Received-SPF: pass (google.com: domain of linux-kernel+bounces-202820-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:4601:e00::3 as permitted sender) client-ip=2604:1380:4601:e00::3;
Received-SPF: Pass (protection.outlook.com: domain of amd.com designates
 165.204.84.17 as permitted sender) receiver=protection.outlook.com;
 client-ip=165.204.84.17; helo=SATLEXMB04.amd.com; pr=C
From: Tom Lendacky <thomas.lendacky@amd.com>
To: <linux-kernel@vger.kernel.org>, <x86@kernel.org>,
	<linux-coco@lists.linux.dev>, <svsm-devel@coconut-svsm.dev>
CC: Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>,
	Borislav Petkov <bp@alien8.de>, Dave Hansen <dave.hansen@linux.intel.com>,
	"H. Peter Anvin" <hpa@zytor.com>, Andy Lutomirski <luto@kernel.org>, "Peter
 Zijlstra" <peterz@infradead.org>, Dan Williams <dan.j.williams@intel.com>,
	Michael Roth <michael.roth@amd.com>, Ashish Kalra <ashish.kalra@amd.com>,
	Joel Becker <jlbec@evilplan.org>, Christoph Hellwig <hch@lst.de>
Subject: [PATCH v5 10/13] fs/configfs: Add a callback to determine attribute visibility
Date: Wed, 5 Jun 2024 10:18:53 -0500
Message-ID: <e555c8740a263fab9f83b2cbb44da1af49a2813c.1717600736.git.thomas.lendacky@amd.com>
In-Reply-To: <cover.1717600736.git.thomas.lendacky@amd.com>
References: <cover.1717600736.git.thomas.lendacky@amd.com>
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Content-Type: text/plain
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 05 Jun 2024 15:20:28.8632
 (UTC)
X-MS-Exchange-CrossTenant-Network-Message-Id: a45c0c8c-85dd-41df-68e5-08dc85730875
X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d
X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=3dd8961f-e488-4e60-8e11-a82d994e183d;Ip=[165.204.84.17];Helo=[SATLEXMB04.amd.com]
X-MS-Exchange-CrossTenant-AuthSource:
	BN3PEPF0000B36D.namprd21.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Anonymous
X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem
X-MS-Exchange-Transport-CrossTenantHeadersStamped: LV3PR12MB9096

In order to support dynamic decisions as to whether an attribute should be
created, add a callback that returns a bool to indicate whether the
attribute should be displayed. If no callback is registered, the attribute
is displayed by default.

Cc: Joel Becker <jlbec@evilplan.org>
Cc: Christoph Hellwig <hch@lst.de>
Co-developed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
---
 fs/configfs/dir.c        | 10 ++++++++++
 include/linux/configfs.h |  3 +++
 2 files changed, 13 insertions(+)

diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c
index 18677cd4e62f..43d6bde1adcc 100644
--- a/fs/configfs/dir.c
+++ b/fs/configfs/dir.c
@@ -580,6 +580,7 @@ static void detach_attrs(struct config_item * item)
 static int populate_attrs(struct config_item *item)
 {
 	const struct config_item_type *t = item->ci_type;
+	struct configfs_group_operations *ops;
 	struct configfs_attribute *attr;
 	struct configfs_bin_attribute *bin_attr;
 	int error = 0;
@@ -587,14 +588,23 @@ static int populate_attrs(struct config_item *item)
 
 	if (!t)
 		return -EINVAL;
+
+	ops = t->ct_group_ops;
+
 	if (t->ct_attrs) {
 		for (i = 0; (attr = t->ct_attrs[i]) != NULL; i++) {
+			if (ops && ops->is_visible && !ops->is_visible(item, attr, i))
+				continue;
+
 			if ((error = configfs_create_file(item, attr)))
 				break;
 		}
 	}
 	if (t->ct_bin_attrs) {
 		for (i = 0; (bin_attr = t->ct_bin_attrs[i]) != NULL; i++) {
+			if (ops && ops->is_bin_visible && !ops->is_bin_visible(item, bin_attr, i))
+				continue;
+
 			error = configfs_create_bin_file(item, bin_attr);
 			if (error)
 				break;
diff --git a/include/linux/configfs.h b/include/linux/configfs.h
index 2606711adb18..c771e9d0d0b9 100644
--- a/include/linux/configfs.h
+++ b/include/linux/configfs.h
@@ -216,6 +216,9 @@ struct configfs_group_operations {
 	struct config_group *(*make_group)(struct config_group *group, const char *name);
 	void (*disconnect_notify)(struct config_group *group, struct config_item *item);
 	void (*drop_item)(struct config_group *group, struct config_item *item);
+	bool (*is_visible)(struct config_item *item, struct configfs_attribute *attr, int n);
+	bool (*is_bin_visible)(struct config_item *item, struct configfs_bin_attribute *attr,
+			       int n);
 };
 
 struct configfs_subsystem {
-- 
2.43.2