1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
2 // vim: ts=8 sw=2 smarttab
4 * Ceph - scalable distributed file system
6 * Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
8 * This is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License version 2.1, as published by the Free Software
11 * Foundation. See file COPYING.
15 #include "common/perf_counters.h"
16 #include "common/dout.h"
17 #include "include/Context.h"
18 #include "msg/Messenger.h"
19 #include "osdc/Journaler.h"
20 #include "common/errno.h"
21 #include "include/assert.h"
22 #include "common/Finisher.h"
24 #define dout_subsys ceph_subsys_journaler
26 #define dout_prefix *_dout << objecter->messenger->get_myname() \
27 << ".journaler." << name << (readonly ? "(ro) ":"(rw) ")
29 using std::chrono::seconds;
32 class Journaler::C_DelayFlush : public Context {
35 C_DelayFlush(Journaler *j) : journaler(j) {}
36 void finish(int r) override {
37 journaler->_do_delayed_flush();
41 void Journaler::set_readonly()
45 ldout(cct, 1) << "set_readonly" << dendl;
49 void Journaler::set_writeable()
53 ldout(cct, 1) << "set_writeable" << dendl;
57 void Journaler::create(file_layout_t *l, stream_format_t const sf)
65 journal_stream.set_format(sf);
68 prezeroing_pos = prezero_pos = write_pos = flush_pos =
69 safe_pos = read_pos = requested_pos = received_pos =
70 expire_pos = trimming_pos = trimmed_pos =
71 next_safe_pos = layout.get_period();
73 ldout(cct, 1) << "created blank journal at inode 0x" << std::hex << ino
74 << std::dec << ", format=" << stream_format << dendl;
77 void Journaler::set_layout(file_layout_t const *l)
83 void Journaler::_set_layout(file_layout_t const *l)
87 assert(layout.pool_id == pg_pool);
88 last_written.layout = layout;
89 last_committed.layout = layout;
91 // prefetch intelligently.
92 // (watch out, this is big if you use big objects or weird striping)
93 uint64_t periods = cct->_conf->journaler_prefetch_periods;
95 periods = 2; // we need at least 2 periods to make progress.
96 fetch_len = layout.get_period() * periods;
100 /***************** HEADER *******************/
102 ostream& operator<<(ostream &out, const Journaler::Header &h)
104 return out << "loghead(trim " << h.trimmed_pos
105 << ", expire " << h.expire_pos
106 << ", write " << h.write_pos
107 << ", stream_format " << (int)(h.stream_format)
111 class Journaler::C_ReadHead : public Context {
115 explicit C_ReadHead(Journaler *l) : ls(l) {}
116 void finish(int r) override {
117 ls->_finish_read_head(r, bl);
121 class Journaler::C_RereadHead : public Context {
126 C_RereadHead(Journaler *l, Context *onfinish_) : ls (l),
127 onfinish(onfinish_) {}
128 void finish(int r) override {
129 ls->_finish_reread_head(r, bl, onfinish);
133 class Journaler::C_ProbeEnd : public Context {
137 explicit C_ProbeEnd(Journaler *l) : ls(l), end(-1) {}
138 void finish(int r) override {
139 ls->_finish_probe_end(r, end);
143 class Journaler::C_ReProbe : public Context {
145 C_OnFinisher *onfinish;
148 C_ReProbe(Journaler *l, C_OnFinisher *onfinish_) :
149 ls(l), onfinish(onfinish_), end(0) {}
150 void finish(int r) override {
151 ls->_finish_reprobe(r, end, onfinish);
155 void Journaler::recover(Context *onread)
159 onread->complete(-EAGAIN);
163 ldout(cct, 1) << "recover start" << dendl;
164 assert(state != STATE_ACTIVE);
168 waitfor_recover.push_back(wrap_finisher(onread));
170 if (state != STATE_UNDEF) {
171 ldout(cct, 1) << "recover - already recovering" << dendl;
175 ldout(cct, 1) << "read_head" << dendl;
176 state = STATE_READHEAD;
177 C_ReadHead *fin = new C_ReadHead(this);
178 _read_head(fin, &fin->bl);
181 void Journaler::_read_head(Context *on_finish, bufferlist *bl)
184 assert(state == STATE_READHEAD || state == STATE_REREADHEAD);
186 object_t oid = file_object_t(ino, 0);
187 object_locator_t oloc(pg_pool);
188 objecter->read_full(oid, oloc, CEPH_NOSNAP, bl, 0, wrap_finisher(on_finish));
191 void Journaler::reread_head(Context *onfinish)
194 _reread_head(wrap_finisher(onfinish));
198 * Re-read the head from disk, and set the write_pos, expire_pos, trimmed_pos
199 * from the on-disk header. This switches the state to STATE_REREADHEAD for
200 * the duration, and you shouldn't start a re-read while other operations are
201 * in-flight, nor start other operations while a re-read is in progress.
