From 036626b19f14bef582f96e556913ae91b1d67881 Mon Sep 17 00:00:00 2001
From: Timo Sirainen <tss@iki.fi>
Date: Wed, 23 Jun 2010 17:52:02 +0100
Subject: [PATCH] Added mail_max_lock_timeout setting. This could be useful
 inside lda/lmtp protocol sections to avoid them from spending too much time
 waiting for locks, since they can easily just return "try again later".

--HG--
branch : HEAD
---
 src/doveadm/doveadm-dump-index.c              |  6 ++----
 src/lib-index/mail-cache.c                    |  9 +++++++--
 src/lib-index/mail-index-lock.c               |  6 ++++--
 src/lib-index/mail-index-private.h            |  1 +
 src/lib-index/mail-index-strmap.c             |  6 ++++--
 src/lib-index/mail-index.c                    | 19 +++++++++++++------
 src/lib-index/mail-index.h                    | 10 ++++++----
 src/lib-index/mail-transaction-log-file.c     |  5 ++++-
 src/lib-index/mail-transaction-log.c          |  4 +++-
 .../index/dbox-common/dbox-sync-rebuild.c     |  5 +++--
 src/lib-storage/index/dbox-multi/mdbox-map.c  |  6 ++++--
 src/lib-storage/index/index-storage.c         | 10 +++++-----
 .../index/maildir/maildir-keywords.c          |  4 +++-
 .../index/maildir/maildir-uidlist.c           |  3 ++-
 src/lib-storage/index/mbox/mbox-lock.c        |  7 +++++--
 src/lib-storage/list/index-mailbox-list.c     |  9 ++++-----
 src/lib-storage/mail-storage-private.h        |  2 ++
 src/lib-storage/mail-storage-settings.c       |  2 ++
 src/lib-storage/mail-storage-settings.h       |  1 +
 src/lib-storage/mail-storage.c                |  7 +++++++
 20 files changed, 82 insertions(+), 40 deletions(-)

diff --git a/src/doveadm/doveadm-dump-index.c b/src/doveadm/doveadm-dump-index.c
index 9bd0808326..1ef50da55d 100644
--- a/src/doveadm/doveadm-dump-index.c
+++ b/src/doveadm/doveadm-dump-index.c
@@ -533,8 +533,7 @@ static void cmd_dump_index(int argc ATTR_UNUSED, char *argv[])
 
 	index = path_open_index(argv[1]);
 	if (index == NULL ||
-	    mail_index_open(index, MAIL_INDEX_OPEN_FLAG_READONLY,
-			    FILE_LOCK_METHOD_FCNTL) <= 0)
+	    mail_index_open(index, MAIL_INDEX_OPEN_FLAG_READONLY) <= 0)
 		i_fatal("Couldn't open index %s", argv[1]);
 	if (argv[2] != NULL)
 		uid = atoi(argv[2]);
@@ -577,8 +576,7 @@ static bool test_dump_index(const char *path)
 	if (index == NULL)
 		return FALSE;
 
-	ret = mail_index_open(index, MAIL_INDEX_OPEN_FLAG_READONLY,
-			      FILE_LOCK_METHOD_FCNTL) > 0;
+	ret = mail_index_open(index, MAIL_INDEX_OPEN_FLAG_READONLY) > 0;
 	if (ret > 0)
 		mail_index_close(index);
 	mail_index_free(&index);
diff --git a/src/lib-index/mail-cache.c b/src/lib-index/mail-cache.c
index d71253c54c..77fb4f7f16 100644
--- a/src/lib-index/mail-cache.c
+++ b/src/lib-index/mail-cache.c
@@ -414,7 +414,8 @@ static struct mail_cache *mail_cache_alloc(struct mail_index *index)
 		(index->flags & MAIL_INDEX_OPEN_FLAG_DOTLOCK_USE_EXCL) != 0;
 	cache->dotlock_settings.nfs_flush =
 		(index->flags & MAIL_INDEX_OPEN_FLAG_NFS_FLUSH) != 0;
-	cache->dotlock_settings.timeout = MAIL_CACHE_LOCK_TIMEOUT;
+	cache->dotlock_settings.timeout =
+		I_MIN(MAIL_CACHE_LOCK_TIMEOUT, index->max_lock_timeout_secs);
 	cache->dotlock_settings.stale_timeout = MAIL_CACHE_LOCK_CHANGE_TIMEOUT;
 
