lib-index: Fixed changing extension record sizes.

map needs to be cloned before any extension record size changes are done.
Otherwise the map cloning will crash or do something broken.

diff --git a/src/lib-index/mail-index-sync-ext.c b/src/lib-index/mail-index-sync-ext.c
index 3abfd4bd9f4a865fbc28589daeb8a7a29326a448..994a2331ac16f71733006d98e104967f7ccfc7ab 100644 (file)
--- a/src/lib-index/mail-index-sync-ext.c
+++ b/src/lib-index/mail-index-sync-ext.c
@@ -259,17 +259,31 @@ sync_ext_resize(const struct mail_transaction_ext_intro *u,
                uint32_t ext_map_idx, struct mail_index_sync_map_ctx *ctx,
                bool no_shrink)
 {
-       struct mail_index_map *map = ctx->view->map;
+       struct mail_index_map *map;
        struct mail_index_ext *ext;
        struct mail_index_ext_header *ext_hdr;
        uint32_t old_padded_hdr_size, new_padded_hdr_size, old_record_size;
-       bool modified = FALSE, reorder = FALSE;
-
-       ext = array_idx_modifiable(&map->extensions, ext_map_idx);
+       bool reorder = FALSE;
 
+       ext = array_idx_modifiable(&ctx->view->map->extensions, ext_map_idx);
        old_padded_hdr_size = MAIL_INDEX_HEADER_SIZE_ALIGN(ext->hdr_size);
        new_padded_hdr_size = MAIL_INDEX_HEADER_SIZE_ALIGN(u->hdr_size);
 
+       if (ext->record_align != u->record_align ||
+           ext->record_size != u->record_size) {
+               /* record changed */
+       } else if (new_padded_hdr_size < old_padded_hdr_size) {
+               /* header is shrunk. do we allow? */
+               if (no_shrink)
+                       return;
+       } else if (ext->hdr_size == u->hdr_size) {
+               /* no changes */
+               return;
+       }
+       /* something changed. get ourself a new map before we start changing
+          anything in it. */
+       map = mail_index_sync_get_atomic_map(ctx);
+
        if (new_padded_hdr_size < old_padded_hdr_size) {
                /* header shrank */
                if (no_shrink)
@@ -279,7 +293,6 @@ sync_ext_resize(const struct mail_transaction_ext_intro *u,
                                      ext->hdr_offset + new_padded_hdr_size,
                                      old_padded_hdr_size - new_padded_hdr_size);
                        ext->hdr_size = u->hdr_size;
-                       modified = TRUE;
                }
        } else if (new_padded_hdr_size > old_padded_hdr_size) {
                /* header grown */
@@ -287,20 +300,17 @@ sync_ext_resize(const struct mail_transaction_ext_intro *u,
                                   ext->hdr_offset + old_padded_hdr_size,
                                   new_padded_hdr_size - old_padded_hdr_size);
                ext->hdr_size = u->hdr_size;
-               modified = TRUE;
        } else {
                if (ext->hdr_size != u->hdr_size) {
                        /* aligned sizes were the same, but the actual sizes
                           had changed */
                        ext->hdr_size = u->hdr_size;
-                       modified = TRUE;
                }
        }
 
        if (ext->record_align < u->record_align ||
            (ext->record_align > u->record_align && !no_shrink)) {
                ext->record_align = u->record_align;
-               modified = TRUE;
                reorder = TRUE;
        }
 
@@ -308,24 +318,19 @@ sync_ext_resize(const struct mail_transaction_ext_intro *u,
        if (ext->record_size < u->record_size ||
            (ext->record_size > u->record_size && !no_shrink)) {
                ext->record_size = u->record_size;
-               modified = TRUE;
                reorder = TRUE;
        }
 
-       if (modified) {
-               i_assert((map->hdr_copy_buf->used % sizeof(uint64_t)) == 0);
-               map->hdr_base = map->hdr_copy_buf->data;
-               map->hdr.header_size = map->hdr_copy_buf->used;
+       i_assert((map->hdr_copy_buf->used % sizeof(uint64_t)) == 0);
+       map->hdr_base = map->hdr_copy_buf->data;
+       map->hdr.header_size = map->hdr_copy_buf->used;
 
-               ext_hdr = get_ext_header(map, ext);
-               ext_hdr->reset_id = ext->reset_id;
-               ext_hdr->hdr_size = ext->hdr_size;
-               ext_hdr->record_offset = ext->record_offset;
-               ext_hdr->record_size = ext->record_size;
-               ext_hdr->record_align = ext->record_align;
-       } else {
-               i_assert(map->hdr_base == map->hdr_copy_buf->data);
-       }
+       ext_hdr = get_ext_header(map, ext);
+       ext_hdr->reset_id = ext->reset_id;
+       ext_hdr->hdr_size = ext->hdr_size;
+       ext_hdr->record_offset = ext->record_offset;
+       ext_hdr->record_size = ext->record_size;
+       ext_hdr->record_align = ext->record_align;
 
        if (new_padded_hdr_size != old_padded_hdr_size) {
                /* move all hdr_offset of all extensions after this one */
@@ -340,13 +345,8 @@ sync_ext_resize(const struct mail_transaction_ext_intro *u,
                }
        }
 
-       if (reorder) {
-               map = mail_index_sync_get_atomic_map(ctx);
+       if (reorder)
                sync_ext_reorder(map, ext_map_idx, old_record_size);
-       } else if (modified) {
-               /* header size changed. recreate index file. */
-               (void)mail_index_sync_get_atomic_map(ctx);
-       }
 }
 
 static bool