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Commit 375b611e authored by Tejun Heo's avatar Tejun Heo Committed by Greg Kroah-Hartman
Browse files

sysfs: remove sysfs_buffer->ops 



Currently, sysfs_ops is fetched during sysfs_open_file() and cached in
sysfs_buffer->ops to be used while the file is open.  This patch
removes the caching and makes each operation directly fetch sysfs_ops.

This patch doesn't introduce any behavior difference and is to prepare
for merging regular and bin file supports.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent aea585ef

fs/sysfs/file.c

+21 −12
Original line number Diff line number Diff line
@@ -45,12 +45,23 @@ struct sysfs_open_dirent { 
struct sysfs_buffer {

	size_t			count;

	char			*page;

	const struct sysfs_ops	*ops;

	struct mutex		mutex;

	int			event;

	struct list_head	list;

};



/*

 * Determine ktype->sysfs_ops for the given sysfs_dirent.  This function

 * must be called while holding an active reference.

 */

static const struct sysfs_ops *sysfs_file_ops(struct sysfs_dirent *sd)

{

	struct kobject *kobj = sd->s_parent->s_dir.kobj;



	lockdep_assert_held(sd);

	return kobj->ktype ? kobj->ktype->sysfs_ops : NULL;

}



/**

 *	fill_read_buffer - allocate and fill buffer from object.

 *	@dentry:	dentry pointer.
@@ -66,7 +77,7 @@ static int fill_read_buffer(struct dentry *dentry, struct sysfs_buffer *buffer) 
{

	struct sysfs_dirent *attr_sd = dentry->d_fsdata;

	struct kobject *kobj = attr_sd->s_parent->s_dir.kobj;

	const struct sysfs_ops *ops = buffer->ops;

	const struct sysfs_ops *ops;

	int ret = 0;

	ssize_t count;
@@ -80,6 +91,8 @@ static int fill_read_buffer(struct dentry *dentry, struct sysfs_buffer *buffer) 
		return -ENODEV;



	buffer->event = atomic_read(&attr_sd->s_attr.open->event);



	ops = sysfs_file_ops(attr_sd);

	count = ops->show(kobj, attr_sd->s_attr.attr, buffer->page);



	sysfs_put_active(attr_sd);
@@ -191,13 +204,14 @@ static int flush_write_buffer(struct dentry *dentry, 
{

	struct sysfs_dirent *attr_sd = dentry->d_fsdata;

	struct kobject *kobj = attr_sd->s_parent->s_dir.kobj;

	const struct sysfs_ops *ops = buffer->ops;

	const struct sysfs_ops *ops;

	int rc;



	/* need attr_sd for attr and ops, its parent for kobj */

	if (!sysfs_get_active(attr_sd))

		return -ENODEV;



	ops = sysfs_file_ops(attr_sd);

	rc = ops->store(kobj, attr_sd->s_attr.attr, buffer->page, count);



	sysfs_put_active(attr_sd);
@@ -205,7 +219,6 @@ static int flush_write_buffer(struct dentry *dentry, 
	return rc;

}





/**

 *	sysfs_write_file - write an attribute.

 *	@file:	file pointer
@@ -334,14 +347,11 @@ static int sysfs_open_file(struct inode *inode, struct file *file) 
		return -ENODEV;



	/* every kobject with an attribute needs a ktype assigned */

	if (kobj->ktype && kobj->ktype->sysfs_ops)

		ops = kobj->ktype->sysfs_ops;

	else {

		WARN(1, KERN_ERR

	ops = sysfs_file_ops(attr_sd);

	if (WARN(!ops, KERN_ERR

		 "missing sysfs attribute operations for kobject: %s\n",

		     kobject_name(kobj));

		 kobject_name(kobj)))

		goto err_out;

	}



	/* File needs write support.

	 * The inode's perms must say it's ok,
@@ -370,7 +380,6 @@ static int sysfs_open_file(struct inode *inode, struct file *file) 
		goto err_out;



	mutex_init(&buffer->mutex);

	buffer->ops = ops;

	file->private_data = buffer;



	/* make sure we have open dirent struct */