libglnx porting: Migrate to new tempfile code

In general this is even cleaner now, though it was better after I
extracted a helper function for the "write tempfile with contents"
bits that were shared between metadata and regular file codepaths.

Closes: #369
Approved by: jlebon

Makefile.am

@@ -19,7 +19,7 @@ include Makefile-decls.am
 
 shortened_sysconfdir = $$(echo "$(sysconfdir)" | sed -e 's|^$(prefix)||' -e 's|^/||')
 
-ACLOCAL_AMFLAGS = -I buildutil ${ACLOCAL_FLAGS}
+ACLOCAL_AMFLAGS = -I buildutil -I libglnx ${ACLOCAL_FLAGS}
 AM_CPPFLAGS += -DDATADIR='"$(datadir)"' -DLIBEXECDIR='"$(libexecdir)"' \
 	-DLOCALEDIR=\"$(datadir)/locale\" -DSYSCONFDIR=\"$(sysconfdir)\" \
 	-DSHORTENED_SYSCONFDIR=\"$(shortened_sysconfdir)\" \

autogen.sh

@@ -36,6 +36,9 @@ fi
 sed -e 's,$(libglnx_srcpath),libglnx,g' < libglnx/Makefile-libglnx.am >libglnx/Makefile-libglnx.am.inc
 sed -e 's,$(libbsdiff_srcpath),bsdiff,g' < bsdiff/Makefile-bsdiff.am >bsdiff/Makefile-bsdiff.am.inc
 
+# FIXME - figure out how to get aclocal to find this by default
+ln -sf ../libglnx/libglnx.m4 buildutil/libglnx.m4
+
 autoreconf --force --install --verbose
 
 test -n "$NOCONFIGURE" || "$srcdir/configure" "$@"

configure.ac

@@ -35,6 +35,7 @@ OSTREE_FEATURES=""
 AC_SUBST([OSTREE_FEATURES])
 
 GLIB_TESTS
+LIBGLNX_CONFIGURE
 
 AC_CHECK_HEADER([sys/xattr.h],,[AC_MSG_ERROR([You must have sys/xattr.h from glibc])])
 

src/libostree/ostree-repo-checkout.c

@@ -45,7 +45,7 @@ checkout_object_for_uncompressed_cache (OstreeRepo      *self,
   gboolean ret = FALSE;
   g_autofree char *temp_filename = NULL;
   g_autoptr(GOutputStream) temp_out = NULL;
-  int fd;
+  glnx_fd_close int fd = -1;
   int res;
   guint32 file_mode;
 
@@ -53,10 +53,11 @@ checkout_object_for_uncompressed_cache (OstreeRepo      *self,
   file_mode = g_file_info_get_attribute_uint32 (src_info, "unix::mode");
   file_mode &= ~(S_ISUID|S_ISGID);
 
-  if (!gs_file_open_in_tmpdir_at (self->tmp_dir_fd, file_mode,
-                                  &temp_filename, &temp_out,
-                                  cancellable, error))
+  if (!glnx_open_tmpfile_linkable_at (self->tmp_dir_fd, ".", O_WRONLY | O_CLOEXEC,
+                                      &fd, &temp_filename,
+                                      error))
     goto out;
+  temp_out = g_unix_output_stream_new (fd, FALSE);
 
   if (g_output_stream_splice (temp_out, content, 0, cancellable, error) < 0)
     goto out;
@@ -64,8 +65,6 @@ checkout_object_for_uncompressed_cache (OstreeRepo      *self,
   if (!g_output_stream_flush (temp_out, cancellable, error))
     goto out;
 
-  fd = g_file_descriptor_based_get_fd ((GFileDescriptorBased*)temp_out);
-
   if (!self->disable_fsync)
     {
       do
@@ -81,23 +80,22 @@ checkout_object_for_uncompressed_cache (OstreeRepo      *self,
   if (!g_output_stream_close (temp_out, cancellable, error))
     goto out;
 
+  if (fchmod (fd, file_mode) < 0)
+    {
+      glnx_set_error_from_errno (error);
+      goto out;
+    }
+
   if (!_ostree_repo_ensure_loose_objdir_at (self->uncompressed_objects_dir_fd,
                                             loose_path,
                                             cancellable, error))
     goto out;
 
