From c3b36723defae32b0a3ef1ac37b58ec57d356b65 Mon Sep 17 00:00:00 2001 From: Xiubo Li Date: Fri, 23 Dec 2022 12:50:31 +0800 Subject: [PATCH] mds: wait reintegrate to finish when unlinking When unlinking a remote dentry while primary dentry has been just unlinked and was trying to reintegrate, which will finally be a RENAME client request to current MDS, the stray dentry. If the RENAME request is sleeping and waiting for some resources just after authpin the CInode, so the unlinking request will mark the remote dentry as UNLINKING state and then add itself to the wait list just waiting for the CInode to be authpined. Then after the RENAME request is retried later it will add to a wait list again and waiting for the UNLINKING state to be cleared. And finally the RENAME and UNLINK requests will be deadlock. This fix will block the UNLINK request if the reintegrate_stray is going on for current dentry. Fixes: https://tracker.ceph.com/issues/58340 Signed-off-by: Xiubo Li --- src/mds/CDentry.cc | 2 + src/mds/CDentry.h | 6 ++- src/mds/MDSRank.cc | 2 + src/mds/MDSRank.h | 25 ++++++++++++ src/mds/Server.cc | 84 +++++++++++++++++++++++++++++++++++++++++ src/mds/Server.h | 4 ++ src/mds/StrayManager.cc | 23 +++++++++-- 7 files changed, 140 insertions(+), 6 deletions(-) diff --git a/src/mds/CDentry.cc b/src/mds/CDentry.cc index 55f2191346f..6f20f53d144 100644 --- a/src/mds/CDentry.cc +++ b/src/mds/CDentry.cc @@ -108,6 +108,8 @@ ostream& operator<<(ostream& out, const CDentry& dn) out << " state=" << dn.get_state(); if (dn.is_new()) out << "|new"; if (dn.state_test(CDentry::STATE_BOTTOMLRU)) out << "|bottomlru"; + if (dn.state_test(CDentry::STATE_UNLINKING)) out << "|unlinking"; + if (dn.state_test(CDentry::STATE_REINTEGRATING)) out << "|reintegrating"; if (dn.get_num_ref()) { out << " |"; diff --git a/src/mds/CDentry.h b/src/mds/CDentry.h index 3f715de2f7e..0d468c6f074 100644 --- a/src/mds/CDentry.h +++ b/src/mds/CDentry.h @@ -87,6 +87,7 @@ public: static const int STATE_PURGINGPINNED = (1<<5); static const int STATE_BOTTOMLRU = (1<<6); static const int STATE_UNLINKING = (1<<7); + static const int STATE_REINTEGRATING = (1<<8); // stray dentry needs notification of releasing reference static const int STATE_STRAY = STATE_NOTIFYREF; static const int MASK_STATE_IMPORT_KEPT = STATE_BOTTOMLRU; @@ -100,8 +101,9 @@ public: static const unsigned EXPORT_NONCE = 1; - const static uint64_t WAIT_UNLINK_STATE = (1<<0); - const static uint64_t WAIT_UNLINK_FINISH = (1<<1); + const static uint64_t WAIT_UNLINK_STATE = (1<<0); + const static uint64_t WAIT_UNLINK_FINISH = (1<<1); + const static uint64_t WAIT_REINTEGRATE_FINISH = (1<<2); uint32_t replica_unlinking_ref = 0; CDentry(std::string_view n, __u32 h, diff --git a/src/mds/MDSRank.cc b/src/mds/MDSRank.cc index 6b8b24d808e..6ebbd880c64 100644 --- a/src/mds/MDSRank.cc +++ b/src/mds/MDSRank.cc @@ -1178,6 +1178,7 @@ bool MDSRank::is_valid_message(const cref_t &m) { type == CEPH_MSG_CLIENT_RECONNECT || type == CEPH_MSG_CLIENT_RECLAIM || type == CEPH_MSG_CLIENT_REQUEST || + type == CEPH_MSG_CLIENT_REPLY || type == MSG_MDS_PEER_REQUEST || type == MSG_MDS_HEARTBEAT || type == MSG_MDS_TABLE_REQUEST || @@ -1231,6 +1232,7 @@ void MDSRank::handle_message(const cref_t &m) ALLOW_MESSAGES_FROM(CEPH_ENTITY_TYPE_CLIENT); // fall-thru case CEPH_MSG_CLIENT_REQUEST: + case CEPH_MSG_CLIENT_REPLY: server->dispatch(m); break; case MSG_MDS_PEER_REQUEST: diff --git a/src/mds/MDSRank.h b/src/mds/MDSRank.h index