quota-maildir.c revision 0563ad5c7f179554623682f6fd7b98596901b49f
/* Copyright (C) 2006 Timo Sirainen */
#include "lib.h"
#include "array.h"
#include "ioloop.h"
#include "nfs-workarounds.h"
#include "file-dotlock.h"
#include "read-full.h"
#include "write-full.h"
#include "str.h"
#include "maildir-storage.h"
#include "quota-private.h"
#include <stdio.h>
#include <stdlib.h>
#include <dirent.h>
#include <sys/stat.h>
#define MAILDIRSIZE_FILENAME "maildirsize"
#define MAILDIRSIZE_STALE_SECS (60*15)
struct maildir_quota_root {
struct quota_root root;
const char *maildirsize_path;
uint64_t message_bytes_limit;
uint64_t message_count_limit;
uint64_t total_bytes;
uint64_t total_count;
int fd;
time_t recalc_last_stamp;
unsigned int limits_initialized:1;
unsigned int master_message_limits:1;
};
struct maildir_list_context {
struct mail_storage *storage;
struct mailbox_list_iterate_context *iter;
struct mailbox_info *info;
string_t *path;
int state;
};
extern struct quota_backend quota_backend_maildir;
struct dotlock_settings dotlock_settings = {
MEMBER(temp_prefix) NULL,
MEMBER(lock_suffix) NULL,
MEMBER(timeout) 0,
MEMBER(stale_timeout) 30,
MEMBER(callback) NULL,
MEMBER(context) NULL,
MEMBER(use_excl_lock) FALSE
};
static int maildir_sum_dir(const char *dir, uint64_t *total_bytes,
uint64_t *total_count)
{
DIR *dirp;
struct dirent *dp;
string_t *path;
const char *p;
size_t len;
uoff_t num;
int ret = 0;
dirp = opendir(dir);
if (dirp == NULL) {
if (errno == ENOENT || errno == ESTALE)
return 0;
i_error("opendir(%s) failed: %m", dir);
return -1;
}
path = t_str_new(256);
str_append(path, dir);
str_append_c(path, '/');
len = str_len(path);
while ((dp = readdir(dirp)) != NULL) {
if (dp->d_name[0] == '.' &&
(dp->d_name[1] == '\0' || dp->d_name[1] == '.'))
continue;
p = strstr(dp->d_name, ",S=");
num = (uoff_t)-1;
if (p != NULL) {
/* ,S=nnnn[:,] */
p += 3;
for (num = 0; *p >= '0' && *p <= '9'; p++)
num = num * 10 + (*p - '0');
if (*p != ':' && *p != '\0' && *p != ',') {
/* not in expected format, fallback to stat() */
num = (uoff_t)-1;
} else {
*total_bytes += num;
*total_count += 1;
}
}
if (num == (uoff_t)-1) {
struct stat st;
str_truncate(path, len);
str_append(path, dp->d_name);
if (stat(str_c(path), &st) == 0) {
*total_bytes += st.st_size;
*total_count += 1;
} else if (errno != ENOENT && errno != ESTALE) {
i_error("stat(%s) failed: %m", str_c(path));
ret = -1;
}
}
}
if (closedir(dirp) < 0) {
i_error("closedir(%s) failed: %m", dir);
return -1;
}
return ret;
}
static struct maildir_list_context *
maildir_list_init(struct mail_storage *storage)
{
struct maildir_list_context *ctx;
ctx = i_new(struct maildir_list_context, 1);
ctx->storage = storage;
ctx->path = str_new(default_pool, 512);
ctx->iter = mailbox_list_iter_init(mail_storage_get_list(storage), "*",
MAILBOX_LIST_ITER_FAST_FLAGS);
return ctx;
}
static const char *
maildir_list_next(struct maildir_list_context *ctx, time_t *mtime_r)
{
struct stat st;
const char *path;
bool is_file;
for (;;) {
if (ctx->state == 0) {
ctx->info = mailbox_list_iter_next(ctx->iter);
if (ctx->info == NULL)
return NULL;
}
t_push();
path = mail_storage_get_mailbox_path(ctx->storage,
ctx->info->name,
&is_file);
str_truncate(ctx->path, 0);
str_append(ctx->path, path);
str_append(ctx->path, ctx->state == 0 ? "/new" : "/cur");
t_pop();
if (++ctx->state == 2)
ctx->state = 0;
if (stat(str_c(ctx->path), &st) == 0)
break;
/* ignore if the directory got lost, stale or if it was
actually a file and not a directory */
if (errno != ENOENT && errno != ESTALE && errno != ENOTDIR) {
i_error("stat(%s) failed: %m", str_c(ctx->path));
ctx->state = 0;
}
}
*mtime_r = st.st_size;
return str_c(ctx->path);
}
static int maildir_list_deinit(struct maildir_list_context *ctx)
{
int ret = mailbox_list_iter_deinit(&ctx->iter);
str_free(&ctx->path);
i_free(ctx);
return ret;
}
static int
maildirs_check_have_changed(struct mail_storage *storage, time_t latest_mtime)
{
struct maildir_list_context *ctx;
time_t mtime;
int ret = 0;
ctx = maildir_list_init(storage);
while (maildir_list_next(ctx, &mtime) != NULL) {
if (mtime > latest_mtime) {
ret = 1;
break;
}
}
if (maildir_list_deinit(ctx) < 0)
