mail-cache.c revision 8ecbb74bc4c7f6f6145da3525941d1d0e20e67f1
/* Copyright (C) 2003-2004 Timo Sirainen */
#include "lib.h"
#include "array.h"
#include "buffer.h"
#include "hash.h"
#include "file-cache.h"
#include "mmap-util.h"
#include "write-full.h"
#include "mail-cache-private.h"
#include <unistd.h>
void mail_cache_set_syscall_error(struct mail_cache *cache,
const char *function)
{
i_assert(function != NULL);
if (ENOSPACE(errno)) {
cache->index->nodiskspace = TRUE;
return;
}
mail_index_set_error(cache->index,
"%s failed with index cache file %s: %m",
function, cache->filepath);
}
void mail_cache_set_corrupted(struct mail_cache *cache, const char *fmt, ...)
{
va_list va;
(void)unlink(cache->filepath);
/* mark the cache as unusable */
cache->hdr = NULL;
va_start(va, fmt);
t_push();
mail_index_set_error(cache->index, "Corrupted index cache file %s: %s",
cache->filepath, t_strdup_vprintf(fmt, va));
t_pop();
va_end(va);
}
void mail_cache_file_close(struct mail_cache *cache)
{
if (cache->mmap_base != NULL) {
if (munmap(cache->mmap_base, cache->mmap_length) < 0)
mail_cache_set_syscall_error(cache, "munmap()");
}
if (cache->file_cache != NULL)
file_cache_set_fd(cache->file_cache, -1);
cache->mmap_base = NULL;
cache->data = NULL;
cache->hdr = NULL;
cache->mmap_length = 0;
if (cache->fd != -1) {
if (close(cache->fd) < 0)
mail_cache_set_syscall_error(cache, "close()");
cache->fd = -1;
}
}
int mail_cache_reopen(struct mail_cache *cache)
{
struct mail_index_view *view;
const struct mail_index_ext *ext;
if (MAIL_CACHE_IS_UNUSABLE(cache) &&
(cache->need_compress || MAIL_INDEX_IS_IN_MEMORY(cache->index))) {
/* reopening does no good */
return 0;
}
mail_cache_file_close(cache);
cache->fd = open(cache->filepath, O_RDWR);
if (cache->fd == -1) {
if (errno == ENOENT)
cache->need_compress = TRUE;
else
mail_cache_set_syscall_error(cache, "open()");
return -1;
}
if (cache->file_cache != NULL)
file_cache_set_fd(cache->file_cache, cache->fd);
if (mail_cache_map(cache, 0, 0) < 0)
return -1;
if (mail_cache_header_fields_read(cache) < 0)
return -1;
view = mail_index_view_open(cache->index);
ext = mail_index_view_get_ext(view, cache->ext_id);
if (ext == NULL || cache->hdr->file_seq != ext->reset_id) {
/* still different - maybe a race condition or maybe the
file_seq really is corrupted. either way, this shouldn't
happen often so we'll just mark cache to be compressed
later which fixes this. */
cache->need_compress = TRUE;
mail_index_view_close(&view);
return 0;
}
mail_index_view_close(&view);
return 1;
}
static bool mail_cache_verify_header(struct mail_cache *cache)
{
const struct mail_cache_header *hdr = cache->data;
/* check that the header is still ok */
if (cache->mmap_length < sizeof(struct mail_cache_header)) {
mail_cache_set_corrupted(cache, "File too small");
return FALSE;
}
if (cache->hdr->version != MAIL_CACHE_VERSION) {
/* version changed - upgrade silently */
return FALSE;
}
if (hdr->compat_sizeof_uoff_t != sizeof(uoff_t) ||
hdr->compat_sizeof_time_t != sizeof(time_t)) {
if (hdr->compat_sizeof_uoff_t == 0 &&
hdr->compat_sizeof_time_t == 0) {
/* FIXME: keep backwards compatibility for a while.
