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+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software
+ * Foundation. See file COPYING.
+ *
+ */
+
+
+#ifndef CEPH_SCATTERLOCK_H
+#define CEPH_SCATTERLOCK_H
+
+#include "SimpleLock.h"
+
+#include "MDSContext.h"
+
+class ScatterLock : public SimpleLock {
+
+ struct more_bits_t {
+ xlist<ScatterLock*>::item item_updated;
+ utime_t update_stamp;
+
+ explicit more_bits_t(ScatterLock *lock) :
+ item_updated(lock)
+ {}
+ };
+
+ mutable std::unique_ptr<more_bits_t> _more;
+
+ more_bits_t *more() {
+ if (!_more)
+ _more.reset(new more_bits_t(this));
+ return _more.get();
+ }
+
+ enum {
+ SCATTER_WANTED = 1 << 8,
+ UNSCATTER_WANTED = 1 << 9,
+ DIRTY = 1 << 10,
+ FLUSHING = 1 << 11,
+ FLUSHED = 1 << 12,
+ };
+
+public:
+ ScatterLock(MDSCacheObject *o, LockType *lt) :
+ SimpleLock(o, lt) {}
+ ~ScatterLock() override {
+ ceph_assert(!_more);
+ }
+
+ bool is_scatterlock() const override {
+ return true;
+ }
+
+ bool is_sync_and_unlocked() const {
+ return
+ SimpleLock::is_sync_and_unlocked() &&
+ !is_dirty() &&
+ !is_flushing();
+ }
+
+ bool can_scatter_pin(client_t loner) {
+ /*
+ LOCK : NOT okay because it can MIX and force replicas to journal something
+ TSYN : also not okay for same reason
+ EXCL : also not okay
+
+ MIX : okay, replica can stall before sending AC_SYNCACK
+ SYNC : okay, replica can stall before sending AC_MIXACK or AC_LOCKACK
+ */
+ return
+ get_state() == LOCK_SYNC ||
+ get_state() == LOCK_MIX;
+ }
+
+ void set_xlock_snap_sync(MDSContext *c)
+ {
+ ceph_assert(get_type() == CEPH_LOCK_IFILE);
+ ceph_assert(state == LOCK_XLOCK || state == LOCK_XLOCKDONE);
+ state = LOCK_XLOCKSNAP;
+ add_waiter(WAIT_STABLE, c);
+ }
+
+ xlist<ScatterLock*>::item *get_updated_item() { return &more()->item_updated; }
+
+ utime_t get_update_stamp() {
+ return _more ? _more->update_stamp : utime_t();
+ }
+
+ void set_update_stamp(utime_t t) { more()->update_stamp = t; }
+
+ void set_scatter_wanted() {
+ state_flags |= SCATTER_WANTED;
+ }
+ void set_unscatter_wanted() {
+ state_flags |= UNSCATTER_WANTED;
+ }
+ void clear_scatter_wanted() {
+ state_flags &= ~SCATTER_WANTED;
+ }
+ void clear_unscatter_wanted() {
+ state_flags &= ~UNSCATTER_WANTED;
+ }
+ bool get_scatter_wanted() const {
+ return state_flags & SCATTER_WANTED;
+ }
+ bool get_unscatter_wanted() const {
+ return state_flags & UNSCATTER_WANTED;
+ }
+
+ bool is_dirty() const override {
+ return state_flags & DIRTY;
+ }
+ bool is_flushing() const override {
+ return state_flags & FLUSHING;
+ }
+ bool is_flushed() const override {
+ return state_flags & FLUSHED;
+ }
+ bool is_dirty_or_flushing() const {
+ return is_dirty() || is_flushing();
+ }
+
+ void mark_dirty() {
+ if (!is_dirty()) {
+ if (!is_flushing())
+ parent->get(MDSCacheObject::PIN_DIRTYSCATTERED);
+ set_dirty();
+ }
+ }
+ void start_flush() {
+ if (is_dirty()) {
+ set_flushing();
+ clear_dirty();
+ }
+ }
+ void finish_flush() {
+ if (is_flushing()) {
+ clear_flushing();
+ set_flushed();
+ if (!is_dirty()) {
+ parent->put(MDSCacheObject::PIN_DIRTYSCATTERED);
+ parent->clear_dirty_scattered(get_type());
+ }
+ }
+ }
+ void clear_flushed() override {
+ state_flags &= ~FLUSHED;
+ }
+ void remove_dirty() {
+ start_flush();
+ finish_flush();
+ clear_flushed();
+ }
+
+ void infer_state_from_strong_rejoin(int rstate, bool locktoo) {
+ if (rstate == LOCK_MIX ||
+ rstate == LOCK_MIX_LOCK || // replica still has wrlocks?
