diff options
Diffstat (limited to 'fs/ceph/mds_client.c')
| -rw-r--r-- | fs/ceph/mds_client.c | 2912 |
1 files changed, 2912 insertions, 0 deletions
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c new file mode 100644 index 0000000..de8ba4a --- /dev/null +++ b/fs/ceph/mds_client.c @@ -0,0 +1,2912 @@ +#include "ceph_debug.h" + +#include <linux/wait.h> +#include <linux/sched.h> + +#include "mds_client.h" +#include "mon_client.h" +#include "super.h" +#include "messenger.h" +#include "decode.h" + +/* + * A cluster of MDS (metadata server) daemons is responsible for + * managing the file system namespace (the directory hierarchy and + * inodes) and for coordinating shared access to storage. Metadata is + * partitioning hierarchically across a number of servers, and that + * partition varies over time as the cluster adjusts the distribution + * in order to balance load. + * + * The MDS client is primarily responsible to managing synchronous + * metadata requests for operations like open, unlink, and so forth. + * If there is a MDS failure, we find out about it when we (possibly + * request and) receive a new MDS map, and can resubmit affected + * requests. + * + * For the most part, though, we take advantage of a lossless + * communications channel to the MDS, and do not need to worry about + * timing out or resubmitting requests. + * + * We maintain a stateful "session" with each MDS we interact with. + * Within each session, we sent periodic heartbeat messages to ensure + * any capabilities or leases we have been issues remain valid. If + * the session times out and goes stale, our leases and capabilities + * are no longer valid. + */ + +static void __wake_requests(struct ceph_mds_client *mdsc, + struct list_head *head); + +const static struct ceph_connection_operations mds_con_ops; + + +/* + * mds reply parsing + */ + +/* + * parse individual inode info + */ +static int parse_reply_info_in(void **p, void *end, + struct ceph_mds_reply_info_in *info) +{ + int err = -EIO; + + info->in = *p; + *p += sizeof(struct ceph_mds_reply_inode) + + sizeof(*info->in->fragtree.splits) * + le32_to_cpu(info->in->fragtree.nsplits); + + ceph_decode_32_safe(p, end, info->symlink_len, bad); + ceph_decode_need(p, end, info->symlink_len, bad); + info->symlink = *p; + *p += info->symlink_len; + + ceph_decode_32_safe(p, end, info->xattr_len, bad); + ceph_decode_need(p, end, info->xattr_len, bad); + info->xattr_data = *p; + *p += info->xattr_len; + return 0; +bad: + return err; +} + +/* + * parse a normal reply, which may contain a (dir+)dentry and/or a + * target inode. + */ +static int parse_reply_info_trace(void **p, void *end, + struct ceph_mds_reply_info_parsed *info) +{ + int err; + + if (info->head->is_dentry) { + err = parse_reply_info_in(p, end, &info->diri); + if (err < 0) + goto out_bad; + + if (unlikely(*p + sizeof(*info->dirfrag) > end)) + goto bad; + info->dirfrag = *p; + *p += sizeof(*info->dirfrag) + + sizeof(u32)*le32_to_cpu(info->dirfrag->ndist); + if (unlikely(*p > end)) + goto bad; + + ceph_decode_32_safe(p, end, info->dname_len, bad); + ceph_decode_need(p, end, info->dname_len, bad); + info->dname = *p; + *p += info->dname_len; + info->dlease = *p; + *p += sizeof(*info->dlease); + } + + if (info->head->is_target) { + err = parse_reply_info_in(p, end, &info->targeti); + if (err < 0) + goto out_bad; + } + + if (unlikely(*p != end)) + goto bad; + return 0; + +bad: + err = -EIO; +out_bad: + pr_err("problem parsing mds trace %d\n", err); + return err; +} + +/* + * parse readdir results + */ +static int parse_reply_info_dir(void **p, void *end, + struct ceph_mds_reply_info_parsed *info) +{ + u32 num, i = 0; + int err; + + info->dir_dir = *p; + if (*p + sizeof(*info->dir_dir) > end) + goto bad; + *p += sizeof(*info->dir_dir) + + sizeof(u32)*le32_to_cpu(info->dir_dir->ndist); + if (*p > end) + goto bad; + + ceph_decode_need(p, end, sizeof(num) + 2, bad); + ceph_decode_32(p, num); + ceph_decode_8(p, info->dir_end); + ceph_decode_8(p, info->dir_complete); + if (num == 0) + goto done; + + /* alloc large array */ + info->dir_nr = num; + info->dir_in = kcalloc(num, sizeof(*info->dir_in) + + sizeof(*info->dir_dname) + + sizeof(*info->dir_dname_len) + + sizeof(*info->dir_dlease), + GFP_NOFS); + if (info->dir_in == NULL) { + err = -ENOMEM; + goto out_bad; + } + info->dir_dname = (void *)(info->dir_in + num); + info->dir_dname_len = (void *)(info->dir_dname + num); + info->dir_dlease = (void *)(info->dir_dname_len + num); + + while (num) { + /* dentry */ + ceph_decode_need(p, end, sizeof(u32)*2, bad); + ceph_decode_32(p, info->dir_dname_len[i]); + ceph_decode_need(p, end, info->dir_dname_len[i], bad); + info->dir_dname[i] = *p; + *p += info->dir_dname_len[i]; + dout("parsed dir dname '%.*s'\n", info->dir_dname_len[i], + info->dir_dname[i]); + info->dir_dlease[i] = *p; + *p += sizeof(struct ceph_mds_reply_lease); + + /* inode */ + err = parse_reply_info_in(p, end, &info->dir_in[i]); + if (err < 0) + goto out_bad; + i++; + num--; + } + +done: + if (*p != end) + goto bad; + return 0; + +bad: + err = -EIO; +out_bad: + pr_err("problem parsing dir contents %d\n", err); + return err; +} + +/* + * parse entire mds reply + */ +static int parse_reply_info(struct ceph_msg *msg, + struct ceph_mds_reply_info_parsed *info) +{ + void *p, *end; + u32 len; + int err; + + info->head = msg->front.iov_base; + p = msg->front.iov_base + sizeof(struct ceph_mds_reply_head); + end = p + msg->front.iov_len - sizeof(struct ceph_mds_reply_head); + + /* trace */ + ceph_decode_32_safe(&p, end, len, bad); + if (len > 0) { + err = parse_reply_info_trace(&p, p+len, info); + if (err < 0) + goto out_bad; + } + + /* dir content */ + ceph_decode_32_safe(&p, end, len, bad); + if (len > 0) { + err = parse_reply_info_dir(&p, p+len, info); + if (err < 0) + goto out_bad; + } + + /* snap blob */ + ceph_decode_32_safe(&p, end, len, bad); + info->snapblob_len = len; + info->snapblob = p; + p += len; + + if (p != end) + goto bad; + return 0; + +bad: + err = -EIO; +out_bad: + pr_err("mds parse_reply err %d\n", err); + return err; +} + +static void destroy_reply_info(struct ceph_mds_reply_info_parsed *info) +{ + kfree(info->dir_in); +} + + +/* + * sessions + */ +static const char *session_state_name(int s) +{ + switch (s) { + case CEPH_MDS_SESSION_NEW: return "new"; + case CEPH_MDS_SESSION_OPENING: return "opening"; + case CEPH_MDS_SESSION_OPEN: return "open"; + case CEPH_MDS_SESSION_HUNG: return "hung"; + case CEPH_MDS_SESSION_CLOSING: return "closing"; + case CEPH_MDS_SESSION_RECONNECTING: return "reconnecting"; + default: return "???"; + } +} + +static struct ceph_mds_session *get_session(struct ceph_mds_session *s) +{ + if (atomic_inc_not_zero(&s->s_ref)) { + dout("mdsc get_session %p %d -> %d\n", s, + atomic_read(&s->s_ref)-1, atomic_read(&s->s_ref)); + return s; + } else { + dout("mdsc get_session %p 0 -- FAIL", s); + return NULL; + } +} + +void ceph_put_mds_session(struct ceph_mds_session *s) +{ + dout("mdsc put_session %p %d -> %d\n", s, + atomic_read(&s->s_ref), atomic_read(&s->s_ref)-1); + if (atomic_dec_and_test(&s->s_ref)) { + ceph_con_shutdown(&s->s_con); + kfree(s); + } +} + +/* + * called under mdsc->mutex + */ +struct ceph_mds_session *__ceph_lookup_mds_session(struct ceph_mds_client *mdsc, + int mds) +{ + struct ceph_mds_session *session; + + if (mds >= mdsc->max_sessions || mdsc->sessions[mds] == NULL) + return NULL; + session = mdsc->sessions[mds]; + dout("lookup_mds_session %p %d\n", session, + atomic_read(&session->s_ref)); + get_session(session); + return session; +} + +static bool __have_session(struct ceph_mds_client *mdsc, int mds) +{ + if (mds >= mdsc->max_sessions) + return false; + return mdsc->sessions[mds]; +} + +/* + * create+register a new session for given mds. + * called under mdsc->mutex. + */ +static struct ceph_mds_session *register_session(struct ceph_mds_client *mdsc, + int mds) +{ + struct ceph_mds_session *s; + + s = kzalloc(sizeof(*s), GFP_NOFS); + s->s_mdsc = mdsc; + s->s_mds = mds; + s->s_state = CEPH_MDS_SESSION_NEW; + s->s_ttl = 0; + s->s_seq = 0; + mutex_init(&s->s_mutex); + + ceph_con_init(mdsc->client->msgr, &s->s_con); + s->s_con.private = s; + s->s_con.ops = &mds_con_ops; + s->s_con.peer_name.type = CEPH_ENTITY_TYPE_MDS; + s->s_con.peer_name.num = cpu_to_le64(mds); + ceph_con_open(&s->s_con, ceph_mdsmap_get_addr(mdsc->mdsmap, mds)); + + spin_lock_init(&s->s_cap_lock); + s->s_cap_gen = 0; + s->s_cap_ttl = 0; + s->s_renew_requested = 0; + s->s_renew_seq = 0; + INIT_LIST_HEAD(&s->s_caps); + s->s_nr_caps = 0; + atomic_set(&s->s_ref, 1); + INIT_LIST_HEAD(&s->s_waiting); + INIT_LIST_HEAD(&s->s_unsafe); + s->s_num_cap_releases = 0; + INIT_LIST_HEAD(&s->s_cap_releases); + INIT_LIST_HEAD(&s->s_cap_releases_done); + INIT_LIST_HEAD(&s->s_cap_flushing); + INIT_LIST_HEAD(&s->s_cap_snaps_flushing); + + dout("register_session mds%d\n", mds); + if (mds >= mdsc->max_sessions) { + int newmax = 1 << get_count_order(mds+1); + struct ceph_mds_session **sa; + + dout("register_session realloc to %d\n", newmax); + sa = kcalloc(newmax, sizeof(void *), GFP_NOFS); + if (sa == NULL) + return ERR_PTR(-ENOMEM); + if (mdsc->sessions) { + memcpy(sa, mdsc->sessions, + mdsc->max_sessions * sizeof(void *)); + kfree(mdsc->sessions); + } + mdsc->sessions = sa; + mdsc->max_sessions = newmax; + } + mdsc->sessions[mds] = s; + atomic_inc(&s->s_ref); /* one ref to sessions[], one to caller */ + return s; +} + +/* + * called under