Some more nits.
On Sun, 23 Jul 2023 01:06:57 +0530
Ajay Kaher <akaher@xxxxxxxxxx> wrote:
> 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()
>
> Signed-off-by: Ajay Kaher <akaher@xxxxxxxxxx>
> Co-developed-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
> Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
> Tested-by: Ching-lin Yu <chinglinyu@xxxxxxxxxx>
> ---
> fs/tracefs/inode.c | 39 +++++++++++++++++++++++++++++++++++++++
> fs/tracefs/internal.h | 19 +++++++++++++++++++
> 2 files changed, 58 insertions(+)
> create mode 100644 fs/tracefs/internal.h
>
> diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c
> index 57ac8aa4a724..2508944cc4d8 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,
> @@ -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;
> diff --git a/fs/tracefs/internal.h b/fs/tracefs/internal.h
> new file mode 100644
> index 000000000000..49b5e8949e1c
> --- /dev/null
> +++ b/fs/tracefs/internal.h
> @@ -0,0 +1,19 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef _TRACEFS_INTERNAL_H
> +#define _TRACEFS_INTERNAL_H
> +
> +enum {
> + TRACEFS_EVENT_INODE = BIT(1),
> +};
Let's not introduce the enum until it is used.
-- Steve
> +
> +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 */
