If index file's header shows that it's unusable (e.g. major version change

or CPU arch change), make sure they're not tried to be used and handle the
rebuilding nicely.

--HG--
branch : HEAD

diff --git a/src/lib-index/mail-index-map.c b/src/lib-index/mail-index-map.c
index 75d43165c96cd56fc95bffcd09fa49eeec9aca26..4d7bbed265a1bd7b5a57a707053c055467604b5b 100644 (file)
--- a/src/lib-index/mail-index-map.c
+++ b/src/lib-index/mail-index-map.c
@@ -808,13 +808,15 @@ struct mail_index_map *mail_index_map_alloc(struct mail_index *index)
        return mail_index_map_clone(&tmp_map);
 }
 
+/* returns -1 = error, 0 = index files are unusable,
+   1 = index files are usable or at least repairable */
 static int mail_index_map_latest_file(struct mail_index *index)
 {
        struct mail_index_map *old_map, *new_map;
        struct stat st;
        unsigned int lock_id;
        uoff_t file_size;
-       bool use_mmap;
+       bool use_mmap, unusable = FALSE;
        int ret, try;
 
        ret = mail_index_reopen_if_changed(index);
@@ -824,7 +826,7 @@ static int mail_index_map_latest_file(struct mail_index *index)
 
                /* the index file is lost/broken. let's hope that we can
                   build it from the transaction log. */
-               return 0;
+               return 1;
        }
 
        /* the index file is still open, lock it */
@@ -858,6 +860,10 @@ static int mail_index_map_latest_file(struct mail_index *index)
                ret = mail_index_read_map(new_map, file_size, &lock_id);
                mail_index_unlock(index, &lock_id);
        }
+       if (ret == 0) {
+               /* the index files are unusable */
+               unusable = TRUE;
+       }
 
        for (try = 0; ret > 0; try++) {
                /* make sure the header is ok before using this mapping */
@@ -868,8 +874,13 @@ static int mail_index_map_latest_file(struct mail_index *index)
                        else if (mail_index_map_parse_keywords(new_map) < 0)
                                ret = 0;
                } T_END;
-               if (ret != 0 || try == 2)
+               if (ret != 0 || try == 2) {
+                       if (ret < 0) {
+                               unusable = TRUE;
+                               ret = 0;
+                       }
                        break;
+               }
 
                /* fsck and try again */
                old_map = index->map;
@@ -885,7 +896,7 @@ static int mail_index_map_latest_file(struct mail_index *index)
        }
        if (ret <= 0) {
                mail_index_unmap(&new_map);
-               return ret;
+               return ret < 0 ? -1 : (unusable ? 0 : 1);
        }
        i_assert(new_map->rec_map->records != NULL);
 
@@ -924,18 +935,24 @@ int mail_index_map(struct mail_index *index,
        }
 
        if (ret == 0) {
-               /* try to open and read the latest index. if it fails for
-                  any reason, we'll fallback to updating the existing mapping
-                  from transaction logs (which we'll also do even if the
-                  reopening succeeds) */
-               (void)mail_index_map_latest_file(index);
-
-               /* if we're creating the index file, we don't have any
-                  logs yet */
-               if (index->log->head != NULL && index->indexid != 0) {
-                       /* and update the map with the latest changes from
-                          transaction log */
-                       ret = mail_index_sync_map(&index->map, type, TRUE);
+               /* try to open and read the latest index. if it fails, we'll
+                  fallback to updating the existing mapping from transaction
+                  logs (which we'll also do even if the reopening succeeds).
+                  if index files are unusable (e.g. major version change)
+                  don't even try to use the transaction log. */
+               if (mail_index_map_latest_file(index) == 0) {
+                       /* make sure we don't try to open the file again */
+                       if (unlink(index->filepath) < 0 && errno != ENOENT)
+                               mail_index_set_syscall_error(index, "unlink()");
+               } else {
+                       /* if we're creating the index file, we don't have any
+                          logs yet */
+                       if (index->log->head != NULL && index->indexid != 0) {
+                               /* and update the map with the latest changes
+                                  from transaction log */
+                               ret = mail_index_sync_map(&index->map, type,
+                                                         TRUE);
+                       }
                }
        }