 	if (!MAIL_INDEX_IS_IN_MEMORY(index) &&
@@ -488,6 +489,7 @@ void mail_cache_free(struct mail_cache **_cache)
 
 static int mail_cache_lock_file(struct mail_cache *cache, bool nonblock)
 {
+	unsigned int timeout_secs;
 	int ret;
 
 	if (cache->last_lock_failed) {
@@ -498,9 +500,12 @@ static int mail_cache_lock_file(struct mail_cache *cache, bool nonblock)
 
 	if (cache->index->lock_method != FILE_LOCK_METHOD_DOTLOCK) {
 		i_assert(cache->file_lock == NULL);
+		timeout_secs = I_MIN(MAIL_CACHE_LOCK_TIMEOUT,
+				     cache->index->max_lock_timeout_secs);
+
 		ret = mail_index_lock_fd(cache->index, cache->filepath,
 					 cache->fd, F_WRLCK,
-					 nonblock ? 0 : MAIL_CACHE_LOCK_TIMEOUT,
+					 nonblock ? 0 : timeout_secs,
 					 &cache->file_lock);
 	} else {
 		enum dotlock_create_flags flags =
diff --git a/src/lib-index/mail-index-lock.c b/src/lib-index/mail-index-lock.c
index 2274ba477d..ddec2e5ee2 100644
--- a/src/lib-index/mail-index-lock.c
+++ b/src/lib-index/mail-index-lock.c
@@ -139,10 +139,12 @@ void mail_index_flush_read_cache(struct mail_index *index, const char *path,
 
 int mail_index_lock_shared(struct mail_index *index, unsigned int *lock_id_r)
 {
+	unsigned int timeout_secs;
 	int ret;
 
-	ret = mail_index_lock(index, F_RDLCK, MAIL_INDEX_SHARED_LOCK_TIMEOUT,
-			      lock_id_r);
+	timeout_secs = I_MIN(MAIL_INDEX_SHARED_LOCK_TIMEOUT,
+			     index->max_lock_timeout_secs);
+	ret = mail_index_lock(index, F_RDLCK, timeout_secs, lock_id_r);
 	if (ret > 0) {
 		mail_index_flush_read_cache(index, index->filepath,
 					    index->fd, TRUE);
diff --git a/src/lib-index/mail-index-private.h b/src/lib-index/mail-index-private.h
index a03c14393c..f31ee057bd 100644
--- a/src/lib-index/mail-index-private.h
+++ b/src/lib-index/mail-index-private.h
@@ -208,6 +208,7 @@ struct mail_index {
 	int lock_type, shared_lock_count, excl_lock_count;
 	unsigned int lock_id_counter;
 	enum file_lock_method lock_method;
+	unsigned int max_lock_timeout_secs;
 
 	struct file_lock *file_lock;
 	struct dotlock *dotlock;
diff --git a/src/lib-index/mail-index-strmap.c b/src/lib-index/mail-index-strmap.c
index a435c07a26..8533d21254 100644
--- a/src/lib-index/mail-index-strmap.c
+++ b/src/lib-index/mail-index-strmap.c
@@ -1041,6 +1041,7 @@ static int mail_index_strmap_recreate(struct mail_index_strmap_view *view)
 
 static int mail_index_strmap_lock(struct mail_index_strmap *strmap)
 {
+	unsigned int timeout_secs;
 	int ret;
 
 	i_assert(strmap->fd != -1);
@@ -1048,9 +1049,10 @@ static int mail_index_strmap_lock(struct mail_index_strmap *strmap)
 	if (strmap->index->lock_method != FILE_LOCK_METHOD_DOTLOCK) {
 		i_assert(strmap->file_lock == NULL);
 
