lib-index: If refreshing finds dovecot.index.log gone, assume the mailbox was deleted

Don't try to recreate the log file again. It can just cause further problems.

A way to reproduce this problem with NFS when INDEX dir is specified:
 * create mailbox foo, select foo, IDLE
 * delete mailbox foo
--> foo's index is recreated back by IDLEing process

diff --git a/src/lib-index/mail-transaction-log.c b/src/lib-index/mail-transaction-log.c
index 622da58676cfab641073c6a61d4e2249a7f6c8f0..5181409853966d69a8c889a41c1368d8faeb71ef 100644 (file)
--- a/src/lib-index/mail-transaction-log.c
+++ b/src/lib-index/mail-transaction-log.c
@@ -336,27 +336,15 @@ mail_transaction_log_refresh(struct mail_transaction_log *log, bool nfs_flush,
                        *reason_r = t_strdup_printf("stat(%s) failed: %m", log->filepath);
                        return -1;
                }
-               /* see if the whole directory got deleted */
-               if (nfs_safe_stat(log->index->dir, &st) < 0 &&
-                   errno == ENOENT) {
-                       log->index->index_deleted = TRUE;
-                       *reason_r = "Index directory was deleted";
-                       return -1;
-               }
-
-               /* the file should always exist at this point. if it doesn't,
-                  someone deleted it manually while the index was open. try to
-                  handle this nicely by creating a new log file. */
-               file = log->head;
-               if (mail_transaction_log_create(log, FALSE) < 0) {
-                       *reason_r = "Failed to create log";
-                       return -1;
-               }
-               i_assert(file->refcount > 0);
-               file->refcount--;
-               log->index->need_recreate = TRUE;
-               *reason_r = "Log created";
-               return 0;
+               /* We shouldn't lose dovecot.index.log unless the mailbox was
+                  deleted or renamed. Just fail this and let the mailbox
+                  opening code figure out whether to create a new log file
+                  or not. Anything else can cause unwanted behavior (e.g.
+                  mailbox deletion not fully finishing due to .nfs* files and
+                  an IDLEing IMAP process creating the index back here). */
+               log->index->index_deleted = TRUE;
+               *reason_r = "Trasnaction log lost while it was open";
+               return -1;
        } else if (log->head->st_ino == st.st_ino &&
                   CMP_DEV_T(log->head->st_dev, st.st_dev)) {
                /* NFS: log files get rotated to .log.2 files instead