+ rstate == LOCK_MIX_SYNC)
+ state = LOCK_MIX;
+ else if (locktoo && rstate == LOCK_LOCK)
+ state = LOCK_LOCK;
+ }
+
+ void encode_state_for_rejoin(bufferlist& bl, int rep) {
+ __s16 s = get_replica_state();
+ if (is_gathering(rep)) {
+ // the recovering mds may hold rejoined wrlocks
+ if (state == LOCK_MIX_SYNC)
+ s = LOCK_MIX_SYNC;
+ else
+ s = LOCK_MIX_LOCK;
+ }
+
+ // If there is a recovering mds who replcated an object when it failed
+ // and scatterlock in the object was in MIX state, It's possible that
+ // the recovering mds needs to take wrlock on the scatterlock when it
+ // replays unsafe requests. So this mds should delay taking rdlock on
+ // the scatterlock until the recovering mds finishes replaying unsafe.
+ // Otherwise unsafe requests may get replayed after current request.
+ //
+ // For example:
+ // The recovering mds is auth mds of a dirfrag, this mds is auth mds
+ // of corresponding inode. when 'rm -rf' the direcotry, this mds should
+ // delay the rmdir request until the recovering mds has replayed unlink
+ // requests.
+ if (s == LOCK_MIX || s == LOCK_MIX_LOCK || s == LOCK_MIX_SYNC)
+ mark_need_recover();
+
+ using ceph::encode;
+ encode(s, bl);
+ }
+
+ void decode_state_rejoin(bufferlist::const_iterator& p, MDSContext::vec& waiters, bool survivor) {
+ SimpleLock::decode_state_rejoin(p, waiters, survivor);
+ if (is_flushing()) {
+ set_dirty();
+ clear_flushing();
+ }
+ }
+
+ bool remove_replica(int from, bool rejoin) {
+ if (rejoin &&
+ (state == LOCK_MIX ||
+ state == LOCK_MIX_SYNC ||
+ state == LOCK_MIX_LOCK2 ||
+ state == LOCK_MIX_TSYN ||
+ state == LOCK_MIX_EXCL))
+ return false;
+ return SimpleLock::remove_replica(from);
+ }
+
+ void print(ostream& out) const override {
+ out << "(";
+ _print(out);
+ if (is_dirty())
+ out << " dirty";
+ if (is_flushing())
+ out << " flushing";
+ if (is_flushed())
+ out << " flushed";
+ if (get_scatter_wanted())
+ out << " scatter_wanted";
+ out << ")";
+ }
+
+private:
+ void set_flushing() {
+ state_flags |= FLUSHING;
+ }
+ void clear_flushing() {
+ state_flags &= ~FLUSHING;
+ }
+ void set_flushed() {
+ state_flags |= FLUSHED;
+ }
+ void set_dirty() {
+ state_flags |= DIRTY;
+ }
+ void clear_dirty() {
+ state_flags &= ~DIRTY;
+ if (_more) {
+ _more->item_updated.remove_myself();
+ _more.reset();
+ }
+ }
+};
+
+#endif