From: Timo Sirainen <tss@iki.fi>
Date: Thu, 3 May 2012 21:48:45 +0000 (+0300)
Subject: lib-index: Removed unused locking code.
X-Git-Tag: 2.2.alpha1~533
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d5498f4d64a97d04a1b608920f23eb2ad2353d05;p=thirdparty%2Fdovecot%2Fcore.git

lib-index: Removed unused locking code.
---

diff --git a/src/lib-index/mail-index-lock.c b/src/lib-index/mail-index-lock.c
index 034bd53b23..5f2d932985 100644
--- a/src/lib-index/mail-index-lock.c
+++ b/src/lib-index/mail-index-lock.c
@@ -36,27 +36,15 @@ int mail_index_lock_fd(struct mail_index *index, const char *path, int fd,
 			      timeout_secs, lock_r);
 }
 
-static int mail_index_lock(struct mail_index *index, int lock_type,
+static int mail_index_lock(struct mail_index *index,
 			   unsigned int timeout_secs, unsigned int *lock_id_r)
 {
 	int ret;
 
-	i_assert(lock_type == F_RDLCK || lock_type == F_WRLCK);
-
-	if (lock_type == F_RDLCK && index->lock_type != F_UNLCK) {
+	if (index->lock_type != F_UNLCK) {
+		/* file is already locked */
 		index->shared_lock_count++;
 		*lock_id_r = index->lock_id_counter;
-		ret = 1;
-	} else if (lock_type == F_WRLCK && index->lock_type == F_WRLCK) {
-		index->excl_lock_count++;
-		*lock_id_r = index->lock_id_counter + 1;
-		ret = 1;
-	} else {
-		ret = 0;
-	}
-
-	if (ret > 0) {
-		/* file is already locked */
 		return 1;
 	}
 
@@ -65,39 +53,25 @@ static int mail_index_lock(struct mail_index *index, int lock_type,
 		/* FIXME: exclusive locking will rewrite the index file every
 		   time. shouldn't really be needed.. reading doesn't require
 		   locks then, though */
-		if (lock_type == F_WRLCK)
-			return 0;
-
 		index->shared_lock_count++;
 		index->lock_type = F_RDLCK;
 		*lock_id_r = index->lock_id_counter;
 		return 1;
 	}
 
-	if (index->file_lock == NULL) {
-		i_assert(index->lock_type == F_UNLCK);
-		ret = mail_index_lock_fd(index, index->filepath, index->fd,
-					 lock_type, timeout_secs,
-					 &index->file_lock);
-	} else {
-		i_assert(index->lock_type == F_RDLCK && lock_type == F_WRLCK);
-		ret = file_lock_try_update(index->file_lock, lock_type);
-	}
+	i_assert(index->lock_type == F_UNLCK);
+	ret = mail_index_lock_fd(index, index->filepath, index->fd,
+				 F_RDLCK, timeout_secs,
+				 &index->file_lock);
 	if (ret <= 0)
 		return ret;
 
 	if (index->lock_type == F_UNLCK)
 		index->lock_id_counter += 2;
-	index->lock_type = lock_type;
-
-	if (lock_type == F_RDLCK) {
-		index->shared_lock_count++;
-		*lock_id_r = index->lock_id_counter;
-	} else {
-		index->excl_lock_count++;
-		*lock_id_r = index->lock_id_counter + 1;
-	}
+	index->lock_type = F_RDLCK;
 
+	index->shared_lock_count++;
+	*lock_id_r = index->lock_id_counter;
 	return 1;
 }
 
@@ -125,7 +99,7 @@ int mail_index_lock_shared(struct mail_index *index, unsigned int *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);
+	ret = mail_index_lock(index, timeout_secs, lock_id_r);
 	if (ret > 0) {
 		mail_index_flush_read_cache(index, index->filepath,
 					    index->fd, TRUE);
@@ -141,48 +115,23 @@ int mail_index_lock_shared(struct mail_index *index, unsigned int *lock_id_r)
 	return -1;
 }
 
-int mail_index_try_lock_exclusive(struct mail_index *index,
-				  unsigned int *lock_id_r)
-{
-	int ret;
-
-	if ((ret = mail_index_lock(index, F_WRLCK, 0, lock_id_r)) > 0) {
-		mail_index_flush_read_cache(index, index->filepath,
-					    index->fd, TRUE);
-	}
-	return ret;
-}
-
 void mail_index_unlock(struct mail_index *index, unsigned int *_lock_id)
 {
 	unsigned int lock_id = *_lock_id;
 
 	*_lock_id = 0;
 
