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Diffstat (limited to 'src/osdc/Journaler.cc')
| -rw-r--r-- | src/osdc/Journaler.cc | 1607 |
1 files changed, 1607 insertions, 0 deletions
diff --git a/src/osdc/Journaler.cc b/src/osdc/Journaler.cc new file mode 100644 index 000000000..6e1cbd930 --- /dev/null +++ b/src/osdc/Journaler.cc @@ -0,0 +1,1607 @@ +// -*- 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. + * + */ + +#include "common/perf_counters.h" +#include "common/dout.h" +#include "include/Context.h" +#include "msg/Messenger.h" +#include "osdc/Journaler.h" +#include "common/errno.h" +#include "include/ceph_assert.h" +#include "common/Finisher.h" + +#define dout_subsys ceph_subsys_journaler +#undef dout_prefix +#define dout_prefix *_dout << objecter->messenger->get_myname() \ + << ".journaler." << name << (readonly ? "(ro) ":"(rw) ") + +using std::chrono::seconds; + + +class Journaler::C_DelayFlush : public Context { + Journaler *journaler; + public: + explicit C_DelayFlush(Journaler *j) : journaler(j) {} + void finish(int r) override { + journaler->_do_delayed_flush(); + } +}; + +void Journaler::set_readonly() +{ + lock_guard l(lock); + + ldout(cct, 1) << "set_readonly" << dendl; + readonly = true; +} + +void Journaler::set_writeable() +{ + lock_guard l(lock); + + ldout(cct, 1) << "set_writeable" << dendl; + readonly = false; +} + +void Journaler::create(file_layout_t *l, stream_format_t const sf) +{ + lock_guard lk(lock); + + ceph_assert(!readonly); + state = STATE_ACTIVE; + + stream_format = sf; + journal_stream.set_format(sf); + _set_layout(l); + + prezeroing_pos = prezero_pos = write_pos = flush_pos = + safe_pos = read_pos = requested_pos = received_pos = + expire_pos = trimming_pos = trimmed_pos = + next_safe_pos = layout.get_period(); + + ldout(cct, 1) << "created blank journal at inode 0x" << std::hex << ino + << std::dec << ", format=" << stream_format << dendl; +} + +void Journaler::set_layout(file_layout_t const *l) +{ + lock_guard lk(lock); + _set_layout(l); +} + +void Journaler::_set_layout(file_layout_t const *l) +{ + layout = *l; + + if (layout.pool_id != pg_pool) { + // user can reset pool id through cephfs-journal-tool + lderr(cct) << "may got older pool id from header layout" << dendl; + ceph_abort(); + } + last_written.layout = layout; + last_committed.layout = layout; + + // prefetch intelligently. + // (watch out, this is big if you use big objects or weird striping) + uint64_t periods = cct->_conf.get_val<uint64_t>("journaler_prefetch_periods"); + fetch_len = layout.get_period() * periods; +} + + +/***************** HEADER *******************/ + +ostream& operator<<(ostream &out, const Journaler::Header &h) +{ + return out << "loghead(trim " << h.trimmed_pos + << ", expire " << h.expire_pos + << ", write " << h.write_pos + << ", stream_format " << (int)(h.stream_format) + << ")"; +} + +class Journaler::C_ReadHead : public Context { + Journaler *ls; +public: + bufferlist bl; + explicit C_ReadHead(Journaler *l) : ls(l) {} + void finish(int r) override { + ls->_finish_read_head(r, bl); + } +}; + +class Journaler::C_RereadHead : public Context { + Journaler *ls; + Context *onfinish; +public: + bufferlist bl; + C_RereadHead(Journaler *l, Context *onfinish_) : ls (l), + onfinish(onfinish_) {} + void finish(int r) override { + ls->_finish_reread_head(r, bl, onfinish); + } +}; + +class Journaler::C_ProbeEnd : public Context { + Journaler *ls; +public: + uint64_t end; + explicit C_ProbeEnd(Journaler *l) : ls(l), end(-1) {} + void finish(int r) override { + ls->_finish_probe_end(r, end); + } +}; + +class Journaler::C_ReProbe : public Context { + Journaler *ls; + C_OnFinisher *onfinish; +public: + uint64_t end; + C_ReProbe(Journaler *l, C_OnFinisher *onfinish_) : + ls(l), onfinish(onfinish_), end(0) {} + void finish(int r) override { + ls->_finish_reprobe(r, end, onfinish); + } +}; + +void Journaler::recover(Context *onread) +{ + lock_guard l(lock); + if (is_stopping()) { + onread->complete(-EAGAIN); + return; + } + + ldout(cct, 1) << "recover start" << dendl; + ceph_assert(state != STATE_ACTIVE); + ceph_assert(readonly); + + if (onread) + waitfor_recover.push_back(wrap_finisher(onread)); + + if (state != STATE_UNDEF) { + ldout(cct, 1) << "recover - already recovering" << dendl; + return; + } + + ldout(cct, 1) << "read_head" << dendl; + state = STATE_READHEAD; + C_ReadHead *fin = new C_ReadHead(this); + _read_head(fin, &fin->bl); +} + +void Journaler::_read_head(Context *on_finish, bufferlist *bl) +{ + // lock is locked + ceph_assert(state == STATE_READHEAD || state == STATE_REREADHEAD); + + object_t oid = file_object_t(ino, 0); + object_locator_t oloc(pg_pool); + objecter->read_full(oid, oloc, CEPH_NOSNAP, bl, 0, wrap_finisher(on_finish)); +} + +void Journaler::reread_head(Context *onfinish) +{ + lock_guard l(lock); + _reread_head(wrap_finisher(onfinish)); +} + +/** + * Re-read the head from disk, and set the write_pos, expire_pos, trimmed_pos + * from the on-disk header. This switches the state to STATE_REREADHEAD for + * the duration, and you shouldn't start a re-read while other operations are + * in-flight, nor start other operations while a re-read is in progress. + * Also, don't call this until the Journaler has finished its recovery and has + * gone