mdsc->mutex + */ +static void unregister_session(struct ceph_mds_client *mdsc, int mds) +{ + dout("unregister_session mds%d %p\n", mds, mdsc->sessions[mds]); + ceph_put_mds_session(mdsc->sessions[mds]); + mdsc->sessions[mds] = NULL; +} + +/* + * drop session refs in request. + * + * should be last request ref, or hold mdsc->mutex + */ +static void put_request_session(struct ceph_mds_request *req) +{ + if (req->r_session) { + ceph_put_mds_session(req->r_session); + req->r_session = NULL; + } +} + +void ceph_mdsc_put_request(struct ceph_mds_request *req) +{ + dout("mdsc put_request %p %d -> %d\n", req, + atomic_read(&req->r_ref), atomic_read(&req->r_ref)-1); + if (atomic_dec_and_test(&req->r_ref)) { + if (req->r_request) + ceph_msg_put(req->r_request); + if (req->r_reply) { + ceph_msg_put(req->r_reply); + destroy_reply_info(&req->r_reply_info); + } + if (req->r_inode) { + ceph_put_cap_refs(ceph_inode(req->r_inode), + CEPH_CAP_PIN); + iput(req->r_inode); + } + if (req->r_locked_dir) + ceph_put_cap_refs(ceph_inode(req->r_locked_dir), + CEPH_CAP_PIN); + if (req->r_target_inode) + iput(req->r_target_inode); + if (req->r_dentry) + dput(req->r_dentry); + if (req->r_old_dentry) { + ceph_put_cap_refs( + ceph_inode(req->r_old_dentry->d_parent->d_inode), + CEPH_CAP_PIN); + dput(req->r_old_dentry); + } + kfree(req->r_path1); + kfree(req->r_path2); + put_request_session(req); + ceph_unreserve_caps(&req->r_caps_reservation); + kfree(req); + } +} + +/* + * lookup session, bump ref if found. + * + * called under mdsc->mutex. + */ +static struct ceph_mds_request *__lookup_request(struct ceph_mds_client *mdsc, + u64 tid) +{ + struct ceph_mds_request *req; + req = radix_tree_lookup(&mdsc->request_tree, tid); + if (req) + ceph_mdsc_get_request(req); + return req; +} + +/* + * Register an in-flight request, and assign a tid. Link to directory + * are modifying (if any). + * + * Called under mdsc->mutex. + */ +static void __register_request(struct ceph_mds_client *mdsc, + struct ceph_mds_request *req, + struct inode *dir) +{ + req->r_tid = ++mdsc->last_tid; + if (req->r_num_caps) + ceph_reserve_caps(&req->r_caps_reservation, req->r_num_caps); + dout("__register_request %p tid %lld\n", req, req->r_tid); + ceph_mdsc_get_request(req); + radix_tree_insert(&mdsc->request_tree, req->r_tid, (void *)req); + + if (dir) { + struct ceph_inode_info *ci = ceph_inode(dir); + + spin_lock(&ci->i_unsafe_lock); + req->r_unsafe_dir = dir; + list_add_tail(&req->r_unsafe_dir_item, &ci->i_unsafe_dirops); + spin_unlock(&ci->i_unsafe_lock); + } +} + +static void __unregister_request(struct ceph_mds_client *mdsc, + struct ceph_mds_request *req) +{ + dout("__unregister_request %p tid %lld\n", req, req->r_tid); + radix_tree_delete(&mdsc->request_tree, req->r_tid); + ceph_mdsc_put_request(req); + + if (req->r_unsafe_dir) { + struct ceph_inode_info *ci = ceph_inode(req->r_unsafe_dir); + + spin_lock(&ci->i_unsafe_lock); + list_del_init(&req->r_unsafe_dir_item); + spin_unlock(&ci->i_unsafe_lock); + } +} + +/* + * Choose mds to send request to next. If there is a hint set in the + * request (e.g., due to a prior forward hint from the mds), use that. + * Otherwise, consult frag tree and/or caps to identify the + * appropriate mds. If all else fails, choose randomly. + * + * Called under mdsc->mutex. + */ +static int __choose_mds(struct ceph_mds_client *mdsc, + struct ceph_mds_request *req) +{ + struct inode *inode; + struct ceph_inode_info *ci; + struct ceph_cap *cap; + int mode = req->r_direct_mode; + int mds = -1; + u32 hash = req->r_direct_hash; + bool is_hash = req->r_direct_is_hash; + + /* + * is there a specific mds we should try? ignore hint if we have + * no session and the mds is not up (active or recovering). + */ + if (req->r_resend_mds >= 0 && + (__have_session(mdsc, req->r_resend_mds) || + ceph_mdsmap_get_state(mdsc->mdsmap, req->r_resend_mds) > 0)) { + dout("choose_mds using resend_mds mds%d\n", + req->r_resend_mds); + return req->r_resend_mds; + } + + if (mode == USE_RANDOM_MDS) + goto random; + + inode = NULL; + if (req->r_inode) { + inode = req->r_inode; + } else if (req->r_dentry) { + if (req->r_dentry->d_inode) { + inode = req->r_dentry->d_inode; + } else { + inode = req->r_dentry->d_parent->d_inode; + hash = req->r_dentry->d_name.hash; + is_hash = true; + } + } + dout("__choose_mds %p is_hash=%d (%d) mode %d\n", inode, (int)is_hash, + (int)hash, mode); + if (!inode) + goto random; + ci = ceph_inode(inode); + + if (is_hash && S_ISDIR(inode->i_mode)) { + struct ceph_inode_frag frag; + int found; + + ceph_choose_frag(ci, hash, &frag, &found); + if (found) { + if (mode == USE_ANY_MDS && frag.ndist > 0) { + u8 r; + + /* choose a random replica */ + get_random_bytes(&r, 1); + r %= frag.ndist; + mds = frag.dist[r]; + dout("choose_mds %p %llx.%llx " + "frag %u mds%d (%d/%d)\n", + inode, ceph_vinop(inode), + frag.frag, frag.mds, + (int)r, frag.ndist); + return mds; + } + + /* since this file/dir wasn't known to be + * replicated, then we want to look for the + * authoritative mds. */ + mode = USE_AUTH_MDS; + if (frag.mds >= 0) { + /* choose auth mds */ + mds = frag.mds; + dout("choose_mds %p %llx.%llx " + "frag %u mds%d (auth)\n", + inode, ceph_vinop(inode), frag.frag, mds); + return mds; + } + } + } + + spin_lock(&inode->i_lock); + cap = NULL; + if (mode == USE_AUTH_MDS) + cap = ci->i_auth_cap; + if (!cap && !RB_EMPTY_ROOT(&ci->i_caps)) + cap = rb_entry(rb_first(&ci->i_caps), struct ceph_cap, ci_node); + if (!cap) { + spin_unlock(&inode->i_lock); + goto random; + } + mds = cap->session->s_mds; + dout("choose_mds %p %llx.%llx mds%d (%scap %p)\n", + inode, ceph_vinop(inode), mds, + cap == ci->i_auth_cap ? "auth " : "", cap); + spin_unlock(&inode->i_lock); + return mds; + +random: + mds = ceph_mdsmap_get_random_mds(mdsc->mdsmap); + dout("choose_mds chose random mds%d\n", mds); + return mds; +} + + +/* + * session messages + */ +static struct ceph_msg *create_session_msg(u32 op, u64 seq) +{ + struct ceph_msg *msg; + struct ceph_mds_session_head *h; + + msg = ceph_msg_new(CEPH_MSG_CLIENT_SESSION, sizeof(*h), 0, 0, NULL); + if (IS_ERR(msg)) { + pr_err("create_session_msg ENOMEM creating msg\n"); + return ERR_PTR(PTR_ERR(msg)); + } + h = msg->front.iov_base; + h->op = cpu_to_le32(op); + h->seq = cpu_to_le64(seq); + return msg; +} + +/* + * send session open request. + * + * called under mdsc->mutex + */ +static int __open_session(struct ceph_mds_client *mdsc, + struct ceph_mds_session *session) +{ + struct ceph_msg *msg; + int mstate; + int mds = session->s_mds; + int err = 0; + + /* wait for mds to go active? */ + mstate = ceph_mdsmap_get_state(mdsc->mdsmap, mds); + dout("open_session to mds%d (%s)\n", mds, + ceph_mds_state_name(mstate)); + session->s_state = CEPH_MDS_SESSION_OPENING; + session->s_renew_requested = jiffies; + + /* send connect message */ + msg = create_session_msg(CEPH_SESSION_REQUEST_OPEN, session->s_seq); + if (IS_ERR(msg)) { + err = PTR_ERR(msg); + goto out; + } + ceph_con_send(&session->s_con, msg); + +out: + return 0; +} + +/* + * session caps + */ + +/* + * Free preallocated cap messages assigned to this session + */ +static void cleanup_cap_releases(struct ceph_mds_session *session) +{ + struct ceph_msg *msg; + + spin_lock(&session->s_cap_lock); + while (!list_empty(&session->s_cap_releases)) { + msg = list_first_entry(&session->s_cap_releases, + struct ceph_msg, list_head); + list_del_init(&msg->list_head); + ceph_msg_put(msg); + } + while (!list_empty(&session->s_cap_releases_done)) { + msg = list_first_entry(&session->s_cap_releases_done, + struct ceph_msg, list_head); + list_del_init(&msg->list_head); + ceph_msg_put(msg); + } + spin_unlock(&session->s_cap_lock); +} + +/* + * Helper to safely iterate over all caps associated with a session. + * + * caller must hold session s_mutex + */ +static int iterate_session_caps(struct ceph_mds_session *session, + int (*cb)(struct inode *, struct ceph_cap *, + void *), void *arg) +{ + struct ceph_cap *cap, *ncap; + struct inode *inode; + int ret; + + dout("iterate_session_caps %p mds%d\n", session, session->s_mds); + spin_lock(&session->s_cap_lock); + list_for_each_entry_safe(cap, ncap, &session->s_caps, session_caps) { + inode = igrab(&cap->ci->vfs_inode); + if (!inode) + continue; + spin_unlock(&session->s_cap_lock); + ret = cb(inode, cap, arg); + iput(inode); + if (ret < 0) + return ret; + spin_lock(&session->s_cap_lock); + } + spin_unlock(&session->s_cap_lock); + + return 0; +} + +static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap, + void *arg) +{ + struct ceph_inode_info *ci = ceph_inode(inode); + dout("removing cap %p, ci is %p, inode is %p\n", + cap, ci, &ci->vfs_inode); + ceph_remove_cap(cap); + return 0; +} + +/* + * caller must hold session s_mutex + */ +static void remove_session_caps(struct ceph_mds_session *session) +{ + dout("remove_session_caps on %p\n", session); + iterate_session_caps(session, remove_session_caps_cb, NULL); + BUG_ON(session->s_nr_caps > 0); + cleanup_cap_releases(session); +} + +/* + * wake up any threads waiting on this session's caps. if the cap is + * old (didn't get renewed on the client reconnect), remove it now. + * + * caller must hold s_mutex. + */ +static int wake_up_session_cb(struct inode *inode, struct ceph_cap *cap, + void *arg) +{ + struct ceph_mds_session *session = arg; + + spin_lock(&inode->i_lock); + if (cap->gen != session->s_cap_gen) { + pr_err("failed reconnect %p %llx.