+		timeout_secs = I_MIN(MAIL_INDEX_STRMAP_TIMEOUT_SECS,
+				     strmap->index->max_lock_timeout_secs);
 		ret = file_wait_lock(strmap->fd, strmap->path, F_WRLCK,
-				     strmap->index->lock_method,
-				     MAIL_INDEX_STRMAP_TIMEOUT_SECS,
+				     strmap->index->lock_method, timeout_secs,
 				     &strmap->file_lock);
 		if (ret <= 0) {
 			mail_index_strmap_set_syscall_error(strmap,
diff --git a/src/lib-index/mail-index.c b/src/lib-index/mail-index.c
index b41376be16..667bde5667 100644
--- a/src/lib-index/mail-index.c
+++ b/src/lib-index/mail-index.c
@@ -44,6 +44,8 @@ struct mail_index *mail_index_alloc(const char *dir, const char *prefix)
 
 	index->mode = 0600;
 	index->gid = (gid_t)-1;
+	index->lock_method = FILE_LOCK_METHOD_FCNTL;
+	index->max_lock_timeout_secs = -1U;
 
 	index->keywords_ext_id =
 		mail_index_ext_register(index, MAIL_INDEX_EXT_KEYWORDS,
@@ -98,6 +100,14 @@ void mail_index_set_permissions(struct mail_index *index,
 	index->gid_origin = i_strdup(gid_origin);
 }
 
+void mail_index_set_lock_method(struct mail_index *index,
+				enum file_lock_method lock_method,
+				unsigned int max_timeout_secs)
+{
+	index->lock_method = lock_method;
+	index->max_lock_timeout_secs = max_timeout_secs;
+}
+
 uint32_t mail_index_ext_register(struct mail_index *index, const char *name,
 				 uint32_t default_hdr_size,
 				 uint16_t default_record_size,
@@ -482,8 +492,7 @@ static int mail_index_open_files(struct mail_index *index,
 	return 1;
 }
 
-int mail_index_open(struct mail_index *index, enum mail_index_open_flags flags,
-		    enum file_lock_method lock_method)
+int mail_index_open(struct mail_index *index, enum mail_index_open_flags flags)
 {
 	int ret;
 
@@ -508,7 +517,6 @@ int mail_index_open(struct mail_index *index, enum mail_index_open_flags flags,
 	index->log_locked = FALSE;
 	index->flags = flags;
 	index->readonly = (flags & MAIL_INDEX_OPEN_FLAG_READONLY) != 0;
-	index->lock_method = lock_method;
 
 	if ((flags & MAIL_INDEX_OPEN_FLAG_NFS_FLUSH) != 0 &&
 	    (flags & MAIL_INDEX_OPEN_FLAG_FSYNC_DISABLE) != 0)
@@ -530,13 +538,12 @@ int mail_index_open(struct mail_index *index, enum mail_index_open_flags flags,
 }
 
 int mail_index_open_or_create(struct mail_index *index,
-			      enum mail_index_open_flags flags,
-			      enum file_lock_method lock_method)
+			      enum mail_index_open_flags flags)
 {
 	int ret;
 
 	flags |= MAIL_INDEX_OPEN_FLAG_CREATE;
-	ret = mail_index_open(index, flags, lock_method);
+	ret = mail_index_open(index, flags);
 	i_assert(ret != 0);
 	return ret < 0 ? -1 : 0;
 }
diff --git a/src/lib-index/mail-index.h b/src/lib-index/mail-index.h
index e62681b51a..dddde3542d 100644
--- a/src/lib-index/mail-index.h
+++ b/src/lib-index/mail-index.h
@@ -213,15 +213,17 @@ void mail_index_set_fsync_types(struct mail_index *index,
 				enum mail_index_sync_type fsync_mask);
 void mail_index_set_permissions(struct mail_index *index,
 				mode_t mode, gid_t gid, const char *gid_origin);
+/* Set locking method and maximum time to wait for a lock (-1U = default). */
+void mail_index_set_lock_method(struct mail_index *index,
+				enum file_lock_method lock_method,
+				unsigned int max_timeout_secs);
 
