Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Ajay Kaher <akaher@vmware.com>
To:     rostedt@goodmis.org, shuah@kernel.org, mhiramat@kernel.org
Cc:     chinglinyu@google.com, linux-kernel@vger.kernel.org,
        linux-kselftest@vger.kernel.org,
        linux-trace-kernel@vger.kernel.org, lkp@intel.com,
        namit@vmware.com, oe-lkp@lists.linux.dev, akaher@vmware.com,
        amakhalov@vmware.com, er.ajay.kaher@gmail.com,
        srivatsa@csail.mit.edu, tkundu@vmware.com, vsirnapalli@vmware.com
Subject: [PATCH v6 05/10] eventfs: Implement eventfs file add functions
Date:   Fri, 28 Jul 2023 23:50:47 +0530
Message-Id: <1690568452-46553-6-git-send-email-akaher@vmware.com>
In-Reply-To: <1690568452-46553-1-git-send-email-akaher@vmware.com>
References: <1690568452-46553-1-git-send-email-akaher@vmware.com>
Content-Type: text/plain
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?POepEnsqCFqrnOjejg5PsinHOt0W6p0oyTUWXLHmW6vW8R4uAUYvp/xMbI57?=
 =?us-ascii?Q?wjnNyQBPOAsbEJFy/p6m8j3raqQtjtbTfZr49jjbFX8NSklQoGU/aq0wzTgR?=
 =?us-ascii?Q?br6LJq8xhSZPS2/qbc73GjDtG20kuCwcDY9OkhE1Xb+CxHJdmuT8RCjcWw0J?=
 =?us-ascii?Q?30WaQmlWBwgih4mr4lab6A6j5P+zQpgsfd28T2FOxVfbDcwkvaGEecL0bpZB?=
 =?us-ascii?Q?HgtWHIOckteucbMJPGHy8+XOSGxTetFjwg7PrcY35WCqWaWTwovo30IgFrMG?=
 =?us-ascii?Q?/TQ/CBdSqNMtfUlueBB/Y9VBNXSRs54sNVzMTb0JKniJYAKb7FF4kbNTEqyo?=
 =?us-ascii?Q?J9AVhoo+MUo5oSmtrSswhVMWOJ5hLiVotj7h0Qt85Ccy9RN4R2sYf0G+D6LJ?=
 =?us-ascii?Q?J4LA4Qo44tZmaM4j0AtdcoA4fooEJHkC3UrKuNkPZnFlyweU+8uHVqtZMXGa?=
 =?us-ascii?Q?nA9GRjNKuKGTvByCD/6oMPQtNuTUAmgF56Td1afuSwS/ReGl+BcBNoxEnXSe?=
 =?us-ascii?Q?Whi8R9I/5aKHR6BwcifHxfAKKOFazrIKGaXLIpfefq+lcwTf1NSDMVbVSBWQ?=
 =?us-ascii?Q?Cx83EP8tSRGSwZZGuDvAE6nWGdorbvu+j2V6NKZaSExr6oXVz7CXTw4wAmiB?=
 =?us-ascii?Q?DmUyYgcw6yOSmRDcSiiyo/0x+nxrrb5hMiYhcn/g9rO9PGPfGfBs672RQoV8?=
 =?us-ascii?Q?F5uSMdjrYLabJpMhRl4pS7f0iOD3aGBqIs0zL5DTsTfD3ImrCKXJyy2urK8N?=