202 * Also, don't call this until the Journaler has finished its recovery and has
205 void Journaler::_reread_head(Context *onfinish)
207 ldout(cct, 10) << "reread_head" << dendl;
208 assert(state == STATE_ACTIVE);
210 state = STATE_REREADHEAD;
211 C_RereadHead *fin = new C_RereadHead(this, onfinish);
212 _read_head(fin, &fin->bl);
215 void Journaler::_finish_reread_head(int r, bufferlist& bl, Context *finish)
219 //read on-disk header into
220 assert(bl.length() || r < 0 );
225 bufferlist::iterator p = bl.begin();
228 } catch (const buffer::error &e) {
229 finish->complete(-EINVAL);
232 prezeroing_pos = prezero_pos = write_pos = flush_pos = safe_pos = next_safe_pos
234 expire_pos = h.expire_pos;
235 trimmed_pos = trimming_pos = h.trimmed_pos;
237 state = STATE_ACTIVE;
243 void Journaler::_finish_read_head(int r, bufferlist& bl)
247 assert(state == STATE_READHEAD);
250 ldout(cct, 0) << "error getting journal off disk" << dendl;
252 ls.swap(waitfor_recover);
253 finish_contexts(cct, ls, r);
257 if (bl.length() == 0) {
258 ldout(cct, 1) << "_finish_read_head r=" << r
259 << " read 0 bytes, assuming empty log" << dendl;
260 state = STATE_ACTIVE;
262 ls.swap(waitfor_recover);
263 finish_contexts(cct, ls, 0);
268 bool corrupt = false;
270 bufferlist::iterator p = bl.begin();
274 if (h.magic != magic) {
275 ldout(cct, 0) << "on disk magic '" << h.magic << "' != my magic '"
276 << magic << "'" << dendl;
278 } else if (h.write_pos < h.expire_pos || h.expire_pos < h.trimmed_pos) {
279 ldout(cct, 0) << "Corrupt header (bad offsets): " << h << dendl;
282 } catch (const buffer::error &e) {
288 ls.swap(waitfor_recover);
289 finish_contexts(cct, ls, -EINVAL);
293 prezeroing_pos = prezero_pos = write_pos = flush_pos = safe_pos = next_safe_pos
295 read_pos = requested_pos = received_pos = expire_pos = h.expire_pos;
296 trimmed_pos = trimming_pos = h.trimmed_pos;
299 _set_layout(&h.layout);
300 stream_format = h.stream_format;
301 journal_stream.set_format(h.stream_format);
303 ldout(cct, 1) << "_finish_read_head " << h
304 << ". probing for end of log (from " << write_pos << ")..."
306 C_ProbeEnd *fin = new C_ProbeEnd(this);
307 state = STATE_PROBING;
308 _probe(fin, &fin->end);
311 void Journaler::_probe(Context *finish, uint64_t *end)
314 ldout(cct, 1) << "probing for end of the log" << dendl;
315 assert(state == STATE_PROBING || state == STATE_REPROBING);
317 filer.probe(ino, &layout, CEPH_NOSNAP,
318 write_pos, end, true, 0, wrap_finisher(finish));
321 void Journaler::_reprobe(C_OnFinisher *finish)
323 ldout(cct, 10) << "reprobe" << dendl;
324 assert(state == STATE_ACTIVE);
326 state = STATE_REPROBING;
327 C_ReProbe *fin = new C_ReProbe(this, finish);
328 _probe(fin, &fin->end);
332 void Journaler::_finish_reprobe(int r, uint64_t new_end,
333 C_OnFinisher *onfinish)
337 assert(new_end >= write_pos || r < 0);
338 ldout(cct, 1) << "_finish_reprobe new_end = " << new_end
339 << " (header had " << write_pos << ")."
341 prezeroing_pos = prezero_pos = write_pos = flush_pos = safe_pos = next_safe_pos = new_end;
342 state = STATE_ACTIVE;
343 onfinish->complete(r);
346 void Journaler::_finish_probe_end(int r, uint64_t end)
350 assert(state == STATE_PROBING);
351 if (r < 0) { // error in probing
354 if (((int64_t)end) == -1) {
356 ldout(cct, 1) << "_finish_probe_end write_pos = " << end << " (header had "
357 << write_pos << "). log was empty. recovered." << dendl;
358 ceph_abort(); // hrm.
360 assert(end >= write_pos);
361 ldout(cct, 1) << "_finish_probe_end write_pos = " << end
362 << " (header had " << write_pos << "). recovered."
