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

	mail-index-fsck.c revision f6d121ba17e01dbf43a3d9c98a024ed8f1eb9043
/* Copyright (C) 2002 Timo Sirainen */

#include "lib.h"
#include "mail-index.h"
#include "mail-index-util.h"

#define CHECK(field) \
    if (old_hdr->field != new_hdr->field) \
        i_warning("fsck: "#field" %u != %u", \
              old_hdr->field, new_hdr->field);


static void print_differences(MailIndexHeader *old_hdr,
                  MailIndexHeader *new_hdr)
{
    if (old_hdr->first_hole_index != new_hdr->first_hole_index) {
        i_warning("fsck: first_hole_position %u != %u",
              old_hdr->first_hole_index,
              new_hdr->first_hole_index);
    }
    CHECK(first_hole_records);

    CHECK(next_uid);

    CHECK(messages_count);
    CHECK(seen_messages_count);
    CHECK(deleted_messages_count);
    CHECK(last_nonrecent_uid);

    if (new_hdr->first_unseen_uid_lowwater != 0 &&
        old_hdr->first_unseen_uid_lowwater >
        new_hdr->first_unseen_uid_lowwater) {
        i_warning("fsck: first_unseen_uid_lowwater %u > %u",
              old_hdr->first_unseen_uid_lowwater,
                          new_hdr->first_unseen_uid_lowwater);
    }

    if (new_hdr->first_deleted_uid_lowwater != 0 &&
        old_hdr->first_deleted_uid_lowwater >
        new_hdr->first_deleted_uid_lowwater) {
        i_warning("fsck: first_deleted_uid_lowwater %u > %u",
              old_hdr->first_deleted_uid_lowwater,
                          new_hdr->first_deleted_uid_lowwater);
    }
}

int mail_index_fsck(MailIndex *index)
{
    /* we verify only the fields in the header. other problems will be
       noticed and fixed while reading the messages. */
    MailIndexHeader old_hdr;
    MailIndexHeader *hdr;
    MailIndexRecord *rec, *end_rec;
    unsigned int max_uid, pos;

    i_assert(index->lock_type != MAIL_LOCK_SHARED);

    if (!mail_index_set_lock(index, MAIL_LOCK_EXCLUSIVE))
        return FALSE;

    hdr = index->header;
    memcpy(&old_hdr, hdr, sizeof(MailIndexHeader));

    hdr->first_hole_index = 0;
    hdr->first_hole_records = 0;

    hdr->messages_count = 0;
    hdr->seen_messages_count = 0;
    hdr->deleted_messages_count = 0;

    hdr->first_unseen_uid_lowwater = 0;
    hdr->first_deleted_uid_lowwater = 0;

    rec = (MailIndexRecord *) ((char *) index->mmap_base +
                   sizeof(MailIndexHeader));
    end_rec = (MailIndexRecord *) ((char *) index->mmap_base +
                       index->mmap_used_length);

    max_uid = 0;
    for (; rec < end_rec; rec++) {
        if (rec->uid == 0) {
            /* expunged message */
            pos = INDEX_RECORD_INDEX(index, rec);
            if (hdr->first_hole_records == 0) {
                hdr->first_hole_index = pos;
                hdr->first_hole_records = 1;
            } else if (hdr->first_hole_index +
                   hdr->first_hole_records == pos) {
                /* hole continues */
                hdr->first_hole_records++;
            }
            continue;
        }

        if (rec->uid < max_uid) {
            index_set_corrupted(index, "UIDs are not ordered "
                        "(%u < %u)", rec->uid, max_uid);
            return FALSE;
        }
        max_uid = rec->uid;

        if (rec->msg_flags & MAIL_SEEN)
            hdr->seen_messages_count++;
        else if (hdr->first_unseen_uid_lowwater)
            hdr->first_unseen_uid_lowwater = rec->uid;

        if (rec->msg_flags & MAIL_DELETED) {
            if (hdr->first_deleted_uid_lowwater == 0)
                                hdr->first_deleted_uid_lowwater = rec->uid;
            hdr->deleted_messages_count++;
        }
        hdr->messages_count++;
    }

    if (hdr->next_uid <= max_uid)
        hdr->next_uid = max_uid+1;
    if (hdr->last_nonrecent_uid >= hdr->next_uid)
        hdr->last_nonrecent_uid = hdr->next_uid-1;

    print_differences(&old_hdr, hdr);

    /* FSCK flag is removed automatically by set_lock() */
    return TRUE;
}