Commit 88f349b4 authored by Ajay Kaher's avatar Ajay Kaher Committed by Steven Rostedt (Google)
Browse files

eventfs: Implement eventfs file add functions 

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.

Link: https://lkml.kernel.org/r/1690568452-46553-6-git-send-email-akaher@vmware.com



Signed-off-by: default avatarAjay Kaher <akaher@vmware.com>
Co-developed-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
Tested-by: default avatarChing-lin Yu <chinglinyu@google.com>
Reported-by: default avatarkernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202305051619.9a469a9a-yujie.liu@intel.com


Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent c1504e51

fs/tracefs/event_inode.c

+86 −0
Original line number Diff line number Diff line
@@ -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;

}

include/linux/tracefs.h

+8 −0
Original line number Diff line number Diff line
@@ -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);