set hdr_modified=TRUE so header gets fixed the next
time cache is locked. */
cache->hdr_modified = TRUE;
} else {
/* architecture change - handle silently(?) */
return -1;
}
}
if (cache->hdr->indexid != cache->index->indexid) {
/* index id changed */
mail_cache_set_corrupted(cache, "indexid changed");
return FALSE;
}
/* only check the header if we're locked */
if (!cache->locked)
return TRUE;
if (hdr->used_file_size < sizeof(struct mail_cache_header)) {
mail_cache_set_corrupted(cache, "used_file_size too small");
return FALSE;
}
if ((hdr->used_file_size % sizeof(uint32_t)) != 0) {
mail_cache_set_corrupted(cache, "used_file_size not aligned");
return FALSE;
}
if (cache->mmap_base != NULL &&
hdr->used_file_size > cache->mmap_length) {
mail_cache_set_corrupted(cache, "used_file_size too large");
return FALSE;
}
return TRUE;
}
int mail_cache_map(struct mail_cache *cache, size_t offset, size_t size)
{
ssize_t ret;
if (size == 0)
size = sizeof(struct mail_cache_header);
if (cache->file_cache != NULL) {
cache->data = NULL;
cache->hdr = NULL;
ret = file_cache_read(cache->file_cache, offset, size);
if (ret < 0) {
// FIXME: ESTALE
mail_cache_set_syscall_error(cache, "read()");
return -1;
}
cache->data = file_cache_get_map(cache->file_cache,
&cache->mmap_length);
cache->hdr = cache->data;
if (offset == 0 && !mail_cache_verify_header(cache)) {
cache->need_compress = TRUE;
return -1;
}
return 0;
}
if (offset < cache->mmap_length &&
size <= cache->mmap_length - offset) {
/* already mapped */
return 0;
}
if (cache->mmap_base != NULL) {
if (munmap(cache->mmap_base, cache->mmap_length) < 0)
mail_cache_set_syscall_error(cache, "munmap()");
} else {
if (cache->fd == -1) {
/* unusable, waiting for compression or
index is in memory */
i_assert(cache->need_compress ||
MAIL_INDEX_IS_IN_MEMORY(cache->index));
return -1;
}
}
/* map the whole file */
cache->hdr = NULL;
cache->mmap_length = 0;
cache->mmap_base = mmap_ro_file(cache->fd, &cache->mmap_length);
if (cache->mmap_base == MAP_FAILED) {
cache->mmap_base = NULL;
cache->data = NULL;
mail_cache_set_syscall_error(cache, "mmap()");
return -1;
}
cache->data = cache->mmap_base;
cache->hdr = cache->mmap_base;
if (!mail_cache_verify_header(cache)) {
cache->need_compress = TRUE;
return -1;
}
return 0;
}
static int mail_cache_open_and_verify(struct mail_cache *cache)
{
if (MAIL_INDEX_IS_IN_MEMORY(cache->index))
return 0;
cache->fd = open(cache->filepath, O_RDWR);
if (cache->fd == -1) {
if (errno == ENOENT) {
cache->need_compress = TRUE;
return 0;
}
mail_cache_set_syscall_error(cache, "open()");
return -1;
}
if (cache->file_cache != NULL)
file_cache_set_fd(cache->file_cache, cache->fd);
if (mail_cache_map(cache, 0, sizeof(struct mail_cache_header)) < 0)
return -1;
return mail_cache_header_fields_read(cache);
}
static struct mail_cache *mail_cache_alloc(struct mail_index *index)
{
struct mail_cache *cache;
cache = i_new(struct mail_cache, 1);
cache->index = index;
cache->fd = -1;
cache->filepath =
i_strconcat(index->filepath, MAIL_CACHE_FILE_SUFFIX, NULL);
cache->field_pool = pool_alloconly_create("Cache fields", 1024);
cache->field_name_hash =
hash_create(default_pool, cache->field_pool, 0,
