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

	mail-index-fsck.c revision e3689d0f073341e844638f34e1e4d0b7bb053cc8
/* Copyright (C) 2004-2007 Timo Sirainen */

#include "lib.h"
#include "ioloop.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 int
mail_index_fsck_map(struct mail_index *index, struct mail_index_map *map,
            bool *lock, const char **error_r)
{
    struct mail_index_header hdr;
    const struct mail_index_record *rec;
    uint32_t file_seq;
    uoff_t file_offset;
    uint32_t i, last_uid;

    *error_r = NULL;

    if (*lock) {
        if (mail_transaction_log_sync_lock(index->log, &file_seq,
                           &file_offset) < 0) {
            *lock = FALSE;
            return -1;
        }
    } else {
        mail_transaction_log_get_head(index->log, &file_seq,
                          &file_offset);
    }

    /* Remember the log head position. If we go back in the index's head
       offset, ignore errors in the log up to this offset. */
    index->fsck_log_head_file_seq = file_seq;
    index->fsck_log_head_file_offset = file_offset;

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

    if (hdr.uid_validity == 0 && hdr.next_uid != 1)
        hdr.uid_validity = ioloop_time;

    hdr.flags &= ~MAIL_INDEX_HDR_FLAG_FSCK;

    if (hdr.log_file_seq < file_seq) {
        hdr.log_file_head_offset = hdr.log_file_tail_offset =
            sizeof(struct mail_transaction_log_header);
    } else {
        if (hdr.log_file_head_offset > file_offset)
            hdr.log_file_head_offset = file_offset;
        if (hdr.log_file_tail_offset > hdr.log_file_head_offset)
            hdr.log_file_tail_offset = hdr.log_file_head_offset;
    }
    hdr.log_file_seq = file_seq;

    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(log_file_seq, !=);
        CHECK(log_file_head_offset, !=);
        CHECK(log_file_tail_offset, !=);

    CHECK(uid_validity, !=);
        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 = NULL;
    struct mail_index_map *map;
    bool lock = !index->log_locked;
    int ret;

    i_warning("fscking index file %s", index->filepath);

    map = mail_index_map_clone(index->map);
    mail_index_unmap(index, &index->map);
    index->map = map;

    ret = mail_index_fsck_map(index, map, &lock, &error);
    if (ret > 0) {
        map->write_base_header = TRUE;
        map->write_atomic = TRUE;

        mail_index_write(index, FALSE);
    }

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

    if (lock)
        mail_transaction_log_sync_unlock(index->log);
    return ret;
}