From: Pasha Tatashin <pasha.tatashin@soleen.com>
Date: Thu, 26 Mar 2026 16:39:42 +0000 (+0000)
Subject: memfd: implement get_id for memfd_luo
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=bc3a5763f4664c5da812eb3f14d55b0c99abd4ab;p=thirdparty%2Fkernel%2Flinux.git

memfd: implement get_id for memfd_luo

Memfds are identified by their underlying inode.  Implement get_id for
memfd_luo to return the inode pointer.  This prevents the same memfd from
being managed twice by LUO if the same inode is pointed by multiple file
objects.

Link: https://lore.kernel.org/20260326163943.574070-3-pasha.tatashin@soleen.com
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Pratyush Yadav (Google) <pratyush@kernel.org>
Cc: David Matlack <dmatlack@google.com>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Samiullah Khawaja <skhawaja@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/mm/memfd_luo.c b/mm/memfd_luo.c
index bc7f4f045edf..9130e6ce396d 100644
--- a/mm/memfd_luo.c
+++ b/mm/memfd_luo.c
@@ -560,6 +560,11 @@ static bool memfd_luo_can_preserve(struct liveupdate_file_handler *handler,
 	return shmem_file(file) && !inode->i_nlink;
 }
 
+static unsigned long memfd_luo_get_id(struct file *file)
+{
+	return (unsigned long)file_inode(file);
+}
+
 static const struct liveupdate_file_ops memfd_luo_file_ops = {
 	.freeze = memfd_luo_freeze,
 	.finish = memfd_luo_finish,
@@ -567,6 +572,7 @@ static const struct liveupdate_file_ops memfd_luo_file_ops = {
 	.preserve = memfd_luo_preserve,
 	.unpreserve = memfd_luo_unpreserve,
 	.can_preserve = memfd_luo_can_preserve,
+	.get_id = memfd_luo_get_id,
 	.owner = THIS_MODULE,
 };