strcase_hash, (hash_cmp_callback_t *)strcasecmp);
cache->dotlock_settings.timeout = MAIL_CACHE_LOCK_TIMEOUT;
cache->dotlock_settings.stale_timeout = MAIL_CACHE_LOCK_CHANGE_TIMEOUT;
if (!MAIL_INDEX_IS_IN_MEMORY(index)) {
if (index->mmap_disable || index->mmap_no_write)
cache->file_cache = file_cache_new(-1);
}
cache->ext_id =
mail_index_ext_register(index, "cache", 0,
sizeof(uint32_t), sizeof(uint32_t));
mail_index_register_expunge_handler(index, cache->ext_id,
mail_cache_expunge_handler);
mail_index_register_sync_handler(index, cache->ext_id,
mail_cache_sync_handler,
MAIL_INDEX_SYNC_HANDLER_INDEX |
(cache->file_cache == NULL ? 0 :
MAIL_INDEX_SYNC_HANDLER_VIEW));
if (cache->file_cache != NULL) {
mail_index_register_sync_lost_handler(index,
mail_cache_sync_lost_handler);
}
return cache;
}
struct mail_cache *mail_cache_open_or_create(struct mail_index *index)
{
struct mail_cache *cache;
cache = mail_cache_alloc(index);
if (mail_cache_open_and_verify(cache) < 0) {
/* failed for some reason - doesn't really matter,
it's disabled for now. */
mail_cache_file_close(cache);
}
return cache;
}
struct mail_cache *mail_cache_create(struct mail_index *index)
{
struct mail_cache *cache;
cache = mail_cache_alloc(index);
cache->need_compress = TRUE;
return cache;
}
void mail_cache_free(struct mail_cache **_cache)
{
struct mail_cache *cache = *_cache;
*_cache = NULL;
if (cache->file_cache != NULL) {
mail_index_unregister_sync_lost_handler(cache->index,
mail_cache_sync_lost_handler);
file_cache_free(&cache->file_cache);
}
mail_index_unregister_expunge_handler(cache->index, cache->ext_id);
mail_index_unregister_sync_handler(cache->index, cache->ext_id);
mail_cache_file_close(cache);
hash_destroy(cache->field_name_hash);
pool_unref(cache->field_pool);
i_free(cache->field_file_map);
i_free(cache->file_field_map);
i_free(cache->fields);
i_free(cache->filepath);
i_free(cache);
}
static int mail_cache_lock_file(struct mail_cache *cache, int lock_type)
{
if (cache->index->lock_method != MAIL_INDEX_LOCK_DOTLOCK) {
return mail_index_lock_fd(cache->index, cache->filepath,
cache->fd, lock_type,
MAIL_INDEX_LOCK_SECS);
}
if (lock_type != F_UNLCK) {
return file_dotlock_create(&cache->dotlock_settings,
cache->filepath, 0, &cache->dotlock);
} else
return file_dotlock_delete(&cache->dotlock);
}
int mail_cache_lock(struct mail_cache *cache)
{
struct mail_index_view *view;
const struct mail_index_ext *ext;
int i, ret;
i_assert(!cache->locked);
if (MAIL_CACHE_IS_UNUSABLE(cache) ||
MAIL_INDEX_IS_IN_MEMORY(cache->index))
return 0;
view = mail_index_view_open(cache->index);
ext = mail_index_view_get_ext(view, cache->ext_id);
if (ext == NULL) {
/* cache not used */
mail_index_view_close(&view);
return 0;
}
if (cache->hdr->file_seq != ext->reset_id) {
/* we want the latest cache file */
if ((ret = mail_cache_reopen(cache)) <= 0) {
mail_index_view_close(&view);
return ret;
}
}
for (i = 0; i < 3; i++) {
ret = mail_cache_lock_file(cache, F_WRLCK);
if (ret <= 0)
break;
cache->locked = TRUE;
if (cache->hdr->file_seq == ext->reset_id) {
/* got it */
break;
}
/* okay, so it was just compressed. try again. */
