From: Timo Sirainen <tss@iki.fi>
Date: Thu, 11 Sep 2008 13:52:47 +0000 (+0300)
Subject: Mail cache: lock_method=dotlock could have caused a process to deadlock with itself.
X-Git-Tag: 1.2.alpha2~61
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=5724e7103eed12fe36b55a7b5a8653284a2184b9;p=thirdparty%2Fdovecot%2Fcore.git

Mail cache: lock_method=dotlock could have caused a process to deadlock with itself.

--HG--
branch : HEAD
---

diff --git a/src/lib-index/mail-cache-compress.c b/src/lib-index/mail-cache-compress.c
index d8879649fd..e64209f5ae 100644
--- a/src/lib-index/mail-cache-compress.c
+++ b/src/lib-index/mail-cache-compress.c
@@ -433,6 +433,7 @@ static int mail_cache_compress_locked(struct mail_cache *cache,
 	cache->fd = fd;
 	cache->st_ino = st.st_ino;
 	cache->st_dev = st.st_dev;
+	cache->field_header_write_pending = FALSE;
 
 	if (cache->file_cache != NULL)
 		file_cache_set_fd(cache->file_cache, cache->fd);
@@ -452,6 +453,8 @@ int mail_cache_compress(struct mail_cache *cache,
 	bool unlock = FALSE;
 	int ret;
 
+	i_assert(!cache->compressing);
+
 	if (MAIL_INDEX_IS_IN_MEMORY(cache->index) || cache->index->readonly)
 		return 0;
 
@@ -463,26 +466,27 @@ int mail_cache_compress(struct mail_cache *cache,
 						    cache->filepath, cache->fd,
 						    FALSE);
 		}
-		return mail_cache_compress_locked(cache, trans, &unlock);
-	}
-
-	switch (mail_cache_lock(cache, FALSE)) {
-	case -1:
-		return -1;
-	case 0:
-		/* couldn't lock, either it's broken or doesn't exist.
-		   just start creating it. */
-		return mail_cache_compress_locked(cache, trans, &unlock);
-	default:
-		/* locking succeeded. */
-		unlock = TRUE;
-		ret = mail_cache_compress_locked(cache, trans, &unlock);
-		if (unlock) {
-			if (mail_cache_unlock(cache) < 0)
-				ret = -1;
+	} else {
+		switch (mail_cache_lock(cache, FALSE)) {
+		case -1:
+			return -1;
+		case 0:
+			/* couldn't lock, either it's broken or doesn't exist.
+			   just start creating it. */
+			break;
+		default:
+			/* locking succeeded. */
+			unlock = TRUE;
 		}
-		return ret;
 	}
+	cache->compressing = TRUE;
+	ret = mail_cache_compress_locked(cache, trans, &unlock);
+	cache->compressing = FALSE;
+	if (unlock) {
+		if (mail_cache_unlock(cache) < 0)
+			ret = -1;
+	}
+	return ret;
 }
 
 bool mail_cache_need_compress(struct mail_cache *cache)
diff --git a/src/lib-index/mail-cache-private.h b/src/lib-index/mail-cache-private.h
index 4825e8f1f3..57e3e48016 100644
--- a/src/lib-index/mail-cache-private.h
+++ b/src/lib-index/mail-cache-private.h
@@ -173,6 +173,7 @@ struct mail_cache {
 	unsigned int locked:1;
 	unsigned int hdr_modified:1;
 	unsigned int field_header_write_pending:1;
+	unsigned int compressing:1;
 };
 
 struct mail_cache_loop_track {
diff --git a/src/lib-index/mail-cache.c b/src/lib-index/mail-cache.c
index 36c5a7f44f..b2df74da28 100644
--- a/src/lib-index/mail-cache.c
+++ b/src/lib-index/mail-cache.c
@@ -667,7 +667,8 @@ void mail_cache_view_close(struct mail_cache_view *view)
 {
 	i_assert(view->trans_view == NULL);
 
-	if (view->cache->field_header_write_pending)
+	if (view->cache->field_header_write_pending &&
+	    !view->cache->compressing)
                 (void)mail_cache_header_fields_update(view->cache);
 
 	buffer_free(&view->cached_exists_buf);