STATE_ACTIVE! + */ +void Journaler::_reread_head(Context *onfinish) +{ + ldout(cct, 10) << "reread_head" << dendl; + ceph_assert(state == STATE_ACTIVE); + + state = STATE_REREADHEAD; + C_RereadHead *fin = new C_RereadHead(this, onfinish); + _read_head(fin, &fin->bl); +} + +void Journaler::_finish_reread_head(int r, bufferlist& bl, Context *finish) +{ + lock_guard l(lock); + if (is_stopping()) { + finish->complete(-EAGAIN); + return; + } + + //read on-disk header into + ceph_assert(bl.length() || r < 0 ); + + // unpack header + if (r == 0) { + Header h; + auto p = bl.cbegin(); + try { + decode(h, p); + } catch (const buffer::error &e) { + finish->complete(-EINVAL); + return; + } + prezeroing_pos = prezero_pos = write_pos = flush_pos = safe_pos = next_safe_pos + = h.write_pos; + expire_pos = h.expire_pos; + trimmed_pos = trimming_pos = h.trimmed_pos; + init_headers(h); + state = STATE_ACTIVE; + } + + finish->complete(r); +} + +void Journaler::_finish_read_head(int r, bufferlist& bl) +{ + lock_guard l(lock); + if (is_stopping()) + return; + + ceph_assert(state == STATE_READHEAD); + + if (r!=0) { + ldout(cct, 0) << "error getting journal off disk" << dendl; + list<Context*> ls; + ls.swap(waitfor_recover); + finish_contexts(cct, ls, r); + return; + } + + if (bl.length() == 0) { + ldout(cct, 1) << "_finish_read_head r=" << r + << " read 0 bytes, assuming empty log" << dendl; + state = STATE_ACTIVE; + list<Context*> ls; + ls.swap(waitfor_recover); + finish_contexts(cct, ls, 0); + return; + } + + // unpack header + bool corrupt = false; + Header h; + auto p = bl.cbegin(); + try { + decode(h, p); + + if (h.magic != magic) { + ldout(cct, 0) << "on disk magic '" << h.magic << "' != my magic '" + << magic << "'" << dendl; + corrupt = true; + } else if (h.write_pos < h.expire_pos || h.expire_pos < h.trimmed_pos) { + ldout(cct, 0) << "Corrupt header (bad offsets): " << h << dendl; + corrupt = true; + } + } catch (const buffer::error &e) { + corrupt = true; + } + + if (corrupt) { + list<Context*> ls; + ls.swap(waitfor_recover); + finish_contexts(cct, ls, -EINVAL); + return; + } + + prezeroing_pos = prezero_pos = write_pos = flush_pos = safe_pos = next_safe_pos + = h.write_pos; + read_pos = requested_pos = received_pos = expire_pos = h.expire_pos; + trimmed_pos = trimming_pos = h.trimmed_pos; + + init_headers(h); + _set_layout(&h.layout); + stream_format = h.stream_format; + journal_stream.set_format(h.stream_format); + + ldout(cct, 1) << "_finish_read_head " << h + << ". probing for end of log (from " << write_pos << ")..." + << dendl; + C_ProbeEnd *fin = new C_ProbeEnd(this); + state = STATE_PROBING; + _probe(fin, &fin->end); +} + +void Journaler::_probe(Context *finish, uint64_t *end) +{ + // lock is locked + ldout(cct, 1) << "probing for end of the log" << dendl; + ceph_assert(state == STATE_PROBING || state == STATE_REPROBING); + // probe the log + filer.probe(ino, &layout, CEPH_NOSNAP, + write_pos, end, true, 0, wrap_finisher(finish)); +} + +void Journaler::_reprobe(C_OnFinisher *finish) +{ + ldout(cct, 10) << "reprobe" << dendl; + ceph_assert(state == STATE_ACTIVE); + + state = STATE_REPROBING; + C_ReProbe *fin = new C_ReProbe(this, finish); + _probe(fin, &fin->end); +} + + +void Journaler::_finish_reprobe(int r, uint64_t new_end, + C_OnFinisher *onfinish) +{ + lock_guard l(lock); + if (is_stopping()) { + onfinish->complete(-EAGAIN); + return; + } + + ceph_assert(new_end >= write_pos || r < 0); + ldout(cct, 1) << "_finish_reprobe new_end = " << new_end + << " (header had " << write_pos << ")." + << dendl; + prezeroing_pos = prezero_pos = write_pos = flush_pos = safe_pos = next_safe_pos = new_end; + state = STATE_ACTIVE; + onfinish->complete(r); +} + +void Journaler::_finish_probe_end(int r, uint64_t end) +{ + lock_guard l(lock); + if (is_stopping()) + return; + + ceph_assert(state == STATE_PROBING); + if (r < 0) { // error in probing + goto out; + } + if (((int64_t)end) == -1) { + end = write_pos; + ldout(cct, 1) << "_finish_probe_end write_pos = " << end << " (header had " + << write_pos << "). log was empty. recovered." << dendl; + ceph_abort(); // hrm. + } else { + ceph_assert(end >= write_pos); + ldout(cct, 1) << "_finish_probe_end write_pos = " << end + << " (header had " << write_pos << "). recovered." + << dendl; + } + + state = STATE_ACTIVE; + + prezeroing_pos = prezero_pos = write_pos = flush_pos = safe_pos = next_safe_pos = end; + +out: + // done. + list<Context*> ls; + ls.swap(waitfor_recover); + finish_contexts(cct, ls, r); +} + +class Journaler::C_RereadHeadProbe : public Context +{ + Journaler *ls; + C_OnFinisher *final_finish; +public: + C_RereadHeadProbe(Journaler *l, C_OnFinisher *finish) : + ls(l), final_finish(finish) {} + void finish(int r) override { + ls->_finish_reread_head_and_probe(r, final_finish); + } +}; + +void Journaler::reread_head_and_probe(Context *onfinish) +{ + lock_guard l(lock); + + ceph_assert(state == STATE_ACTIVE); + _reread_head(new C_RereadHeadProbe(this, wrap_finisher(onfinish))); +} + +void Journaler::_finish_reread_head_and_probe(int r, C_OnFinisher *onfinish) +{ + // Expect to be called back from finish_reread_head, which already takes lock + // lock is locked + if (is_stopping()) { + onfinish->complete(-EAGAIN); + return; + } + + // Let the