-  if (G_UNLIKELY (renameat (self->tmp_dir_fd, temp_filename,
-                            self->uncompressed_objects_dir_fd, loose_path) == -1))
-    {
-      if (errno != EEXIST)
-        {
-          glnx_set_error_from_errno (error);
-          g_prefix_error (error, "Storing file '%s': ", temp_filename);
-          goto out;
-        }
-      else
-        (void) unlinkat (self->tmp_dir_fd, temp_filename, 0);
-    }
+  if (!glnx_link_tmpfile_at (self->tmp_dir_fd, GLNX_LINK_TMPFILE_NOREPLACE_IGNORE_EXIST,
+                             fd, temp_filename,
+                             self->uncompressed_objects_dir_fd, loose_path,
+                             error))
+    goto out;
 
   ret = TRUE;
  out:
@@ -292,9 +290,16 @@ checkout_file_unioning_from_input_at (OstreeRepo     *repo,
                                                xattrs, cancellable, error))
             goto out;
         }
+      if (G_UNLIKELY (renameat (destination_dfd, temp_filename,
+                                destination_dfd, destination_name) == -1))
+        {
+          glnx_set_error_from_errno (error);
+          goto out;
+        }
     }
   else if (g_file_info_get_file_type (file_info) == G_FILE_TYPE_REGULAR)
     {
+      glnx_fd_close int temp_fd = -1;
       g_autoptr(GOutputStream) temp_out = NULL;
       guint32 file_mode;
 
@@ -303,25 +308,25 @@ checkout_file_unioning_from_input_at (OstreeRepo     *repo,
       if (options->mode == OSTREE_REPO_CHECKOUT_MODE_USER)
         file_mode &= ~(S_ISUID|S_ISGID);
 
-      if (!gs_file_open_in_tmpdir_at (destination_dfd, file_mode,
-                                      &temp_filename, &temp_out,
-                                      cancellable, error))
+      if (!glnx_open_tmpfile_linkable_at (destination_dfd, ".", O_WRONLY | O_CLOEXEC,
+                                          &temp_fd, &temp_filename,
+                                          error))
         goto out;
+      temp_out = g_unix_output_stream_new (temp_fd, FALSE);
 
       if (!write_regular_file_content (repo, options, temp_out, file_info, xattrs, input,
                                        cancellable, error))
         goto out;
+
+      if (!glnx_link_tmpfile_at (destination_dfd, GLNX_LINK_TMPFILE_REPLACE,
+                                 temp_fd, temp_filename, destination_dfd,
+                                 destination_name,
+                                 error))
+        goto out;
     }
   else
     g_assert_not_reached ();
 
-  if (G_UNLIKELY (renameat (destination_dfd, temp_filename,
-                            destination_dfd, destination_name) == -1))
-    {
-      glnx_set_error_from_errno (error);
-      goto out;
-    }
-
   ret = TRUE;
  out:
   return ret;

src/libostree/ostree-repo-commit.c

@@ -25,6 +25,7 @@
 #include <glib-unix.h>
 #include <gio/gfiledescriptorbased.h>
 #include <gio/gunixinputstream.h>
+#include <gio/gunixoutputstream.h>
 #include "otutil.h"
 
 #include "ostree-core-private.h"
@@ -114,6 +115,7 @@ _ostree_repo_commit_loose_final (OstreeRepo        *self,
                                  const char        *checksum,
                                  OstreeObjectType   objtype,
                                  int                temp_dfd,
+                                 int                fd,
                                  const char        *temp_filename,
                                  GCancellable      *cancellable,
                                  GError           **error)
@@ -133,17 +135,26 @@ _ostree_repo_commit_loose_final (OstreeRepo        *self,
                                             cancellable, error))
     goto out;
 
-  if (G_UNLIKELY (renameat (temp_dfd, temp_filename,
-                            dest_dfd, tmpbuf) == -1))
+  if (fd != -1)
     {
-      if (errno != EEXIST)
+      if (!glnx_link_tmpfile_at (temp_dfd, GLNX_LINK_TMPFILE_NOREPLACE_IGNORE_EXIST,
+                                 fd, temp_filename, dest_dfd, tmpbuf, error))
+        goto out;
+    }
+  else
+    {
+      if (G_UNLIKELY (renameat (temp_dfd, temp_filename,
+                                dest_dfd, tmpbuf) == -1))
         {
-          glnx_set_error_from_errno (error);
-          g_prefix_error (error, "Storing file '%s': ", temp_filename);
-          goto out;
+          if (errno != EEXIST)
+            {
+              glnx_set_error_from_errno (error);
+              g_prefix_error (error, "Storing file '%s': ", temp_filename);
+              goto out;
+            }
+          else
+            (void) unlinkat (temp_dfd, temp_filename, 0);
         }
-      else
-        (void) unlinkat (temp_dfd, temp_filename, 0);
     }
 