 /* Open index. Returns 1 if ok, 0 if index doesn't exist and CREATE flags
    wasn't given, -1 if error. */
-int mail_index_open(struct mail_index *index, enum mail_index_open_flags flags,
-		    enum file_lock_method lock_method);
+int mail_index_open(struct mail_index *index, enum mail_index_open_flags flags);
 /* Open or create index. Returns 0 if ok, -1 if error. */
 int mail_index_open_or_create(struct mail_index *index,
-			      enum mail_index_open_flags flags,
-			      enum file_lock_method lock_method);
+			      enum mail_index_open_flags flags);
 void mail_index_close(struct mail_index *index);
 /* unlink() all the index files. */
 int mail_index_unlink(struct mail_index *index);
diff --git a/src/lib-index/mail-transaction-log-file.c b/src/lib-index/mail-transaction-log-file.c
index 477cdbb865..cb6a555887 100644
--- a/src/lib-index/mail-transaction-log-file.c
+++ b/src/lib-index/mail-transaction-log-file.c
@@ -320,6 +320,7 @@ mail_transaction_log_file_undotlock(struct mail_transaction_log_file *file)
 
 int mail_transaction_log_file_lock(struct mail_transaction_log_file *file)
 {
+	unsigned int lock_timeout_secs;
 	int ret;
 
 	if (file->locked)
@@ -334,8 +335,10 @@ int mail_transaction_log_file_lock(struct mail_transaction_log_file *file)
 		return mail_transaction_log_file_dotlock(file);
 
 	i_assert(file->file_lock == NULL);
+	lock_timeout_secs = I_MIN(MAIL_TRANSCATION_LOG_LOCK_TIMEOUT,
+				  file->log->index->max_lock_timeout_secs);
 	ret = mail_index_lock_fd(file->log->index, file->filepath, file->fd,
-				 F_WRLCK, MAIL_TRANSCATION_LOG_LOCK_TIMEOUT,
+				 F_WRLCK, lock_timeout_secs,
 				 &file->file_lock);
 	if (ret > 0) {
 		file->locked = TRUE;
diff --git a/src/lib-index/mail-transaction-log.c b/src/lib-index/mail-transaction-log.c
index a878a4f5d6..7be2a762fd 100644
--- a/src/lib-index/mail-transaction-log.c
+++ b/src/lib-index/mail-transaction-log.c
@@ -37,7 +37,9 @@ mail_transaction_log_alloc(struct mail_index *index)
 	log = i_new(struct mail_transaction_log, 1);
 	log->index = index;
 
-	log->dotlock_settings.timeout = MAIL_TRANSCATION_LOG_LOCK_TIMEOUT;
+	log->dotlock_settings.timeout =
+		I_MIN(MAIL_TRANSCATION_LOG_LOCK_TIMEOUT,
+		      index->max_lock_timeout_secs);;
 	log->dotlock_settings.stale_timeout =
 		MAIL_TRANSCATION_LOG_LOCK_CHANGE_TIMEOUT;
 