%llx cap %p " + "(gen %d < session %d)\n", inode, ceph_vinop(inode), + cap, cap->gen, session->s_cap_gen); + __ceph_remove_cap(cap, NULL); + } + wake_up(&ceph_inode(inode)->i_cap_wq); + spin_unlock(&inode->i_lock); + return 0; +} + +static void wake_up_session_caps(struct ceph_mds_session *session) +{ + dout("wake_up_session_caps %p mds%d\n", session, session->s_mds); + iterate_session_caps(session, wake_up_session_cb, session); +} + +/* + * Send periodic message to MDS renewing all currently held caps. The + * ack will reset the expiration for all caps from this session. + * + * caller holds s_mutex + */ +static int send_renew_caps(struct ceph_mds_client *mdsc, + struct ceph_mds_session *session) +{ + struct ceph_msg *msg; + int state; + + if (time_after_eq(jiffies, session->s_cap_ttl) && + time_after_eq(session->s_cap_ttl, session->s_renew_requested)) + pr_info("mds%d caps stale\n", session->s_mds); + + /* do not try to renew caps until a recovering mds has reconnected + * with its clients. */ + state = ceph_mdsmap_get_state(mdsc->mdsmap, session->s_mds); + if (state < CEPH_MDS_STATE_RECONNECT) { + dout("send_renew_caps ignoring mds%d (%s)\n", + session->s_mds, ceph_mds_state_name(state)); + return 0; + } + + dout("send_renew_caps to mds%d (%s)\n", session->s_mds, + ceph_mds_state_name(state)); + session->s_renew_requested = jiffies; + msg = create_session_msg(CEPH_SESSION_REQUEST_RENEWCAPS, + ++session->s_renew_seq); + if (IS_ERR(msg)) + return PTR_ERR(msg); + ceph_con_send(&session->s_con, msg); + return 0; +} + +/* + * Note new cap ttl, and any transition from stale -> not stale (fresh?). + */ +static void renewed_caps(struct ceph_mds_client *mdsc, + struct ceph_mds_session *session, int is_renew) +{ + int was_stale; + int wake = 0; + + spin_lock(&session->s_cap_lock); + was_stale = is_renew && (session->s_cap_ttl == 0 || + time_after_eq(jiffies, session->s_cap_ttl)); + + session->s_cap_ttl = session->s_renew_requested + + mdsc->mdsmap->m_session_timeout*HZ; + + if (was_stale) { + if (time_before(jiffies, session->s_cap_ttl)) { + pr_info("mds%d caps renewed\n", session->s_mds); + wake = 1; + } else { + pr_info("mds%d caps still stale\n", session->s_mds); + } + } + dout("renewed_caps mds%d ttl now %lu, was %s, now %s\n", + session->s_mds, session->s_cap_ttl, was_stale ? "stale" : "fresh", + time_before(jiffies, session->s_cap_ttl) ? "stale" : "fresh"); + spin_unlock(&session->s_cap_lock); + + if (wake) + wake_up_session_caps(session); +} + +/* + * send a session close request + */ +static int request_close_session(struct ceph_mds_client *mdsc, + struct ceph_mds_session *session) +{ + struct ceph_msg *msg; + int err = 0; + + dout("request_close_session mds%d state %s seq %lld\n", + session->s_mds, session_state_name(session->s_state), + session->s_seq); + msg = create_session_msg(CEPH_SESSION_REQUEST_CLOSE, session->s_seq); + if (IS_ERR(msg)) + err = PTR_ERR(msg); + else + ceph_con_send(&session->s_con, msg); + return err; +} + +/* + * Called with s_mutex held. + */ +static int __close_session(struct ceph_mds_client *mdsc, + struct ceph_mds_session *session) +{ + if (session->s_state >= CEPH_MDS_SESSION_CLOSING) + return 0; + session->s_state = CEPH_MDS_SESSION_CLOSING; + return request_close_session(mdsc, session); +} + +/* + * Trim old(er) caps. + * + * Because we can't cache an inode without one or more caps, we do + * this indirectly: if a cap is unused, we prune its aliases, at which + * point the inode will hopefully get dropped to. + * + * Yes, this is a bit sloppy. Our only real goal here is to respond to + * memory pressure from the MDS, though, so it needn't be perfect. + */ +static int trim_caps_cb(struct inode *inode, struct ceph_cap *cap, void *arg) +{ + struct ceph_mds_session *session = arg; + struct ceph_inode_info *ci = ceph_inode(inode); + int used, oissued, mine; + + if (session->s_trim_caps <= 0) + return -1; + + spin_lock(&inode->i_lock); + mine = cap->issued | cap->implemented; + used = __ceph_caps_used(ci); + oissued = __ceph_caps_issued_other(ci, cap); + + dout("trim_caps_cb %p cap %p mine %s oissued %s used %s\n", + inode, cap, ceph_cap_string(mine), ceph_cap_string(oissued), + ceph_cap_string(used)); + if (ci->i_dirty_caps) + goto out; /* dirty caps */ + if ((used & ~oissued) & mine) + goto out; /* we need these caps */ + + session->s_trim_caps--; + if (oissued) { + /* we aren't the only cap.. just remove us */ + __ceph_remove_cap(cap, NULL); + } else { + /* try to drop referring dentries */ + spin_unlock(&inode->i_lock); + d_prune_aliases(inode); + dout("trim_caps_cb %p cap %p pruned, count now %d\n", + inode, cap, atomic_read(&inode->i_count)); + return 0; + } + +out: + spin_unlock(&inode->i_lock); + return 0; +} + +/* + * Trim session cap count down to some max number. + */ +static int trim_caps(struct ceph_mds_client *mdsc, + struct ceph_mds_session *session, + int max_caps) +{ + int trim_caps = session->s_nr_caps - max_caps; + + dout("trim_caps mds%d start: %d / %d, trim %d\n", + session->s_mds, session->s_nr_caps, max_caps, trim_caps); + if (trim_caps > 0) { + session->s_trim_caps = trim_caps; + iterate_session_caps(session, trim_caps_cb, session); + dout("trim_caps mds%d done: %d / %d, trimmed %d\n", + session->s_mds, session->s_nr_caps, max_caps, + trim_caps - session->s_trim_caps); + } + return 0; +} + +/* + * Allocate cap_release messages. If there is a partially full message + * in the queue, try to allocate enough to cover it's remainder, so that + * we can send it immediately. + * + * Called under s_mutex. + */ +static int add_cap_releases(struct ceph_mds_client *mdsc, + struct ceph_mds_session *session, + int extra) +{ + struct ceph_msg *msg; + struct ceph_mds_cap_release *head; + int err = -ENOMEM; + + if (extra < 0) + extra = mdsc->client->mount_args.cap_release_safety; + + spin_lock(&session->s_cap_lock); + + if (!list_empty(&session->s_cap_releases)) { + msg = list_first_entry(&session->s_cap_releases, + struct ceph_msg, + list_head); + head = msg->front.iov_base; + extra += CEPH_CAPS_PER_RELEASE - le32_to_cpu(head->num); + } + + while (session->s_num_cap_releases < session->s_nr_caps + extra) { + spin_unlock(&session->s_cap_lock); + msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPRELEASE, PAGE_CACHE_SIZE, + 0, 0, NULL); + if (!msg) + goto out_unlocked; + dout("add_cap_releases %p msg %p now %d\n", session, msg, + (int)msg->front.iov_len); + head = msg->front.iov_base; + head->num = cpu_to_le32(0); + msg->front.iov_len = sizeof(*head); + spin_lock(&session->s_cap_lock); + list_add(&msg->list_head, &session->s_cap_releases); + session->s_num_cap_releases += CEPH_CAPS_PER_RELEASE; + } + + if (!list_empty(&session->s_cap_releases)) { + msg = list_first_entry(&session->s_cap_releases, + struct ceph_msg, + list_head); + head = msg->front.iov_base; + if (head->num) { + dout(" queueing non-full %p (%d)\n", msg, + le32_to_cpu(head->num)); + list_move_tail(&msg->list_head, + &session->s_cap_releases_done); + session->s_num_cap_releases -= + CEPH_CAPS_PER_RELEASE - le32_to_cpu(head->num); + } + } + err = 0; + spin_unlock(&session->s_cap_lock); +out_unlocked: + return err; +} + +/* + * flush all dirty inode data to disk. + * + * returns true if we've flushed through want_flush_seq + */ +static int check_cap_flush(struct ceph_mds_client *mdsc, u64 want_flush_seq) +{ + int mds, ret = 1; + + dout("check_cap_flush want %lld\n", want_flush_seq); + mutex_lock(&mdsc->mutex); + for (mds = 0; ret && mds < mdsc->max_sessions; mds++) { + struct ceph_mds_session *session = mdsc->sessions[mds]; + + if (!session) + continue; + get_session(session); + mutex_unlock(&mdsc->mutex); + + mutex_lock(&session->s_mutex); + if (!list_empty(&session->s_cap_flushing)) { + struct ceph_inode_info *ci = + list_entry(session->s_cap_flushing.next, + struct ceph_inode_info, + i_flushing_item); + struct inode *inode = &ci->vfs_inode; + + spin_lock(&inode->i_lock); + if (ci->i_cap_flush_seq <= want_flush_seq) { + dout("check_cap_flush still flushing %p " + "seq %lld <= %lld to mds%d\n", inode, + ci->i_cap_flush_seq, want_flush_seq, + session->s_mds); + ret = 0; + } + spin_unlock(&inode->i_lock); + } + mutex_unlock(&session->s_mutex); + ceph_put_mds_session(session); + + if (!ret) + return ret; + mutex_lock(&mdsc->mutex); + } + + mutex_unlock(&mdsc->mutex); + dout("check_cap_flush ok, flushed thru %lld\n", want_flush_seq); + return ret; +} + +/* + * called under s_mutex + */ +static void send_cap_releases(struct ceph_mds_client *mdsc, + struct ceph_mds_session *session) +{ + struct ceph_msg *msg; + + dout("send_cap_releases mds%d\n", session->s_mds); + while (1) { + spin_lock(&session->s_cap_lock); + if (list_empty(&session->s_cap_releases_done)) + break; + msg = list_first_entry(&session->s_cap_releases_done, + struct ceph_msg, list_head); + list_del_init(&msg->list_head); + spin_unlock(&session->s_cap_lock); + msg->hdr.front_len = cpu_to_le32(msg->front.iov_len); + dout("send_cap_releases mds%d %p\n", session->s_mds, msg); + ceph_con_send(&session->s_con, msg); + } + spin_unlock(&session->s_cap_lock); +} + +/* + * requests + */ + +/* + * Create an mds request. + */ +struct ceph_mds_request * +ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode) +{ + struct ceph_mds_request *req = kzalloc(sizeof(*req), GFP_NOFS); + + if (!req) + return ERR_PTR(-ENOMEM); + + req->r_started = jiffies; + req->r_resend_mds = -1; + INIT_LIST_HEAD(&req->r_unsafe_dir_item); + req->r_fmode = -1; + atomic_set(&req->r_ref, 1); /* one for request_tree, one for caller */ + INIT_LIST_HEAD(&req->r_wait); + init_completion(&req->r_completion); + init_completion(&req->r_safe_completion); + INIT_LIST_HEAD(&req->r_unsafe_item); + + req->r_op = op; + req->r_direct_mode = mode; + return req; +} + +/* + * return oldest (lowest) tid in request tree, 0 if none. + * + * called under mdsc->mutex. + */ +static u64 __get_oldest_tid(struct ceph_mds_client *mdsc) +{ + struct ceph_mds_request *first; + if (radix_tree_gang_lookup(&mdsc->request_tree, + (void **)&first, 0, 1) <= 0) + return 0; + return first->r_tid; +} + +/* + * Build a dentry's path. Allocate on heap; caller must kfree. Based + * on build_path_from_dentry in fs/cifs/dir.c. + * + * If @stop_on_nosnap, generate path relative to the first non-snapped + * inode. + * + * Encode hidden .snap dirs as a double /, i.e. + * foo/.snap/bar -> foo//bar + */ +char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *base, + int stop_on_nosnap) +{ + struct dentry *temp; + char *path; + int len, pos; + + if (dentry == NULL) + return ERR_PTR(-EINVAL); + +retry: + len = 0; + for (temp = dentry; !IS_ROOT(temp);) { + struct inode *inode = temp->d_inode; + if (inode && ceph_snap(inode) == CEPH_SNAPDIR) + len++; /* slash only */ + else if (stop_on_nosnap && inode && + ceph_snap(inode) == CEPH_NOSNAP) + break; + else + len += 1 + temp->d_name.len; + temp = temp->d_parent; + if (temp == NULL) { + pr_err("build_path_dentry corrupt dentry %p\n", dentry); + return ERR_PTR(-EINVAL); + } + } + if (len) + len--; /* no leading '/' */ + + path = kmalloc(len+1, GFP_NOFS); + if (path == NULL) + return ERR_PTR(-ENOMEM); + pos = len; + path[pos] = 0; /* trailing null */ + for (temp = dentry; !IS_ROOT(temp) && pos != 0; ) { + struct inode *inode = temp->d_inode; + + if (inode && ceph_snap(inode) == CEPH_SNAPDIR) { + dout("build_path_dentry path+%d: %p SNAPDIR\n", + pos, temp); + } else if (stop_on_nosnap && inode && + ceph_snap(inode) == CEPH_NOSNAP) { + break; + } else { + pos -= temp->d_name.len; + if (pos < 0) + break; + strncpy(path + pos, temp->d_name.name, + temp->d_name.len); + dout("build_path_dentry path+%d: %p '%.*s'\n", + pos, temp, temp->d_name.len, path + pos); + } + if (pos) + path[--pos] = '/'; + temp = temp->d_parent; + if (temp == NULL) { + pr_err("build_path_dentry corrupt dentry\n"); + kfree(path); + return ERR_PTR(-EINVAL); + } + } + if (pos != 0) { + pr_err("build_path_dentry did not end path lookup where " + "expected, namelen is %d, pos is %d\n", len, pos); + /* presumably this is only possible if racing with a + rename of one of the parent directories (we can not + lock the dentries above us to prevent this, but + retrying should be harmless) */ + kfree(path); + goto retry; + } + + *base = ceph_ino(temp->d_inode); + *plen = len; + dout("build_path_dentry on %p %d built %llx '%.*s'\n", + dentry, atomic_read(&dentry->d_count), *base, len, path); + return path; +} + +static int build_dentry_path(struct dentry *dentry, + const char **ppath, int *ppathlen, u64 *pino, + int *pfreepath) +{ + char *path; + + if (ceph_snap(dentry->d_parent->d_inode) == CEPH_NOSNAP) { + *pino = ceph_ino(dentry->d_parent->d_inode); + *ppath = dentry->d_name.name; + *ppathlen = dentry->d_name.len; + return 0; + } + path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1); + if (IS_ERR(path)) + return PTR_ERR(path); + *ppath = path; + *pfreepath = 1; + return 0; +} + +static int build_inode_path(struct inode *inode, + const char **ppath, int *ppathlen, u64 *pino, + int *pfreepath) +{ + struct dentry *dentry; + char *path; + + if (ceph_snap(inode) == CEPH_NOSNAP) { + *pino = ceph_ino(inode); + *ppathlen = 0; + return 0; + } + dentry = d_find_alias(inode); + path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1); + dput(dentry); + if (IS_ERR(path)) + return PTR_ERR(path); + *ppath = path; + *pfreepath = 1; + return 0; +} + +/* + * request arguments may be specified via an inode *, a dentry *, or + * an explicit ino+path. + */ +static int set_request_path_attr(struct inode *rinode, struct dentry *rdentry, + const char *rpath, u64 rino, + const char **ppath, int *pathlen, + u64 *ino, int *freepath) +{ + int r = 0; + + if (rinode) { + r = build_inode_path(rinode, ppath, pathlen, ino, freepath); + dout(" inode %p %llx.%llx\n", rinode, ceph_ino(rinode), + ceph_snap(rinode)); + } else if (rdentry) { + r = build_dentry_path(rdentry, ppath, pathlen, ino, freepath); + dout(" dentry %p %llx/%.*s\n", rdentry, *ino, *pathlen, + *ppath); + } else if (rpath) { + *ino = rino; + *ppath = rpath; + *pathlen = strlen(rpath); + dout(" path %.*s\n", *pathlen, rpath); + } + + return r; +} + +/* + * called under mdsc->mutex + */ +static struct ceph_msg *create_request_message(struct ceph_mds_client *mdsc, + struct ceph_mds_request *req, + int mds) +{ + struct ceph_msg *msg; + struct ceph_mds_request_head *head; + const char *path1 = NULL; + const char *path2 = NULL; + u64 ino1 = 0, ino2 = 0; + int pathlen1 = 0, pathlen2 = 0; + int freepath1 = 0, freepath2 = 0; + int len; + u16 releases; + void *p, *end; + int ret; + + ret = set_request_path_attr(req->r_inode, req->r_dentry, + req->r_path1, req->r_ino1.ino, + &path1, &pathlen1, &ino1, &freepath1); + if (ret < 0) { + msg = ERR_PTR(ret); + goto out; + } + + ret = set_request_path_attr(NULL, req->r_old_dentry, + req->r_path2, req->r_ino2.ino, + &path2, &pathlen2, &ino2, &freepath2); + if (ret < 0) { + msg = ERR_PTR(ret); + goto out_free1; + } + + len = sizeof(*head) + + pathlen1 + pathlen2 + 2*(sizeof(u32) + sizeof(u64)); + + /* calculate (max) length for cap releases */ + len += sizeof(struct ceph_mds_request_release) * + (!!req->r_inode_drop + !!req->r_dentry_drop + + !!req->r_old_inode_drop + !!req->r_old_dentry_drop); + if (req->r_dentry_drop) + len += req->r_dentry->d_name.len; + if (req->r_old_dentry_drop) + len += req->r_old_dentry->d_name.len; + + msg = ceph_msg_new(CEPH_MSG_CLIENT_REQUEST, len, 0, 0, NULL); + if (IS_ERR(msg)) + goto out_free2; + + head = msg->front.iov_base; + p = msg->front.iov_base + sizeof(*head); + end = msg->front.iov_base + msg->front.iov_len; + + head->mdsmap_epoch = cpu_to_le32(mdsc->mdsmap->m_epoch); + head->op = cpu_to_le32(req->r_op); + head->caller_uid = cpu_to_le32(current_fsuid()); + head->caller_gid = cpu_to_le32(current_fsgid()); + head->args = req->r_args; + + ceph_encode_filepath(&p, end, ino1, path1); + ceph_encode_filepath(&p, end, ino2, path2); + + /* cap releases */ + releases = 0; + if (req->r_inode_drop) + releases += ceph_encode_inode_release(&p, + req->r_inode ? req->r_inode : req->r_dentry->d_inode, + mds, req->r_inode_drop, req->r_inode_unless, 0); + if (req->r_dentry_drop) + releases += ceph_encode_dentry_release(&p, req->r_dentry, + mds, req->r_dentry_drop, req->r_dentry_unless); + if (req->r_old_dentry_drop) + releases += ceph_encode_dentry_release(&p, req->r_old_dentry, + mds, req->r_old_dentry_drop, req->r_old_dentry_unless); + if (req->r_old_inode_drop) + releases += ceph_encode_inode_release(&p, + req->r_old_dentry->d_inode, + mds, req->r_old_inode_drop, req->r_old_inode_unless, 0); + head->num_releases = cpu_to_le16(releases); + + BUG_ON(p > end); + msg->front.iov_len = p - msg->front.iov_base; + msg->hdr.front_len = cpu_to_le32(msg->front.iov_len); + + msg->pages = req->r_pages; + msg->nr_pages = req->r_num_pages; + msg->hdr.data_len = cpu_to_le32(req->r_data_len); + msg->hdr.data_off = cpu_to_le16(0); + +out_free2: + if (freepath2) + kfree((char *)path2); +out_free1: + if (freepath1) + kfree((char *)path1); +out: + return msg; +} + +/* + * called under mdsc->mutex if error, under no mutex if + * success. + */ +static void complete_request(struct ceph_mds_client *mdsc, + struct ceph_mds_request *req) +{ + if (req->r_callback) + req->r_callback(mdsc, req); + else + complete(&req->r_completion); +} + +/* + * called under mdsc->mutex + */ +static int __prepare_send_request(struct ceph_mds_client *mdsc, + struct ceph_mds_request *req, + int mds) +{ + struct ceph_mds_request_head *rhead; + struct ceph_msg *msg; + int flags = 0; + + req->r_mds = mds; + req->r_attempts++; + dout("prepare_send_request %p tid %lld %s (attempt %d)\n", req, + req->r_tid, ceph_mds_op_name(req->r_op), req->r_attempts); + + if (req->r_request) { + ceph_msg_put(req->r_request); + req->r_request = NULL; + } + msg = create_request_message(mdsc, req, mds); + if (IS_ERR(msg)) { + req->r_reply = ERR_PTR(PTR_ERR(msg)); + complete_request(mdsc, req); + return -PTR_ERR(msg); + } + req->r_request = msg; + + rhead = msg->front.iov_base; + rhead->tid = cpu_to_le64(req->r_tid); + rhead->oldest_client_tid = cpu_to_le64(__get_oldest_tid(mdsc)); + if (req->r_got_unsafe) + flags |= CEPH_MDS_FLAG_REPLAY; + if (req->r_locked_dir) + flags |= CEPH_MDS_FLAG_WANT_DENTRY; + rhead->flags = cpu_to_le32(flags); + rhead->num_fwd = req->r_num_fwd; + rhead->num_retry = req->r_attempts - 1; + + dout(" r_locked_dir = %p\n", req->r_locked_dir); + + if (req->r_target_inode && req->r_got_unsafe) + rhead->ino = cpu_to_le64(ceph_ino(req->r_target_inode)); + else + rhead->ino = 0; + return 0; +} + +/* + * send request, or put it on the appropriate wait list. + */ +static int __do_request(struct ceph_mds_client *mdsc, + struct ceph_mds_request *req) +{ + struct ceph_mds_session *session = NULL; + int mds = -1; + int err = -EAGAIN; + + if (req->r_reply) + goto out; + + if (req->r_timeout && + time_after_eq(jiffies, req->r_started + req->r_timeout)) { + dout("do_request timed out\n"); + err = -EIO; + goto finish; + } + + mds = __choose_mds(mdsc, req); + if (mds < 0 || + ceph_mdsmap_get_state(mdsc->mdsmap, mds) < CEPH_MDS_STATE_ACTIVE) { + dout("do_request no mds or not active, waiting for map\n"); + list_add(&req->r_wait, &mdsc->waiting_for_map); + goto out; + } + + /* get, open session */ + session = __ceph_lookup_mds_session(mdsc, mds); + if (!session) + session = register_session(mdsc, mds); + dout("do_request mds%d session %p state %s\n", mds, session, + session_state_name(session->s_state)); + if (session->s_state != CEPH_MDS_SESSION_OPEN && + session->s_state != CEPH_MDS_SESSION_HUNG) { + if (session->s_state == CEPH_MDS_SESSION_NEW || + session->s_state == CEPH_MDS_SESSION_CLOSING) + __open_session(mdsc, session); + list_add(&req->r_wait, &session->s_waiting); + goto out_session; + } + + /* send request */ + req->r_session = get_session(session); + req->r_resend_mds = -1; /* forget any previous mds hint */ + + if (req->r_request_started == 0) /* note request start time */ + req->r_request_started = jiffies; + + err = __prepare_send_request(mdsc, req, mds); + if (!err) { + ceph_msg_get(req->r_request); + ceph_con_send(&session->s_con, req->r_request); + } + +out_session: + ceph_put_mds_session(session); +out: + return err; + +finish: + req->r_reply = ERR_PTR(err); + complete_request(mdsc, req); + goto out; +} + +/* + * called under mdsc->mutex + */ +static void __wake_requests(struct ceph_mds_client *mdsc, + struct list_head *head) +{ + struct ceph_mds_request *req, *nreq; + + list_for_each_entry_safe(req, nreq, head, r_wait) { + list_del_init(&req->r_wait); + __do_request(mdsc, req); + } +} + +/* + * Wake up threads with requests pending for @mds, so that they can + * resubmit their requests to a possibly different mds. If @all is set, + * wake up if their requests has been forwarded to @mds, too. + */ +static void kick_requests(struct ceph_mds_client *mdsc, int mds, int all) +{ + struct ceph_mds_request *reqs[10]; + u64 nexttid = 0; + int i, got; + + dout("kick_requests mds%d\n", mds); + while (nexttid <= mdsc->last_tid) { + got = radix_tree_gang_lookup(&mdsc->request_tree, + (void **)&reqs, nexttid, 10); + if (got == 0) + break; + nexttid = reqs[got-1]->r_tid + 1; + for (i = 0; i < got; i++) { + if (reqs[i]->r_got_unsafe) + continue; + if (reqs[i]->r_session && + reqs[i]->r_session->s_mds == mds) { + dout(" kicking tid %llu\n", reqs[i]->r_tid); + put_request_session(reqs[i]); + __do_request(mdsc, reqs[i]); + } + } + } +} + +void ceph_mdsc_submit_request(struct ceph_mds_client *mdsc, + struct ceph_mds_request *req) +{ + dout("submit_request on %p\n", req); + mutex_lock(&mdsc->mutex); + __register_request(mdsc, req, NULL); + __do_request(mdsc, req); + mutex_unlock(&mdsc->mutex); +} + +/* + * Synchrously perform an mds request. Take care of all of the + * session setup, forwarding, retry details. + */ +int ceph_mdsc_do_request(struct ceph_mds_client *mdsc, + struct inode *dir, + struct ceph_mds_request *req) +{ + int err; + + dout("do_request on %p\n", req); + + /* take CAP_PIN refs for r_inode, r_locked_dir, r_old_dentry */ + if (req->r_inode) + ceph_get_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN); + if (req->r_locked_dir) + ceph_get_cap_refs(ceph_inode(req->r_locked_dir), CEPH_CAP_PIN); + if (req->r_old_dentry) + ceph_get_cap_refs( + ceph_inode(req->r_old_dentry->d_parent->d_inode), + CEPH_CAP_PIN); + + /* issue */ + mutex_lock(&mdsc->mutex); + __register_request(mdsc, req, dir); + __do_request(mdsc, req); + + /* wait */ + if (!req->r_reply) { + mutex_unlock(&mdsc->mutex); + if (req->r_timeout) { + err = wait_for_completion_timeout(&req->r_completion, + req->r_timeout); + if (err > 0) + err = 0; + else if (err == 0) + req->r_reply = ERR_PTR(-EIO); + } else { + wait_for_completion(&req->r_completion); + } + mutex_lock(&mdsc->mutex); + } + + if (IS_ERR(req->r_reply)) { + err = PTR_ERR(req->r_reply); + req->r_reply = NULL; + + /* clean up */ + __unregister_request(mdsc, req); + if (!list_empty(&req->r_unsafe_item)) + list_del_init(&req->r_unsafe_item); + complete(&req->r_safe_completion); + } else if (req->r_err) { + err = req->r_err; + } else { + err = le32_to_cpu(req->r_reply_info.head->result); + } + mutex_unlock(&mdsc->mutex); + + dout("do_request %p done, result %d\n", req, err); + return err; +} + +/* + * Handle mds reply. + * + * We take the session mutex and parse and process the reply immediately. + * This preserves the logical ordering of replies, capabilities, etc., sent + * by the MDS as they are applied to our local cache. + */ +static void handle_reply(struct ceph_mds_session *session, struct ceph_msg *msg) +{ + struct ceph_mds_client *mdsc = session->s_mdsc; + struct ceph_mds_request *req; + struct ceph_mds_reply_head *head = msg->front.iov_base; + struct ceph_mds_reply_info_parsed *rinfo; /* parsed reply info */ + u64 tid; + int err, result; + int mds; + + if (msg->hdr.src.name.type != CEPH_ENTITY_TYPE_MDS) + return; + if (msg->front.iov_len < sizeof(*head)) { + pr_err("mdsc_handle_reply got corrupt (short) reply\n"); + return; + } + + /* get request, session */ + tid = le64_to_cpu(head->tid); + mutex_lock(&mdsc->mutex); + req = __lookup_request(mdsc, tid); + if (!req) { + dout("handle_reply on unknown tid %llu\n", tid); + mutex_unlock(&mdsc->mutex); + return; + } + dout("handle_reply %p\n", req); + mds = le64_to_cpu(msg->hdr.src.name.num); + + /* correct session? */ + if (!req->r_session && req->r_session != session) { + pr_err("mdsc_handle_reply got %llu on session mds%d" + " not mds%d\n", tid, session->s_mds, + req->r_session ? req->r_session->s_mds : -1); + mutex_unlock(&mdsc->mutex); + goto out; + } + + /* dup? */ + if ((req->r_got_unsafe && !head->safe) || + (req->r_got_safe && head->safe)) { + pr_warning("got a dup %s reply on %llu from mds%d\n", + head->safe ? "safe" : "unsafe", tid, mds); + mutex_unlock(&mdsc->mutex); + goto out; + } + + result = le32_to_cpu(head->result); + + /* + * Tolerate 2 consecutive ESTALEs from the same mds. + * FIXME: we should be looking at the cap migrate_seq. + */ + if (result == -ESTALE) { + req->r_direct_mode = USE_AUTH_MDS; + req->r_num_stale++; + if (req->r_num_stale <= 2) { + __do_request(mdsc, req); + mutex_unlock(&mdsc->mutex); + goto out; + } + } else { + req->r_num_stale = 0; + } + + if (head->safe) { + req->r_got_safe = true; + __unregister_request(mdsc, req); + complete(&req->r_safe_completion); + + if (req->r_got_unsafe) { + /* + * We already handled the unsafe response, now do the + * cleanup. No need to examine the response; the MDS + * doesn't include any result info in the safe + * response. And even if it did, there is nothing + * useful we could do with a revised return value. + */ + dout("got safe reply %llu, mds%d\n", tid, mds); + list_del_init(&req->r_unsafe_item); + + /* last unsafe request during umount? */ + if (mdsc->stopping && !__get_oldest_tid(mdsc)) + complete(&mdsc->safe_umount_waiters); + mutex_unlock(&mdsc->mutex); + goto out; + } + } + + BUG_ON(req->r_reply); + + if (!head->safe) { + req->r_got_unsafe = true; + list_add_tail(&req->r_unsafe_item, &req->r_session->s_unsafe); + } + + dout("handle_reply tid %lld result %d\n", tid, result); + rinfo = &req->r_reply_info; + err = parse_reply_info(msg, rinfo); + mutex_unlock(&mdsc->mutex); + + mutex_lock(&session->s_mutex); + if (err < 0) { + pr_err("mdsc_handle_reply got corrupt reply mds%d\n", mds); + goto out_err; + } + + /* snap trace */ + if (rinfo->snapblob_len) { + down_write(&mdsc->snap_rwsem); + ceph_update_snap_trace(mdsc, rinfo->snapblob, + rinfo->snapblob + rinfo->snapblob_len, + le32_to_cpu(head->op) == CEPH_MDS_OP_RMSNAP); + downgrade_write(&mdsc->snap_rwsem); + } else { + down_read(&mdsc->snap_rwsem); + } + + /* insert trace into our cache */ + err = ceph_fill_trace(mdsc->client->sb, req, req->r_session); + if (err == 0) { + if (result == 0 && rinfo->dir_nr) + ceph_readdir_prepopulate(req, req->r_session); + ceph_unreserve_caps(&req->r_caps_reservation); + } + + up_read(&mdsc->snap_rwsem); +out_err: + if (err) { + req->r_err = err; + } else { + req->r_reply = msg; + ceph_msg_get(msg); + } + + add_cap_releases(mdsc, req->r_session, -1); + mutex_unlock(&session->s_mutex); + + /* kick calling process */ + complete_request(mdsc, req); +out: + ceph_mdsc_put_request(req); + return; +} + + + +/* + * handle mds notification that our request has been forwarded. + */ +static void handle_forward(struct ceph_mds_client *mdsc, struct ceph_msg *msg) +{ + struct ceph_mds_request *req; + u64 tid; + u32 next_mds; + u32 fwd_seq; + u8 must_resend; + int err = -EINVAL; + void *p = msg->front.iov_base; + void *end = p + msg->front.iov_len; + int from_mds, state; + + if (msg->hdr.src.name.type != CEPH_ENTITY_TYPE_MDS) + goto bad; + from_mds = le64_to_cpu(msg->hdr.src.name.num); + + ceph_decode_need(&p, end, sizeof(u64)+2*sizeof(u32), bad); + ceph_decode_64(&p, tid); + ceph_decode_32(&p, next_mds); + ceph_decode_32(&p, fwd_seq); + ceph_decode_8(&p, must_resend); + + WARN_ON(must_resend); /* shouldn't happen. */ + + mutex_lock(&mdsc->mutex); + req = __lookup_request(mdsc, tid); + if (!req) { + dout("forward %llu dne\n", tid); + goto out; /* dup reply? */ + } + + state = mdsc->sessions[next_mds]->s_state; + if (fwd_seq <= req->r_num_fwd) { + dout("forward %llu to mds%d - old seq %d <= %d\n", + tid, next_mds, req->r_num_fwd, fwd_seq); + } else { + /* resend. forward race not