpool_get(&monc->msgpool_mount_ack);
+ case CEPH_MSG_MON_SUBSCRIBE_ACK:
+ return ceph_msgpool_get(&monc->msgpool_subscribe_ack);
+ case CEPH_MSG_STATFS_REPLY:
+ return ceph_msgpool_get(&monc->msgpool_statfs_reply);
+ }
+ return ceph_alloc_msg(con, hdr);
+}
+
+/*
+ * If the monitor connection resets, pick a new monitor and resubmit
+ * any pending requests.
+ */
+static void mon_fault(struct ceph_connection *con)
+{
+ struct ceph_mon_client *monc = con->private;
+
+ if (!monc)
+ return;
+
+ dout("mon_fault\n");
+ mutex_lock(&monc->mutex);
+ if (!con->private)
+ goto out;
+
+ if (monc->con && !monc->hunting)
+ pr_info("ceph mon%d %u.%u.%u.%u:%u session lost, "
+ "hunting for new mon\n", monc->cur_mon,
+ IPQUADPORT(monc->con->peer_addr.ipaddr));
+
+ __close_session(monc);
+ if (!monc->hunting) {
+ /* start hunting */
+ monc->hunting = true;
+ if (__open_session(monc) == 0) {
+ __send_subscribe(monc);
+ __resend_statfs(monc);
+ }
+ } else {
+ /* already hunting, let's wait a bit */
+ __schedule_delayed(monc);
+ }
+out:
+ mutex_unlock(&monc->mutex);
+}
+
+const static struct ceph_connection_operations mon_con_ops = {
+ .get = ceph_con_get,
+ .put = ceph_con_put,
+ .dispatch = dispatch,
+ .fault = mon_fault,
+ .alloc_msg = mon_alloc_msg,
+ .alloc_middle = ceph_alloc_middle,
+};
diff --git a/fs/ceph/mon_client.h b/fs/ceph/mon_client.h
new file mode 100644
index 0000000..5258c56
--- /dev/null
+++ b/fs/ceph/mon_client.h
@@ -0,0 +1,109 @@
+#ifndef _FS_CEPH_MON_CLIENT_H
+#define _FS_CEPH_MON_CLIENT_H
+
+#include <linux/completion.h>
+#include <linux/radix-tree.h>
+
+#include "messenger.h"
+#include "msgpool.h"
+
+struct ceph_client;
+struct ceph_mount_args;
+
+/*
+ * The monitor map enumerates the set of all monitors.
+ */
+struct ceph_monmap {
+ struct ceph_fsid fsid;
+ u32 epoch;
+ u32 num_mon;
+ struct ceph_entity_inst mon_inst[0];
+};
+
+struct ceph_mon_client;
+struct ceph_mon_statfs_request;
+
+
+/*
+ * Generic mechanism for resending monitor requests.
+ */
+typedef void (*ceph_monc_request_func_t)(struct ceph_mon_client *monc,
+ int newmon);
+
+/* a pending monitor request */
+struct ceph_mon_request {
+ struct ceph_mon_client *monc;
+ struct delayed_work delayed_work;
+ unsigned long delay;
+ ceph_monc_request_func_t do_request;
+};
+
+/*
+ * statfs() is done a bit differently because we need to get data back
+ * to the caller
+ */
+struct ceph_mon_statfs_request {
+ u64 tid;
+ int result;
+ struct ceph_statfs *buf;
+ struct completion completion;
+ unsigned long last_attempt, delay; /* jiffies */
+ struct ceph_msg *request; /* original request */
+};
+
+struct ceph_mon_client {
+ struct ceph_client *client;
+ struct ceph_monmap *monmap;
+
+ struct mutex mutex;
+ struct delayed_work delayed_work;
+
+ bool hunting;
+ int cur_mon; /* last monitor i contacted */
+ unsigned long sub_sent, sub_renew_after;
+ struct ceph_connection *con;
+
+ /* msg pools */
+ struct ceph_msgpool msgpool_mount_ack;
+ struct ceph_msgpool msgpool_subscribe_ack;
+ struct ceph_msgpool msgpool_statfs_reply;
+
+ /* pending statfs requests */
+ struct radix_tree_root statfs_request_tree;
+ int num_statfs_requests;
+ u64 last_tid;
+
+ /* mds/osd map or mount requests */
+ bool want_mount;
+ int want_next_osdmap; /* 1 = want, 2 = want+asked */
+ u32 have_osdmap, have_mdsmap;
+
+ struct dentry *debugfs_file;
+};
+
+extern struct ceph_monmap *ceph_monmap_decode(void *p, void *end);
+extern int ceph_monmap_contains(struct ceph_monmap *m,
+ struct ceph_entity_addr *addr);
+
+extern int ceph_monc_init(struct ceph_mon_client *monc, struct ceph_client *cl);
+extern void ceph_monc_stop(struct ceph_mon_client *monc);
+
+/*
+ * The model here is to indicate that we need a new map of at least
+ * epoch @want, and also call in when we receive a map. We will
+ * periodically rerequest the map from the monitor cluster until we
+ * get what we want.
+ */
+extern int ceph_monc_got_mdsmap(struct ceph_mon_client *monc, u32 have);
+extern int ceph_monc_got_osdmap(struct ceph_mon_client *monc, u32 have);
+
+extern void ceph_monc_request_next_osdmap(struct ceph_mon_client *monc);
+
+extern int ceph_monc_request_mount(struct ceph_mon_client *monc);
+
+extern int ceph_monc_do_statfs(struct ceph_mon_client *monc,
+ struct ceph_statfs *buf);
+
+
+
+#endif
--
1.5.6.5