c00af5fe084..3e353cf962b 100644 --- a/src/mds/MDSRank.h +++ b/src/mds/MDSRank.h @@ -151,6 +151,29 @@ class Finisher; class ScrubStack; class C_ExecAndReply; +struct MDSMetaRequest { +private: + int _op; + CDentry *_dentry; + ceph_tid_t _tid; +public: + explicit MDSMetaRequest(int op, CDentry *dn, ceph_tid_t tid) : + _op(op), _dentry(dn), _tid(tid) { + if (_dentry) { + _dentry->get(CDentry::PIN_PURGING); + } + } + ~MDSMetaRequest() { + if (_dentry) { + _dentry->put(CDentry::PIN_PURGING); + } + } + + CDentry *get_dentry() { return _dentry; } + int get_op() { return _op; } + ceph_tid_t get_tid() { return _tid; } +}; + /** * The public part of this class's interface is what's exposed to all * the various subsystems (server, mdcache, etc), such as pointers @@ -416,6 +439,8 @@ class MDSRank { PerfCounters *logger = nullptr, *mlogger = nullptr; OpTracker op_tracker; + std::map internal_client_requests; + // The last different state I held before current MDSMap::DaemonState last_state = MDSMap::STATE_BOOT; // The state assigned to me by the MDSMap diff --git a/src/mds/Server.cc b/src/mds/Server.cc index d7ae5836c9a..c43e995928d 100644 --- a/src/mds/Server.cc +++ b/src/mds/Server.cc @@ -31,6 +31,7 @@ #include "Mutation.h" #include "MetricsHandler.h" #include "cephfs_features.h" +#include "MDSContext.h" #include "msg/Messenger.h" @@ -360,6 +361,9 @@ void Server::dispatch(const cref_t &m) case CEPH_MSG_CLIENT_REQUEST: handle_client_request(ref_cast(m)); return; + case CEPH_MSG_CLIENT_REPLY: + handle_client_reply(ref_cast(m)); + return; case CEPH_MSG_CLIENT_RECLAIM: handle_client_reclaim(ref_cast(m)); return; @@ -2296,6 +2300,10 @@ void Server::reply_client_request(MDRequestRef& mdr, const ref_t & mds->send_message_client(reply, session); } + if (client_inst.name.is_mds() && reply->get_op() == CEPH_MDS_OP_RENAME) { + mds->send_message(reply, mdr->client_request->get_connection()); + } + if (req->is_queued_for_replay() && (mdr->has_completed || reply->get_result() < 0)) { if (reply->get_result() < 0) { @@ -2528,6 +2536,38 @@ void Server::handle_client_request(const cref_t &req) return; } +void Server::handle_client_reply(const cref_t &reply) +{ + dout(4) << "handle_client_reply " << *reply << dendl; + + ceph_assert(reply->is_safe()); + ceph_tid_t tid = reply->get_tid(); + + if (mds->internal_client_requests.count(tid) == 0) { + dout(1) << " no pending request on tid " << tid << dendl; + return; + } + + auto &req = mds->internal_client_requests.at(tid); + CDentry *dn = req.get_dentry(); + + switch (reply->get_op()) { + case CEPH_MDS_OP_RENAME: + if (dn) { + dn->state_clear(CDentry::STATE_REINTEGRATING); + + MDSContext::vec finished; + dn->take_waiting(CDentry::WAIT_REINTEGRATE_FINISH, finished); + mds->queue_waiters(finished); + } + break; + default: + dout(5) << " unknown client op " << reply->get_op() << dendl; + } + + mds->internal_client_requests.erase(tid); +} + void Server::handle_osd_map() { /* Note that we check the OSDMAP_FULL flag directly rather than @@ -6844,6 +6884,45 @@ void Server::wait_for_pending_unlink(CDentry *dn, MDRequestRef& mdr) dn->add_waiter(CDentry::WAIT_UNLINK_FINISH, new C_WaitUnlinkToFinish(mdcache, dn, fin)); } +struct C_WaitReintegrateToFinish : public MDSContext { +protected: + MDCache *mdcache; + CDentry *dn; + MDSContext *fin; + + MDSRank *get_mds() override + { + ceph_assert(mdcache != NULL); + return mdcache->mds; + } + +public: + C_WaitReintegrateToFinish(MDCache *m, CDentry *d, MDSContext *f) : + mdcache(m), dn(d), fin(f) {} + void finish(int r) override { + fin->complete(r); + dn->put(CDentry::PIN_PURGING); + } +}; + +bool Server::is_reintegrate_pending(CDentry *dn) +{ + CDentry::linkage_t *dnl = dn->get_projected_linkage(); + if (!dnl->is_null() && dn->state_test(CDentry::STATE_REINTEGRATING)) { + return true; + } + return false; +} + +void Server::wait_for_pending_reintegrate(CDentry *dn, MDRequestRef& mdr) +{ + dout(20) << __func__ << " dn " << *dn << dendl; + mds->locker->drop_locks(mdr.get()); + auto fin = new C_MDS_RetryRequest(mdcache, mdr); + dn->get(CDentry::PIN_PURGING); + dn->add_waiter(CDentry::WAIT_REINTEGRATE_FINISH, new C_WaitReintegrateToFinish(mdcache, dn, fin)); +} + // MKNOD class C_MDS_mknod_finish : public ServerLogContext { @@ -7914,6 +7993,11 @@ void Server::handle_client_unlink(MDRequestRef& mdr) if (!dn) return; + if (is_reintegrate_pending(dn)) { + wait_for_pending_reintegrate(dn, mdr); + return; + } + // notify replica MDSes the dentry is under unlink if (!dn->state_test(CDentry::STATE_UNLINKING)) { dn->state_set(CDentry::STATE_UNLINKING); diff --git a/src/mds/Server.h b/src/mds/Server.h index ba38ccb2db4..1d5518fdf31 100644 --- a/src/mds/Server.h +++ b/src/mds/Server.h @@ -159,6 +159,7 @@ public: // -- requests -- void handle_client_request(const cref_t &m); + void handle_client_reply(const cref_t &m); void journal_and_reply(MDRequestRef& mdr, CInode *tracei, CDentry *tracedn, LogEvent *le, MDSLogContextBase *fin); @@ -238,6 +239,9 @@ public: bool is_unlink_pending(CDentry *dn); void wait_for_pending_unlink(CDentry *dn, MDRequestRef& mdr); + bool is_reintegrate_pending(CDentry *dn); + void wait_for_pending_reintegrate(CDentry *dn, MDRequestRef& mdr); + // open void handle_client_open(MDRequestRef& mdr); void handle_client_openc(MDRequestRef& mdr); // O_CREAT variant. diff --git a/src/mds/StrayManager.cc b/src/mds/StrayManager.cc index f57c5fe509f..d5827d48002 100644 --- a/src/mds/StrayManager.cc +++ b/src/mds/StrayManager.cc @@ -687,19 +687,27 @@ void StrayManager::reintegrate_stray(CDentry *straydn, CDentry *rdn) dout(10) << __func__ << " " << *straydn << " to " << *rdn << dendl; logger->inc(l_mdc_strays_reintegrated); - + // rename it to remote linkage . filepath src(straydn->get_name(), straydn->get_dir()->ino()); filepath dst(rdn->get_name(), rdn->get_dir()->ino()); + ceph_tid_t tid = mds->issue_tid(); + auto req = make_message(CEPH_MDS_OP_RENAME); req->set_filepath(dst); req->set_filepath2(src); - req->set_tid(mds->issue_tid()); + req->set_tid(tid); + + rdn->state_set(CDentry::STATE_REINTEGRATING); + mds->internal_client_requests.emplace(std::piecewise_construct, + std::make_tuple(tid), + std::make_tuple(CEPH_MDS_OP_RENAME, + rdn, tid)); mds->send_message_mds(req, rdn->authority().first); } - + void StrayManager::migrate_stray(CDentry *dn, mds_rank_t to) { dout(10) << __func__ << " " << *dn << " to mds." << to << dendl; @@ -713,10 +721,17 @@ void StrayManager::migrate_stray(CDentry *dn, mds_rank_t to) filepath src(dn->get_name(), dirino); filepath dst(dn->get_name(), MDS_INO_STRAY(to, MDS_INO_STRAY_INDEX(dirino))); + ceph_tid_t tid = mds->issue_tid(); + auto req = make_message(CEPH_MDS_OP_RENAME); req->set_filepath(dst); req->set_filepath2(src); - req->set_tid(mds->issue_tid()); + req->set_tid(tid); + + mds->internal_client_requests.emplace(std::piecewise_construct, + std::make_tuple(tid), + std::make_tuple(CEPH_MDS_OP_RENAME, + nullptr, tid)); mds->send_message_mds(req, to); } -- 2.39.5