possible; mds would drop */ + dout("forward %llu to mds%d (we resend)\n", tid, next_mds); + req->r_num_fwd = fwd_seq; + req->r_resend_mds = next_mds; + put_request_session(req); + __do_request(mdsc, req); + } + ceph_mdsc_put_request(req); +out: + mutex_unlock(&mdsc->mutex); + return; + +bad: + pr_err("mdsc_handle_forward decode error err=%d\n", err); +} + +/* + * handle a mds session control message + */ +static void handle_session(struct ceph_mds_session *session, + struct ceph_msg *msg) +{ + struct ceph_mds_client *mdsc = session->s_mdsc; + u32 op; + u64 seq; + int mds; + struct ceph_mds_session_head *h = msg->front.iov_base; + int wake = 0; + + if (msg->hdr.src.name.type != CEPH_ENTITY_TYPE_MDS) + return; + mds = le64_to_cpu(msg->hdr.src.name.num); + + /* decode */ + if (msg->front.iov_len != sizeof(*h)) + goto bad; + op = le32_to_cpu(h->op); + seq = le64_to_cpu(h->seq); + + mutex_lock(&mdsc->mutex); + /* FIXME: this ttl calculation is generous */ + session->s_ttl = jiffies + HZ*mdsc->mdsmap->m_session_autoclose; + mutex_unlock(&mdsc->mutex); + + mutex_lock(&session->s_mutex); + + dout("handle_session mds%d %s %p state %s seq %llu\n", + mds, ceph_session_op_name(op), session, + session_state_name(session->s_state), seq); + + if (session->s_state == CEPH_MDS_SESSION_HUNG) { + session->s_state = CEPH_MDS_SESSION_OPEN; + pr_info("mds%d came back\n", session->s_mds); + } + + switch (op) { + case CEPH_SESSION_OPEN: + session->s_state = CEPH_MDS_SESSION_OPEN; + renewed_caps(mdsc, session, 0); + wake = 1; + if (mdsc->stopping) + __close_session(mdsc, session); + break; + + case CEPH_SESSION_RENEWCAPS: + if (session->s_renew_seq == seq) + renewed_caps(mdsc, session, 1); + break; + + case CEPH_SESSION_CLOSE: + unregister_session(mdsc, mds); + remove_session_caps(session); + wake = 1; /* for good measure */ + complete(&mdsc->session_close_waiters); + kick_requests(mdsc, mds, 0); /* cur only */ + break; + + case CEPH_SESSION_STALE: + pr_info("mds%d caps went stale, renewing\n", + session->s_mds); + spin_lock(&session->s_cap_lock); + session->s_cap_gen++; + session->s_cap_ttl = 0; + spin_unlock(&session->s_cap_lock); + send_renew_caps(mdsc, session); + break; + + case CEPH_SESSION_RECALL_STATE: + trim_caps(mdsc, session, le32_to_cpu(h->max_caps)); + break; + + default: + pr_err("mdsc_handle_session bad op %d mds%d\n", op, mds); + WARN_ON(1); + } + + mutex_unlock(&session->s_mutex); + if (wake) { + mutex_lock(&mdsc->mutex); + __wake_requests(mdsc, &session->s_waiting); + mutex_unlock(&mdsc->mutex); + } + return; + +bad: + pr_err("mdsc_handle_session corrupt message mds%d len %d\n", mds, + (int)msg->front.iov_len); + return; +} + + +/* + * called under session->mutex. + */ +static void replay_unsafe_requests(struct ceph_mds_client *mdsc, + struct ceph_mds_session *session) +{ + struct ceph_mds_request *req, *nreq; + int err; + + dout("replay_unsafe_requests mds%d\n", session->s_mds); + + mutex_lock(&mdsc->mutex); + list_for_each_entry_safe(req, nreq, &session->s_unsafe, r_unsafe_item) { + err = __prepare_send_request(mdsc, req, session->s_mds); + if (!err) { + ceph_msg_get(req->r_request); + ceph_con_send(&session->s_con, req->r_request); + } + } + mutex_unlock(&mdsc->mutex); +} + +/* + * Encode information about a cap for a reconnect with the MDS. + */ +struct encode_caps_data { + void **pp; + void *end; + int *num_caps; +}; + +static int encode_caps_cb(struct inode *inode, struct ceph_cap *cap, + void *arg) +{ + struct ceph_mds_cap_reconnect *rec; + struct ceph_inode_info *ci; + struct encode_caps_data *data = (struct encode_caps_data *)arg; + void *p = *(data->pp); + void *end = data->end; + char *path; + int pathlen, err; + u64 pathbase; + struct dentry *dentry; + + ci = cap->ci; + + dout(" adding %p ino %llx.%llx cap %p %lld %s\n", + inode, ceph_vinop(inode), cap, cap->cap_id, + ceph_cap_string(cap->issued)); + ceph_decode_need(&p, end, sizeof(u64), needmore); + ceph_encode_64(&p, ceph_ino(inode)); + + dentry = d_find_alias(inode); + if (dentry) { + path = ceph_mdsc_build_path(dentry, &pathlen, &pathbase, 0); + if (IS_ERR(path)) { + err = PTR_ERR(path); + BUG_ON(err); + } + } else { + path = NULL; + pathlen = 0; + } + ceph_decode_need(&p, end, pathlen+4, needmore); + ceph_encode_string(&p, end, path, pathlen); + + ceph_decode_need(&p, end, sizeof(*rec), needmore); + rec = p; + p += sizeof(*rec); + BUG_ON(p > end); + spin_lock(&inode->i_lock); + cap->seq = 0; /* reset cap seq */ + cap->issue_seq = 0; /* and issue_seq */ + rec->cap_id = cpu_to_le64(cap->cap_id); + rec->pathbase = cpu_to_le64(pathbase); + rec->wanted = cpu_to_le32(__ceph_caps_wanted(ci)); + rec->issued = cpu_to_le32(cap->issued); + rec->size = cpu_to_le64(inode->i_size); + ceph_encode_timespec(&rec->mtime, &inode->i_mtime); + ceph_encode_timespec(&rec->atime, &inode->i_atime); + rec->snaprealm = cpu_to_le64(ci->i_snap_realm->ino); + spin_unlock(&inode->i_lock); + + kfree(path); + dput(dentry); + (*data->num_caps)++; + *(data->pp) = p; + return 0; +needmore: + return -ENOSPC; +} + + +/* + * If an MDS fails and recovers, clients need to reconnect in order to + * reestablish shared state. This includes all caps issued through + * this session _and_ the snap_realm hierarchy. Because it's not + * clear which snap realms the mds cares about, we send everything we + * know about.. that ensures we'll then get any new info the + * recovering MDS might have. + * + * This is a relatively heavyweight operation, but it's rare. + * + * called with mdsc->mutex held. + */ +static void send_mds_reconnect(struct ceph_mds_client *mdsc, int mds) +{ + struct ceph_mds_session *session; + struct ceph_msg *reply; + int newlen, len = 4 + 1; + void *p, *end; + int err; + int num_caps, num_realms = 0; + int got; + u64 next_snap_ino = 0; + __le32 *pnum_caps, *pnum_realms; + struct encode_caps_data iter_args; + + pr_info("reconnect to recovering mds%d\n", mds); + + /* find session */ + session = __ceph_lookup_mds_session(mdsc, mds); + mutex_unlock(&mdsc->mutex); /* drop lock for duration */ + + if (session) { + mutex_lock(&session->s_mutex); + + session->s_state = CEPH_MDS_SESSION_RECONNECTING; + session->s_seq = 0; + + ceph_con_open(&session->s_con, + ceph_mdsmap_get_addr(mdsc->mdsmap, mds)); + + /* replay unsafe requests */ + replay_unsafe_requests(mdsc, session); + + /* estimate needed space */ + len += session->s_nr_caps * + (100+sizeof(struct ceph_mds_cap_reconnect)); + pr_info("estimating i need %d bytes for %d caps\n", + len, session->s_nr_caps); + } else { + dout("no session for mds%d, will send short reconnect\n", + mds); + } + + down_read(&mdsc->snap_rwsem); + +retry: + /* build reply */ + reply = ceph_msg_new(CEPH_MSG_CLIENT_RECONNECT, len, 0, 0, NULL); + if (IS_ERR(reply)) { + err = PTR_ERR(reply); + pr_err("send_mds_reconnect ENOMEM on %d for mds%d\n", + len, mds); + goto out; + } + p = reply->front.iov_base; + end = p + len; + + if (!session) { + ceph_encode_8(&p, 1); /* session was closed */ + ceph_encode_32(&p, 0); + goto send; + } + dout("session %p state %s\n", session, + session_state_name(session->s_state)); + + /* traverse this session's caps */ + ceph_encode_8(&p, 0); + pnum_caps = p; + ceph_encode_32(&p, session->s_nr_caps); + num_caps = 0; + + iter_args.pp = &p; + iter_args.end = end; + iter_args.num_caps = &num_caps; + err = iterate_session_caps(session, encode_caps_cb, &iter_args); + if (err == -ENOSPC) + goto needmore; + if (err < 0) + goto out; + *pnum_caps = cpu_to_le32(num_caps); + + /* + * snaprealms. we provide mds with the ino, seq (version), and + * parent for all of our realms. If the mds has any newer info, + * it will tell us. + */ + next_snap_ino = 0; + /* save some space for the snaprealm count */ + pnum_realms = p; + ceph_decode_need(&p, end, sizeof(*pnum_realms), needmore); + p += sizeof(*pnum_realms); + num_realms = 0; + while (1) { + struct ceph_snap_realm *realm; + struct ceph_mds_snaprealm_reconnect *sr_rec; + got = radix_tree_gang_lookup(&mdsc->snap_realms, + (void **)&realm, next_snap_ino, 1); + if (!got) + break; + + dout(" adding snap realm %llx seq %lld parent %llx\n", + realm->ino, realm->seq, realm->parent_ino); + ceph_decode_need(&p, end, sizeof(*sr_rec), needmore); + sr_rec = p; + sr_rec->ino = cpu_to_le64(realm->ino); + sr_rec->seq = cpu_to_le64(realm->seq); + sr_rec->parent = cpu_to_le64(realm->parent_ino); + p += sizeof(*sr_rec); + num_realms++; + next_snap_ino = realm->ino + 1; + } + *pnum_realms = cpu_to_le32(num_realms); + +send: + reply->front.iov_len = p - reply->front.iov_base; + reply->hdr.front_len = cpu_to_le32(reply->front.iov_len); + dout("final len was %u (guessed %d)\n", + (unsigned)reply->front.iov_len, len); + ceph_con_send(&session->s_con, reply); + + if (session) { + session->s_state = CEPH_MDS_SESSION_OPEN; + __wake_requests(mdsc, &session->s_waiting); + } + +out: + up_read(&mdsc->snap_rwsem); + if (session) { + mutex_unlock(&session->s_mutex); + ceph_put_mds_session(session); + } + mutex_lock(&mdsc->mutex); + return; + +needmore: + /* + * we need a larger buffer. this doesn't very accurately + * factor in snap realms, but it's safe. + */ + num_caps += num_realms; + newlen = len * ((100 * (session->s_nr_caps+3)) / (num_caps + 1)) / 100; + pr_info("i guessed %d, and did %d of %d caps, retrying with %d\n", + len, num_caps, session->s_nr_caps, newlen); + len = newlen; + ceph_msg_put(reply); + goto retry; +} + + +/* + * compare old and new mdsmaps, kicking requests + * and