   ret = TRUE;
@@ -173,10 +184,18 @@ commit_loose_object_trusted (OstreeRepo        *self,
   if (self->mode == OSTREE_REPO_MODE_ARCHIVE_Z2
       && self->target_owner_uid != -1) 
     {
-      if (G_UNLIKELY (fchownat (self->tmp_dir_fd, temp_filename,
-                                self->target_owner_uid,
-                                self->target_owner_gid,
-                                AT_SYMLINK_NOFOLLOW) == -1))
+      if (fd != -1)
+        {
+          if (fchown (fd, self->target_owner_uid, self->target_owner_gid) < 0)
+            {
+              glnx_set_error_from_errno (error);
+              goto out;
+            }
+        }
+      else if (G_UNLIKELY (fchownat (self->tmp_dir_fd, temp_filename,
+                                     self->target_owner_uid,
+                                     self->target_owner_gid,
+                                     AT_SYMLINK_NOFOLLOW) == -1))
         {
           glnx_set_error_from_errno (error);
           goto out;
@@ -293,7 +312,7 @@ commit_loose_object_trusted (OstreeRepo        *self,
     }
 
   if (!_ostree_repo_commit_loose_final (self, checksum, objtype,
-                                        self->tmp_dir_fd, temp_filename,
+                                        self->tmp_dir_fd, fd, temp_filename,
                                         cancellable, error))
     goto out;
   
@@ -466,9 +485,13 @@ _ostree_repo_open_content_bare (OstreeRepo          *self,
 
   if (!have_obj)
     {
-      if (!gs_file_open_in_tmpdir_at (self->tmp_dir_fd, 0644, &temp_filename, &ret_stream,
-                                      cancellable, error))
+      int fd;
+
+      if (!glnx_open_tmpfile_linkable_at (self->tmp_dir_fd, ".", O_WRONLY|O_CLOEXEC,
+                                          &fd, &temp_filename, error))
         goto out;
+
+      ret_stream = g_unix_output_stream_new (fd, TRUE);
       
       if (!fallocate_stream ((GFileDescriptorBased*)ret_stream, content_len,
                              cancellable, error))
@@ -518,6 +541,42 @@ _ostree_repo_commit_trusted_content_bare (OstreeRepo          *self,
   return ret;
 }
 
+static gboolean
+create_regular_tmpfile_linkable_with_content (OstreeRepo *self,
+                                              guint64 length,
+                                              GInputStream *input,
+                                              int *out_fd,
+                                              char **out_path,
+                                              GCancellable *cancellable,
+                                              GError **error)
+{
+  g_autoptr(GOutputStream) temp_out = NULL;
+  glnx_fd_close int temp_fd = -1;
+  g_autofree char *temp_filename = NULL;
+
+  if (!glnx_open_tmpfile_linkable_at (self->tmp_dir_fd, ".", O_WRONLY|O_CLOEXEC,
+                                      &temp_fd, &temp_filename,
+                                      error))
+    return FALSE;
+  temp_out = g_unix_output_stream_new (temp_fd, FALSE);
+
+  if (!fallocate_stream ((GFileDescriptorBased*)temp_out, length,
+                         cancellable, error))
+    return FALSE;
+
+  if (g_output_stream_splice (temp_out, input, 0,
+                              cancellable, error) < 0)
+    return FALSE;
+  if (fchmod (temp_fd, 0644) < 0)
+    {
+      glnx_set_error_from_errno (error);
+      return FALSE;
+    }
+  *out_fd = temp_fd; temp_fd = -1;
+  *out_path = g_steal_pointer (&temp_filename);
+  return TRUE;
+}
+
 static gboolean
 write_object (OstreeRepo         *self,
               OstreeObjectType    objtype,
@@ -539,11 +598,11 @@ write_object (OstreeRepo         *self,
   g_autoptr(GInputStream) file_input = NULL;
   g_autoptr(GFileInfo) file_info = NULL;
   g_autoptr(GVariant) xattrs = NULL;
-  g_autoptr(GOutputStream) temp_out = NULL;
   gboolean have_obj;
   GChecksum *checksum = NULL;
   gboolean temp_file_is_regular;
   gboolean temp_file_is_symlink;
+  glnx_fd_close int temp_fd = -1;
   gboolean object_is_symlink = FALSE;
   gssize unpacked_size = 0;
   gboolean indexable = FALSE;
@@ -623,16 +682,9 @@ write_object (OstreeRepo         *self,
         {
           guint64 size = g_file_info_get_size (file_info);
 