366 state = STATE_ACTIVE;
368 prezeroing_pos = prezero_pos = write_pos = flush_pos = safe_pos = next_safe_pos = end;
373 ls.swap(waitfor_recover);
374 finish_contexts(cct, ls, r);
377 class Journaler::C_RereadHeadProbe : public Context
380 C_OnFinisher *final_finish;
382 C_RereadHeadProbe(Journaler *l, C_OnFinisher *finish) :
383 ls(l), final_finish(finish) {}
384 void finish(int r) override {
385 ls->_finish_reread_head_and_probe(r, final_finish);
389 void Journaler::reread_head_and_probe(Context *onfinish)
393 assert(state == STATE_ACTIVE);
394 _reread_head(new C_RereadHeadProbe(this, wrap_finisher(onfinish)));
397 void Journaler::_finish_reread_head_and_probe(int r, C_OnFinisher *onfinish)
399 // Expect to be called back from finish_reread_head, which already takes lock
402 assert(!r); //if we get an error, we're boned
409 class Journaler::C_WriteHead : public Context {
413 C_OnFinisher *oncommit;
414 C_WriteHead(Journaler *l, Header& h_, C_OnFinisher *c) : ls(l), h(h_),
416 void finish(int r) override {
417 ls->_finish_write_head(r, h, oncommit);
421 void Journaler::write_head(Context *oncommit)
424 _write_head(oncommit);
428 void Journaler::_write_head(Context *oncommit)
431 assert(state == STATE_ACTIVE);
432 last_written.trimmed_pos = trimmed_pos;
433 last_written.expire_pos = expire_pos;
434 last_written.unused_field = expire_pos;
435 last_written.write_pos = safe_pos;
436 last_written.stream_format = stream_format;
437 ldout(cct, 10) << "write_head " << last_written << dendl;
439 // Avoid persisting bad pointers in case of bugs
440 assert(last_written.write_pos >= last_written.expire_pos);
441 assert(last_written.expire_pos >= last_written.trimmed_pos);
443 last_wrote_head = ceph::real_clock::now();
446 ::encode(last_written, bl);
449 object_t oid = file_object_t(ino, 0);
450 object_locator_t oloc(pg_pool);
451 objecter->write_full(oid, oloc, snapc, bl, ceph::real_clock::now(), 0,
452 wrap_finisher(new C_WriteHead(
454 wrap_finisher(oncommit))),
458 void Journaler::_finish_write_head(int r, Header &wrote,
459 C_OnFinisher *oncommit)
464 lderr(cct) << "_finish_write_head got " << cpp_strerror(r) << dendl;
465 handle_write_error(r);
469 ldout(cct, 10) << "_finish_write_head " << wrote << dendl;
470 last_committed = wrote;
472 oncommit->complete(r);
479 /***************** WRITING *******************/
481 class Journaler::C_Flush : public Context {
484 ceph::real_time stamp;
486 C_Flush(Journaler *l, int64_t s, ceph::real_time st)
487 : ls(l), start(s), stamp(st) {}
488 void finish(int r) override {
489 ls->_finish_flush(r, start, stamp);
493 void Journaler::_finish_flush(int r, uint64_t start, ceph::real_time stamp)
499 lderr(cct) << "_finish_flush got " << cpp_strerror(r) << dendl;
500 handle_write_error(r);
504 assert(start < flush_pos);
508 ceph::timespan lat = ceph::real_clock::now() - stamp;
509 logger->tinc(logger_key_lat, lat);
513 auto it = pending_safe.find(start);
514 assert(it != pending_safe.end());
515 pending_safe.erase(it);
516 if (pending_safe.empty())
517 safe_pos = next_safe_pos;
519 safe_pos = pending_safe.begin()->second;
521 ldout(cct, 10) << "_finish_flush safe from " << start
522 << ", pending_safe " << pending_safe
523 << ", (prezeroing/prezero)/write/flush/safe positions now "
524 << "(" << prezeroing_pos << "/" << prezero_pos << ")/"
525 << write_pos << "/" << flush_pos << "/" << safe_pos
528 // kick waiters <= safe_pos
529 if (!waitfor_safe.empty()) {
531 while (!waitfor_safe.empty()) {
532 auto it = waitfor_safe.begin();
533 if (it->first > safe_pos)
535 ls.splice(ls.end(), it->second);
536 waitfor_safe.erase(it);
538 finish_contexts(cct, ls);
544 uint64_t Journaler::append_entry(bufferlist& bl)
549 uint32_t s = bl.length();
552 size_t delta = bl.length() + journal_stream.get_envelope_size();
553 // write_buf space is nearly full
554 if (!write_buf_throttle.get_or_fail(delta)) {
556 ldout(cct, 10) << "write_buf_throttle wait, delta " << delta << dendl;
557 write_buf_throttle.get(delta);
560 ldout(cct, 20) << "write_buf_throttle get, delta " << delta << dendl;
561 size_t wrote = journal_stream.write(bl, &write_buf, write_pos);
562 ldout(cct, 10) << "append_entry len " << s << " to " << write_pos << "~"
566 // flush previous object?
567 uint64_t su = get_layout_period();
569 uint64_t write_off = write_pos % su;
570 uint64_t write_obj = write_pos / su;
571 uint64_t flush_obj = flush_pos / su;
572 if (write_obj != flush_obj) {
573 ldout(cct, 10) << " flushing completed object(s) (su " << su << " wro "
574 << write_obj << " flo " << flush_obj << ")" << dendl;
575 _do_flush(write_buf.length() - write_off);
577 // if _do_flush() skips flushing some data, it does do a best effort to
578 // update next_safe_pos.
579 if (write_buf.length() > 0 &&
580 write_buf.length() <= wrote) { // the unflushed data are within this entry
581 // set next_safe_pos to end of previous entry
582 next_safe_pos = write_pos - wrote;
590 void Journaler::_do_flush(unsigned amount)
592 if (write_pos == flush_pos)
594 assert(write_pos > flush_pos);
598 uint64_t len = write_pos - flush_pos;
599 assert(len == write_buf.length());
600 if (amount && amount < len)
603 // zero at least two full periods ahead. this ensures
604 // that the next object will not exist.