diff --git a/src/lib-storage/index/dbox-common/dbox-sync-rebuild.c b/src/lib-storage/index/dbox-common/dbox-sync-rebuild.c
index 187d29ef90..edc231ab5d 100644
--- a/src/lib-storage/index/dbox-common/dbox-sync-rebuild.c
+++ b/src/lib-storage/index/dbox-common/dbox-sync-rebuild.c
@@ -168,8 +168,9 @@ dbox_sync_index_rebuild_init(struct mailbox *box,
 	if (box->storage->set->mmap_disable)
 #endif
 		open_flags |= MAIL_INDEX_OPEN_FLAG_MMAP_DISABLE;
-	if (mail_index_open(ctx->backup_index, open_flags,
-			    box->storage->set->parsed_lock_method) <= 0)
+	mail_index_set_lock_method(ctx->backup_index,
+				   box->storage->set->parsed_lock_method, -1U);
+	if (mail_index_open(ctx->backup_index, open_flags) <= 0)
 		mail_index_free(&ctx->backup_index);
 	else
 		ctx->backup_view = mail_index_view_open(ctx->backup_index);
diff --git a/src/lib-storage/index/dbox-multi/mdbox-map.c b/src/lib-storage/index/dbox-multi/mdbox-map.c
index be278b366c..046f638127 100644
--- a/src/lib-storage/index/dbox-multi/mdbox-map.c
+++ b/src/lib-storage/index/dbox-multi/mdbox-map.c
@@ -57,6 +57,9 @@ mdbox_map_init(struct mdbox_storage *storage, struct mailbox_list *root_list,
 	map->set = storage->set;
 	map->path = i_strdup(path);
 	map->index = mail_index_alloc(path, MDBOX_GLOBAL_INDEX_PREFIX);
+	mail_index_set_lock_method(map->index,
+		MAP_STORAGE(map)->set->parsed_lock_method,
+		mail_storage_get_lock_timeout(MAP_STORAGE(map), -1U));
 	map->root_list = root_list;
 	map->map_ext_id = mail_index_ext_register(map->index, "map",
 				sizeof(struct mdbox_map_mail_index_header),
@@ -137,8 +140,7 @@ static int mdbox_map_open_internal(struct mdbox_map *map, bool create_missing)
 		if (mdbox_map_mkdir_storage(map) < 0)
 			return -1;
 	}
-	ret = mail_index_open(map->index, open_flags,
-			      MAP_STORAGE(map)->set->parsed_lock_method);
+	ret = mail_index_open(map->index, open_flags);
 	if (ret < 0) {
 		mail_storage_set_internal_error(MAP_STORAGE(map));
 		mail_index_reset_error(map->index);
diff --git a/src/lib-storage/index/index-storage.c b/src/lib-storage/index/index-storage.c
index aaa0d1409c..ca67f08479 100644
--- a/src/lib-storage/index/index-storage.c
+++ b/src/lib-storage/index/index-storage.c
@@ -187,8 +187,6 @@ void index_storage_lock_notify_reset(struct mailbox *box)
 int index_storage_mailbox_open(struct mailbox *box, bool move_to_memory)
 {
 	struct index_mailbox_context *ibox = INDEX_STORAGE_CONTEXT(box);
-	enum file_lock_method lock_method =
-		box->storage->set->parsed_lock_method;
 	enum mail_index_open_flags index_flags;
 	int ret;
 
@@ -211,7 +209,7 @@ int index_storage_mailbox_open(struct mailbox *box, bool move_to_memory)
 		return -1;
 	}
 
-	ret = mail_index_open(box->index, index_flags, lock_method);
+	ret = mail_index_open(box->index, index_flags);
 	if (ret <= 0 || move_to_memory) {
 		if ((index_flags & MAIL_INDEX_OPEN_FLAG_NEVER_IN_MEMORY) != 0) {
 			i_assert(ret <= 0);
@@ -223,8 +221,7 @@ int index_storage_mailbox_open(struct mailbox *box, bool move_to_memory)
 			/* try opening once more. it should be created
 			   directly into memory now. */
 			if (mail_index_open_or_create(box->index,
-						      index_flags,
-						      lock_method) < 0)
+						      index_flags) < 0)
 				i_panic("in-memory index creation failed");
 		}
 	}
@@ -290,6 +287,9 @@ void index_storage_mailbox_alloc(struct mailbox *box, const char *name,
 	mail_index_set_permissions(box->index, box->file_create_mode,
 				   box->file_create_gid,
 				   box->file_create_gid_origin);
+	mail_index_set_lock_method(box->index,
+		box->storage->set->parsed_lock_method,
+		mail_storage_get_lock_timeout(box->storage, -1U));
 }
 