 =?us-ascii?Q?a5lTx9UDRAPZGkN2FF8pGX54chBpJl2lOu1739Rvdy2HRRQKIYfe2W0pJfxp?=
 =?us-ascii?Q?276SF1n8GQMgcir8uxNdSqUlmQEFJLvTW3dKRXQgUCAq5mkQqgp/KDBPTfCN?=
 =?us-ascii?Q?98OdetX4MSYIZUztqgCK/Ym7a5Y2d3gOFMC0Ttu8K11Sqz231Xipqs22TUZ6?=
 =?us-ascii?Q?wUtLZ3bjbWzNd7psB6Jh2t76Zla+u2joV5oLbyd3vw7YbYY0y6oqwUfszXma?=
 =?us-ascii?Q?6ME9oT2eKKQsHXseuoM6Wk82Q8VD3zGDqUkjo+HniRBdNxVEUpnM/eBhBZ6q?=
 =?us-ascii?Q?XiZd3Jil7v3vEZycZJPZ4/yHbpUe3hCDQ2a+O3FiwbPyZQJj9BQyCKxdx+1l?=
 =?us-ascii?Q?B+M/XYA/XsKB070d7Z6K/dfmJEbAYEfCFr7X5ekRQEtyA81MVewE4wD9Iyul?=
 =?us-ascii?Q?dCH7+9uZ0ywwCoptZtnLDxTf+ZJ5fM6gDDLehQqSqOThYwj1efmBSvLdd/kz?=
 =?us-ascii?Q?MYExPTNv8en8VmNlWeb71ZLzxfPfB2d3U9i2acXKY0zjDbZ56iLyOVKg5eCn?=
 =?us-ascii?Q?4e/FQvbRar3O2NZYpKfe1UxgvfovgkzKpnm+TM+hMoYbkp/sEifuQ/KNkE+7?=
 =?us-ascii?Q?nwd4zzrxkIO72o/eLpmMynRYZRwkxVltCYLkjNe8S8vtfcdvufM+BhoR8KWO?=
 =?us-ascii?Q?KA/rMbrPy9HVQ5GKQcPEfJWbYtPA9yHa2pGD6o9HXVfymm2olm211OHCohWz?=
 =?us-ascii?Q?s3R1TSofIQEuxI1DSjJTX/ra+rr8skJxL8rfwqL6xPaAMllqMpazsYkQOs1j?=
 =?us-ascii?Q?WqDKrVxA7rtTbY4r33TywbvaqPprbLQoDyD1Ga+u?=
X-OriginatorOrg: vmware.com
X-MS-Exchange-CrossTenant-Network-Message-Id: a45cb9d8-a454-47c0-6f33-08db8f977212
X-MS-Exchange-CrossTenant-AuthSource: PH0PR05MB8703.namprd05.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 28 Jul 2023 18:21:22.1401
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: b39138ca-3cee-4b4a-a4d6-cd83d9dd62f0
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: AOxc26G07v7y9WjvQQ2BWt8gGkN1s/oAwaMIWbvUG6mEL2PFsnOOirGH+a31IOs9sE/wqbYiyhsL8MSwgNkPrQ==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: SN7PR05MB9264
X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,
        DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE,
        RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_NONE,T_SCC_BODY_TEXT_LINE,
        URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