605 uint64_t period = get_layout_period();
606 if (flush_pos + len + 2*period > prezero_pos) {
609 int64_t newlen = prezero_pos - flush_pos - period;
611 ldout(cct, 10) << "_do_flush wanted to do " << flush_pos << "~" << len
612 << " already too close to prezero_pos " << prezero_pos
613 << ", zeroing first" << dendl;
614 waiting_for_zero = true;
617 if (static_cast<uint64_t>(newlen) < len) {
618 ldout(cct, 10) << "_do_flush wanted to do " << flush_pos << "~" << len
619 << " but hit prezero_pos " << prezero_pos
620 << ", will do " << flush_pos << "~" << newlen << dendl;
623 waiting_for_zero = false;
626 waiting_for_zero = false;
628 ldout(cct, 10) << "_do_flush flushing " << flush_pos << "~" << len << dendl;
630 // submit write for anything pending
631 // flush _start_ pos to _finish_flush
632 ceph::real_time now = ceph::real_clock::now();
635 Context *onsafe = new C_Flush(this, flush_pos, now); // on COMMIT
636 pending_safe[flush_pos] = next_safe_pos;
641 if (len == write_buf.length()) {
642 write_bl.swap(write_buf);
643 next_safe_pos = write_pos;
645 write_buf.splice(0, len, &write_bl);
646 // Keys of waitfor_safe map are journal entry boundaries.
647 // Try finding a journal entry that we are actually flushing
648 // and set next_safe_pos to end of it. This is best effort.
649 // The one we found may not be the lastest flushing entry.
650 auto p = waitfor_safe.lower_bound(flush_pos + len);
651 if (p != waitfor_safe.end()) {
652 if (p->first > flush_pos + len && p != waitfor_safe.begin())
654 if (p->first <= flush_pos + len && p->first > next_safe_pos)
655 next_safe_pos = p->first;
659 filer.write(ino, &layout, snapc,
660 flush_pos, len, write_bl, ceph::real_clock::now(),
662 wrap_finisher(onsafe), write_iohint);
665 assert(write_buf.length() == write_pos - flush_pos);
666 write_buf_throttle.put(len);
667 ldout(cct, 20) << "write_buf_throttle put, len " << len << dendl;
670 << "_do_flush (prezeroing/prezero)/write/flush/safe pointers now at "
671 << "(" << prezeroing_pos << "/" << prezero_pos << ")/" << write_pos
672 << "/" << flush_pos << "/" << safe_pos << dendl;
678 void Journaler::wait_for_flush(Context *onsafe)
682 onsafe->complete(-EAGAIN);
685 _wait_for_flush(onsafe);
688 void Journaler::_wait_for_flush(Context *onsafe)
692 // all flushed and safe?
693 if (write_pos == safe_pos) {
694 assert(write_buf.length() == 0);
696 << "flush nothing to flush, (prezeroing/prezero)/write/flush/safe "
697 "pointers at " << "(" << prezeroing_pos << "/" << prezero_pos << ")/"
698 << write_pos << "/" << flush_pos << "/" << safe_pos << dendl;
700 finisher->queue(onsafe, 0);
707 waitfor_safe[write_pos].push_back(wrap_finisher(onsafe));
711 void Journaler::flush(Context *onsafe)
714 _flush(wrap_finisher(onsafe));
717 void Journaler::_flush(C_OnFinisher *onsafe)
721 if (write_pos == flush_pos) {
722 assert(write_buf.length() == 0);
723 ldout(cct, 10) << "flush nothing to flush, (prezeroing/prezero)/write/"
724 "flush/safe pointers at " << "(" << prezeroing_pos << "/" << prezero_pos
725 << ")/" << write_pos << "/" << flush_pos << "/" << safe_pos
732 _wait_for_flush(onsafe);
736 if (_write_head_needed()) {
741 bool Journaler::_write_head_needed()
743 return last_wrote_head + seconds(cct->_conf->journaler_write_head_interval)
744 < ceph::real_clock::now();
748 /*************** prezeroing ******************/
750 struct C_Journaler_Prezero : public Context {
751 Journaler *journaler;
753 C_Journaler_Prezero(Journaler *j, uint64_t f, uint64_t l)
754 : journaler(j), from(f), len(l) {}
755 void finish(int r) override {
756 journaler->_finish_prezero(r, from, len);
760 void Journaler::_issue_prezero()
762 assert(prezeroing_pos >= flush_pos);
764 // we need to zero at least two periods, minimum, to ensure that we
765 // have a full empty object/period in front of us.
766 uint64_t num_periods = MAX(2, cct->_conf->journaler_prezero_periods);
769 * issue zero requests based on write_pos, even though the invariant
770 * is that we zero ahead of flush_pos.