-	if ((lock_id & 1) == 0) {
-		/* shared lock */
-		if (!mail_index_is_locked(index, lock_id)) {
-			/* unlocking some older generation of the index file.
-			   we've already closed the file so just ignore this. */
-			return;
-		}
-
-		i_assert(index->shared_lock_count > 0);
-		index->shared_lock_count--;
-	} else {
-		/* exclusive lock */
-		i_assert(lock_id == index->lock_id_counter + 1);
-		i_assert(index->excl_lock_count > 0);
-		i_assert(index->lock_type == F_WRLCK);
-		if (--index->excl_lock_count == 0 &&
-		    index->shared_lock_count > 0) {
-			/* drop back to a shared lock. */
-			index->lock_type = F_RDLCK;
-			(void)file_lock_try_update(index->file_lock, F_RDLCK);
-		}
+	/* shared lock */
+	if (!mail_index_is_locked(index, lock_id)) {
+		/* unlocking some older generation of the index file.
+		   we've already closed the file so just ignore this. */
+		return;
 	}
 
-	if (index->shared_lock_count == 0 && index->excl_lock_count == 0) {
+	i_assert(index->shared_lock_count > 0);
+	index->shared_lock_count--;
+
+	if (index->shared_lock_count == 0) {
 		index->lock_id_counter += 2;
 		index->lock_type = F_UNLCK;
 		if (index->lock_method != FILE_LOCK_METHOD_DOTLOCK) {
diff --git a/src/lib-index/mail-index-map-read.c b/src/lib-index/mail-index-map-read.c
index fe13215098..5bf2138b60 100644
--- a/src/lib-index/mail-index-map-read.c
+++ b/src/lib-index/mail-index-map-read.c
@@ -400,7 +400,6 @@ int mail_index_map(struct mail_index *index,
 {
 	int ret;
 
-	i_assert(index->lock_type != F_WRLCK);
 	i_assert(!index->mapping);
 
 	index->mapping = TRUE;
diff --git a/src/lib-index/mail-index-private.h b/src/lib-index/mail-index-private.h
index bbfe202560..3bba027c39 100644
--- a/src/lib-index/mail-index-private.h
+++ b/src/lib-index/mail-index-private.h
@@ -205,7 +205,7 @@ struct mail_index {
 	/* syncing will update this if non-NULL */
 	struct mail_index_transaction_commit_result *sync_commit_result;
 
-	int lock_type, shared_lock_count, excl_lock_count;
+	int lock_type, shared_lock_count;
 	unsigned int lock_id_counter;
 	enum file_lock_method lock_method;
 	unsigned int max_lock_timeout_secs;
@@ -275,9 +275,6 @@ void mail_index_flush_read_cache(struct mail_index *index, const char *path,
 
 /* Returns 0 = ok, -1 = error. */
 int mail_index_lock_shared(struct mail_index *index, unsigned int *lock_id_r);
-/* Returns 1 = ok, 0 = already locked, -1 = error. */
-int mail_index_try_lock_exclusive(struct mail_index *index,
-				  unsigned int *lock_id_r);
 void mail_index_unlock(struct mail_index *index, unsigned int *lock_id);
 /* Returns TRUE if given lock_id is valid. */
 bool mail_index_is_locked(struct mail_index *index, unsigned int lock_id);
diff --git a/src/lib-index/mail-index.c b/src/lib-index/mail-index.c
index d100332bf7..667f219c70 100644
--- a/src/lib-index/mail-index.c
+++ b/src/lib-index/mail-index.c
@@ -570,7 +570,6 @@ int mail_index_open(struct mail_index *index, enum mail_index_open_flags flags)
 		i_strconcat(index->dir, "/", index->prefix, NULL);
 
 	index->shared_lock_count = 0;
-	index->excl_lock_count = 0;
 	index->lock_type = F_UNLCK;
 	index->lock_id_counter = 2;
 
@@ -629,7 +628,6 @@ void mail_index_close_file(struct mail_index *index)
 	index->lock_id_counter += 2;
 	index->lock_type = F_UNLCK;
 	index->shared_lock_count = 0;
-	index->excl_lock_count = 0;
 }
 
 void mail_index_close(struct mail_index *index)
@@ -695,7 +693,6 @@ int mail_index_reopen_if_changed(struct mail_index *index)
 
 	i_assert(index->shared_lock_count == 0 ||
 		 (index->flags & MAIL_INDEX_OPEN_FLAG_NFS_FLUSH) == 0);
-	i_assert(index->excl_lock_count == 0);
 
 	if (MAIL_INDEX_IS_IN_MEMORY(index))
 		return 0;