[PATCH v4 08/10] eventfs: Implement tracefs_inode_cache

Ajay Kaher
2023-07-13T11:34:15Z

Creating tracefs_inode_cache which is a cache of tracefs_inode.
Adding helping functions:
tracefs_alloc_inode()
tracefs_free_inode()

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>
---
fs/tracefs/inode.c | 39 +++++++++++++++++++++++++++++++++++++++
1 file changed, 39 insertions(+)

diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c
index 7dc692a5fee1..76820d3e97eb 100644
--- a/fs/tracefs/inode.c
+++ b/fs/tracefs/inode.c
@@ -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,
@@ -675,10 +698,26 @@ 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;
--
2.39.0