caller know that the operation has failed or was intentionally + // failed since the caller has been blocklisted. + if (r == -EBLOCKLISTED) { + onfinish->complete(r); + return; + } + + ceph_assert(!r); //if we get an error, we're boned + _reprobe(onfinish); +} + + +// WRITING + +class Journaler::C_WriteHead : public Context { +public: + Journaler *ls; + Header h; + C_OnFinisher *oncommit; + C_WriteHead(Journaler *l, Header& h_, C_OnFinisher *c) : ls(l), h(h_), + oncommit(c) {} + void finish(int r) override { + ls->_finish_write_head(r, h, oncommit); + } +}; + +void Journaler::write_head(Context *oncommit) +{ + lock_guard l(lock); + _write_head(oncommit); +} + + +void Journaler::_write_head(Context *oncommit) +{ + ceph_assert(!readonly); + ceph_assert(state == STATE_ACTIVE); + last_written.trimmed_pos = trimmed_pos; + last_written.expire_pos = expire_pos; + last_written.unused_field = expire_pos; + last_written.write_pos = safe_pos; + last_written.stream_format = stream_format; + ldout(cct, 10) << "write_head " << last_written << dendl; + + // Avoid persisting bad pointers in case of bugs + ceph_assert(last_written.write_pos >= last_written.expire_pos); + ceph_assert(last_written.expire_pos >= last_written.trimmed_pos); + + last_wrote_head = ceph::real_clock::now(); + + bufferlist bl; + encode(last_written, bl); + SnapContext snapc; + + object_t oid = file_object_t(ino, 0); + object_locator_t oloc(pg_pool); + objecter->write_full(oid, oloc, snapc, bl, ceph::real_clock::now(), 0, + wrap_finisher(new C_WriteHead( + this, last_written, + wrap_finisher(oncommit))), + 0, 0, write_iohint); +} + +void Journaler::_finish_write_head(int r, Header &wrote, + C_OnFinisher *oncommit) +{ + lock_guard l(lock); + + if (r < 0) { + lderr(cct) << "_finish_write_head got " << cpp_strerror(r) << dendl; + handle_write_error(r); + return; + } + ceph_assert(!readonly); + ldout(cct, 10) << "_finish_write_head " << wrote << dendl; + last_committed = wrote; + if (oncommit) { + oncommit->complete(r); + } + + _trim(); // trim? +} + + +/***************** WRITING *******************/ + +class Journaler::C_Flush : public Context { + Journaler *ls; + uint64_t start; + ceph::real_time stamp; +public: + C_Flush(Journaler *l, int64_t s, ceph::real_time st) + : ls(l), start(s), stamp(st) {} + void finish(int r) override { + ls->_finish_flush(r, start, stamp); + } +}; + +void Journaler::_finish_flush(int r, uint64_t start, ceph::real_time stamp) +{ + lock_guard l(lock); + ceph_assert(!readonly); + + if (r < 0) { + lderr(cct) << "_finish_flush got " << cpp_strerror(r) << dendl; + handle_write_error(r); + return; + } + + ceph_assert(start < flush_pos); + + // calc latency? + if (logger) { + ceph::timespan lat = ceph::real_clock::now() - stamp; + logger->tinc(logger_key_lat, lat); + } + + // adjust safe_pos + auto it = pending_safe.find(start); + ceph_assert(it != pending_safe.end()); + uint64_t min_next_safe_pos = pending_safe.begin()->second; + pending_safe.erase(it); + if (pending_safe.empty()) + safe_pos = next_safe_pos; + else + safe_pos = min_next_safe_pos; + + ldout(cct, 10) << "_finish_flush safe from " << start + << ", pending_safe " << pending_safe + << ", (prezeroing/prezero)/write/flush/safe positions now " + << "(" << prezeroing_pos << "/" << prezero_pos << ")/" + << write_pos << "/" << flush_pos << "/" << safe_pos + << dendl; + + // kick waiters <= safe_pos + if (!waitfor_safe.empty()) { + list<Context*> ls; + while (!waitfor_safe.empty()) { + auto it = waitfor_safe.begin(); + if (it->first > safe_pos) + break; + ls.splice(ls.end(), it->second); + waitfor_safe.erase(it); + } + finish_contexts(cct, ls); + } +} + + + +uint64_t Journaler::append_entry(bufferlist& bl) +{ + unique_lock l(lock); + + ceph_assert(!readonly); + uint32_t s = bl.length(); + + // append + size_t delta = bl.length() + journal_stream.get_envelope_size(); + // write_buf space is nearly full + if (!write_buf_throttle.get_or_fail(delta)) { + l.unlock(); + ldout(cct, 10) << "write_buf_throttle wait, delta " << delta << dendl; + write_buf_throttle.get(delta); + l.lock(); + } + ldout(cct, 20) << "write_buf_throttle get, delta " << delta << dendl; + size_t wrote = journal_stream.write(bl, &write_buf, write_pos); + ldout(cct, 10) << "append_entry len " << s << " to " << write_pos << "~" + << wrote << dendl; + write_pos += wrote; + + // flush previous object? + uint64_t su = get_layout_period(); + ceph_assert(su > 0); + uint64_t write_off = write_pos % su; + uint64_t write_obj = write_pos / su; + uint64_t flush_obj = flush_pos / su; + if (write_obj != flush_obj) { + ldout(cct, 10) << " flushing completed object(s) (su " << su << " wro " + << write_obj << " flo " << flush_obj << ")" << dendl; + _do_flush(write_buf.length() - write_off); + + // if _do_flush() skips flushing some data, it does do a best effort to + // update next_safe_pos. + if (write_buf.length() > 0 && + write_buf.length() <= wrote) { // the unflushed data are within this entry + // set next_safe_pos to end of previous entry + next_safe_pos = write_pos - wrote; + } + } + + return write_pos; +} + + +void Journaler::_do_flush(unsigned amount) +{ + if (is_stopping()) + return; + if (write_pos == flush_pos) + return; + ceph_assert(write_pos > flush_pos); + ceph_assert(!readonly); + + // flush + uint64_t len = write_pos - flush_pos; + ceph_assert(len == write_buf.length()); + if (amount && amount < len) + len = amount; + + // zero at least two full periods ahead. this ensures + // that the next object will not exist. + uint64_t period = get_layout_period(); + if (flush_pos + len + 2*period > prezero_pos) { + _issue_prezero(); + + int64_t newlen = prezero_pos - flush_pos - period; + if (newlen <= 0) { + ldout(cct, 10) << "_do_flush wanted to do " << flush_pos << "~" << len + << " already too close to prezero_pos " << prezero_pos + << ", zeroing first" << dendl; + waiting_for_zero_pos = flush_pos + len; + return; + } + if (static_cast<uint64_t>(newlen) < len) { + ldout(cct, 10) << "_do_flush wanted to do " << flush_pos << "~" << len + << " but hit prezero_pos " << prezero_pos + << ", will do " << flush_pos << "~" << newlen << dendl; + waiting_for_zero_pos = flush_pos + len; + len = newlen; + } + } + ldout(cct, 10) << "_do_flush flushing " << flush_pos << "~" << len << dendl; + + // submit write for anything pending + // flush _start_ pos to _finish_flush + ceph::real_time now = ceph::real_clock::now(); + SnapContext snapc; + + Context *onsafe = new C_Flush(this, flush_pos, now); // on COMMIT + pending_safe[flush_pos] = next_safe_pos; + + bufferlist write_bl; + + // adjust pointers + if (len == write_buf.length()) { + write_bl.swap(write_buf); + next_safe_pos = write_pos; + } else { + write_buf.splice(0, len, &write_bl); + // Keys of waitfor_safe map are journal entry boundaries. + // Try finding a journal entry that we are actually flushing + // and set next_safe_pos to end of it. This is best effort. + // The one we found may not be the lastest flushing entry. + auto p = waitfor_safe.lower_bound(flush_pos + len); + if (p != waitfor_safe.end()) { + if (p->first > flush_pos + len && p != waitfor_safe.begin()) + --p; + if (p->first <= flush_pos + len && p->first > next_safe_pos) + next_safe_pos = p->first; + } + } + + filer.write(ino, &layout, snapc, + flush_pos, len, write_bl, ceph::real_clock::now(), + 0, + wrap_finisher(onsafe), write_iohint); + + flush_pos += len; + ceph_assert(write_buf.length() == write_pos - flush_pos); + write_buf_throttle.put(len); + ldout(cct, 20) << "write_buf_throttle put, len " << len << dendl; + + ldout(cct, 10) + << "_do_flush (prezeroing/prezero)/write/flush/safe pointers now at " + << "(" << prezeroing_pos << "/" << prezero_pos << ")/" << write_pos + << "/" << flush_pos << "/" << safe_pos << dendl; + + _issue_prezero(); +} + + +void Journaler::wait_for_flush(Context *onsafe) +{ + lock_guard l(lock); + if (is_stopping()) { + if (onsafe) + onsafe->complete(-EAGAIN); + return; + } + _wait_for_flush(onsafe); +} + +void Journaler::_wait_for_flush(Context *onsafe) +{ + ceph_assert(!readonly); + + // all flushed and safe? + if (write_pos == safe_pos) { + ceph_assert(write_buf.length() == 0); + ldout(cct, 10) + << "flush nothing to flush, (prezeroing/prezero)/write/flush/safe " + "pointers at " << "(" << prezeroing_pos << "/" << prezero_pos << ")/" + << write_pos << "/" << flush_pos << "/" << safe_pos << dendl; + if (onsafe) { + finisher->queue(onsafe, 0); + } + return; + } + + // queue waiter + if (onsafe) { + waitfor_safe[write_pos].push_back(wrap_finisher(onsafe)); + } +} + +void Journaler::flush(Context *onsafe) +{ + lock_guard l(lock); + if (is_stopping()) { + if (onsafe) + onsafe->complete(-EAGAIN); + return; + } + _flush(wrap_finisher(onsafe)); +} + +void Journaler::_flush(C_OnFinisher *onsafe) +{ + ceph_assert(!readonly); + + if (write_pos == flush_pos) { + ceph_assert(write_buf.length() == 0); + ldout(cct, 10) << "flush nothing to flush, (prezeroing/prezero)/write/" + "flush/safe pointers at " << "(" << prezeroing_pos << "/" << prezero_pos + << ")/" << write_pos << "/" << flush_pos << "/" << safe_pos + << dendl; + if (onsafe) { + onsafe->complete(0); + } + } else { + _do_flush(); + _wait_for_flush(onsafe); + } + + // write head? + if (_write_head_needed()) { + _write_head(); + } +} + +bool Journaler::_write_head_needed() +{ + return last_wrote_head + seconds(cct->_conf.get_val<int64_t>("journaler_write_head_interval")) + < ceph::real_clock::now(); +} + + +/*************** prezeroing ******************/ + +struct C_Journaler_Prezero : public Context { + Journaler *journaler; + uint64_t from, len; + C_Journaler_Prezero(Journaler *j, uint64_t f, uint64_t l) + : journaler(j), from(f), len(l) {} + void finish(int r) override { + journaler->_finish_prezero(r, from, len); + } +}; + +void Journaler::_issue_prezero() +{ + ceph_assert(prezeroing_pos >= flush_pos); + + uint64_t num_periods = cct->_conf.get_val<uint64_t>("journaler_prezero_periods"); + /* + * issue zero requests based on write_pos, even though the invariant + * is that we zero ahead of flush_pos. + */ + uint64_t period = get_layout_period(); + uint64_t to = write_pos + period * num_periods + period - 1; + to -= to % period; + + if (prezeroing_pos >= to) { + ldout(cct, 20) << "_issue_prezero target " << to << " <= prezeroing_pos " + << prezeroing_pos << dendl; + return; + } + + while (prezeroing_pos < to) { + uint64_t len; + if (prezeroing_pos % period == 0) { + len = period; + ldout(cct, 10) << "_issue_prezero removing " << prezeroing_pos << "~" + << period << " (full