+++ /dev/null
-// -*- 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) 2014 john spray <john.spray@inktank.com>
- *
- * 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 "include/rados/librados.hpp"
-#include "mds/JournalPointer.h"
-
-#include "mds/events/ESubtreeMap.h"
-
-#include "JournalScanner.h"
-
-#define dout_context g_ceph_context
-#define dout_subsys ceph_subsys_mds
-
-/**
- * Read journal header, followed by sequential scan through journal space.
- *
- * Return 0 on success, else error code. Note that success has the special meaning
- * that we were able to apply our checks, it does *not* mean that the journal is
- * healthy.
- */
-int JournalScanner::scan(bool const full)
-{
- int r = 0;
-
- r = scan_pointer();
- if (r < 0) {
- return r;
- }
-
- if (pointer_present) {
- r = scan_header();
- if (r < 0) {
- return r;
- }
- }
-
- if (full && header_present) {
- r = scan_events();
- if (r < 0) {
- return r;
- }
- }
-
- return 0;
-}
-
-
-int JournalScanner::scan_pointer()
-{
- // Issue read
- std::string const pointer_oid = obj_name(MDS_INO_LOG_POINTER_OFFSET + rank, 0);
- bufferlist pointer_bl;
- int r = io.read(pointer_oid, pointer_bl, INT_MAX, 0);
- if (r == -ENOENT) {
- // 'Successfully' discovered the pointer is missing.
- derr << "Pointer " << pointer_oid << " is absent" << dendl;
- return 0;
- } else if (r < 0) {
- // Error preventing us interrogating pointer
- derr << "Pointer " << pointer_oid << " is unreadable" << dendl;
- return r;
- } else {
- dout(4) << "Pointer " << pointer_oid << " is readable" << dendl;
- pointer_present = true;
-
- JournalPointer jp;
- try {
- bufferlist::iterator q = pointer_bl.begin();
- jp.decode(q);
- } catch(buffer::error &e) {
- derr << "Pointer " << pointer_oid << " is corrupt: " << e.what() << dendl;
- return 0;
- }
-
- pointer_valid = true;
- ino = jp.front;
- return 0;
- }
-}
-
-
-int JournalScanner::scan_header()
-{
- int r;
-
- bufferlist header_bl;
- std::string header_name = obj_name(0);
- dout(4) << "JournalScanner::scan: reading header object '" << header_name << "'" << dendl;
- r = io.read(header_name, header_bl, INT_MAX, 0);
- if (r < 0) {
- derr << "Header " << header_name << " is unreadable" << dendl;
- return 0; // "Successfully" found an error
- } else {
- header_present = true;
- }
-
- bufferlist::iterator header_bl_i = header_bl.begin();
- header = new Journaler::Header();
- try
- {
- header->decode(header_bl_i);
- }
- catch (buffer::error &e)
- {
- derr << "Header is corrupt (" << e.what() << ")" << dendl;
- delete header;
- header = NULL;
- return 0; // "Successfully" found an error
- }
-
- if (header->magic != std::string(CEPH_FS_ONDISK_MAGIC)) {
- derr << "Header is corrupt (bad magic)" << dendl;
- return 0; // "Successfully" found an error
- }
- if (!((header->trimmed_pos <= header->expire_pos) && (header->expire_pos <= header->write_pos))) {
- derr << "Header is invalid (inconsistent offsets)" << dendl;
- return 0; // "Successfully" found an error
- }
- header_valid = true;
-
- return 0;
-}
-
-
-int JournalScanner::scan_events()
-{
- uint64_t object_size = g_conf->mds_log_segment_size;
- if (object_size == 0) {
- // Default layout object size
- object_size = file_layout_t::get_default().object_size;
- }
-
- uint64_t read_offset = header->expire_pos;
- dout(10) << std::hex << "Header 0x"
- << header->trimmed_pos << " 0x"
- << header->expire_pos << " 0x"
- << header->write_pos << std::dec << dendl;
- dout(10) << "Starting journal scan from offset 0x" << std::hex << read_offset << std::dec << dendl;
-
- // TODO also check for extraneous objects before the trimmed pos or after the write pos,
- // which would indicate a bogus header.