 int index_storage_mailbox_enable(struct mailbox *box,
diff --git a/src/lib-storage/index/maildir/maildir-keywords.c b/src/lib-storage/index/maildir/maildir-keywords.c
index 13e864baee..90f27dd56a 100644
--- a/src/lib-storage/index/maildir/maildir-keywords.c
+++ b/src/lib-storage/index/maildir/maildir-keywords.c
@@ -81,7 +81,9 @@ maildir_keywords_init_readonly(struct mailbox *box)
 		box->storage->set->dotlock_use_excl;
 	mk->dotlock_settings.nfs_flush =
 		box->storage->set->mail_nfs_storage;
-	mk->dotlock_settings.timeout = KEYWORDS_LOCK_STALE_TIMEOUT + 2;
+	mk->dotlock_settings.timeout =
+		mail_storage_get_lock_timeout(box->storage,
+					      KEYWORDS_LOCK_STALE_TIMEOUT + 2);
 	mk->dotlock_settings.stale_timeout = KEYWORDS_LOCK_STALE_TIMEOUT;
 	mk->dotlock_settings.temp_prefix =
 		mailbox_list_get_temp_prefix(box->list);
diff --git a/src/lib-storage/index/maildir/maildir-uidlist.c b/src/lib-storage/index/maildir/maildir-uidlist.c
index cbaffc27db..d373e98ef9 100644
--- a/src/lib-storage/index/maildir/maildir-uidlist.c
+++ b/src/lib-storage/index/maildir/maildir-uidlist.c
@@ -273,7 +273,8 @@ struct maildir_uidlist *maildir_uidlist_init(struct maildir_mailbox *mbox)
 	uidlist->dotlock_settings.nfs_flush =
 		mbox->box.storage->set->mail_nfs_storage;
 	uidlist->dotlock_settings.timeout =
-		MAILDIR_UIDLIST_LOCK_STALE_TIMEOUT + 2;
+		mail_storage_get_lock_timeout(&mbox->storage->storage,
+			MAILDIR_UIDLIST_LOCK_STALE_TIMEOUT + 2);
 	uidlist->dotlock_settings.stale_timeout =
 		MAILDIR_UIDLIST_LOCK_STALE_TIMEOUT;
 	uidlist->dotlock_settings.callback = dotlock_callback;
diff --git a/src/lib-storage/index/mbox/mbox-lock.c b/src/lib-storage/index/mbox/mbox-lock.c
index 2a677b97a4..e84554ff62 100644
--- a/src/lib-storage/index/mbox/mbox-lock.c
+++ b/src/lib-storage/index/mbox/mbox-lock.c
@@ -405,7 +405,8 @@ mbox_lock_dotlock_int(struct mbox_lock_context *ctx, int lock_type, bool try)
 	memset(&set, 0, sizeof(set));
 	set.use_excl_lock = mbox->storage->storage.set->dotlock_use_excl;
 	set.nfs_flush = mbox->storage->storage.set->mail_nfs_storage;
-	set.timeout = mbox->storage->set->mbox_lock_timeout;
+	set.timeout = mail_storage_get_lock_timeout(&mbox->storage->storage,
+				mbox->storage->set->mbox_lock_timeout);
 	set.stale_timeout = mbox->storage->set->mbox_dotlock_change_timeout;
 	set.callback = dotlock_callback;
 	set.context = ctx;
@@ -707,7 +708,9 @@ static int mbox_update_locking(struct mbox_mailbox *mbox, int lock_type,
 		return 1;
 	}
 
-	max_wait_time = time(NULL) + mbox->storage->set->mbox_lock_timeout;
+	max_wait_time = time(NULL) +
+		mail_storage_get_lock_timeout(&mbox->storage->storage,
+			mbox->storage->set->mbox_lock_timeout);
 
 	memset(&ctx, 0, sizeof(ctx));
 	ctx.mbox = mbox;
diff --git a/src/lib-storage/list/index-mailbox-list.c b/src/lib-storage/list/index-mailbox-list.c
index 92f18cf0b6..d069aa9fdb 100644
--- a/src/lib-storage/list/index-mailbox-list.c
+++ b/src/lib-storage/list/index-mailbox-list.c
@@ -457,19 +457,18 @@ static int index_mailbox_list_open_indexes(struct mailbox_list *list,
 	struct index_mailbox_list *ilist = INDEX_LIST_CONTEXT(list);
 	const char *path;
 	enum mail_index_open_flags index_flags = 0;
-	enum file_lock_method lock_method = list->mail_set->parsed_lock_method;
 	int ret;
 
 	index_flags = mail_storage_settings_to_index_flags(list->mail_set);
 