772 uint64_t period = get_layout_period();
773 uint64_t to = write_pos + period * num_periods + period - 1;
776 if (prezeroing_pos >= to) {
777 ldout(cct, 20) << "_issue_prezero target " << to << " <= prezeroing_pos "
778 << prezeroing_pos << dendl;
782 while (prezeroing_pos < to) {
784 if (prezeroing_pos % period == 0) {
786 ldout(cct, 10) << "_issue_prezero removing " << prezeroing_pos << "~"
787 << period << " (full period)" << dendl;
789 len = period - (prezeroing_pos % period);
790 ldout(cct, 10) << "_issue_prezero zeroing " << prezeroing_pos << "~"
791 << len << " (partial period)" << dendl;
794 Context *c = wrap_finisher(new C_Journaler_Prezero(this, prezeroing_pos,
796 filer.zero(ino, &layout, snapc, prezeroing_pos, len,
797 ceph::real_clock::now(), 0, c);
798 prezeroing_pos += len;
802 // Lock cycle because we get called out of objecter callback (holding
803 // objecter read lock), but there are also cases where we take the journaler
804 // lock before calling into objecter to do I/O.
805 void Journaler::_finish_prezero(int r, uint64_t start, uint64_t len)
809 ldout(cct, 10) << "_prezeroed to " << start << "~" << len
810 << ", prezeroing/prezero was " << prezeroing_pos << "/"
811 << prezero_pos << ", pending " << pending_zero
813 if (r < 0 && r != -ENOENT) {
814 lderr(cct) << "_prezeroed got " << cpp_strerror(r) << dendl;
815 handle_write_error(r);
819 assert(r == 0 || r == -ENOENT);
821 if (start == prezero_pos) {
823 while (!pending_zero.empty() &&
824 pending_zero.begin().get_start() == prezero_pos) {
825 interval_set<uint64_t>::iterator b(pending_zero.begin());
826 prezero_pos += b.get_len();
827 pending_zero.erase(b);
830 if (waiting_for_zero) {
834 pending_zero.insert(start, len);
836 ldout(cct, 10) << "_prezeroed prezeroing/prezero now " << prezeroing_pos
837 << "/" << prezero_pos
838 << ", pending " << pending_zero
844 /***************** READING *******************/
847 class Journaler::C_Read : public Context {
853 C_Read(Journaler *j, uint64_t o, uint64_t l) : ls(j), offset(o), length(l) {}
854 void finish(int r) override {
855 ls->_finish_read(r, offset, length, bl);
859 class Journaler::C_RetryRead : public Context {
862 explicit C_RetryRead(Journaler *l) : ls(l) {}
864 void finish(int r) override {
865 // Should only be called from waitfor_safe i.e. already inside lock
866 // (ls->lock is locked
871 void Journaler::_finish_read(int r, uint64_t offset, uint64_t length,
877 ldout(cct, 0) << "_finish_read got error " << r << dendl;
880 ldout(cct, 10) << "_finish_read got " << offset << "~" << bl.length()
882 if (bl.length() < length) {
883 ldout(cct, 0) << "_finish_read got less than expected (" << length << ")"
891 C_OnFinisher *f = on_readable;
898 prefetch_buf[offset].swap(bl);
901 _assimilate_prefetch();
902 } catch (const buffer::error &err) {
903 lderr(cct) << "_decode error from assimilate_prefetch" << dendl;
906 C_OnFinisher *f = on_readable;
915 void Journaler::_assimilate_prefetch()
917 bool was_readable = readable;
919 bool got_any = false;
920 while (!prefetch_buf.empty()) {
921 map<uint64_t,bufferlist>::iterator p = prefetch_buf.begin();
922 if (p->first != received_pos) {
923 uint64_t gap = p->first - received_pos;
924 ldout(cct, 10) << "_assimilate_prefetch gap of " << gap
925 << " from received_pos " << received_pos
926 << " to first prefetched buffer " << p->first << dendl;
930 ldout(cct, 10) << "_assimilate_prefetch " << p->first << "~"
931 << p->second.length() << dendl;
932 received_pos += p->second.length();
933 read_buf.claim_append(p->second);
934 assert(received_pos <= requested_pos);
935 prefetch_buf.erase(p);
940 ldout(cct, 10) << "_assimilate_prefetch read_buf now " << read_pos << "~"
941 << read_buf.length() << ", read pointers " << read_pos
942 << "/" << received_pos << "/" << requested_pos
945 // Update readability (this will also hit any decode errors resulting
947 readable = _is_readable();
950 if ((got_any && !was_readable && readable) || read_pos == write_pos) {
952 ldout(cct, 10) << "_finish_read now readable (or at journal end) readable="
953 << readable << " read_pos=" << read_pos << " write_pos="
954 << write_pos << dendl;
956 C_OnFinisher *f = on_readable;
963 void Journaler::_issue_read(uint64_t len)
965 // stuck at safe_pos? (this is needed if we are reading the tail of
966 // a journal we are also writing to)
967 assert(requested_pos <= safe_pos);
968 if (requested_pos == safe_pos) {
969 ldout(cct, 10) << "_issue_read requested_pos = safe_pos = " << safe_pos
970 << ", waiting" << dendl;
971 assert(write_pos > requested_pos);
972 if (pending_safe.empty()) {
976 // Make sure keys of waitfor_safe map are journal entry boundaries.