-          if (!gs_file_open_in_tmpdir_at (self->tmp_dir_fd, 0644, &temp_filename, &temp_out,
-                                          cancellable, error))
-            goto out;
-
-          if (!fallocate_stream ((GFileDescriptorBased*)temp_out, size,
-                                 cancellable, error))
-            goto out;
-
-          if (g_output_stream_splice (temp_out, file_input, 0,
-                                      cancellable, error) < 0)
+          if (!create_regular_tmpfile_linkable_with_content (self, size, file_input,
+                                                             &temp_fd, &temp_filename,
+                                                             cancellable, error))
             goto out;
         }
       else if (repo_mode == OSTREE_REPO_MODE_BARE && temp_file_is_symlink)
@@ -648,15 +700,17 @@ write_object (OstreeRepo         *self,
           g_autoptr(GVariant) file_meta = NULL;
           g_autoptr(GConverter) zlib_compressor = NULL;
           g_autoptr(GOutputStream) compressed_out_stream = NULL;
+          g_autoptr(GOutputStream) temp_out = NULL;
 
           if (self->generate_sizes)
             indexable = TRUE;
 
-          if (!gs_file_open_in_tmpdir_at (self->tmp_dir_fd, 0644,
-                                          &temp_filename, &temp_out,
-                                          cancellable, error))
+          if (!glnx_open_tmpfile_linkable_at (self->tmp_dir_fd, ".", O_WRONLY|O_CLOEXEC,
+                                              &temp_fd, &temp_filename,
+                                              error))
             goto out;
           temp_file_is_regular = TRUE;
+          temp_out = g_unix_output_stream_new (temp_fd, FALSE);
 
           file_meta = _ostree_zlib_file_header_new (file_info, xattrs);
 
@@ -676,33 +730,29 @@ write_object (OstreeRepo         *self,
               if (unpacked_size < 0)
                 goto out;
             }
+
+          if (!g_output_stream_flush (temp_out, cancellable, error))
+            goto out;
+
+          if (fchmod (temp_fd, 0644) < 0)
+            {
+              glnx_set_error_from_errno (error);
+              goto out;
+            }
         }
       else
         g_assert_not_reached ();
     }
   else
     {
-      if (!gs_file_open_in_tmpdir_at (self->tmp_dir_fd, 0644, &temp_filename, &temp_out,
-                                      cancellable, error))
-        goto out;
-
-      if (!fallocate_stream ((GFileDescriptorBased*)temp_out, file_object_length,
-                             cancellable, error))
-        goto out;
-
-      if (g_output_stream_splice (temp_out, checksum_input ? (GInputStream*)checksum_input : input,
-                                  0,
-                                  cancellable, error) < 0)
+      if (!create_regular_tmpfile_linkable_with_content (self, file_object_length,
+                                                         checksum_input ? (GInputStream*)checksum_input : input,
+                                                         &temp_fd, &temp_filename,
+                                                         cancellable, error))
         goto out;
       temp_file_is_regular = TRUE;
     }
 
-  if (temp_out)
-    {
-      if (!g_output_stream_flush (temp_out, cancellable, error))
-        goto out;
-    }
-
   if (!checksum)
     actual_checksum = expected_checksum;
   else
@@ -724,7 +774,7 @@ write_object (OstreeRepo         *self,
     {
       struct stat stbuf;
 
-      if (fstatat (self->tmp_dir_fd, temp_filename, &stbuf, AT_SYMLINK_NOFOLLOW) == -1)
+      if (fstat (temp_fd, &stbuf) == -1)
         {
           glnx_set_error_from_errno (error);
           goto out;
@@ -742,7 +792,6 @@ write_object (OstreeRepo         *self,
   if (do_commit)
     {
       guint32 uid, gid, mode;
-      int fd = -1;
 
       if (file_info)
         {
@@ -752,15 +801,12 @@ write_object (OstreeRepo         *self,
         }
       else
         uid = gid = mode = 0;
-
-      if (temp_out)
-        fd = g_file_descriptor_based_get_fd ((GFileDescriptorBased*)temp_out);
       
       if (!commit_loose_object_trusted (self, actual_checksum, objtype,
                                         temp_filename,
                                         object_is_symlink,
                                         uid, gid, mode,
-                                        xattrs, fd,
+                                        xattrs, temp_fd,
                                         cancellable, error))
         goto out;
 

src/libostree/ostree-repo-private.h

@@ -255,6 +255,7 @@ _ostree_repo_commit_loose_final (OstreeRepo        *self,
                                  const char        *checksum,
                                  OstreeObjectType   objtype,
                                  int                temp_dfd,
+                                 int                fd,
                                  const char        *temp_filename,
                                  GCancellable      *cancellable,
                                  GError           **error);

src/libostree/ostree-repo-pull.c

@@ -726,7 +726,7 @@ content_fetch_on_complete (GObject        *object,
       if (!have_object)
         {
           if (!_ostree_repo_commit_loose_final (pull_data->repo, checksum, OSTREE_OBJECT_TYPE_FILE,
-                                                _ostree_fetcher_get_dfd (fetcher), temp_path,
+                                                _ostree_fetcher_get_dfd (fetcher), -1, temp_path,
                                                 cancellable, error))
             goto out;
         }