-
- bufferlist read_buf;
- bool gap = false;
- uint64_t gap_start = -1;
- for (uint64_t obj_offset = (read_offset / object_size); ; obj_offset++) {
- uint64_t offset_in_obj = 0;
- if (obj_offset * object_size < header->expire_pos) {
- // Skip up to expire_pos from start of the object
- // (happens for the first object we read)
- offset_in_obj = header->expire_pos - obj_offset * object_size;
- }
-
- // Read this journal segment
- bufferlist this_object;
- std::string const oid = obj_name(obj_offset);
- int r = io.read(oid, this_object, INT_MAX, offset_in_obj);
-
- // Handle absent journal segments
- if (r < 0) {
- if (obj_offset > (header->write_pos / object_size)) {
- dout(4) << "Reached end of journal objects" << dendl;
- break;
- } else {
- derr << "Missing object " << oid << dendl;
- }
-
- objects_missing.push_back(obj_offset);
- gap = true;
- gap_start = read_offset;
- continue;
- } else {
- dout(4) << "Read 0x" << std::hex << this_object.length() << std::dec
- << " bytes from " << oid << " gap=" << gap << dendl;
- objects_valid.push_back(oid);
- this_object.copy(0, this_object.length(), read_buf);
- }
-
- if (gap) {
- // No valid data at the current read offset, scan forward until we find something valid looking
- // or have to drop out to load another object.
- dout(4) << "Searching for sentinel from 0x" << std::hex << read_offset
- << ", 0x" << read_buf.length() << std::dec << " bytes available" << dendl;
-
- do {
- bufferlist::iterator p = read_buf.begin();
- uint64_t candidate_sentinel;
- ::decode(candidate_sentinel, p);
-
- dout(4) << "Data at 0x" << std::hex << read_offset << " = 0x" << candidate_sentinel << std::dec << dendl;
-
- if (candidate_sentinel == JournalStream::sentinel) {
- dout(4) << "Found sentinel at 0x" << std::hex << read_offset << std::dec << dendl;
- ranges_invalid.push_back(Range(gap_start, read_offset));
- gap = false;
- break;
- } else {
- // No sentinel, discard this byte
- read_buf.splice(0, 1);
- read_offset += 1;
- }
- } while (read_buf.length() >= sizeof(JournalStream::sentinel));
- dout(4) << "read_buf size is " << read_buf.length() << dendl;
- } else {
- dout(10) << "Parsing data, 0x" << std::hex << read_buf.length() << std::dec << " bytes available" << dendl;
- while(true) {
- // TODO: detect and handle legacy format journals: can do many things
- // on them but on read errors have to give up instead of searching
- // for sentinels.
- JournalStream journal_stream(JOURNAL_FORMAT_RESILIENT);
- bool readable = false;
- try {
- uint64_t need;
- readable = journal_stream.readable(read_buf, &need);
- } catch (buffer::error &e) {
- readable = false;
- dout(4) << "Invalid container encoding at 0x" << std::hex << read_offset << std::dec << dendl;
- gap = true;
- gap_start = read_offset;
- read_buf.splice(0, 1);
- read_offset += 1;
- break;
- }
-
- if (!readable) {
- // Out of data, continue to read next object
- break;
- }
-
- bufferlist le_bl; //< Serialized LogEvent blob
- dout(10) << "Attempting decode at 0x" << std::hex << read_offset << std::dec << dendl;
- // This cannot fail to decode because we pre-checked that a serialized entry
- // blob would be readable.
- uint64_t start_ptr = 0;
- uint64_t consumed = journal_stream.read(read_buf, &le_bl, &start_ptr);
- dout(10) << "Consumed 0x" << std::hex << consumed << std::dec << " bytes" << dendl;
- if (start_ptr != read_offset) {
- derr << "Bad entry start ptr (0x" << std::hex << start_ptr << ") at 0x"
- << read_offset << std::dec << dendl;
- gap = true;
- gap_start = read_offset;
- // FIXME: given that entry was invalid, should we be skipping over it?
- // maybe push bytes back onto start of read_buf and just advance one byte
- // to start scanning instead. e.g. if a bogus size value is found it can
- // cause us to consume and thus skip a bunch of following valid events.