closing out old connections as necessary + * + * called under mdsc->mutex. + */ +static void check_new_map(struct ceph_mds_client *mdsc, + struct ceph_mdsmap *newmap, + struct ceph_mdsmap *oldmap) +{ + int i; + int oldstate, newstate; + struct ceph_mds_session *s; + + dout("check_new_map new %u old %u\n", + newmap->m_epoch, oldmap->m_epoch); + + for (i = 0; i < oldmap->m_max_mds && i < mdsc->max_sessions; i++) { + if (mdsc->sessions[i] == NULL) + continue; + s = mdsc->sessions[i]; + oldstate = ceph_mdsmap_get_state(oldmap, i); + newstate = ceph_mdsmap_get_state(newmap, i); + + dout("check_new_map mds%d state %s -> %s (session %s)\n", + i, ceph_mds_state_name(oldstate), + ceph_mds_state_name(newstate), + session_state_name(s->s_state)); + + if (memcmp(ceph_mdsmap_get_addr(oldmap, i), + ceph_mdsmap_get_addr(newmap, i), + sizeof(struct ceph_entity_addr))) { + if (s->s_state == CEPH_MDS_SESSION_OPENING) { + /* the session never opened, just close it + * out now */ + __wake_requests(mdsc, &s->s_waiting); + unregister_session(mdsc, i); + } else { + /* just close it */ + mutex_unlock(&mdsc->mutex); + mutex_lock(&s->s_mutex); + mutex_lock(&mdsc->mutex); + ceph_con_close(&s->s_con); + mutex_unlock(&s->s_mutex); + s->s_state = CEPH_MDS_SESSION_RESTARTING; + } + + /* kick any requests waiting on the recovering mds */ + kick_requests(mdsc, i, 1); + } else if (oldstate == newstate) { + continue; /* nothing new with this mds */ + } + + /* + * send reconnect? + */ + if (s->s_state == CEPH_MDS_SESSION_RESTARTING && + newstate >= CEPH_MDS_STATE_RECONNECT) + send_mds_reconnect(mdsc, i); + + /* + * kick requests on any mds that has gone active. + * + * kick requests on cur or forwarder: we may have sent + * the request to mds1, mds1 told us it forwarded it + * to mds2, but then we learn mds1 failed and can't be + * sure it successfully forwarded our request before + * it died. + */ + if (oldstate < CEPH_MDS_STATE_ACTIVE && + newstate >= CEPH_MDS_STATE_ACTIVE) { + kick_requests(mdsc, i, 1); + ceph_kick_flushing_caps(mdsc, s); + } + } +} + + + +/* + * leases + */ + +/* + * caller must hold session s_mutex, dentry->d_lock + */ +void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry) +{ + struct ceph_dentry_info *di = ceph_dentry(dentry); + + ceph_put_mds_session(di->lease_session); + di->lease_session = NULL; +} + +static void handle_lease(struct ceph_mds_client *mdsc, struct ceph_msg *msg) +{ + struct super_block *sb = mdsc->client->sb; + struct inode *inode; + struct ceph_mds_session *session; + struct ceph_inode_info *ci; + struct dentry *parent, *dentry; + struct ceph_dentry_info *di; + int mds; + struct ceph_mds_lease *h = msg->front.iov_base; + struct ceph_vino vino; + int mask; + struct qstr dname; + int release = 0; + + if (msg->hdr.src.name.type != CEPH_ENTITY_TYPE_MDS) + return; + mds = le64_to_cpu(msg->hdr.src.name.num); + dout("handle_lease from mds%d\n", mds); + + /* decode */ + if (msg->front.iov_len < sizeof(*h) + sizeof(u32)) + goto bad; + vino.ino = le64_to_cpu(h->ino); + vino.snap = CEPH_NOSNAP; + mask = le16_to_cpu(h->mask); + dname.name = (void *)h + sizeof(*h) + sizeof(u32); + dname.len = msg->front.iov_len - sizeof(*h) - sizeof(u32); + if (dname.len != get_unaligned_le32(h+1)) + goto bad; + + /* find session */ + mutex_lock(&mdsc->mutex); + session = __ceph_lookup_mds_session(mdsc, mds); + mutex_unlock(&mdsc->mutex); + if (!session) { + pr_err("handle_lease got lease but no session mds%d\n", mds); + return; + } + + mutex_lock(&session->s_mutex); + session->s_seq++; + + /* lookup inode */ + inode = ceph_find_inode(sb, vino); + dout("handle_lease '%s', mask %d, ino %llx %p\n", + ceph_lease_op_name(h->action), mask, vino.ino, inode); + if (inode == NULL) { + dout("handle_lease no inode %llx\n", vino.ino); + goto release; + } + ci = ceph_inode(inode); + + /* dentry */ + parent = d_find_alias(inode); + if (!parent) { + dout("no parent dentry on inode %p\n", inode); + WARN_ON(1); + goto release; /* hrm... */ + } + dname.hash = full_name_hash(dname.name, dname.len); + dentry = d_lookup(parent, &dname); + dput(parent); + if (!dentry) + goto release; + + spin_lock(&dentry->d_lock); + di = ceph_dentry(dentry); + switch (h->action) { + case CEPH_MDS_LEASE_REVOKE: + if (di && di->lease_session == session) { + h->seq = cpu_to_le32(di->lease_seq); + __ceph_mdsc_drop_dentry_lease(dentry); + } + release = 1; + break; + + case CEPH_MDS_LEASE_RENEW: + if (di && di->lease_session == session && + di->lease_gen == session->s_cap_gen && + di->lease_renew_from && + di->lease_renew_after == 0) { + unsigned long duration = + le32_to_cpu(h->duration_ms) * HZ / 1000; + + di->lease_seq = le32_to_cpu(h->seq); + dentry->d_time = di->lease_renew_from + duration; + di->lease_renew_after = di->lease_renew_from + + (duration >> 1); + di->lease_renew_from = 0; + } + break; + } + spin_unlock(&dentry->d_lock); + dput(dentry); + + if (!release) + goto out; + +release: + /* let's just reuse the same message */ + h->action = CEPH_MDS_LEASE_REVOKE_ACK; + ceph_msg_get(msg); + ceph_con_send(&session->s_con, msg); + +out: + iput(inode); + mutex_unlock(&session->s_mutex); + ceph_put_mds_session(session); + return; + +bad: + pr_err("corrupt lease message\n"); +} + +void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session, + struct inode *inode, + struct dentry *dentry, char action, + u32 seq) +{ + struct ceph_msg *msg; + struct ceph_mds_lease *lease; + int len = sizeof(*lease) + sizeof(u32); + int dnamelen = 0; + + dout("lease_send_msg inode %p dentry %p %s to mds%d\n", + inode, dentry, ceph_lease_op_name(action), session->s_mds); + dnamelen = dentry->d_name.len; + len += dnamelen; + + msg = ceph_msg_new(CEPH_MSG_CLIENT_LEASE, len, 0, 0, NULL); + if (IS_ERR(msg)) + return; + lease = msg->front.iov_base; + lease->action = action; + lease->mask = cpu_to_le16(CEPH_LOCK_DN); + lease->ino = cpu_to_le64(ceph_vino(inode).ino); + lease->first = lease->last = cpu_to_le64(ceph_vino(inode).snap); + lease->seq = cpu_to_le32(seq); + put_unaligned_le32(dnamelen, lease + 1); + memcpy((void *)(lease + 1) + 4, dentry->d_name.name, dnamelen); + + /* + * if this is a preemptive lease RELEASE, no need to + * flush request stream, since the actual request will + * soon follow. + */ + msg->more_to_follow = (action == CEPH_MDS_LEASE_RELEASE); + + ceph_con_send(&session->s_con, msg); +} + +/* + * Preemptively release a lease we expect to invalidate anyway. + * Pass @inode always, @dentry is optional. + */ +void ceph_mdsc_lease_release(struct ceph_mds_client *mdsc, struct inode *inode, + struct dentry *dentry, int mask) +{ + struct ceph_dentry_info *di; + struct ceph_mds_session *session; + u32 seq; + + BUG_ON(inode == NULL); + BUG_ON(dentry == NULL); + BUG_ON(mask != CEPH_LOCK_DN); + + /* is dentry lease valid? */ + spin_lock(&dentry->d_lock); + di = ceph_dentry(dentry); + if (!di || !di->lease_session || + di->lease_session->s_mds < 0 || + di->lease_gen != di->lease_session->s_cap_gen || + !time_before(jiffies, dentry->d_time)) { + dout("lease_release inode %p dentry %p -- " + "no lease on %d\n", + inode, dentry, mask); + spin_unlock(&dentry->d_lock); + return; + } + + /* we do have a lease on this dentry; note mds and seq */ + session = ceph_get_mds_session(di->lease_session); + seq = di->lease_seq; + __ceph_mdsc_drop_dentry_lease(dentry); + spin_unlock(&dentry->d_lock); + + dout("lease_release inode %p dentry %p mask %d to mds%d\n", + inode, dentry, mask, session->s_mds); + ceph_mdsc_lease_send_msg(session, inode, dentry, + CEPH_MDS_LEASE_RELEASE, seq); + ceph_put_mds_session(session); +} + +/* + * drop all leases (and dentry refs) in preparation for umount + */ +static void drop_leases(struct ceph_mds_client *mdsc) +{ + int i; + + dout("drop_leases\n"); + mutex_lock(&mdsc->mutex); + for (i = 0; i < mdsc->max_sessions; i++) { + struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i); + if (!s) + continue; + mutex_unlock(&mdsc->mutex); + mutex_lock(&s->s_mutex); + mutex_unlock(&s->s_mutex); + ceph_put_mds_session(s); + mutex_lock(&mdsc->mutex); + } + mutex_unlock(&mdsc->mutex); +} + + + +/* + * delayed work -- periodically trim expired leases, renew caps with mds + */ +static void schedule_delayed(struct ceph_mds_client *mdsc) +{ + int delay = 5; + unsigned hz = round_jiffies_relative(HZ * delay); + schedule_delayed_work(&mdsc->delayed_work, hz); +} + +static void delayed_work(struct work_struct *work) +{ + int i; + struct ceph_mds_client *mdsc = + container_of(work, struct ceph_mds_client, delayed_work.work); + int renew_interval; + int renew_caps; + + dout("mdsc delayed_work\n"); + ceph_check_delayed_caps(mdsc, 0); + + mutex_lock(&mdsc->mutex); + renew_interval = mdsc->mdsmap->m_session_timeout >> 2; + renew_caps = time_after_eq(jiffies, HZ*renew_interval + + mdsc->last_renew_caps); + if (renew_caps) + mdsc->last_renew_caps = jiffies; + + for (i = 0; i < mdsc->max_sessions; i++) { + struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i); + if (s == NULL) + continue; + if (s->s_state == CEPH_MDS_SESSION_CLOSING) { + dout("resending session close request for mds%d\n", + s->s_mds); + request_close_session(mdsc, s); + ceph_put_mds_session(s); + continue; + } + if (s->s_ttl && time_after(jiffies, s->s_ttl)) { + if (s->s_state == CEPH_MDS_SESSION_OPEN) { + s->s_state = CEPH_MDS_SESSION_HUNG; + pr_info("mds%d hung\n", s->s_mds); + } + } + if (s->s_state < CEPH_MDS_SESSION_OPEN) { + /* this mds is failed or recovering, just