return -1;
return ret;
}
static int maildirsize_write(struct maildir_quota_root *root, const char *path)
{
struct dotlock *dotlock;
string_t *str;
int fd;
i_assert(root->fd == -1);
dotlock_settings.use_excl_lock = getenv("DOTLOCK_USE_EXCL") != NULL;
fd = file_dotlock_open(&dotlock_settings, path,
DOTLOCK_CREATE_FLAG_NONBLOCK, &dotlock);
if (fd == -1) {
if (errno == EAGAIN) {
/* someone's just in the middle of updating it */
return -1;
}
i_error("file_dotlock_open(%s) failed: %m", path);
return -1;
}
str = t_str_new(128);
if (root->message_bytes_limit != (uint64_t)-1) {
str_printfa(str, "%lluS",
(unsigned long long)root->message_bytes_limit);
}
if (root->message_count_limit != (uint64_t)-1) {
if (str_len(str) > 0)
str_append_c(str, ',');
str_printfa(str, "%lluC",
(unsigned long long)root->message_count_limit);
}
str_printfa(str, "\n%llu %llu\n",
(unsigned long long)root->total_bytes,
(unsigned long long)root->total_count);
if (write_full(fd, str_data(str), str_len(str)) < 0) {
i_error("write_full(%s) failed: %m", path);
file_dotlock_delete(&dotlock);
return -1;
}
/* keep the fd open since we might want to update it later */
if (file_dotlock_replace(&dotlock,
DOTLOCK_REPLACE_FLAG_DONT_CLOSE_FD) < 0) {
i_error("file_dotlock_replace(%s) failed: %m", path);
return -1;
}
root->fd = fd;
return 0;
}
static void maildirsize_recalculate_init(struct maildir_quota_root *root)
{
root->total_bytes = root->total_count = 0;
root->recalc_last_stamp = 0;
}
static int maildirsize_recalculate_storage(struct maildir_quota_root *root,
struct mail_storage *storage)
{
struct maildir_list_context *ctx;
const char *dir;
time_t mtime;
int ret = 0;
ctx = maildir_list_init(storage);
while ((dir = maildir_list_next(ctx, &mtime)) != NULL) {
if (mtime > root->recalc_last_stamp)
root->recalc_last_stamp = mtime;
t_push();
if (maildir_sum_dir(dir, &root->total_bytes,
&root->total_count) < 0)
ret = -1;
t_pop();
}
if (maildir_list_deinit(ctx) < 0)
ret = -1;
return ret;
}
static int maildirsize_recalculate_finish(struct maildir_quota_root *root,
int ret)
{
if (ret == 0) {
/* maildir didn't change, we can write the maildirsize file */
ret = maildirsize_write(root, root->maildirsize_path);
}
if (ret != 0) {
/* make sure it gets rebuilt later */
if (unlink(root->maildirsize_path) < 0 &&
errno != ENOENT && errno != ESTALE) {
i_error("unlink(%s) failed: %m",
root->maildirsize_path);
}
}
return ret;
}
static int maildirsize_recalculate(struct maildir_quota_root *root)
{
struct mail_storage *const *storages;
unsigned int i, count;
int ret = 0;
maildirsize_recalculate_init(root);
/* count mails from all storages */
storages = array_get(&root->root.quota->storages, &count);
for (i = 0; i < count; i++) {
if (maildirsize_recalculate_storage(root, storages[i]) < 0) {
ret = -1;
break;
}
}
if (ret == 0) {
/* check if any of the directories have changed */
for (i = 0; i < count; i++) {
ret = maildirs_check_have_changed(storages[i],
root->recalc_last_stamp);
if (ret != 0)
break;
}
}
return maildirsize_recalculate_finish(root, ret);
}
static int maildirsize_parse(struct maildir_quota_root *root,
int fd, const char *const *lines)
{
unsigned long long bytes;
uint64_t message_bytes_limit, message_count_limit;
long long bytes_diff, total_bytes;
int count_diff, total_count;
unsigned int line_count = 0;
const char *const *limit;
char *pos;
if (*lines == NULL)
return -1;
/* first line contains the limits. 0 value mean unlimited. */
message_bytes_limit = (uint64_t)-1;
message_count_limit = (uint64_t)-1;
for (limit = t_strsplit(lines[0], ","); *limit != NULL; limit++) {
bytes = strtoull(*limit, &pos, 10);
if (pos[0] != '\0' && pos[1] == '\0') {
switch (pos[0]) {
case 'C':
if (bytes != 0)
message_count_limit = bytes;
break;
case 'S':
if (bytes != 0)
message_bytes_limit = bytes;
break;
}
}
}
if (!root->master_message_limits) {
/* we don't know the limits, use whatever the file says */
root->message_bytes_limit = message_bytes_limit;
root->message_count_limit = message_count_limit;
} else if (root->message_bytes_limit != message_bytes_limit ||
root->message_count_limit != message_count_limit) {
/* we know the limits and they've changed.
