mail-index-write.c revision 57dd2621d4230bc2e06c69a4b9f8cf8f0ff2bc93
bcb4e51a409d94ae670de96afb8483a4f7855294Stephan Bosch/* Copyright (c) 2003-2016 Dovecot authors, see the included COPYING file */
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen#include "lib.h"
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen#include "read-full.h"
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen#include "write-full.h"
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen#include "ostream.h"
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen#include "mail-index-private.h"
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen#include "mail-transaction-log-private.h"
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen#include <stdio.h>
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen#define MAIL_INDEX_MIN_UPDATE_SIZE 1024
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen/* if we're updating >= count-n messages, recreate the index */
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen#define MAIL_INDEX_MAX_OVERWRITE_NEG_SEQ_COUNT 10
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainenstatic int mail_index_create_backup(struct mail_index *index)
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen{
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen const char *backup_path, *tmp_backup_path;
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen int ret;
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen if (index->fd != -1) {
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen /* we very much want to avoid creating a backup file that
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen hasn't been written to disk yet */
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen if (fdatasync(index->fd) < 0) {
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen mail_index_set_error(index, "fdatasync(%s) failed: %m",
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen index->filepath);
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen return -1;
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen }
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen }
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen backup_path = t_strconcat(index->filepath, ".backup", NULL);
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen tmp_backup_path = t_strconcat(backup_path, ".tmp", NULL);
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen ret = link(index->filepath, tmp_backup_path);
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen if (ret < 0 && errno == EEXIST) {
d47bd663deb1846980e6759c87297741a5459890Timo Sirainen if (unlink(tmp_backup_path) < 0 && errno != ENOENT) {
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen mail_index_set_error(index, "unlink(%s) failed: %m",
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen tmp_backup_path);
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen return -1;
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen }
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen ret = link(index->filepath, tmp_backup_path);
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen }
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen if (ret < 0) {
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen if (errno == ENOENT) {
d47bd663deb1846980e6759c87297741a5459890Timo Sirainen /* no dovecot.index file, ignore */
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen return 0;
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen }
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen mail_index_set_error(index, "link(%s, %s) failed: %m",
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen index->filepath, tmp_backup_path);
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen return -1;
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen }
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen if (rename(tmp_backup_path, backup_path) < 0) {
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen mail_index_set_error(index, "rename(%s, %s) failed: %m",
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen tmp_backup_path, backup_path);
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen return -1;
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen }
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen return 0;
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen}
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainenstatic int mail_index_recreate(struct mail_index *index)
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen{
f5982bb5b0a704e88fa2b44b0b74e365d13103b9Timo Sirainen struct mail_index_map *map = index->map;
struct ostream *output;
unsigned int base_size;
const char *path;
int ret = 0, fd;
i_assert(!MAIL_INDEX_IS_IN_MEMORY(index));
i_assert(map->hdr.indexid == index->indexid);
i_assert((map->hdr.flags & MAIL_INDEX_HDR_FLAG_CORRUPTED) == 0);
i_assert(index->indexid != 0);
fd = mail_index_create_tmp_file(index, index->filepath, &path);
if (fd == -1)
return -1;
output = o_stream_create_fd_file(fd, 0, FALSE);
o_stream_cork(output);
base_size = I_MIN(map->hdr.base_header_size, sizeof(map->hdr));
o_stream_nsend(output, &map->hdr, base_size);
o_stream_nsend(output, CONST_PTR_OFFSET(map->hdr_base, base_size),
map->hdr.header_size - base_size);
o_stream_nsend(output, map->rec_map->records,
map->rec_map->records_count * map->hdr.record_size);
o_stream_nflush(output);
if (o_stream_nfinish(output) < 0) {
mail_index_file_set_syscall_error(index, path, "write()");
ret = -1;
}
o_stream_destroy(&output);
if (ret == 0 && index->fsync_mode != FSYNC_MODE_NEVER) {
if (fdatasync(fd) < 0) {
mail_index_file_set_syscall_error(index, path,
"fdatasync()");
ret = -1;
}
}
if (close(fd) < 0) {
mail_index_file_set_syscall_error(index, path, "close()");
ret = -1;
}
if ((index->flags & MAIL_INDEX_OPEN_FLAG_KEEP_BACKUPS) != 0)
(void)mail_index_create_backup(index);
if (ret == 0 && rename(path, index->filepath) < 0) {
mail_index_set_error(index, "rename(%s, %s) failed: %m",
path, index->filepath);
ret = -1;
}
if (ret < 0)
i_unlink(path);
return ret;
}
void mail_index_write(struct mail_index *index, bool want_rotate)
{
struct mail_index_map *map = index->map;
struct mail_index_header *hdr = &map->hdr;
i_assert(index->log_sync_locked);
if (index->readonly)
return;
/* rotate the .log before writing index, so the index will point to
the latest log. */
if (want_rotate &&
hdr->log_file_seq == index->log->head->hdr.file_seq &&
hdr->log_file_tail_offset == hdr->log_file_head_offset) {
if (mail_transaction_log_rotate(index->log, FALSE) == 0) {
struct mail_transaction_log_file *file =
index->log->head;
i_assert(file->hdr.prev_file_seq == hdr->log_file_seq);
i_assert(file->hdr.prev_file_offset == hdr->log_file_head_offset);
hdr->log_file_seq = file->hdr.file_seq;
hdr->log_file_head_offset =
hdr->log_file_tail_offset = file->hdr.hdr_size;
}
}
if (!MAIL_INDEX_IS_IN_MEMORY(index)) {
if (mail_index_recreate(index) < 0) {
(void)mail_index_move_to_memory(index);
return;
}
}
index->last_read_log_file_seq = hdr->log_file_seq;
index->last_read_log_file_tail_offset = hdr->log_file_tail_offset;
}