On 2025-10-01, Alejandro Colomar [off-list ref] wrote:

Hi Aleksa,

On Wed, Oct 01, 2025 at 05:35:45PM +1000, Aleksa Sarai wrote:

quoted

On 2025-10-01, Askar Safin [off-list ref] wrote:

quoted

Aleksa Sarai [off-list ref]:

quoted

+mntfd2 = open_tree(mntfd1, "", OPEN_TREE_CLONE,
+                   &attr, sizeof(attr));

Your whole so-called "open_tree_attr example" doesn't contain any open_tree_attr
calls. :)

I think you meant open_tree_attr here.

Oops.

quoted

quoted

+\&
+/* Create a new copy with the id-mapping cleared */
+memset(&attr, 0, sizeof(attr));
+attr.attr_clr = MOUNT_ATTR_IDMAP;
+mntfd3 = open_tree(mntfd1, "", OPEN_TREE_CLONE,
+                   &attr, sizeof(attr));

And here.

Oops x2.

quoted

Otherwise your whole patchset looks good. Add to whole patchset:
Reviewed-by: Askar Safin <redacted>

I've applied the patch, with the following amendment:

	diff --git i/man/man2/open_tree.2 w/man/man2/open_tree.2
	index 8b48f3b78..f6f2fbecd 100644
	--- i/man/man2/open_tree.2
	+++ w/man/man2/open_tree.2
	@@ -683,14 +683,14 @@ .SS open_tree_attr()
	 .\" Using .attr_clr is not strictly necessary but makes the intent clearer.
	 attr.attr_set = MOUNT_ATTR_IDMAP;
	 attr.userns_fd = nsfd2;
	-mntfd2 = open_tree(mntfd1, "", OPEN_TREE_CLONE,
	-                   &attr, sizeof(attr));
	+mntfd2 = open_tree_attr(mntfd1, "", OPEN_TREE_CLONE,
	+                        &attr, sizeof(attr));
	 \&
	 /* Create a new copy with the id-mapping cleared */
	 memset(&attr, 0, sizeof(attr));
	 attr.attr_clr = MOUNT_ATTR_IDMAP;
	-mntfd3 = open_tree(mntfd1, "", OPEN_TREE_CLONE,
	-                   &attr, sizeof(attr));
	+mntfd3 = open_tree_attr(mntfd1, "", OPEN_TREE_CLONE,
	+                        &attr, sizeof(attr));
	 .EE
	 .in
	 .P


(Hopefully I got it right.)

That looks correct -- thanks!

-- 
Aleksa Sarai
Senior Software Engineer (Containers)
SUSE Linux GmbH
https://www.cyphar.com/