mdbox: Fixed race condition when mailbox GUID was looked up before mailbox create...

diff --git a/src/lib-storage/index/dbox-multi/mdbox-storage.c b/src/lib-storage/index/dbox-multi/mdbox-storage.c
index a80a515d716874583f2989e3379509a624da4ebf..afd37a78ca15f9232b85c009cb519c1f8c0accb3 100644 (file)
--- a/src/lib-storage/index/dbox-multi/mdbox-storage.c
+++ b/src/lib-storage/index/dbox-multi/mdbox-storage.c
@@ -370,9 +370,19 @@ void mdbox_set_file_corrupted(struct dbox_file *file)
 static int
 mdbox_mailbox_get_guid(struct mdbox_mailbox *mbox, guid_128_t guid_r)
 {
+       const struct mail_index_header *idx_hdr;
        struct mdbox_index_header hdr;
        bool need_resize;
+       int ret = 0;
 
+       i_assert(!mbox->creating);
+
+       /* there's a race condition between mkdir and getting the mailbox GUID.
+          normally this is handled by mdbox syncing, but GUID can be looked up
+          without syncing. when mbox->creating=TRUE, the errors are hidden
+          and we'll simply finish the mailbox creation */
+       idx_hdr = mail_index_get_header(mbox->box.view);
+       mbox->creating = idx_hdr->uid_validity == 0 && idx_hdr->next_uid == 1;
        if (mdbox_read_header(mbox, &hdr, &need_resize) < 0)
                memset(&hdr, 0, sizeof(hdr));
 
@@ -380,10 +390,12 @@ mdbox_mailbox_get_guid(struct mdbox_mailbox *mbox, guid_128_t guid_r)
                /* regenerate it */
                if (mdbox_write_index_header(&mbox->box, NULL, NULL) < 0 ||
                    mdbox_read_header(mbox, &hdr, &need_resize) < 0)
-                       return -1;
+                       ret = -1;
        }
-       memcpy(guid_r, hdr.mailbox_guid, GUID_128_SIZE);
-       return 0;
+       if (ret == 0)
+               memcpy(guid_r, hdr.mailbox_guid, GUID_128_SIZE);
+       mbox->creating = FALSE;
+       return ret;
 }
 
 static int