lib-index: Improve errors - return reason in mail_transaction_log_refresh()

diff --git a/src/lib-index/mail-transaction-log.c b/src/lib-index/mail-transaction-log.c
index eec4375ffc47aeb7446a1edfa9fb5a9ec23fd9a8..e48eb6b4d7084672d1bf619d70663e339be915dc 100644 (file)
--- a/src/lib-index/mail-transaction-log.c
+++ b/src/lib-index/mail-transaction-log.c
@@ -284,16 +284,18 @@ int mail_transaction_log_rotate(struct mail_transaction_log *log, bool reset)
 }
 
 static int
-mail_transaction_log_refresh(struct mail_transaction_log *log, bool nfs_flush)
+mail_transaction_log_refresh(struct mail_transaction_log *log, bool nfs_flush,
+                            const char **reason_r)
 {
         struct mail_transaction_log_file *file;
        struct stat st;
-       const char *reason;
 
        i_assert(log->head != NULL);
 
-       if (MAIL_TRANSACTION_LOG_FILE_IN_MEMORY(log->head))
+       if (MAIL_TRANSACTION_LOG_FILE_IN_MEMORY(log->head)) {
+               *reason_r = "Log is in memory";
                return 0;
+       }
 
        if (nfs_flush && log->nfs_flush)
                nfs_flush_file_handle_cache(log->filepath);
@@ -302,12 +304,14 @@ mail_transaction_log_refresh(struct mail_transaction_log *log, bool nfs_flush)
                        mail_index_file_set_syscall_error(log->index,
                                                          log->filepath,
                                                          "stat()");
+                       *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;
                }
 
@@ -315,11 +319,14 @@ mail_transaction_log_refresh(struct mail_transaction_log *log, bool nfs_flush)
                   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)
+               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;
        } else if (log->head->st_ino == st.st_ino &&
                   CMP_DEV_T(log->head->st_dev, st.st_dev)) {
@@ -328,11 +335,12 @@ mail_transaction_log_refresh(struct mail_transaction_log *log, bool nfs_flush)
                   the existing file has already been unlinked here
                   (in which case inodes could match but point to
                   different files) */
+               *reason_r = "Log inode is unchanged";
                return 0;
        }
 
        file = mail_transaction_log_file_alloc(log, log->filepath);
-       if (mail_transaction_log_file_open(file, &reason) <= 0) {
+       if (mail_transaction_log_file_open(file, reason_r) <= 0) {
                mail_transaction_log_file_free(&file);
                return -1;
        }
@@ -342,6 +350,7 @@ mail_transaction_log_refresh(struct mail_transaction_log *log, bool nfs_flush)
        if (--log->head->refcount == 0)
                mail_transaction_logs_clean(log);
        mail_transaction_log_set_head(log, file);
+       *reason_r = "Log reopened";
        return 0;
 }
 
@@ -370,6 +379,7 @@ int mail_transaction_log_find_file(struct mail_transaction_log *log,
                                   const char **reason_r)
 {
        struct mail_transaction_log_file *file;
+       const char *reason;
        int ret;
 
        if (file_seq > log->head->hdr.file_seq) {
@@ -381,23 +391,26 @@ int mail_transaction_log_find_file(struct mail_transaction_log *log,
                        return 0;
                }
 
-               if (mail_transaction_log_refresh(log, FALSE) < 0) {
-                       *reason_r = "Log refresh failed";
+               if (mail_transaction_log_refresh(log, FALSE, &reason) < 0) {
+                       *reason_r = reason;
                        return -1;
                }
                if (file_seq > log->head->hdr.file_seq) {
                        if (!nfs_flush || !log->nfs_flush) {
-                               *reason_r = "Requested newer log than exists";
+                               *reason_r = t_strdup_printf(
+                                       "Requested newer log than exists: %s", reason);
                                return 0;
                        }
                        /* try again, this time flush attribute cache */
-                       if (mail_transaction_log_refresh(log, TRUE) < 0) {
-                               *reason_r = "Log refresh with NFS flush failed";
+                       if (mail_transaction_log_refresh(log, TRUE, &reason) < 0) {
+                               *reason_r = t_strdup_printf(
+                                       "Log refresh with NFS flush failed: %s", reason);
                                return -1;
                        }
                        if (file_seq > log->head->hdr.file_seq) {
-                               *reason_r = "Requested newer log than exists - "
-                                       "still after NFS flush";
+                               *reason_r = t_strdup_printf(
+                                       "Requested newer log than exists - "
+                                       "still after NFS flush: %s", reason);
                                return 0;
                        }
                }
@@ -438,6 +451,7 @@ int mail_transaction_log_lock_head(struct mail_transaction_log *log,
 {
        struct mail_transaction_log_file *file;
        time_t lock_wait_started, lock_secs = 0;
+       const char *reason;
        int ret = 0;
 
        if (!log->log_2_unlink_checked) {
@@ -466,7 +480,7 @@ int mail_transaction_log_lock_head(struct mail_transaction_log *log,
                        return -1;
 
                file->refcount++;
-               ret = mail_transaction_log_refresh(log, TRUE);
+               ret = mail_transaction_log_refresh(log, TRUE, &reason);
                if (--file->refcount == 0) {
                        mail_transaction_log_file_unlock(file, t_strdup_printf(
                                "trying to lock head for %s", lock_reason));