-	if (mail_index_open_or_create(ilist->mail_index, index_flags,
-				      lock_method) < 0) {
+	mail_index_set_lock_method(ilist->mail_index,
+				   list->mail_set->parsed_lock_method, -1U);
+	if (mail_index_open_or_create(ilist->mail_index, index_flags) < 0) {
 		if (mail_index_move_to_memory(ilist->mail_index) < 0) {
 			/* try opening once more. it should be created
 			   directly into memory now. */
 			ret = mail_index_open_or_create(ilist->mail_index,
-							index_flags,
-							lock_method);
+							index_flags);
 			if (ret < 0) {
 				/* everything failed. there's a bug in the
 				   code, but just work around it by disabling
diff --git a/src/lib-storage/mail-storage-private.h b/src/lib-storage/mail-storage-private.h
index 82a0b6658a..40a66a5270 100644
--- a/src/lib-storage/mail-storage-private.h
+++ b/src/lib-storage/mail-storage-private.h
@@ -469,5 +469,7 @@ void mailbox_refresh_permissions(struct mailbox *box);
 /* Returns -1 if error, 0 if failed with EEXIST, 1 if ok */
 int mailbox_create_fd(struct mailbox *box, const char *path, int flags,
 		      int *fd_r);
+unsigned int mail_storage_get_lock_timeout(struct mail_storage *storage,
+					   unsigned int secs);
 
 #endif
diff --git a/src/lib-storage/mail-storage-settings.c b/src/lib-storage/mail-storage-settings.c
index 98b1683812..f58f2699aa 100644
--- a/src/lib-storage/mail-storage-settings.c
+++ b/src/lib-storage/mail-storage-settings.c
@@ -28,6 +28,7 @@ static const struct setting_define mail_storage_setting_defines[] = {
 	DEF(SET_UINT, mail_cache_min_mail_count),
 	DEF(SET_TIME, mailbox_idle_check_interval),
 	DEF(SET_UINT, mail_max_keyword_length),
+	DEF(SET_TIME, mail_max_lock_timeout),
 	DEF(SET_BOOL, mail_save_crlf),
 	DEF(SET_BOOL, fsync_disable),
 	DEF(SET_BOOL, mmap_disable),
@@ -51,6 +52,7 @@ const struct mail_storage_settings mail_storage_default_settings = {
 	.mail_cache_min_mail_count = 0,
 	.mailbox_idle_check_interval = 30,
 	.mail_max_keyword_length = 50,
+	.mail_max_lock_timeout = 0,
 	.mail_save_crlf = FALSE,
 	.fsync_disable = FALSE,
 	.mmap_disable = FALSE,
diff --git a/src/lib-storage/mail-storage-settings.h b/src/lib-storage/mail-storage-settings.h
index 0e6da85c61..c4465fb617 100644
--- a/src/lib-storage/mail-storage-settings.h
+++ b/src/lib-storage/mail-storage-settings.h
@@ -15,6 +15,7 @@ struct mail_storage_settings {
 	unsigned int mail_cache_min_mail_count;
 	unsigned int mailbox_idle_check_interval;
 	unsigned int mail_max_keyword_length;
+	unsigned int mail_max_lock_timeout;
 	bool mail_save_crlf;
 	bool fsync_disable;
 	bool mmap_disable;
diff --git a/src/lib-storage/mail-storage.c b/src/lib-storage/mail-storage.c
index fc42858112..6b53b1f20d 100644
--- a/src/lib-storage/mail-storage.c
+++ b/src/lib-storage/mail-storage.c
@@ -1466,3 +1466,10 @@ int mailbox_create_fd(struct mailbox *box, const char *path, int flags,
 	*fd_r = fd;
 	return 1;
 }
+
+unsigned int mail_storage_get_lock_timeout(struct mail_storage *storage,
+					   unsigned int secs)
+{
+	return storage->set->mail_max_lock_timeout == 0 ? secs :
+		I_MIN(secs, storage->set->mail_max_lock_timeout);
+}
-- 
2.47.3