(void)mail_cache_unlock(cache);
if ((ret = mail_cache_reopen(cache)) <= 0)
break;
ret = 0;
}
if (ret > 0) {
/* make sure our header is up to date */
if (cache->file_cache != NULL) {
file_cache_invalidate(cache->file_cache, 0,
sizeof(struct mail_cache_header));
}
if (mail_cache_map(cache, 0, 0) == 0)
cache->hdr_copy = *cache->hdr;
else {
(void)mail_cache_unlock(cache);
ret = -1;
}
}
mail_index_view_close(&view);
i_assert((ret <= 0 && !cache->locked) || (ret > 0 && cache->locked));
return ret;
}
static void mail_cache_update_need_compress(struct mail_cache *cache)
{
const struct mail_cache_header *hdr = cache->hdr;
unsigned int cont_percentage;
uoff_t max_del_space;
cont_percentage = hdr->continued_record_count * 100 /
(cache->index->map->records_count == 0 ? 1 :
cache->index->map->records_count);
if (cont_percentage >= COMPRESS_CONTINUED_PERCENTAGE &&
hdr->used_file_size >= COMPRESS_MIN_SIZE) {
/* too many continued rows, compress */
cache->need_compress = TRUE;
}
/* see if we've reached the max. deleted space in file */
max_del_space = hdr->used_file_size / 100 * COMPRESS_PERCENTAGE;
if (hdr->deleted_space >= max_del_space &&
hdr->used_file_size >= COMPRESS_MIN_SIZE)
cache->need_compress = TRUE;
}
int mail_cache_unlock(struct mail_cache *cache)
{
int ret = 0;
i_assert(cache->locked);
if (cache->field_header_write_pending)
ret = mail_cache_header_fields_update(cache);
cache->locked = FALSE;
if (MAIL_CACHE_IS_UNUSABLE(cache)) {
/* we found it to be broken during the lock. just clean up. */
cache->hdr_modified = FALSE;
return -1;
}
if (cache->hdr_modified) {
/* FIXME: for backwards compatibility - keep them for a while */
cache->hdr_copy.compat_sizeof_uoff_t = sizeof(uoff_t);
cache->hdr_copy.compat_sizeof_time_t = sizeof(time_t);
cache->hdr_modified = FALSE;
if (mail_cache_write(cache, &cache->hdr_copy,
sizeof(cache->hdr_copy), 0) < 0)
ret = -1;
mail_cache_update_need_compress(cache);
}
(void)mail_cache_lock_file(cache, F_UNLCK);
return ret;
}
int mail_cache_write(struct mail_cache *cache, const void *data, size_t size,
uoff_t offset)
{
if (pwrite_full(cache->fd, data, size, offset) < 0) {
mail_cache_set_syscall_error(cache, "pwrite_full()");
return -1;
}
if (cache->file_cache != NULL) {
file_cache_write(cache->file_cache, data, size, offset);
/* data/hdr pointers may change if file cache was grown */
cache->data = file_cache_get_map(cache->file_cache,
&cache->mmap_length);
cache->hdr = cache->data;
}
return 0;
}
struct mail_cache_view *
mail_cache_view_open(struct mail_cache *cache, struct mail_index_view *iview)
{
struct mail_cache_view *view;
view = i_new(struct mail_cache_view, 1);
view->cache = cache;
view->view = iview;
ARRAY_CREATE(&view->tmp_offsets, default_pool, uint32_t, 32);
view->cached_exists_buf =
buffer_create_dynamic(default_pool,
cache->file_fields_count + 10);
return view;
}
void mail_cache_view_close(struct mail_cache_view *view)
{
if (view->cache->field_header_write_pending)
(void)mail_cache_header_fields_update(view->cache);
if (view->trans_view != NULL)
mail_index_view_close(&view->trans_view);
array_free(&view->tmp_offsets);
buffer_free(view->cached_exists_buf);
i_free(view);
}