vitastor/src/disk_tool_journal.cpp

// Copyright (c) Vitaliy Filippov, 2019+
// License: VNPL-1.1 (see README.md for details)

#include "disk_tool.h"

int disk_tool_t::dump_journal()
{
    if (dsk.journal_block_size < DIRECT_IO_ALIGNMENT || (dsk.journal_block_size % DIRECT_IO_ALIGNMENT) ||
        dsk.journal_block_size > 128*1024)
    {
        fprintf(stderr, "Invalid journal block size\n");
        return 1;
    }
    first = true;
    if (json)
        printf("[\n");
    if (all)
    {
        dsk.journal_fd = open(dsk.journal_device.c_str(), O_DIRECT|O_RDONLY);
        if (dsk.journal_fd < 0)
        {
            fprintf(stderr, "Failed to open journal device %s: %s\n", dsk.journal_device.c_str(), strerror(errno));
            return 1;
        }
        void *journal_buf = memalign_or_die(MEM_ALIGNMENT, dsk.journal_block_size);
        journal_pos = 0;
        while (journal_pos < dsk.journal_len)
        {
            int r = pread(dsk.journal_fd, journal_buf, dsk.journal_block_size, dsk.journal_offset+journal_pos);
            assert(r == dsk.journal_block_size);
            uint64_t s;
            for (s = 0; s < dsk.journal_block_size; s += 8)
            {
                if (*((uint64_t*)((uint8_t*)journal_buf+s)) != 0)
                    break;
            }
            if (json)
            {
                printf("%s{\"offset\":\"0x%lx\"", first ? "" : ",\n", journal_pos);
                first = false;
            }
            if (s == dsk.journal_block_size)
            {
                if (json)
                    printf(",\"type\":\"zero\"}");
                else
                    printf("offset %08lx: zeroes\n", journal_pos);
                journal_pos += dsk.journal_block_size;
            }
            else if (((journal_entry*)journal_buf)->magic == JOURNAL_MAGIC)
            {
                if (!json)
                    printf("offset %08lx:\n", journal_pos);
                else
                    printf(",\"entries\":[\n");
                first2 = true;
                process_journal_block(journal_buf, [this](int num, journal_entry *je) { dump_journal_entry(num, je, json); });
                if (json)
                    printf(first2 ? "]}" : "\n]}");
            }
            else
            {
                if (json)
                    printf(",\"type\":\"data\",\"pattern\":\"%08lx\"}", *((uint64_t*)journal_buf));
                else
                    printf("offset %08lx: no magic in the beginning, looks like random data (pattern=%08lx)\n", journal_pos, *((uint64_t*)journal_buf));
                journal_pos += dsk.journal_block_size;
            }
        }
        free(journal_buf);
        close(dsk.journal_fd);
        dsk.journal_fd = -1;
    }
    else
    {
        process_journal([this](void *data)
        {
            first2 = true;
            if (!json)
                printf("offset %08lx:\n", journal_pos);
            auto pos = journal_pos;
            int r = process_journal_block(data, [this, pos](int num, journal_entry *je)
            {
                if (json && first2)
                {
                    printf("%s{\"offset\":\"0x%lx\",\"entries\":[\n", first ? "" : ",\n", pos);
                    first = false;
                }
                dump_journal_entry(num, je, json);
            });
            if (json)
                printf(first2 ? "" : "\n]}");
            else if (r <= 0)
                printf("end of the journal\n");
            return r;
        });
    }
    if (json)
        printf(first ? "]\n" : "\n]\n");
    return 0;
}

int disk_tool_t::process_journal(std::function<int(void*)> block_fn)
{
    dsk.journal_fd = open(dsk.journal_device.c_str(), O_DIRECT|O_RDONLY);
    if (dsk.journal_fd < 0)
    {
        fprintf(stderr, "Failed to open journal device %s: %s\n", dsk.journal_device.c_str(), strerror(errno));
        return 1;
    }
    void *data = memalign_or_die(MEM_ALIGNMENT, dsk.journal_block_size);
    journal_pos = 0;
    int r = pread(dsk.journal_fd, data, dsk.journal_block_size, dsk.journal_offset+journal_pos);
    assert(r == dsk.journal_block_size);
    journal_entry *je = (journal_entry*)(data);
    if (je->magic != JOURNAL_MAGIC || je->type != JE_START || je_crc32(je) != je->crc32)
    {
        fprintf(stderr, "offset %08lx: journal superblock is invalid\n", journal_pos);
        r = 1;
    }
    else
    {
        started = false;
        crc32_last = 0;
        block_fn(data);
        started = false;
        crc32_last = 0;
        journal_pos = je->start.journal_start;
        while (1)
        {
            if (journal_pos >= dsk.journal_len)
                journal_pos = dsk.journal_block_size;
            r = pread(dsk.journal_fd, data, dsk.journal_block_size, dsk.journal_offset+journal_pos);
            assert(r == dsk.journal_block_size);
            r = block_fn(data);
            if (r <= 0)
                break;
        }
    }
    close(dsk.journal_fd);
    dsk.journal_fd = -1;
    free(data);
    return r;
}

