src/lib-index/mail-index-fsck.c

	mail-index-fsck.c revision 77f386273491b3a20b49b2a5a9db4b6e360615f9
/* Copyright (C) 2004 Timo Sirainen */

#include "lib.h"
#include "mail-index-private.h"
#include "mail-transaction-log.h"

static void mail_index_fsck_error(struct mail_index *index,
                  const char *fmt, ...) __attr_format__(2, 3);
static void mail_index_fsck_error(struct mail_index *index,
                  const char *fmt, ...)
{
    va_list va;

    va_start(va, fmt);
    mail_index_set_error(index, "Fixed index file %s: %s",
                 index->filepath, t_strdup_vprintf(fmt, va));
    va_end(va);
}

#define CHECK(field, oper) \
    if (hdr.field oper map->hdr.field) { \
        mail_index_fsck_error(index, #field" %u -> %u", \
                      map->hdr.field, hdr.field); \
    }

static void
mail_index_fsck_locked(struct mail_index *index, struct mail_index_header *hdr)
{
    uint32_t log_seq;
    uoff_t log_offset;

    mail_transaction_log_get_head(index->log, &log_seq, &log_offset);

    if (hdr->log_file_int_offset > hdr->log_file_ext_offset) {
        mail_index_fsck_error(index,
            "log_file_int_offset > log_file_ext_offset");
        hdr->log_file_int_offset = hdr->log_file_ext_offset;
    }

    if ((hdr->log_file_seq == log_seq &&
         hdr->log_file_ext_offset > log_offset) ||
        (hdr->log_file_seq != log_seq &&
         !mail_transaction_log_is_head_prev(index->log,
                        hdr->log_file_seq,
                        hdr->log_file_ext_offset))) {
        mail_index_fsck_error(index,
            "log file sync pos %u,%u -> %u, %"PRIuUOFF_T,
            hdr->log_file_seq, hdr->log_file_ext_offset,
            log_seq, log_offset);
        hdr->log_file_seq = log_seq;
        hdr->log_file_int_offset =
            hdr->log_file_ext_offset = log_offset;
    }
}

static int
mail_index_fsck_map(struct mail_index *index, struct mail_index_map *map,
            const char **error_r)
{
    struct mail_index_header hdr;
    const struct mail_index_record *rec;
    unsigned int records_count;
    uint32_t i, last_uid;

    *error_r = NULL;

    /* locking already does the most important sanity checks for header */
    hdr = map->hdr;

    if (hdr.uid_validity == 0 && hdr.next_uid != 1) {
        *error_r = "uid_validity = 0 && next_uid != 1";
        return 0;
    }

    if (!index->log_locked)
        records_count = map->hdr.messages_count;
    else {
        records_count = map->records_count;
        mail_index_fsck_locked(index, &hdr);
    }

    hdr.flags &= ~MAIL_INDEX_HDR_FLAG_FSCK;

    hdr.messages_count = 0;
    hdr.recent_messages_count = 0;
    hdr.seen_messages_count = 0;
    hdr.deleted_messages_count = 0;

    hdr.first_recent_uid_lowwater = 0;
    hdr.first_unseen_uid_lowwater = 0;
    hdr.first_deleted_uid_lowwater = 0;

    rec = map->records; last_uid = 0;
    for (i = 0; i < map->records_count; i++) {
        if (rec->uid <= last_uid) {
            *error_r = "Record UIDs are not ordered";
            return 0;
        }

        hdr.messages_count++;
        if ((rec->flags & MAIL_RECENT) != 0)
            hdr.recent_messages_count++;
        if ((rec->flags & MAIL_SEEN) != 0)
            hdr.seen_messages_count++;
        if ((rec->flags & MAIL_DELETED) != 0)
            hdr.deleted_messages_count++;

        if ((rec->flags & MAIL_RECENT) != 0 &&
            hdr.first_recent_uid_lowwater == 0)
            hdr.first_recent_uid_lowwater = rec->uid;
        if ((rec->flags & MAIL_SEEN) == 0 &&
            hdr.first_unseen_uid_lowwater == 0)
            hdr.first_unseen_uid_lowwater = rec->uid;
        if ((rec->flags & MAIL_DELETED) != 0 &&
            hdr.first_deleted_uid_lowwater == 0)
            hdr.first_deleted_uid_lowwater = rec->uid;

        last_uid = rec->uid;
        rec = CONST_PTR_OFFSET(rec, hdr.record_size);
    }

    if (hdr.next_uid <= last_uid) {
        mail_index_fsck_error(index, "next_uid %u -> %u",
                      hdr.next_uid, last_uid+1);
        hdr.next_uid = last_uid+1;
    }

    if (hdr.first_recent_uid_lowwater == 0)
                hdr.first_recent_uid_lowwater = hdr.next_uid;
    if (hdr.first_unseen_uid_lowwater == 0)
                hdr.first_unseen_uid_lowwater = hdr.next_uid;
    if (hdr.first_deleted_uid_lowwater == 0)
                hdr.first_deleted_uid_lowwater = hdr.next_uid;

        CHECK(messages_count, !=);
        CHECK(recent_messages_count, !=);
        CHECK(seen_messages_count, !=);
        CHECK(deleted_messages_count, !=);

        CHECK(first_recent_uid_lowwater, <);
        CHECK(first_unseen_uid_lowwater, <);
        CHECK(first_deleted_uid_lowwater, <);

    map->hdr = hdr;
    return 1;
}

int mail_index_fsck(struct mail_index *index)
{
    const char *error;
    unsigned int lock_id;
    uint32_t file_seq;
    uoff_t file_offset;
    int ret;
    bool lock_log;

    if (index->sync_update) {
        /* we're modifying index, don't do anything */
        return 1;
    }

    i_warning("fscking index file %s", index->filepath);
        lock_log = !index->log_locked;
    if (lock_log) {
        if (mail_transaction_log_sync_lock(index->log, &file_seq,
                           &file_offset) < 0)
            return -1;
    }
    if (mail_index_lock_exclusive(index, &lock_id) < 0) {
                mail_transaction_log_sync_unlock(index->log);
        return -1;
    }

    error = NULL;
    ret = mail_index_map(index, TRUE);
    if (ret > 0) {
        ret = mail_index_fsck_map(index, index->map, &error);
        if (ret > 0) {
            if (mail_index_write_base_header(index,
                             &index->map->hdr) < 0)
                ret = -1;
        }
    }

    mail_index_unlock(index, lock_id);
    if (lock_log)
        mail_transaction_log_sync_unlock(index->log);

    if (error != NULL) {
        mail_index_set_error(index, "Corrupted index file %s: %s",
                     index->filepath, error);
    }
    if (ret == 0)
        mail_index_mark_corrupted(index);
    return ret;
}