Commit ba37ff75 authored by Ajay Kaher's avatar Ajay Kaher Committed by Steven Rostedt (Google)
Browse files

eventfs: Implement tracefs_inode_cache 

Create a kmem cache of tracefs_inodes. To be more efficient, as there are
lots of tracefs inodes, create its own cache. This also allows to see how
many tracefs inodes have been created.

Add helper functions:
tracefs_alloc_inode()
tracefs_free_inode()
get_tracefs()

Link: https://lkml.kernel.org/r/1690568452-46553-3-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>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent ee41106a

fs/tracefs/inode.c

+39 −0
Original line number Diff line number Diff line
@@ -21,13 +21,33 @@ 
#include <linux/parser.h>

#include <linux/magic.h>

#include <linux/slab.h>

#include "internal.h"



#define TRACEFS_DEFAULT_MODE	0700

static struct kmem_cache *tracefs_inode_cachep __ro_after_init;



static struct vfsmount *tracefs_mount;

static int tracefs_mount_count;

static bool tracefs_registered;



static struct inode *tracefs_alloc_inode(struct super_block *sb)

{

	struct tracefs_inode *ti;



	ti = kmem_cache_alloc(tracefs_inode_cachep, GFP_KERNEL);

	if (!ti)

		return NULL;



	ti->flags = 0;



	return &ti->vfs_inode;

}



static void tracefs_free_inode(struct inode *inode)

{

	kmem_cache_free(tracefs_inode_cachep, get_tracefs(inode));

}



static ssize_t default_read_file(struct file *file, char __user *buf,

				 size_t count, loff_t *ppos)

{
@@ -346,6 +366,9 @@ static int tracefs_show_options(struct seq_file *m, struct dentry *root) 
}



static const struct super_operations tracefs_super_operations = {

	.alloc_inode    = tracefs_alloc_inode,

	.free_inode     = tracefs_free_inode,

	.drop_inode     = generic_delete_inode,

	.statfs		= simple_statfs,

	.remount_fs	= tracefs_remount,

	.show_options	= tracefs_show_options,
@@ -628,10 +651,26 @@ bool tracefs_initialized(void) 
	return tracefs_registered;

}



static void init_once(void *foo)

{

	struct tracefs_inode *ti = (struct tracefs_inode *) foo;



	inode_init_once(&ti->vfs_inode);

}



static int __init tracefs_init(void)

{

	int retval;



	tracefs_inode_cachep = kmem_cache_create("tracefs_inode_cache",

						 sizeof(struct tracefs_inode),

						 0, (SLAB_RECLAIM_ACCOUNT|

						     SLAB_MEM_SPREAD|

						     SLAB_ACCOUNT),

						 init_once);

	if (!tracefs_inode_cachep)

		return -ENOMEM;



	retval = sysfs_create_mount_point(kernel_kobj, "tracing");

	if (retval)

		return -EINVAL;

fs/tracefs/internal.h

0 → 100644
+15 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 */

#ifndef _TRACEFS_INTERNAL_H

#define _TRACEFS_INTERNAL_H



struct tracefs_inode {

	unsigned long           flags;

	void                    *private;

	struct inode            vfs_inode;

};



static inline struct tracefs_inode *get_tracefs(const struct inode *inode)

{

	return container_of(inode, struct tracefs_inode, vfs_inode);

}

#endif /* _TRACEFS_INTERNAL_H */