From 03b5df77b4fabcbfa5996b5cdfb7d7038dec3e05 Mon Sep 17 00:00:00 2001 From: "Yan, Zheng" Date: Thu, 14 Feb 2019 15:33:35 +0800 Subject: [PATCH] mds: avoid evaluating stray dentry multiple times If we call eval_stray(delay=true) for a dentry, the dentry will get evaluated twice. We can avoid the extra evaluation by directly put dentry into the delayed_eval_stray list. Signed-off-by: "Yan, Zheng" --- src/mds/MDCache.cc | 10 ++++++---- src/mds/MDCache.h | 1 - src/mds/StrayManager.cc | 41 ++++++++++++++++++++++------------------- src/mds/StrayManager.h | 20 +++++++++----------- 4 files changed, 37 insertions(+), 35 deletions(-) diff --git a/src/mds/MDCache.cc b/src/mds/MDCache.cc index aa46c17cc59..7f410d89b4b 100644 --- a/src/mds/MDCache.cc +++ b/src/mds/MDCache.cc @@ -7510,7 +7510,7 @@ void MDCache::dentry_remove_replica(CDentry *dn, mds_rank_t from, setlock); // Replicated strays might now be elegible for purge - CDentry::linkage_t *dnl = dn->get_linkage(); + CDentry::linkage_t *dnl = dn->get_projected_linkage(); if (dnl->is_primary()) { maybe_eval_stray(dnl->get_inode()); } @@ -12900,9 +12900,11 @@ void MDCache::maybe_eval_stray(CInode *in, bool delay) { return; } - if (dn->get_projected_linkage()->is_primary() && - dn->get_dir()->get_inode()->is_stray()) { - stray_manager.eval_stray(dn, delay); + if (dn->get_dir()->get_inode()->is_stray()) { + if (delay) + stray_manager.queue_delayed(dn); + else + stray_manager.eval_stray(dn); } } diff --git a/src/mds/MDCache.h b/src/mds/MDCache.h index dbf8a0073eb..5e666857b65 100644 --- a/src/mds/MDCache.h +++ b/src/mds/MDCache.h @@ -1078,7 +1078,6 @@ protected: void scan_stray_dir(dirfrag_t next=dirfrag_t()); StrayManager stray_manager; friend struct C_MDC_RetryScanStray; - friend class C_IO_MDC_FetchedBacktrace; // == messages == public: diff --git a/src/mds/StrayManager.cc b/src/mds/StrayManager.cc index 786ca51ab50..ffbbc7ded8c 100644 --- a/src/mds/StrayManager.cc +++ b/src/mds/StrayManager.cc @@ -338,15 +338,28 @@ void StrayManager::_enqueue(CDentry *dn, bool trunc) } } +void StrayManager::queue_delayed(CDentry *dn) +{ + if (!started) + return; + + if (dn->state_test(CDentry::STATE_EVALUATINGSTRAY)) + return; + + if (!dn->item_stray.is_on_list()) { + delayed_eval_stray.push_back(&dn->item_stray); + num_strays_delayed++; + logger->set(l_mdc_num_strays_delayed, num_strays_delayed); + } +} void StrayManager::advance_delayed() { if (!started) return; - for (elist::iterator p = delayed_eval_stray.begin(); !p.end(); ) { - CDentry *dn = *p; - ++p; + while (!delayed_eval_stray.empty()) { + CDentry *dn = delayed_eval_stray.front(); dn->item_stray.remove_myself(); num_strays_delayed--; @@ -408,7 +421,7 @@ struct C_MDC_EvalStray : public StrayManagerContext { } }; -bool StrayManager::_eval_stray(CDentry *dn, bool delay) +bool StrayManager::_eval_stray(CDentry *dn) { dout(10) << "eval_stray " << *dn << dendl; CDentry::linkage_t *dnl = dn->get_projected_linkage(); @@ -427,17 +440,13 @@ bool StrayManager::_eval_stray(CDentry *dn, bool delay) // call eval_stray() after purge() ceph_assert(!dn->state_test(CDentry::STATE_PURGING)); - if (!dn->is_auth()) { + if (!dn->is_auth()) return false; - } if (!started) - delay = true; + return false; if (dn->item_stray.is_on_list()) { - if (delay) - return false; - dn->item_stray.remove_myself(); num_strays_delayed--; logger->set(l_mdc_num_strays_delayed, num_strays_delayed); @@ -501,14 +510,8 @@ bool StrayManager::_eval_stray(CDentry *dn, bool delay) dout(20) << " too many dn refs" << dendl; return false; } - if (delay) { - if (!dn->item_stray.is_on_list()) { - delayed_eval_stray.push_back(&dn->item_stray); - num_strays_delayed++; - logger->set(l_mdc_num_strays_delayed, num_strays_delayed); - } // don't purge multiversion inode with snap data - } else if (in->snaprealm && in->snaprealm->has_past_parents() && + if (in->snaprealm && in->snaprealm->has_past_parents() && !in->old_inodes.empty()) { // A file with snapshots: we will truncate the HEAD revision // but leave the metadata intact. @@ -546,14 +549,14 @@ void StrayManager::activate() purge_queue.activate(); } -bool StrayManager::eval_stray(CDentry *dn, bool delay) +bool StrayManager::eval_stray(CDentry *dn) { // avoid nested eval_stray if (dn->state_test(CDentry::STATE_EVALUATINGSTRAY)) return false; dn->state_set(CDentry::STATE_EVALUATINGSTRAY); - bool ret = _eval_stray(dn, delay); + bool ret = _eval_stray(dn); dn->state_clear(CDentry::STATE_EVALUATINGSTRAY); return ret; } diff --git a/src/mds/StrayManager.h b/src/mds/StrayManager.h index c0842de878e..53e42110312 100644 --- a/src/mds/StrayManager.h +++ b/src/mds/StrayManager.h @@ -117,7 +117,7 @@ class StrayManager * @returns true if the dentry will be purged (caller should never * take more refs after this happens), else false. */ - bool _eval_stray(CDentry *dn, bool delay=false); + bool _eval_stray(CDentry *dn); void _eval_stray_remote(CDentry *stray_dn, CDentry *remote_dn); @@ -127,21 +127,19 @@ class StrayManager void set_logger(PerfCounters *l) {logger = l;} void activate(); - bool eval_stray(CDentry *dn, bool delay=false); + bool eval_stray(CDentry *dn); void set_num_strays(uint64_t num); uint64_t get_num_strays() const { return num_strays; } /** - * Where eval_stray was previously invoked with delay=true, call - * eval_stray again for any dentries that were put on the - * delayed_eval_stray list as a result of the original call. - * - * Used so that various places can call eval_stray(delay=true) during - * an operation to identify dentries of interest, and then call - * this function later during trim in order to do the final - * evaluation (and resulting actions) while not in the middle of another - * metadata operation. + * Queue dentry for later evaluation. (evaluate it while not in the + * middle of another metadata operation) + */ + void queue_delayed(CDentry *dn); + + /** + * Eval strays in the delayed_eval_stray list */ void advance_delayed(); -- 2.39.5