the file must be rewritten. */
return 0;
}
/* rest of the lines contains <bytes> <count> diffs */
total_bytes = 0; total_count = 0;
for (lines++; *lines != NULL; lines++, line_count++) {
if (sscanf(*lines, "%lld %d", &bytes_diff, &count_diff) != 2)
return -1;
total_bytes += bytes_diff;
total_count += count_diff;
}
/* we end always with LF, which shows up as empty last line. there
should be no other empty lines */
if (lines[1] != NULL)
return -1;
if (total_bytes < 0 || total_count < 0) {
/* corrupted */
return -1;
}
if ((uint64_t)total_bytes > root->message_bytes_limit ||
(uint64_t)total_count > root->message_count_limit) {
/* we're over quota. don't trust these values if the file
contains more than the initial summary line, or if the file
is older than 15 minutes. */
struct stat st;
if (line_count > 1)
return 0;
if (fstat(fd, &st) < 0 ||
st.st_mtime < ioloop_time - MAILDIRSIZE_STALE_SECS)
return 0;
}
root->total_bytes = (uint64_t)total_bytes;
root->total_count = (uint64_t)total_count;
return 1;
}
static int maildirsize_read(struct maildir_quota_root *root)
{
char buf[5120+1];
unsigned int i, size;
int fd, ret = 0;
t_push();
if (root->fd != -1) {
if (close(root->fd) < 0)
i_error("close(%s) failed: %m", root->maildirsize_path);
root->fd = -1;
}
fd = nfs_safe_open(root->maildirsize_path, O_RDWR | O_APPEND);
if (fd == -1) {
if (errno == ENOENT)
ret = 0;
else {
ret = -1;
i_error("open(%s) failed: %m", root->maildirsize_path);
}
t_pop();
return ret;
}
/* @UNSAFE */
size = 0;
while (size < sizeof(buf)-1 &&
(ret = read(fd, buf + size, sizeof(buf)-1 - size)) != 0) {
if (ret < 0) {
if (errno == ESTALE)
break;
i_error("read(%s) failed: %m", root->maildirsize_path);
}
size += ret;
}
if (ret < 0 || size >= sizeof(buf)-1) {
/* error / recalculation needed. */
(void)close(fd);
t_pop();
return ret < 0 ? -1 : 0;
}
/* file is smaller than 5120 bytes, which means we can use it */
root->total_bytes = root->total_count = 0;
/* skip the last line if there's no LF at the end. Remove the last LF
so we don't get one empty line in the strsplit. */
while (size > 0 && buf[size-1] != '\n') size--;
if (size > 0) size--;
buf[size] = '\0';
/* If there are any NUL bytes, the file is broken. */
for (i = 0; i < size; i++) {
if (buf[i] == '\0')
break;
}
if (i == size &&
maildirsize_parse(root, fd, t_strsplit(buf, "\n")) > 0) {
root->fd = fd;
ret = 1;
} else {
/* broken file / need recalculation */
(void)close(fd);
root->fd = -1;
ret = 0;
}
t_pop();
return ret;
}
static void maildirquota_init_limits(struct maildir_quota_root *root)
{
root->limits_initialized = TRUE;
if (root->root.default_rule.bytes_limit != 0 ||
root->root.default_rule.count_limit != 0) {
root->master_message_limits = TRUE;
root->message_bytes_limit = root->root.default_rule.bytes_limit;
root->message_count_limit = root->root.default_rule.count_limit;
}
}
static int maildirquota_refresh(struct maildir_quota_root *root)
{
int ret;
if (!root->limits_initialized)
maildirquota_init_limits(root);
ret = maildirsize_read(root);
if (ret == 0) {
if (root->message_bytes_limit == (uint64_t)-1 &&
root->message_count_limit == (uint64_t)-1) {
/* no quota */
return 0;
}
ret = maildirsize_recalculate(root);
}
return ret < 0 ? -1 : 0;
}
static int maildirsize_update(struct maildir_quota_root *root,
