From: Timo Sirainen <tss@iki.fi>
Date: Mon, 15 Nov 2010 15:19:13 +0000 (+0000)
Subject: sdbox: Fixed race condition when one session opens a mailbox while another is still... 
X-Git-Tag: 2.0.8~97
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=e22ac7474fb36e3e3dcfeb70ea5f54ea812aa2d0;p=thirdparty%2Fdovecot%2Fcore.git

sdbox: Fixed race condition when one session opens a mailbox while another is still creating it.
This happened mostly when nonexistent INBOX was being opened by multiple
sessions at the same time.
---

diff --git a/src/lib-storage/index/dbox-single/sdbox-storage.c b/src/lib-storage/index/dbox-single/sdbox-storage.c
index 80bfc36586..ae4e6cbd4a 100644
--- a/src/lib-storage/index/dbox-single/sdbox-storage.c
+++ b/src/lib-storage/index/dbox-single/sdbox-storage.c
@@ -228,8 +228,21 @@ static int sdbox_mailbox_open(struct mailbox *box)
 		return -1;
 
 	/* get/generate mailbox guid */
-	if (sdbox_read_header(mbox, &hdr, TRUE) < 0)
-		memset(&hdr, 0, sizeof(hdr));
+	if (sdbox_read_header(mbox, &hdr, FALSE) < 0) {
+		/* it's possible that this mailbox is just now being created
+		   by another process. lock it first and see if the header is
+		   available then. */
+		struct mail_index_sync_ctx *sync_ctx;
+		struct mail_index_view *view;
+		struct mail_index_transaction *trans;
+
+		if (mail_index_sync_begin(box->index, &sync_ctx,
+					  &view, &trans, 0) > 0)
+			(void)mail_index_sync_commit(&sync_ctx);
+
+		if (sdbox_read_header(mbox, &hdr, TRUE) < 0)
+			memset(&hdr, 0, sizeof(hdr));
+	}
 
 	if (mail_guid_128_is_empty(hdr.mailbox_guid)) {
 		/* regenerate it */