int disk_tool_t::process_journal_block(void *buf, std::function<void(int, journal_entry*)> iter_fn)
{
    uint32_t pos = 0;
    journal_pos += dsk.journal_block_size;
    int entry = 0;
    bool wrapped = false;
    while (pos <= dsk.journal_block_size-JOURNAL_ENTRY_HEADER_SIZE)
    {
        journal_entry *je = (journal_entry*)((uint8_t*)buf + pos);
        if (je->magic != JOURNAL_MAGIC || je->type < JE_MIN || je->type > JE_MAX ||
            !all && started && je->crc32_prev != crc32_last || pos > dsk.journal_block_size-je->size)
        {
            break;
        }
        bool crc32_valid = je_crc32(je) == je->crc32;
        if (!all && !crc32_valid)
        {
            break;
        }
        started = true;
        crc32_last = je->crc32;
        if (je->type == JE_SMALL_WRITE || je->type == JE_SMALL_WRITE_INSTANT)
        {
            journal_calc_data_pos = journal_pos;
            if (journal_pos + je->small_write.len > dsk.journal_len)
            {
                // data continues from the beginning of the journal
                journal_calc_data_pos = journal_pos = dsk.journal_block_size;
                wrapped = true;
            }
            journal_pos += je->small_write.len;
            if (journal_pos >= dsk.journal_len)
            {
                journal_pos = dsk.journal_block_size;
                wrapped = true;
            }
            small_write_data = memalign_or_die(MEM_ALIGNMENT, je->small_write.len);
            assert(pread(dsk.journal_fd, small_write_data, je->small_write.len, dsk.journal_offset+je->small_write.data_offset) == je->small_write.len);
            data_crc32 = crc32c(0, small_write_data, je->small_write.len);
        }
        iter_fn(entry, je);
        if (je->type == JE_SMALL_WRITE || je->type == JE_SMALL_WRITE_INSTANT)
        {
            free(small_write_data);
            small_write_data = NULL;
        }
        pos += je->size;
        entry++;
    }
    if (wrapped)
    {
        journal_pos = dsk.journal_len;
    }
    return entry;
}

void disk_tool_t::dump_journal_entry(int num, journal_entry *je, bool json)
{
    if (json)
    {
        if (!first2)
            printf(",\n");
        first2 = false;
        printf(
            "{\"crc32\":\"%08x\",\"valid\":%s,\"crc32_prev\":\"%08x\"",
            je->crc32, (je_crc32(je) == je->crc32 ? "true" : "false"), je->crc32_prev
        );
    }
    else
    {
        printf(
            "entry % 3d: crc32=%08x %s prev=%08x ",
            num, je->crc32, (je_crc32(je) == je->crc32 ? "(valid)" : "(invalid)"), je->crc32_prev
        );
    }
    if (je->type == JE_START)
    {
        printf(
            json ? ",\"type\":\"start\",\"start\":\"0x%lx\"}" : "je_start start=%08lx\n",
            je->start.journal_start
        );
    }
    else if (je->type == JE_SMALL_WRITE || je->type == JE_SMALL_WRITE_INSTANT)
    {
        printf(
            json ? ",\"type\":\"small_write%s\",\"inode\":\"0x%lx\",\"stripe\":\"0x%lx\",\"ver\":\"%lu\",\"offset\":%u,\"len\":%u,\"loc\":\"0x%lx\""
                : "je_small_write%s oid=%lx:%lx ver=%lu offset=%u len=%u loc=%08lx",
            je->type == JE_SMALL_WRITE_INSTANT ? "_instant" : "",
            je->small_write.oid.inode, je->small_write.oid.stripe,
            je->small_write.version, je->small_write.offset, je->small_write.len,
            je->small_write.data_offset
        );
        if (journal_calc_data_pos != je->small_write.data_offset)
        {
            printf(json ? ",\"bad_loc\":true,\"calc_loc\":\"0x%lx\""
                : " (mismatched, calculated = %lu)", journal_pos);
        }
        printf(
            json ? ",\"data_crc32\":\"%08x\",\"data_valid\":%s}" : " data_crc32=%08x%s\n",
            je->small_write.crc32_data,
            (data_crc32 != je->small_write.crc32_data
                ? (json ? "false" : " (invalid)")
                : (json ? "true" : " (valid)"))
        );
    }
    else if (je->type == JE_BIG_WRITE || je->type == JE_BIG_WRITE_INSTANT)
    {
        printf(
            json ? ",\"type\":\"big_write%s\",\"inode\":\"0x%lx\",\"stripe\":\"0x%lx\",\"ver\":\"%lu\",\"loc\":\"0x%lx\"}"
                : "je_big_write%s oid=%lx:%lx ver=%lu loc=%08lx\n",
            je->type == JE_BIG_WRITE_INSTANT ? "_instant" : "",
            je->big_write.oid.inode, je->big_write.oid.stripe, je->big_write.version, je->big_write.location
        );
    }
    else if (je->type == JE_STABLE)
    {
        printf(
            json ? ",\"type\":\"stable\",\"inode\":\"0x%lx\",\"stripe\":\"0x%lx\",\"ver\":\"%lu\"}"
                : "je_stable oid=%lx:%lx ver=%lu\n",
            je->stable.oid.inode, je->stable.oid.stripe, je->stable.version
        );
    }
    else if (je->type == JE_ROLLBACK)
    {
        printf(
            json ? ",\"type\":\"rollback\",\"inode\":\"0x%lx\",\"stripe\":\"0x%lx\",\"ver\":\"%lu\"}"
                : "je_rollback oid=%lx:%lx ver=%lu\n",
            je->rollback.oid.inode, je->rollback.oid.stripe, je->rollback.version
        );
    }
    else if (je->type == JE_DELETE)
    {
        printf(
            json ? ",\"type\":\"delete\",\"inode\":\"0x%lx\",\"stripe\":\"0x%lx\",\"ver\":\"%lu\"}"
                : "je_delete oid=%lx:%lx ver=%lu\n",
            je->del.oid.inode, je->del.oid.stripe, je->del.version
        );
    }
}