int count_diff, int64_t bytes_diff)
{
const char *str;
int ret = 0;
if (count_diff == 0 && bytes_diff == 0)
return 0;
t_push();
/* We rely on O_APPEND working in here. That isn't NFS-safe, but it
isn't necessarily that bad because the file is recreated once in
a while, and sooner if corruption cases calculations to go
over quota. This is also how Maildir++ spec specifies it should be
done.. */
str = t_strdup_printf("%lld %d\n", (long long)bytes_diff, count_diff);
if (write_full(root->fd, str, strlen(str)) < 0) {
ret = -1;
if (errno == ESTALE) {
/* deleted/replaced already, ignore */
} else {
i_error("write_full(%s) failed: %m",
root->maildirsize_path);
}
}
t_pop();
return ret;
}
static struct quota_root *maildir_quota_alloc(void)
{
struct maildir_quota_root *root;
root = i_new(struct maildir_quota_root, 1);
root->fd = -1;
root->message_bytes_limit = (uint64_t)-1;
root->message_count_limit = (uint64_t)-1;
return &root->root;
}
static void maildir_quota_deinit(struct quota_root *_root)
{
struct maildir_quota_root *root = (struct maildir_quota_root *)_root;
if (root->fd != -1)
(void)close(root->fd);
i_free(root);
}
static void
maildir_quota_root_storage_added(struct quota_root *_root,
struct mail_storage *storage)
{
struct maildir_quota_root *root = (struct maildir_quota_root *)_root;
const char *control_dir;
if (root->maildirsize_path != NULL)
return;
control_dir = mail_storage_get_mailbox_control_dir(storage, "");
root->maildirsize_path =
p_strconcat(_root->pool, control_dir,
"/"MAILDIRSIZE_FILENAME, NULL);
}
static void
maildir_quota_storage_added(struct quota *quota,
struct mail_storage *_storage)
{
struct maildir_storage *storage =
(struct maildir_storage *)_storage;
struct quota_root **roots;
unsigned int i, count;
if (strcmp(_storage->name, "maildir") != 0)
return;
roots = array_get_modifiable(&quota->roots, &count);
for (i = 0; i < count; i++) {
if (roots[i]->backend.name == quota_backend_maildir.name)
maildir_quota_root_storage_added(roots[i], _storage);
}
/* For newly generated filenames add ,S=size. */
storage->save_size_in_filename = TRUE;
}
static const char *const *
maildir_quota_root_get_resources(struct quota_root *root __attr_unused__)
{
static const char *resources_both[] = {
QUOTA_NAME_STORAGE_KILOBYTES,
QUOTA_NAME_MESSAGES,
NULL
};
return resources_both;
}
static int
maildir_quota_get_resource(struct quota_root *_root, const char *name,
uint64_t *value_r, uint64_t *limit __attr_unused__)
{
struct maildir_quota_root *root = (struct maildir_quota_root *)_root;
if (maildirquota_refresh(root) < 0)
return -1;
if (strcmp(name, QUOTA_NAME_STORAGE_BYTES) == 0)
*value_r = root->total_bytes;
else if (strcmp(name, QUOTA_NAME_MESSAGES) == 0)
*value_r = root->total_count;
else
return 0;
return 1;
}
static int
maildir_quota_update(struct quota_root *_root,
struct quota_transaction_context *ctx)
{
struct maildir_quota_root *root =
(struct maildir_quota_root *) _root;
if (root->fd != -1) {
/* if writing fails, we don't care all that much */
(void)maildirsize_update(root, ctx->count_used,
ctx->bytes_used);
}
return 0;
}
struct quota_backend quota_backend_maildir = {
"maildir",
{
maildir_quota_alloc,
NULL,
maildir_quota_deinit,
maildir_quota_storage_added,
maildir_quota_root_get_resources,
maildir_quota_get_resource,
maildir_quota_update
}
};