- read_offset += consumed;
- break;
- }
-
- LogEvent *le = LogEvent::decode(le_bl);
-
- if (le) {
- dout(10) << "Valid entry at 0x" << std::hex << read_offset << std::dec << dendl;
-
- if (le->get_type() == EVENT_SUBTREEMAP
- || le->get_type() == EVENT_SUBTREEMAP_TEST) {
- ESubtreeMap *sle = dynamic_cast<ESubtreeMap*>(le);
- if (sle->expire_pos > read_offset) {
- errors.insert(std::make_pair(
- read_offset, EventError(
- -ERANGE,
- "ESubtreeMap has expire_pos ahead of its own position")));
- }
- }
-
- if (filter.apply(read_offset, *le)) {
- events[read_offset] = EventRecord(le, consumed);
- } else {
- delete le;
- }
- events_valid.push_back(read_offset);
- read_offset += consumed;
- } else {
- dout(10) << "Invalid entry at 0x" << std::hex << read_offset << std::dec << dendl;
- gap = true;
- gap_start = read_offset;
- read_offset += consumed;
- }
- }
- }
- }
-
- if (gap) {
- // Ended on a gap, assume it ran to end
- ranges_invalid.push_back(Range(gap_start, -1));
- }
-
- dout(4) << "Scanned objects, " << objects_missing.size() << " missing, " << objects_valid.size() << " valid" << dendl;
- dout(4) << "Events scanned, " << ranges_invalid.size() << " gaps" << dendl;
- dout(4) << "Found " << events_valid.size() << " valid events" << dendl;
- dout(4) << "Selected " << events.size() << " events events for processing" << dendl;
-
- return 0;
-}
-
-
-JournalScanner::~JournalScanner()
-{
- if (header) {
- delete header;
- header = NULL;
- }
- dout(4) << events.size() << " events" << dendl;
- for (EventMap::iterator i = events.begin(); i != events.end(); ++i) {
- delete i->second.log_event;
- }
- events.clear();
-}
-
-
-/**
- * Whether the journal data looks valid and replayable
- */
-bool JournalScanner::is_healthy() const
-{
- return (pointer_present && pointer_valid
- && header_present && header_valid
- && ranges_invalid.empty()
- && objects_missing.empty());
-}
-
-
-/**
- * Whether the journal data can be read from RADOS
- */
-bool JournalScanner::is_readable() const
-{
- return (header_present && header_valid && objects_missing.empty());
-}
-
-
-/**
- * Calculate the object name for a given offset
- */
-std::string JournalScanner::obj_name(inodeno_t ino, uint64_t offset) const
-{
- char name[60];
- snprintf(name, sizeof(name), "%llx.%08llx",
- (unsigned long long)(ino),
- (unsigned long long)offset);
- return std::string(name);
-}
-
-
-std::string JournalScanner::obj_name(uint64_t offset) const
-{
- return obj_name(ino, offset);
-}
-
-
-/*
- * Write a human readable summary of the journal health
- */
-void JournalScanner::report(std::ostream &out) const
-{
- out << "Overall journal integrity: " << (is_healthy() ? "OK" : "DAMAGED") << std::endl;
-
- if (!pointer_present) {
- out << "Pointer not found" << std::endl;
- } else if (!pointer_valid) {
- out << "Pointer could not be decoded" << std::endl;
- }
-
- if (!header_present) {
- out << "Header not found" << std::endl;
- } else if (!header_valid) {
- out << "Header could not be decoded" << std::endl;
- }
-
- if (objects_missing.size()) {
- out << "Objects missing:" << std::endl;
- for (std::vector<uint64_t>::const_iterator om = objects_missing.begin();
- om != objects_missing.end(); ++om) {
- out << " 0x" << std::hex << *om << std::dec << std::endl;
- }
- }
-
- if (ranges_invalid.size()) {
- out << "Corrupt regions:" << std::endl;
- for (std::vector<Range>::const_iterator r = ranges_invalid.begin();
- r != ranges_invalid.end(); ++r) {
- out << " 0x" << std::hex << r->first << "-" << r->second << std::dec << std::endl;
- }
- }
-}
-
Code Review / stor4nfv.git / blobdiff