From ba75bb98cfb93b62c54af25bf67ff90857264bbe Mon Sep 17 00:00:00 2001 From: Sage Weil Date: Tue, 6 Oct 2009 11:31:11 -0700 Subject: [PATCH] ceph: monitor client 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 --- fs/ceph/mon_client.c | 694 +++++++++++++++++++++++++++++++++++++++++++ fs/ceph/mon_client.h | 109 +++++++ 2 files changed, 803 insertions(+) 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 000000000000..b0c95cec5df8 --- /dev/null +++ b/fs/ceph/mon_client.c @@ -0,0 +1,694 @@ +#include "ceph_debug.h" + +#include +#include +#include + +#include "mon_client.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 %s\n", i, + pr_addr(&m->mon_inst[i].addr.in_addr)); + 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("mon%d %s session established\n", + monc->cur_mon, pr_addr(&monc->con->peer_addr.in_addr)); + 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("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("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("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("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("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("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("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("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("mon%d %s session lost, " + "hunting for new mon\n", monc->cur_mon, + pr_addr(&monc->con->peer_addr.in_addr)); + + __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 000000000000..5258c5693b03 --- /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 +#include + +#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