period)" << dendl; + } else { + len = period - (prezeroing_pos % period); + ldout(cct, 10) << "_issue_prezero zeroing " << prezeroing_pos << "~" + << len << " (partial period)" << dendl; + } + SnapContext snapc; + Context *c = wrap_finisher(new C_Journaler_Prezero(this, prezeroing_pos, + len)); + filer.zero(ino, &layout, snapc, prezeroing_pos, len, + ceph::real_clock::now(), 0, c); + prezeroing_pos += len; + } +} + +// Lock cycle because we get called out of objecter callback (holding +// objecter read lock), but there are also cases where we take the journaler +// lock before calling into objecter to do I/O. +void Journaler::_finish_prezero(int r, uint64_t start, uint64_t len) +{ + lock_guard l(lock); + + ldout(cct, 10) << "_prezeroed to " << start << "~" << len + << ", prezeroing/prezero was " << prezeroing_pos << "/" + << prezero_pos << ", pending " << pending_zero + << dendl; + if (r < 0 && r != -ENOENT) { + lderr(cct) << "_prezeroed got " << cpp_strerror(r) << dendl; + handle_write_error(r); + return; + } + + ceph_assert(r == 0 || r == -ENOENT); + + if (start == prezero_pos) { + prezero_pos += len; + while (!pending_zero.empty() && + pending_zero.begin().get_start() == prezero_pos) { + interval_set<uint64_t>::iterator b(pending_zero.begin()); + prezero_pos += b.get_len(); + pending_zero.erase(b); + } + + if (waiting_for_zero_pos > flush_pos) { + _do_flush(waiting_for_zero_pos - flush_pos); + } + + if (prezero_pos == prezeroing_pos && + !waitfor_prezero.empty()) { + list<Context*> ls; + ls.swap(waitfor_prezero); + finish_contexts(cct, ls, 0); + } + } else { + pending_zero.insert(start, len); + } + ldout(cct, 10) << "_prezeroed prezeroing/prezero now " << prezeroing_pos + << "/" << prezero_pos + << ", pending " << pending_zero + << dendl; +} + +void Journaler::wait_for_prezero(Context *onfinish) +{ + ceph_assert(onfinish); + lock_guard l(lock); + + if (prezero_pos == prezeroing_pos) { + finisher->queue(onfinish, 0); + return; + } + waitfor_prezero.push_back(wrap_finisher(onfinish)); +} + + +/***************** READING *******************/ + + +class Journaler::C_Read : public Context { + Journaler *ls; + uint64_t offset; + uint64_t length; +public: + bufferlist bl; + C_Read(Journaler *j, uint64_t o, uint64_t l) : ls(j), offset(o), length(l) {} + void finish(int r) override { + ls->_finish_read(r, offset, length, bl); + } +}; + +class Journaler::C_RetryRead : public Context { + Journaler *ls; +public: + explicit C_RetryRead(Journaler *l) : ls(l) {} + + void finish(int r) override { + // Should only be called from waitfor_safe i.e. already inside lock + // (ls->lock is locked + ls->_prefetch(); + } +}; + +void Journaler::_finish_read(int r, uint64_t offset, uint64_t length, + bufferlist& bl) +{ + lock_guard l(lock); + + if (r < 0) { + ldout(cct, 0) << "_finish_read got error " << r << dendl; + error = r; + } else { + ldout(cct, 10) << "_finish_read got " << offset << "~" << bl.length() + << dendl; + if (bl.length() < length) { + ldout(cct, 0) << "_finish_read got less than expected (" << length << ")" + << dendl; + error = -EINVAL; + } + } + + if (error) { + if (on_readable) { + C_OnFinisher *f = on_readable; + on_readable = 0; + f->complete(error); + } + return; + } + + prefetch_buf[offset].swap(bl); + + try { + _assimilate_prefetch(); + } catch (const buffer::error &err) { + lderr(cct) << "_decode error from assimilate_prefetch" << dendl; + error = -EINVAL; + if (on_readable) { + C_OnFinisher *f = on_readable; + on_readable = 0; + f->complete(error); + } + return; + } + _prefetch(); +} + +void Journaler::_assimilate_prefetch() +{ + bool was_readable = readable; + + bool got_any = false; + while (!prefetch_buf.empty()) { + map<uint64_t,bufferlist>::iterator p = prefetch_buf.begin(); + if (p->first != received_pos) { + uint64_t gap = p->first - received_pos; + ldout(cct, 10) << "_assimilate_prefetch gap of " << gap + << " from received_pos " << received_pos + << " to first prefetched buffer " << p->first << dendl; + break; + } + + ldout(cct, 10) << "_assimilate_prefetch " << p->first << "~" + << p->second.length() << dendl; + received_pos += p->second.length(); + read_buf.claim_append(p->second); + ceph_assert(received_pos <= requested_pos); + prefetch_buf.erase(p); + got_any = true; + } + + if (got_any) { + ldout(cct, 10) << "_assimilate_prefetch read_buf now " << read_pos << "~" + << read_buf.length() << ", read pointers read_pos=" << read_pos + << " received_pos=" << received_pos << " requested_pos=" << requested_pos + << dendl; + + // Update readability (this will also hit any decode errors resulting + // from bad data) + readable = _is_readable(); + } + + if ((got_any && !was_readable && readable) || read_pos == write_pos) { + // readable! + ldout(cct, 10) << "_finish_read now readable (or at journal end) readable=" + << readable << " read_pos=" << read_pos << " write_pos=" + << write_pos << dendl; + if (on_readable) { + C_OnFinisher *f = on_readable; + on_readable = 0; + f->complete(0); + } + } +} + +void Journaler::_issue_read(uint64_t len) +{ + // stuck at safe_pos? (this is needed if we are reading the tail of + // a journal we are also writing to) + ceph_assert(requested_pos <= safe_pos); + if (requested_pos == safe_pos) { + ldout(cct, 10) << "_issue_read requested_pos = safe_pos = " << safe_pos + << ", waiting" << dendl; + ceph_assert(write_pos > requested_pos); + if (pending_safe.empty()) { + _flush(NULL); + } + + // Make sure keys of waitfor_safe map are journal entry boundaries. + // The key we used here is either next_safe_pos or old value of + // next_safe_pos. next_safe_pos is always set to journal entry + // boundary. + auto p = pending_safe.rbegin(); + if (p != pending_safe.rend()) + waitfor_safe[p->second].push_back(new C_RetryRead(this)); + else + waitfor_safe[next_safe_pos].push_back(new C_RetryRead(this)); + return; + } + + // don't read too much + if (requested_pos + len > safe_pos) { + len = safe_pos - requested_pos; + ldout(cct, 10) << "_issue_read reading only up to safe_pos " << safe_pos + << dendl; + } + + // go. + ldout(cct, 10) << "_issue_read reading " << requested_pos << "~" << len + << ", read pointers read_pos=" << read_pos << " received_pos=" << received_pos + << " requested_pos+len=" << (requested_pos+len) << dendl; + + // step by period (object). _don't_ do a single big filer.read() + // here because it will wait for all object reads to complete before + // giving us back any data. this way we can process whatever bits + // come in that are contiguous. + uint64_t period = get_layout_period(); + while (len > 0) { + uint64_t e = requested_pos + period; + e -= e % period; + uint64_t l = e - requested_pos; + if (l > len) + l = len; + C_Read *c = new C_Read(this, requested_pos, l); + filer.read(ino, &layout, CEPH_NOSNAP, requested_pos, l, &c->bl, 0, + wrap_finisher(c), CEPH_OSD_OP_FLAG_FADVISE_DONTNEED); + requested_pos += l; + len -= l; + } +} + +void Journaler::_prefetch() +{ + if (is_stopping()) + return; + + ldout(cct, 10) << "_prefetch" << dendl; + // prefetch + uint64_t pf; + if (temp_fetch_len) { + ldout(cct, 10) << "_prefetch temp_fetch_len " << temp_fetch_len << dendl; + pf = temp_fetch_len; + temp_fetch_len = 0; + } else { + pf = fetch_len; + } + + uint64_t raw_target = read_pos + pf; + + // read full log segments, so increase if necessary + uint64_t period = get_layout_period(); + uint64_t remainder = raw_target % period; + uint64_t adjustment = remainder ? period - remainder : 0; + uint64_t target = raw_target + adjustment; + + // don't read past the log tail + if (target > write_pos) + target = write_pos; + + if (requested_pos < target) { + uint64_t len = target - requested_pos; + ldout(cct, 10) << "_prefetch " << pf << " requested_pos " << requested_pos + << " < target " << target << " (" << raw_target + << "), prefetching " << len << dendl; + + if (pending_safe.empty() && write_pos > safe_pos) { + // If we are reading and writing the journal, then we may need + // to issue a flush if one isn't already in progress. + // Avoid doing a flush every time so that if we do write/read/write/read + // we don't end up flushing after every write. + ldout(cct, 10) << "_prefetch: requested_pos=" << requested_pos + << ", read_pos=" << read_pos + << ", write_pos=" << write_pos + << ", safe_pos=" << safe_pos << dendl; + _do_flush(); + } + + _issue_read(len); + } +} + + +/* + * _is_readable() - return true if next entry is ready. + */ +bool Journaler::_is_readable() +{ + // anything to read? + if (read_pos == write_pos) + return false; + + // Check if the retrieve bytestream has enough for an entry + uint64_t need; + if (journal_stream.readable(read_buf, &need)) { + return true; + } + + ldout (cct, 10) << "_is_readable read_buf.length() == " << read_buf.length() + << ", but need " << need << " for next entry; fetch_len is " + << fetch_len << dendl; + + // partial fragment at the end? + if (received_pos == write_pos) { + ldout(cct, 10) << "is_readable() detected partial entry at tail, " + "adjusting write_pos to " << read_pos << dendl; + + // adjust write_pos + prezeroing_pos = prezero_pos = write_pos = flush_pos = safe_pos = next_safe_pos = read_pos; + ceph_assert(write_buf.length() == 0); + ceph_assert(waitfor_safe.empty()); + + // reset read state + requested_pos = received_pos = read_pos; + read_buf.clear(); + + // FIXME: truncate on disk? + + return false; + } + + if (need > fetch_len) { + temp_fetch_len = need; + ldout(cct, 10) << "_is_readable noting temp_fetch_len " << temp_fetch_len + << dendl; + } + + ldout(cct, 10) << "_is_readable: not readable, returning false" << dendl; + return false; +} + +/* + * is_readable() - kickstart prefetch, too + */ +bool Journaler::is_readable() +{ + lock_guard l(lock); + + if (error != 0) { + return false; + } + + bool r = readable; + _prefetch(); + return r; +} + +class Journaler::C_EraseFinish : public Context { + Journaler *journaler; + C_OnFinisher *completion; + public: + C_EraseFinish(Journaler *j, C_OnFinisher *c) : journaler(j), completion(c) {} + void finish(int r) override { + journaler->_finish_erase(r, completion); + } +}; + +/** + * Entirely erase the journal, including header. For use when you + * have already made a copy of the journal somewhere else. + */ +void Journaler::erase(Context *completion) +{ + lock_guard l(lock); + + // Async delete the journal data + uint64_t first = trimmed_pos / get_layout_period(); + uint64_t num = (write_pos - trimmed_pos) / get_layout_period() + 2; + filer.purge_range(ino, &layout, SnapContext(), first, num, + ceph::real_clock::now(), 0, + wrap_finisher(new