Add the following functions to add files to evenfs:

eventfs_add_events_file() to add the data needed to create a specific file
located at the top level events directory. The dentry/inode will be
created when the events directory is scanned.

eventfs_add_file() to add the data needed for files within the directories
below the top level events directory. The dentry/inode of the file will be
created when the directory that the file is in is scanned.

Signed-off-by: Ajay Kaher <akaher@vmware.com>
Co-developed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Tested-by: Ching-lin Yu <chinglinyu@google.com>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202305051619.9a469a9a-yujie.liu@intel.com
---
 fs/tracefs/event_inode.c | 86 ++++++++++++++++++++++++++++++++++++++++
 include/linux/tracefs.h  |  8 ++++
 2 files changed, 94 insertions(+)

diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c
index 8f334b122e46..9e4843be9dc9 100644
--- a/fs/tracefs/event_inode.c
+++ b/fs/tracefs/event_inode.c
@@ -209,3 +209,89 @@ struct eventfs_file *eventfs_add_dir(const char *name,
 	mutex_unlock(&eventfs_mutex);
 	return ef;
 }
+
+/**
+ * eventfs_add_events_file - add the data needed to create a file for later reference
+ * @name: the name of the file to create.
+ * @mode: the permission that the file should have.
+ * @parent: parent dentry for this file.
+ * @data: something that the caller will want to get to later on.
+ * @fop: struct file_operations that should be used for this file.
+ *
+ * This function is used to add the information needed to create a
+ * dentry/inode within the top level events directory. The file created
+ * will have the @mode permissions. The @data will be used to fill the
+ * inode.i_private when the open() call is done. The dentry and inodes are
+ * all created when they are referenced, and removed when they are no
+ * longer referenced.
+ */
+int eventfs_add_events_file(const char *name, umode_t mode,
+			 struct dentry *parent, void *data,
+			 const struct file_operations *fop)
+{
+	struct tracefs_inode *ti;
+	struct eventfs_inode *ei;
+	struct eventfs_file *ef;
+
+	if (!parent)
+		return -EINVAL;
+
+	if (!(mode & S_IFMT))
+		mode |= S_IFREG;
+
+	if (!parent->d_inode)
+		return -EINVAL;
+
+	ti = get_tracefs(parent->d_inode);
+	if (!(ti->flags & TRACEFS_EVENT_INODE))
+		return -EINVAL;
+
+	ei = ti->private;
+	ef = eventfs_prepare_ef(name, mode, fop, NULL, data);
+
+	if (IS_ERR(ef))
+		return -ENOMEM;
+
+	mutex_lock(&eventfs_mutex);
+	list_add_tail(&ef->list, &ei->e_top_files);
+	mutex_unlock(&eventfs_mutex);
+	return 0;
+}
+
+/**
+ * eventfs_add_file - add eventfs file to list to create later
+ * @name: the name of the file to create.
+ * @mode: the permission that the file should have.
+ * @ef_parent: parent eventfs_file for this file.
+ * @data: something that the caller will want to get to later on.
+ * @fop: struct file_operations that should be used for this file.
+ *
+ * This function is used to add the information needed to create a
+ * file within a subdirectory of the events directory. The file created
+ * will have the @mode permissions. The @data will be used to fill the
+ * inode.i_private when the open() call is done. The dentry and inodes are
+ * all created when they are referenced, and removed when they are no
+ * longer referenced.
+ */
+int eventfs_add_file(const char *name, umode_t mode,
+		     struct eventfs_file *ef_parent,
+		     void *data,
+		     const struct file_operations *fop)
+{
+	struct eventfs_file *ef;
+
+	if (!ef_parent)
+		return -EINVAL;
+
+	if (!(mode & S_IFMT))
+		mode |= S_IFREG;
+
+	ef = eventfs_prepare_ef(name, mode, fop, NULL, data);
+	if (IS_ERR(ef))
+		return -ENOMEM;
+
+	mutex_lock(&eventfs_mutex);
+	list_add_tail(&ef->list, &ef_parent->ei->e_top_files);
+	mutex_unlock(&eventfs_mutex);
+	return 0;
+}
diff --git a/include/linux/tracefs.h b/include/linux/tracefs.h
index 432e5e6f7901..54c9cbd0389b 100644
--- a/include/linux/tracefs.h
+++ b/include/linux/tracefs.h
@@ -32,6 +32,14 @@ struct eventfs_file *eventfs_add_subsystem_dir(const char *name,
 struct eventfs_file *eventfs_add_dir(const char *name,
 				     struct eventfs_file *ef_parent);
 
+int eventfs_add_file(const char *name, umode_t mode,
+		     struct eventfs_file *ef_parent, void *data,
+		     const struct file_operations *fops);
+
+int eventfs_add_events_file(const char *name, umode_t mode,
+			 struct dentry *parent, void *data,
+			 const struct file_operations *fops);
+
 struct dentry *tracefs_create_file(const char *name, umode_t mode,
 				   struct dentry *parent, void *data,
 				   const struct file_operations *fops);
-- 
2.39.0