# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1654617628 -7200
# Node ID c9db9e4c9f4044afc78a59d7c9b0ec8034c16f55
# Parent  04881b15def85420412ee2e6293230d89a2938fe
Introduced file_mmap_only which does not map a memory region in the task.

diff -r 04881b15def8 -r c9db9e4c9f40 libfsclient/include/fsclient/file.h
--- a/libfsclient/include/fsclient/file.h	Tue Jun 07 01:14:05 2022 +0200
+++ b/libfsclient/include/fsclient/file.h	Tue Jun 07 18:00:28 2022 +0200
@@ -112,6 +112,8 @@
 long file_mmap(file_t *file, offset_t position, offset_t length,
                offset_t start_visible, offset_t end_visible,
                l4re_rm_flags_t region_flags);
+long file_mmap_only(file_t *file, offset_t position, offset_t length,
+                    offset_t start_visible, offset_t end_visible);
 flags_t file_opening_flags(l4re_rm_flags_t rm_flags);
 l4re_rm_flags_t file_region_flags(flags_t flags);
 long file_resize(file_t *file, offset_t size);
diff -r 04881b15def8 -r c9db9e4c9f40 libfsclient/lib/src/file.cc
--- a/libfsclient/lib/src/file.cc	Tue Jun 07 01:14:05 2022 +0200
+++ b/libfsclient/lib/src/file.cc	Tue Jun 07 18:00:28 2022 +0200
@@ -356,15 +356,11 @@
                l4re_rm_flags_t region_flags)
 {
   char *memory = file->memory;
-  client_MappedFile mapped_file(file->ref);
-  long err = mapped_file.mmap(position, length, start_visible, end_visible,
-                              &file->start_pos, &file->end_pos, &file->size);
+  long err = file_mmap_only(file, position, length, start_visible, end_visible);
 
   if (err)
     return err;
 
-  _update_extent(file);
-
   err = ipc_attach_dataspace_align(file->ref, file_span(file),
                                    L4RE_RM_F_SEARCH_ADDR | region_flags,
                                    L4_PAGESHIFT,
@@ -378,6 +374,24 @@
   return L4_EOK;
 }
 
+/* Request access to a region of the given file, obtaining an updated file size
+   and populated data details. The region is not mapped, however. */
+
+long file_mmap_only(file_t *file, offset_t position, offset_t length,
+                    offset_t start_visible, offset_t end_visible)
+{
+  client_MappedFile mapped_file(file->ref);
+  long err = mapped_file.mmap(position, length, start_visible, end_visible,
+                              &file->start_pos, &file->end_pos, &file->size);
+
+  if (err)
+    return err;
+
+  _update_extent(file);
+
+  return L4_EOK;
+}
+
 /* Return opening flags compatible with the given region flags. */
 
 flags_t file_opening_flags(l4re_rm_flags_t rm_flags)
diff -r 04881b15def8 -r c9db9e4c9f40 tests/Makefile
--- a/tests/Makefile	Tue Jun 07 01:14:05 2022 +0200
+++ b/tests/Makefile	Tue Jun 07 18:00:28 2022 +0200
@@ -30,7 +30,7 @@
 
 # Individual interfaces.
 
-CLIENT_INTERFACES_CC			= dataspace mapped_file
+CLIENT_INTERFACES_CC			= dataspace
 
 # Generated and plain source files.
 
diff -r 04881b15def8 -r c9db9e4c9f40 tests/dstest_file_mapping.cc
--- a/tests/dstest_file_mapping.cc	Tue Jun 07 01:14:05 2022 +0200
+++ b/tests/dstest_file_mapping.cc	Tue Jun 07 18:00:28 2022 +0200
@@ -32,29 +32,6 @@
 #include <mem/memory_utils.h>
 
 #include "dataspace_client.h"
-#include "mapped_file_client.h"
-
-
-
-/* NOTE: Copied from libfsclient. */
-
-static void _update_extent(file_t *file)
-{
-  /* Handle files ending after or within the region. */
-
-  if (file->size > file->start_pos)
-  {
-    if (file->size > file->end_pos)
-      file->data_end = file->end_pos - file->start_pos;
-    else
-      file->data_end = file->size - file->start_pos;
-  }
-
-  /* Handle files ending before the region. */
-
-  else
-    file->data_end = 0;
-}
 
 
 
@@ -91,11 +68,9 @@
     return 1;
   }
 
-  /* A region of the file is mapped. */
+  /* A region of the file is mapped but not attached. */
 
-  client_MappedFile mapped_file(file.ref);
-
-  err = mapped_file.mmap(0, page(10), 0, 0, &file.start_pos, &file.end_pos, &file.size);
+  err = file_mmap_only(&file, 0, page(10), 0, 0);
 
   if (err)
   {
@@ -106,7 +81,6 @@
   /* Fix up the file data structure manually. */
 
   file.memory = (char *) 0x2000000;
-  _update_extent(&file);
 
   /* Explicitly map the file into this address space, without region mapper
      usage. The receive window base must be a multiple of its size. */