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: 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>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
This commit is contained in:
Ajay Kaher 2023-07-28 23:50:44 +05:30 committed by Steven Rostedt (Google)
parent ee41106a12
commit ba37ff75e0
2 changed files with 54 additions and 0 deletions

View file

@ -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;

15
fs/tracefs/internal.h Normal file
View file

@ -0,0 +1,15 @@
/* 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 */