wait */ + ceph_put_mds_session(s); + continue; + } + mutex_unlock(&mdsc->mutex); + + mutex_lock(&s->s_mutex); + if (renew_caps) + send_renew_caps(mdsc, s); + else + ceph_con_keepalive(&s->s_con); + add_cap_releases(mdsc, s, -1); + send_cap_releases(mdsc, s); + mutex_unlock(&s->s_mutex); + ceph_put_mds_session(s); + + mutex_lock(&mdsc->mutex); + } + mutex_unlock(&mdsc->mutex); + + schedule_delayed(mdsc); +} + + +void ceph_mdsc_init(struct ceph_mds_client *mdsc, struct ceph_client *client) +{ + mdsc->client = client; + mutex_init(&mdsc->mutex); + mdsc->mdsmap = kzalloc(sizeof(*mdsc->mdsmap), GFP_NOFS); + init_completion(&mdsc->safe_umount_waiters); + init_completion(&mdsc->session_close_waiters); + INIT_LIST_HEAD(&mdsc->waiting_for_map); + mdsc->sessions = NULL; + mdsc->max_sessions = 0; + mdsc->stopping = 0; + init_rwsem(&mdsc->snap_rwsem); + INIT_RADIX_TREE(&mdsc->snap_realms, GFP_NOFS); + INIT_LIST_HEAD(&mdsc->snap_empty); + spin_lock_init(&mdsc->snap_empty_lock); + mdsc->last_tid = 0; + INIT_RADIX_TREE(&mdsc->request_tree, GFP_NOFS); + INIT_DELAYED_WORK(&mdsc->delayed_work, delayed_work); + mdsc->last_renew_caps = jiffies; + INIT_LIST_HEAD(&mdsc->cap_delay_list); + spin_lock_init(&mdsc->cap_delay_lock); + INIT_LIST_HEAD(&mdsc->snap_flush_list); + spin_lock_init(&mdsc->snap_flush_lock); + mdsc->cap_flush_seq = 0; + INIT_LIST_HEAD(&mdsc->cap_dirty); + mdsc->num_cap_flushing = 0; + spin_lock_init(&mdsc->cap_dirty_lock); + init_waitqueue_head(&mdsc->cap_flushing_wq); + spin_lock_init(&mdsc->dentry_lru_lock); + INIT_LIST_HEAD(&mdsc->dentry_lru); +} + +/* + * Wait for safe replies on open mds requests. If we time out, drop + * all requests from the tree to avoid dangling dentry refs. + */ +static void wait_requests(struct ceph_mds_client *mdsc) +{ + struct ceph_mds_request *req; + struct ceph_client *client = mdsc->client; + + mutex_lock(&mdsc->mutex); + if (__get_oldest_tid(mdsc)) { + mutex_unlock(&mdsc->mutex); + dout("wait_requests waiting for requests\n"); + wait_for_completion_timeout(&mdsc->safe_umount_waiters, + client->mount_args.mount_timeout * HZ); + mutex_lock(&mdsc->mutex); + + /* tear down remaining requests */ + while (radix_tree_gang_lookup(&mdsc->request_tree, + (void **)&req, 0, 1)) { + dout("wait_requests timed out on tid %llu\n", + req->r_tid); + radix_tree_delete(&mdsc->request_tree, req->r_tid); + ceph_mdsc_put_request(req); + } + } + mutex_unlock(&mdsc->mutex); + dout("wait_requests done\n"); +} + +/* + * called before mount is ro, and before dentries are torn down. + * (hmm, does this still race with new lookups?) + */ +void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc) +{ + dout("pre_umount\n"); + mdsc->stopping = 1; + + drop_leases(mdsc); + ceph_check_delayed_caps(mdsc, 1); + wait_requests(mdsc); +} + +/* + * wait for all write mds requests to flush. + */ +static void wait_unsafe_requests(struct ceph_mds_client *mdsc, u64 want_tid) +{ + struct ceph_mds_request *req; + u64 next_tid = 0; + int got; + + mutex_lock(&mdsc->mutex); + dout("wait_unsafe_requests want %lld\n", want_tid); + while (1) { + got = radix_tree_gang_lookup(&mdsc->request_tree, (void **)&req, + next_tid, 1); + if (!got) + break; + if (req->r_tid > want_tid) + break; + + next_tid = req->r_tid + 1; + if ((req->r_op & CEPH_MDS_OP_WRITE) == 0) + continue; /* not a write op */ + + ceph_mdsc_get_request(req); + mutex_unlock(&mdsc->mutex); + dout("wait_unsafe_requests wait on %llu (want %llu)\n", + req->r_tid, want_tid); + wait_for_completion(&req->r_safe_completion); + mutex_lock(&mdsc->mutex); + ceph_mdsc_put_request(req); + } + mutex_unlock(&mdsc->mutex); + dout("wait_unsafe_requests done\n"); +} + +void ceph_mdsc_sync(struct ceph_mds_client *mdsc) +{ + u64 want_tid, want_flush; + + dout("sync\n"); + mutex_lock(&mdsc->mutex); + want_tid = mdsc->last_tid; + want_flush = mdsc->cap_flush_seq; + mutex_unlock(&mdsc->mutex); + dout("sync want tid %lld flush_seq %lld\n", want_tid, want_flush); + + ceph_check_delayed_caps(mdsc, 1); + + wait_unsafe_requests(mdsc, want_tid); + wait_event(mdsc->cap_flushing_wq, check_cap_flush(mdsc, want_flush)); +} + + +/* + * called after sb is ro. + */ +void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc) +{ + struct ceph_mds_session *session; + int i; + int n; + struct ceph_client *client = mdsc->client; + unsigned long started, timeout = client->mount_args.mount_timeout * HZ; + + dout("close_sessions\n"); + + mutex_lock(&mdsc->mutex); + + /* close sessions */ + started = jiffies; + while (time_before(jiffies, started + timeout)) { + dout("closing sessions\n"); + n = 0; + for (i = 0; i < mdsc->max_sessions; i++) { + session = __ceph_lookup_mds_session(mdsc, i); + if (!session) + continue; + mutex_unlock(&mdsc->mutex); + mutex_lock(&session->s_mutex); + __close_session(mdsc, session); + mutex_unlock(&session->s_mutex); + ceph_put_mds_session(session); + mutex_lock(&mdsc->mutex); + n++; + } + if (n == 0) + break; + + if (client->mount_state == CEPH_MOUNT_SHUTDOWN) + break; + + dout("waiting for sessions to close\n"); + mutex_unlock(&mdsc->mutex); + wait_for_completion_timeout(&mdsc->session_close_waiters, + timeout); + mutex_lock(&mdsc->mutex); + } + + /* tear down remaining sessions */ + for (i = 0; i < mdsc->max_sessions; i++) { + if (mdsc->sessions[i]) { + session = get_session(mdsc->sessions[i]); + unregister_session(mdsc, i); + mutex_unlock(&mdsc->mutex); + mutex_lock(&session->s_mutex); + remove_session_caps(session); + mutex_unlock(&session->s_mutex); + ceph_put_mds_session(session); + mutex_lock(&mdsc->mutex); + } + } + + WARN_ON(!list_empty(&mdsc->cap_delay_list)); + + mutex_unlock(&mdsc->mutex); + + ceph_cleanup_empty_realms(mdsc); + + cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */ + + dout("stopped\n"); +} + +void ceph_mdsc_stop(struct ceph_mds_client *mdsc) +{ + dout("stop\n"); + cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */ + if (mdsc->mdsmap) + ceph_mdsmap_destroy(mdsc->mdsmap); + kfree(mdsc->sessions); +} + + +/* + * handle mds map update. + */ +void ceph_mdsc_handle_map(struct ceph_mds_client *mdsc, struct ceph_msg *msg) +{ + u32 epoch; + u32 maplen; + void *p = msg->front.iov_base; + void *end = p + msg->front.iov_len; + struct ceph_mdsmap *newmap, *oldmap; + struct ceph_fsid fsid; + int err = -EINVAL; + + ceph_decode_need(&p, end, sizeof(fsid)+2*sizeof(u32), bad); + ceph_decode_copy(&p, &fsid, sizeof(fsid)); + if (ceph_fsid_compare(&fsid, &mdsc->client->monc.monmap->fsid)) { + pr_err("got mdsmap with wrong fsid\n"); + return; + } + ceph_decode_32(&p, epoch); + ceph_decode_32(&p, maplen); + dout("handle_map epoch %u len %d\n", epoch, (int)maplen); + + /* do we need it? */ + ceph_monc_got_mdsmap(&mdsc->client->monc, epoch); + mutex_lock(&mdsc->mutex); + if (mdsc->mdsmap && epoch <= mdsc->mdsmap->m_epoch) { + dout("handle_map epoch %u <= our %u\n", + epoch, mdsc->mdsmap->m_epoch); + mutex_unlock(&mdsc->mutex); + return; + } + + newmap = ceph_mdsmap_decode(&p, end); + if (IS_ERR(newmap)) { + err = PTR_ERR(newmap); + goto bad_unlock; + } + + /* swap into place */ + if (mdsc->mdsmap) { + oldmap = mdsc->mdsmap; + mdsc->mdsmap = newmap; + check_new_map(mdsc, newmap, oldmap); + ceph_mdsmap_destroy(oldmap); + } else { + mdsc->mdsmap = newmap; /* first mds map */ + } + mdsc->client->sb->s_maxbytes = mdsc->mdsmap->m_max_file_size; + + __wake_requests(mdsc, &mdsc->waiting_for_map); + + mutex_unlock(&mdsc->mutex); + schedule_delayed(mdsc); + return; + +bad_unlock: + mutex_unlock(&mdsc->mutex); +bad: + pr_err("error decoding mdsmap %d\n", err); + return; +} + +static struct ceph_connection *con_get(struct ceph_connection *con) +{ + struct ceph_mds_session *s = con->private; + + if (get_session(s)) { + dout("mdsc con_get %p %d -> %d\n", s, + atomic_read(&s->s_ref) - 1, atomic_read(&s->s_ref)); + return con; + } + dout("mdsc con_get %p FAIL\n", s); + return NULL; +} + +static void con_put(struct ceph_connection *con) +{ + struct ceph_mds_session *s = con->private; + + dout("mdsc con_put %p %d -> %d\n", s, atomic_read(&s->s_ref), + atomic_read(&s->s_ref) - 1); + ceph_put_mds_session(s); +} + +/* + * if the client is unresponsive for long enough, the mds will kill + * the session entirely. + */ +static void peer_reset(struct ceph_connection *con) +{ + struct ceph_mds_session *s = con->private; + + pr_err("mds%d gave us the boot. IMPLEMENT RECONNECT.\n", + s->s_mds); +} + +static void dispatch(struct ceph_connection *con, struct ceph_msg *msg) +{ + struct ceph_mds_session *s = con->private; + struct ceph_mds_client *mdsc = s->s_mdsc; + int type = le16_to_cpu(msg->hdr.type); + + switch (type) { + case CEPH_MSG_MDS_MAP: + ceph_mdsc_handle_map(mdsc, msg); + break; + case CEPH_MSG_CLIENT_SESSION: + handle_session(s, msg); + break; + case CEPH_MSG_CLIENT_REPLY: + handle_reply(s, msg); + break; + case CEPH_MSG_CLIENT_REQUEST_FORWARD: + handle_forward(mdsc, msg); + break; + case CEPH_MSG_CLIENT_CAPS: + ceph_handle_caps(s, msg); + break; + case CEPH_MSG_CLIENT_SNAP: + ceph_handle_snap(mdsc, msg); + break; + case CEPH_MSG_CLIENT_LEASE: + handle_lease(mdsc, msg); + break; + + default: + pr_err("received unknown message type %d %s\n", type, + ceph_msg_type_name(type)); + } + ceph_msg_put(msg); +} + +const static struct ceph_connection_operations mds_con_ops = { + .get = con_get, + .put = con_put, + .dispatch = dispatch, + .peer_reset = peer_reset, + .alloc_msg = ceph_alloc_msg, + .alloc_middle = ceph_alloc_middle, +}; + + + + +/* eof */ |