977 // The key we used here is either next_safe_pos or old value of
978 // next_safe_pos. next_safe_pos is always set to journal entry
980 auto p = pending_safe.rbegin();
981 if (p != pending_safe.rend())
982 waitfor_safe[p->second].push_back(new C_RetryRead(this));
984 waitfor_safe[next_safe_pos].push_back(new C_RetryRead(this));
988 // don't read too much
989 if (requested_pos + len > safe_pos) {
990 len = safe_pos - requested_pos;
991 ldout(cct, 10) << "_issue_read reading only up to safe_pos " << safe_pos
996 ldout(cct, 10) << "_issue_read reading " << requested_pos << "~" << len
997 << ", read pointers " << read_pos << "/" << received_pos
998 << "/" << (requested_pos+len) << dendl;
1000 // step by period (object). _don't_ do a single big filer.read()
1001 // here because it will wait for all object reads to complete before
1002 // giving us back any data. this way we can process whatever bits
1003 // come in that are contiguous.
1004 uint64_t period = get_layout_period();
1006 uint64_t e = requested_pos + period;
1008 uint64_t l = e - requested_pos;
1011 C_Read *c = new C_Read(this, requested_pos, l);
1012 filer.read(ino, &layout, CEPH_NOSNAP, requested_pos, l, &c->bl, 0,
1013 wrap_finisher(c), CEPH_OSD_OP_FLAG_FADVISE_DONTNEED);
1019 void Journaler::_prefetch()
1021 ldout(cct, 10) << "_prefetch" << dendl;
1024 if (temp_fetch_len) {
1025 ldout(cct, 10) << "_prefetch temp_fetch_len " << temp_fetch_len << dendl;
1026 pf = temp_fetch_len;
1032 uint64_t raw_target = read_pos + pf;
1034 // read full log segments, so increase if necessary
1035 uint64_t period = get_layout_period();
1036 uint64_t remainder = raw_target % period;
1037 uint64_t adjustment = remainder ? period - remainder : 0;
1038 uint64_t target = raw_target + adjustment;
1040 // don't read past the log tail
1041 if (target > write_pos)
1044 if (requested_pos < target) {
1045 uint64_t len = target - requested_pos;
1046 ldout(cct, 10) << "_prefetch " << pf << " requested_pos " << requested_pos
1047 << " < target " << target << " (" << raw_target
1048 << "), prefetching " << len << dendl;
1050 if (pending_safe.empty() && write_pos > safe_pos) {
1051 // If we are reading and writing the journal, then we may need
1052 // to issue a flush if one isn't already in progress.
1053 // Avoid doing a flush every time so that if we do write/read/write/read
1054 // we don't end up flushing after every write.
1055 ldout(cct, 10) << "_prefetch: requested_pos=" << requested_pos
1056 << ", read_pos=" << read_pos
1057 << ", write_pos=" << write_pos
1058 << ", safe_pos=" << safe_pos << dendl;
1068 * _is_readable() - return true if next entry is ready.
1070 bool Journaler::_is_readable()
1072 // anything to read?
1073 if (read_pos == write_pos)
1076 // Check if the retrieve bytestream has enough for an entry
1078 if (journal_stream.readable(read_buf, &need)) {
1082 ldout (cct, 10) << "_is_readable read_buf.length() == " << read_buf.length()
1083 << ", but need " << need << " for next entry; fetch_len is "
1084 << fetch_len << dendl;
1086 // partial fragment at the end?
1087 if (received_pos == write_pos) {
1088 ldout(cct, 10) << "is_readable() detected partial entry at tail, "
1089 "adjusting write_pos to " << read_pos << dendl;
1092 prezeroing_pos = prezero_pos = write_pos = flush_pos = safe_pos = next_safe_pos = read_pos;
1093 assert(write_buf.length() == 0);
1094 assert(waitfor_safe.empty());
1097 requested_pos = received_pos = read_pos;
1100 // FIXME: truncate on disk?
1105 if (need > fetch_len) {
1106 temp_fetch_len = need;
1107 ldout(cct, 10) << "_is_readable noting temp_fetch_len " << temp_fetch_len
1111 ldout(cct, 10) << "_is_readable: not readable, returning false" << dendl;
1116 * is_readable() - kickstart prefetch, too
1118 bool Journaler::is_readable()
1131 class Journaler::C_EraseFinish : public Context {
1132 Journaler *journaler;
1133 C_OnFinisher *completion;
1135 C_EraseFinish(Journaler *j, C_OnFinisher *c) : journaler(j), completion(c) {}
1136 void finish(int r) override {
1137 journaler->_finish_erase(r, completion);
1142 * Entirely erase the journal, including header. For use when you
1143 * have already made a copy of the journal somewhere else.
1145 void Journaler::erase(Context *completion)
1149 // Async delete the journal data
1150 uint64_t first = trimmed_pos / get_layout_period();
1151 uint64_t num = (write_pos - trimmed_pos) / get_layout_period() + 2;
1152 filer.purge_range(ino, &layout, SnapContext(), first, num,
1153 ceph::real_clock::now(), 0,
1154 wrap_finisher(new C_EraseFinish(
1155 this, wrap_finisher(completion))));
1157 // We will not start the operation to delete the header until
1158 // _finish_erase has seen the data deletion succeed: otherwise if
1159 // there was an error deleting data we might prematurely delete the
1160 // header thereby lose our reference to the data.
