diff mbox series

[v5,02/10] eventfs: Implement tracefs_inode_cache

Message ID 1690054625-31939-3-git-send-email-akaher@vmware.com (mailing list archive)
State New
Headers show
Series tracing: introducing eventfs | expand

Commit Message

Ajay Kaher July 22, 2023, 7:36 p.m. UTC 
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@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 +++++++++++++++++++++++++++++++++++++++
 fs/tracefs/internal.h | 19 +++++++++++++++++++
 2 files changed, 58 insertions(+)
 create mode 100644 fs/tracefs/internal.h

Comments

Steven Rostedt July 25, 2023, 11:06 p.m. UTC | #1 
Some more nits.

On Sun, 23 Jul 2023 01:06:57 +0530
Ajay Kaher <akaher@vmware.com> 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@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 +++++++++++++++++++++++++++++++++++++++
>  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 */
Ajay Kaher July 26, 2023, 6:45 p.m. UTC | #2 
>> 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.


Ok, I will move this to v6 04/10.
Let me know once you will complete the review of v5.

-Ajay
Steven Rostedt July 26, 2023, 9:39 p.m. UTC | #3 
On Wed, 26 Jul 2023 18:45:34 +0000
Ajay Kaher <akaher@vmware.com> wrote:

> Ok, I will move this to v6 04/10.
> Let me know once you will complete the review of v5.

OK, I finished my review. Mostly more nits. Hopefully v6 will be what I
pull into linux-next.

-- Steve
diff mbox series

Patch

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),
+};
+
+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 */