C_EraseFinish( + this, wrap_finisher(completion)))); + + // We will not start the operation to delete the header until + // _finish_erase has seen the data deletion succeed: otherwise if + // there was an error deleting data we might prematurely delete the + // header thereby lose our reference to the data. +} + +void Journaler::_finish_erase(int data_result, C_OnFinisher *completion) +{ + lock_guard l(lock); + if (is_stopping()) { + completion->complete(-EAGAIN); + return; + } + + if (data_result == 0) { + // Async delete the journal header + filer.purge_range(ino, &layout, SnapContext(), 0, 1, + ceph::real_clock::now(), + 0, wrap_finisher(completion)); + } else { + lderr(cct) << "Failed to delete journal " << ino << " data: " + << cpp_strerror(data_result) << dendl; + completion->complete(data_result); + } +} + +/* try_read_entry(bl) + * read entry into bl if it's ready. + * otherwise, do nothing. + */ +bool Journaler::try_read_entry(bufferlist& bl) +{ + lock_guard l(lock); + + if (!readable) { + ldout(cct, 10) << "try_read_entry at " << read_pos << " not readable" + << dendl; + return false; + } + + uint64_t start_ptr; + size_t consumed; + try { + consumed = journal_stream.read(read_buf, &bl, &start_ptr); + if (stream_format >= JOURNAL_FORMAT_RESILIENT) { + ceph_assert(start_ptr == read_pos); + } + } catch (const buffer::error &e) { + lderr(cct) << __func__ << ": decode error from journal_stream" << dendl; + error = -EINVAL; + return false; + } + + ldout(cct, 10) << "try_read_entry at " << read_pos << " read " + << read_pos << "~" << consumed << " (have " + << read_buf.length() << ")" << dendl; + + read_pos += consumed; + try { + // We were readable, we might not be any more + readable = _is_readable(); + } catch (const buffer::error &e) { + lderr(cct) << __func__ << ": decode error from _is_readable" << dendl; + error = -EINVAL; + return false; + } + + // prefetch? + _prefetch(); + + // If bufferlist consists of discontiguous memory, decoding types whose + // denc_traits needs contiguous memory is inefficient. The bufferlist may + // get copied to temporary memory multiple times (copy_shallow() in + // src/include/denc.h actually does deep copy) + if (bl.get_num_buffers() > 1) + bl.rebuild(); + return true; +} + +void Journaler::wait_for_readable(Context *onreadable) +{ + lock_guard l(lock); + if (is_stopping()) { + finisher->queue(onreadable, -EAGAIN); + return; + } + + ceph_assert(on_readable == 0); + if (!readable) { + ldout(cct, 10) << "wait_for_readable at " << read_pos << " onreadable " + << onreadable << dendl; + on_readable = wrap_finisher(onreadable); + } else { + // race with OSD reply + finisher->queue(onreadable, 0); + } +} + +bool Journaler::have_waiter() const +{ + return on_readable != nullptr; +} + + + + +/***************** TRIMMING *******************/ + + +class Journaler::C_Trim : public Context { + Journaler *ls; + uint64_t to; +public: + C_Trim(Journaler *l, int64_t t) : ls(l), to(t) {} + void finish(int r) override { + ls->_finish_trim(r, to); + } +}; + +void Journaler::trim() +{ + lock_guard l(lock); + _trim(); +} + +void Journaler::_trim() +{ + if (is_stopping()) + return; + + ceph_assert(!readonly); + uint64_t period = get_layout_period(); + uint64_t trim_to = last_committed.expire_pos; + trim_to -= trim_to % period; + ldout(cct, 10) << "trim last_commited head was " << last_committed + << ", can trim to " << trim_to + << dendl; + if (trim_to == 0 || trim_to == trimming_pos) { + ldout(cct, 10) << "trim already trimmed/trimming to " + << trimmed_pos << "/" << trimming_pos << dendl; + return; + } + + if (trimming_pos > trimmed_pos) { + ldout(cct, 10) << "trim already trimming atm, try again later. " + "trimmed/trimming is " << trimmed_pos << "/" << trimming_pos << dendl; + return; + } + + // trim + ceph_assert(trim_to <= write_pos); + ceph_assert(trim_to <= expire_pos); + ceph_assert(trim_to > trimming_pos); + ldout(cct, 10) << "trim trimming to " << trim_to + << ", trimmed/trimming/expire are " + << trimmed_pos << "/" << trimming_pos << "/" << expire_pos + << dendl; + + // delete range of objects + uint64_t first = trimming_pos / period; + uint64_t num = (trim_to - trimming_pos) / period; + SnapContext snapc; + filer.purge_range(ino, &layout, snapc, first, num, + ceph::real_clock::now(), 0, + wrap_finisher(new C_Trim(this, trim_to))); + trimming_pos = trim_to; +} + +void Journaler::_finish_trim(int r, uint64_t to) +{ + lock_guard l(lock); + + ceph_assert(!readonly); + ldout(cct, 10) << "_finish_trim trimmed_pos was " << trimmed_pos + << ", trimmed/trimming/expire now " + << to << "/" << trimming_pos << "/" << expire_pos + << dendl; + if (r < 0 && r != -ENOENT) { + lderr(cct) << "_finish_trim got " << cpp_strerror(r) << dendl; + handle_write_error(r); + return; + } + + ceph_assert(r >= 0 || r == -ENOENT); + + ceph_assert(to <= trimming_pos); + ceph_assert(to > trimmed_pos); + trimmed_pos = to; +} + +void Journaler::handle_write_error(int r) +{ + // lock is locked + + lderr(cct) << "handle_write_error " << cpp_strerror(r) << dendl; + if (on_write_error) { + on_write_error->complete(r); + on_write_error = NULL; + called_write_error = true; + } else if (called_write_error) { + /* We don't call error handler more than once, subsequent errors + * are dropped -- this is okay as long as the error handler does + * something dramatic like respawn */ + lderr(cct) << __func__ << ": multiple write errors, handler already called" + << dendl; + } else { + ceph_abort_msg("unhandled write error"); + } +} + + +/** + * Test whether the 'read_buf' byte stream has enough data to read + * an entry + * + * sets 'next_envelope_size' to the number of bytes needed to advance (enough + * to get the next header if header was unavailable, or enough to get the whole + * next entry if the header was available but the body wasn't). + */ +bool JournalStream::readable(bufferlist &read_buf, uint64_t *need) const +{ + ceph_assert(need != NULL); + + uint32_t entry_size = 0; + uint64_t entry_sentinel = 0; + auto p = read_buf.cbegin(); + + // Do we have enough data to decode an entry prefix? + if (format >= JOURNAL_FORMAT_RESILIENT) { + *need = sizeof(entry_size) + sizeof(entry_sentinel); + } else { + *need = sizeof(entry_size); + } + if (read_buf.length() >= *need) { + if (format >= JOURNAL_FORMAT_RESILIENT) { + decode(entry_sentinel, p); + if (entry_sentinel != sentinel) { + throw buffer::malformed_input("Invalid sentinel"); + } + } + + decode(entry_size, p); + } else { + return false; + } + + // Do we have enough data to decode an entry prefix, payload and suffix? + if (format >= JOURNAL_FORMAT_RESILIENT) { + *need = JOURNAL_ENVELOPE_RESILIENT + entry_size; + } else { + *need = JOURNAL_ENVELOPE_LEGACY + entry_size; + } + if (read_buf.length() >= *need) { + return true; // No more bytes needed + } + + return false; +} + + +/** + * Consume one entry from a journal byte stream 'from', splicing a + * serialized LogEvent blob into 'entry'. + * + * 'entry' must be non null and point to an empty bufferlist. + * + * 'from' must contain sufficient valid data (i.e. readable is true). + * + * 'start_ptr' will be set to the entry's start pointer, if the collection + * format provides it. It may not be null. + * + * @returns The number of bytes consumed from the `from` byte stream. Note + * that this is not equal to the length of `entry`, which contains + * the inner serialized LogEvent and not the envelope. + */ +size_t JournalStream::read(bufferlist &from, bufferlist *entry, + uint64_t *start_ptr) +{ + ceph_assert(start_ptr != NULL); + ceph_assert(entry != NULL); + ceph_assert(entry->length() == 0); + + uint32_t entry_size = 0; + + // Consume envelope prefix: entry_size and entry_sentinel + auto from_ptr = from.cbegin(); + if (format >= JOURNAL_FORMAT_RESILIENT) { + uint64_t entry_sentinel = 0; + decode(entry_sentinel, from_ptr); + // Assertion instead of clean check because of precondition of this + // fn is that readable() already passed + ceph_assert(entry_sentinel == sentinel); + } + decode(entry_size, from_ptr); + + // Read out the payload + from_ptr.copy(entry_size, *entry); + + // Consume the envelope suffix (start_ptr) + if (format >= JOURNAL_FORMAT_RESILIENT) { + decode(*start_ptr, from_ptr); + } else { + *start_ptr = 0; + } + + // Trim the input buffer to discard the bytes we have consumed + from.splice(0, from_ptr.get_off()); + + return from_ptr.get_off(); +} + + +/** + * Append one entry + */ +size_t JournalStream::write(bufferlist &entry, bufferlist *to, + uint64_t const &start_ptr) +{ + ceph_assert(to != NULL); + + uint32_t const entry_size = entry.length(); + if (format >= JOURNAL_FORMAT_RESILIENT) { + encode(sentinel, *to); + } + encode(entry_size, *to); + to->claim_append(entry); + if (format >= JOURNAL_FORMAT_RESILIENT) { + encode(start_ptr, *to); + } + + if (format >= JOURNAL_FORMAT_RESILIENT) { + return JOURNAL_ENVELOPE_RESILIENT + entry_size; + } else { + return JOURNAL_ENVELOPE_LEGACY + entry_size; + } +} + +/** + * set write error callback + * + * Set a callback/context to trigger if we get a write error from + * the objecter. This may be from an explicit request (e.g., flush) + * or something async the journaler did on its own (e.g., journal + * header update). + * + * It is only used once; if the caller continues to use the + * Journaler and wants to hear about errors, it needs to reset the + * error_handler. + * + * @param c callback/context to trigger on error + */ +void Journaler::set_write_error_handler(Context *c) { + lock_guard l(lock); + ceph_assert(!on_write_error); + on_write_error = wrap_finisher(c); + called_write_error = false; +} + + +/** + * Wrap a context in a C_OnFinisher, if it is non-NULL + * + * Utility function to avoid lots of error-prone and verbose + * NULL checking on contexts passed in. + */ +C_OnFinisher *Journaler::wrap_finisher(Context *c) +{ + if (c != NULL) { + return new C_OnFinisher(c, finisher); + } else { + return NULL; + } +} + +void Journaler::shutdown() +{ + lock_guard l(lock); + + ldout(cct, 1) << __func__ << dendl; + + state = STATE_STOPPING; + readable = false; + + // Kick out anyone reading from journal + error = -EAGAIN; + if (on_readable) { + C_OnFinisher *f = on_readable; + on_readable = 0; + f->complete(-EAGAIN); + } + + list<Context*> ls; + ls.swap(waitfor_recover); + finish_contexts(cct, ls, -ESHUTDOWN); + + std::map<uint64_t, std::list<Context*> >::iterator i; + for (i = waitfor_safe.begin(); i != waitfor_safe.end(); ++i) { + finish_contexts(cct, i->second, -EAGAIN); + } + waitfor_safe.clear(); +} + |