1163 void Journaler::_finish_erase(int data_result, C_OnFinisher *completion)
1167 if (data_result == 0) {
1168 // Async delete the journal header
1169 filer.purge_range(ino, &layout, SnapContext(), 0, 1,
1170 ceph::real_clock::now(),
1171 0, wrap_finisher(completion));
1173 lderr(cct) << "Failed to delete journal " << ino << " data: "
1174 << cpp_strerror(data_result) << dendl;
1175 completion->complete(data_result);
1179 /* try_read_entry(bl)
1180 * read entry into bl if it's ready.
1181 * otherwise, do nothing.
1183 bool Journaler::try_read_entry(bufferlist& bl)
1188 ldout(cct, 10) << "try_read_entry at " << read_pos << " not readable"
1196 consumed = journal_stream.read(read_buf, &bl, &start_ptr);
1197 if (stream_format >= JOURNAL_FORMAT_RESILIENT) {
1198 assert(start_ptr == read_pos);
1200 } catch (const buffer::error &e) {
1201 lderr(cct) << __func__ << ": decode error from journal_stream" << dendl;
1206 ldout(cct, 10) << "try_read_entry at " << read_pos << " read "
1207 << read_pos << "~" << consumed << " (have "
1208 << read_buf.length() << ")" << dendl;
1210 read_pos += consumed;
1212 // We were readable, we might not be any more
1213 readable = _is_readable();
1214 } catch (const buffer::error &e) {
1215 lderr(cct) << __func__ << ": decode error from _is_readable" << dendl;
1225 void Journaler::wait_for_readable(Context *onreadable)
1229 finisher->queue(onreadable, -EAGAIN);
1233 assert(on_readable == 0);
1235 ldout(cct, 10) << "wait_for_readable at " << read_pos << " onreadable "
1236 << onreadable << dendl;
1237 on_readable = wrap_finisher(onreadable);
1239 // race with OSD reply
1240 finisher->queue(onreadable, 0);
1244 bool Journaler::have_waiter() const
1246 return on_readable != nullptr;
1252 /***************** TRIMMING *******************/
1255 class Journaler::C_Trim : public Context {
1259 C_Trim(Journaler *l, int64_t t) : ls(l), to(t) {}
1260 void finish(int r) override {
1261 ls->_finish_trim(r, to);
1265 void Journaler::trim()
1271 void Journaler::_trim()
1274 uint64_t period = get_layout_period();
1275 uint64_t trim_to = last_committed.expire_pos;
1276 trim_to -= trim_to % period;
1277 ldout(cct, 10) << "trim last_commited head was " << last_committed
1278 << ", can trim to " << trim_to
1280 if (trim_to == 0 || trim_to == trimming_pos) {
1281 ldout(cct, 10) << "trim already trimmed/trimming to "
1282 << trimmed_pos << "/" << trimming_pos << dendl;
1286 if (trimming_pos > trimmed_pos) {
1287 ldout(cct, 10) << "trim already trimming atm, try again later. "
1288 "trimmed/trimming is " << trimmed_pos << "/" << trimming_pos << dendl;
1293 assert(trim_to <= write_pos);
1294 assert(trim_to <= expire_pos);
1295 assert(trim_to > trimming_pos);
1296 ldout(cct, 10) << "trim trimming to " << trim_to
1297 << ", trimmed/trimming/expire are "
1298 << trimmed_pos << "/" << trimming_pos << "/" << expire_pos
1301 // delete range of objects
1302 uint64_t first = trimming_pos / period;
1303 uint64_t num = (trim_to - trimming_pos) / period;
1305 filer.purge_range(ino, &layout, snapc, first, num,
1306 ceph::real_clock::now(), 0,
1307 wrap_finisher(new C_Trim(this, trim_to)));
1308 trimming_pos = trim_to;
1311 void Journaler::_finish_trim(int r, uint64_t to)
1316 ldout(cct, 10) << "_finish_trim trimmed_pos was " << trimmed_pos
1317 << ", trimmed/trimming/expire now "
1318 << to << "/" << trimming_pos << "/" << expire_pos
1320 if (r < 0 && r != -ENOENT) {
1321 lderr(cct) << "_finish_trim got " << cpp_strerror(r) << dendl;
1322 handle_write_error(r);
1326 assert(r >= 0 || r == -ENOENT);
1328 assert(to <= trimming_pos);
1329 assert(to > trimmed_pos);
1333 void Journaler::handle_write_error(int r)
1337 lderr(cct) << "handle_write_error " << cpp_strerror(r) << dendl;
1338 if (on_write_error) {
1339 on_write_error->complete(r);
1340 on_write_error = NULL;
1341 called_write_error = true;
1342 } else if (called_write_error) {
1343 /* We don't call error handler more than once, subsequent errors
1344 * are dropped -- this is okay as long as the error handler does
1345 * something dramatic like respawn */
1346 lderr(cct) << __func__ << ": multiple write errors, handler already called"
1349 assert(0 == "unhandled write error");
1355 * Test whether the 'read_buf' byte stream has enough data to read
1358 * sets 'next_envelope_size' to the number of bytes needed to advance (enough
1359 * to get the next header if header was unavailable, or enough to get the whole
1360 * next entry if the header was available but the body wasn't).
1362 bool JournalStream::readable(bufferlist &read_buf, uint64_t *need) const
1364 assert(need != NULL);
1366 uint32_t entry_size = 0;
1367 uint64_t entry_sentinel = 0;
1368 bufferlist::iterator p = read_buf.begin();
1370 // Do we have enough data to decode an entry prefix?
1371 if (format >= JOURNAL_FORMAT_RESILIENT) {
1372 *need = sizeof(entry_size) + sizeof(entry_sentinel);
1374 *need = sizeof(entry_size);
1376 if (read_buf.length() >= *need) {
1377 if (format >= JOURNAL_FORMAT_RESILIENT) {
1378 ::decode(entry_sentinel, p);
1379 if (entry_sentinel != sentinel) {
1380 throw buffer::malformed_input("Invalid sentinel");
1384 ::decode(entry_size, p);
1389 // Do we have enough data to decode an entry prefix, payload and suffix?
1390 if (format >= JOURNAL_FORMAT_RESILIENT) {
1391 *need = JOURNAL_ENVELOPE_RESILIENT + entry_size;
1393 *need = JOURNAL_ENVELOPE_LEGACY + entry_size;
1395 if (read_buf.length() >= *need) {
1396 return true; // No more bytes needed
1404 * Consume one entry from a journal byte stream 'from', splicing a
1405 * serialized LogEvent blob into 'entry'.
1407 * 'entry' must be non null and point to an empty bufferlist.
1409 * 'from' must contain sufficient valid data (i.e. readable is true).
1411 * 'start_ptr' will be set to the entry's start pointer, if the collection
1412 * format provides it. It may not be null.
1414 * @returns The number of bytes consumed from the `from` byte stream. Note
1415 * that this is not equal to the length of `entry`, which contains
1416 * the inner serialized LogEvent and not the envelope.
1418 size_t JournalStream::read(bufferlist &from, bufferlist *entry,
1419 uint64_t *start_ptr)
1421 assert(start_ptr != NULL);
1422 assert(entry != NULL);
1423 assert(entry->length() == 0);
1425 uint32_t entry_size = 0;
1427 // Consume envelope prefix: entry_size and entry_sentinel
1428 bufferlist::iterator from_ptr = from.begin();
1429 if (format >= JOURNAL_FORMAT_RESILIENT) {
1430 uint64_t entry_sentinel = 0;
1431 ::decode(entry_sentinel, from_ptr);
1432 // Assertion instead of clean check because of precondition of this
1433 // fn is that readable() already passed
1434 assert(entry_sentinel == sentinel);
1436 ::decode(entry_size, from_ptr);
1438 // Read out the payload
1439 from_ptr.copy(entry_size, *entry);
1441 // Consume the envelope suffix (start_ptr)
1442 if (format >= JOURNAL_FORMAT_RESILIENT) {
1443 ::decode(*start_ptr, from_ptr);
1448 // Trim the input buffer to discard the bytes we have consumed
1449 from.splice(0, from_ptr.get_off());
1451 return from_ptr.get_off();
1458 size_t JournalStream::write(bufferlist &entry, bufferlist *to,
1459 uint64_t const &start_ptr)
1463 uint32_t const entry_size = entry.length();
1464 if (format >= JOURNAL_FORMAT_RESILIENT) {
1465 ::encode(sentinel, *to);
1467 ::encode(entry_size, *to);
1468 to->claim_append(entry);
1469 if (format >= JOURNAL_FORMAT_RESILIENT) {
1470 ::encode(start_ptr, *to);
1473 if (format >= JOURNAL_FORMAT_RESILIENT) {
1474 return JOURNAL_ENVELOPE_RESILIENT + entry_size;
1476 return JOURNAL_ENVELOPE_LEGACY + entry_size;
1481 * set write error callback
1483 * Set a callback/context to trigger if we get a write error from
1484 * the objecter. This may be from an explicit request (e.g., flush)
1485 * or something async the journaler did on its own (e.g., journal
1488 * It is only used once; if the caller continues to use the
1489 * Journaler and wants to hear about errors, it needs to reset the
1492 * @param c callback/context to trigger on error
1494 void Journaler::set_write_error_handler(Context *c) {
1496 assert(!on_write_error);
1497 on_write_error = wrap_finisher(c);
1498 called_write_error = false;
1503 * Wrap a context in a C_OnFinisher, if it is non-NULL
1505 * Utility function to avoid lots of error-prone and verbose
1506 * NULL checking on contexts passed in.
1508 C_OnFinisher *Journaler::wrap_finisher(Context *c)
1511 return new C_OnFinisher(c, finisher);
1517 void Journaler::shutdown()
1521 ldout(cct, 1) << __func__ << dendl;
1526 // Kick out anyone reading from journal
1529 C_OnFinisher *f = on_readable;
1531 f->complete(-EAGAIN);
1534 finish_contexts(cct, waitfor_recover, -ESHUTDOWN);
1536 std::map<uint64_t, std::list<Context*> >::iterator i;
1537 for (i = waitfor_safe.begin(); i != waitfor_safe.end(); ++i) {
1538 finish_contexts(cct, i->second, -EAGAIN);
1540 waitfor_safe.clear();