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Commit 496f7394 authored by Tejun Heo's avatar Tejun Heo Committed by Greg Kroah-Hartman
Browse files

sysfs, kernfs: introduce kernfs_create_file[_ns]() 



Introduce kernfs interface to create a file which takes and returns
sysfs_dirents.

The actual file creation part is separated out from
sysfs_add_file_mode_ns() into kernfs_create_file_ns().  The former now
only decides the kernfs_ops to use and the file's size and invokes the
latter.

This patch doesn't introduce behavior changes.

v2: Dummy implementation for !CONFIG_SYSFS updated to return -ENOSYS.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent a7dc66df

fs/sysfs/file.c

+42 −11
Original line number Diff line number Diff line
@@ -912,14 +912,11 @@ static const struct kernfs_ops sysfs_bin_kfops_rw = { 


int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd,

			   const struct attribute *attr, bool is_bin,

			   umode_t amode, const void *ns)

			   umode_t mode, const void *ns)

{

	umode_t mode = (amode & S_IALLUGO) | S_IFREG;

	const struct kernfs_ops *ops;

	struct sysfs_addrm_cxt acxt;

	struct sysfs_dirent *sd;

	loff_t size;

	int rc;



	if (!is_bin) {

		struct kobject *kobj = dir_sd->priv;
@@ -956,14 +953,47 @@ int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd, 
		size = battr->size;

	}



	sd = sysfs_new_dirent(attr->name, mode, SYSFS_KOBJ_ATTR);

	sd = kernfs_create_file_ns(dir_sd, attr->name, mode, size,

				   ops, (void *)attr, ns);

	if (IS_ERR(sd)) {

		if (PTR_ERR(sd) == -EEXIST)

			sysfs_warn_dup(dir_sd, attr->name);

		return PTR_ERR(sd);

	}

	return 0;

}



/**

 * kernfs_create_file_ns - create a file

 * @parent: directory to create the file in

 * @name: name of the file

 * @mode: mode of the file

 * @size: size of the file

 * @ops: kernfs operations for the file

 * @priv: private data for the file

 * @ns: optional namespace tag of the file

 *

 * Returns the created node on success, ERR_PTR() value on error.

 */

struct sysfs_dirent *kernfs_create_file_ns(struct sysfs_dirent *parent,

					   const char *name,

					   umode_t mode, loff_t size,

					   const struct kernfs_ops *ops,

					   void *priv, const void *ns)

{

	struct sysfs_addrm_cxt acxt;

	struct sysfs_dirent *sd;

	int rc;



	sd = sysfs_new_dirent(name, (mode & S_IALLUGO) | S_IFREG,

			      SYSFS_KOBJ_ATTR);

	if (!sd)

		return -ENOMEM;

		return ERR_PTR(-ENOMEM);



	sd->s_attr.ops = ops;

	sd->s_attr.size = size;

	sd->s_ns = ns;

	sd->priv = (void *)attr;

	sd->priv = priv;

	sysfs_dirent_init_lockdep(sd);



	/*
@@ -977,13 +1007,14 @@ int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd, 
		sd->s_flags |= SYSFS_FLAG_HAS_MMAP;



	sysfs_addrm_start(&acxt);

	rc = sysfs_add_one(&acxt, sd, dir_sd);

	rc = __sysfs_add_one(&acxt, sd, parent);

	sysfs_addrm_finish(&acxt);



	if (rc)

	if (rc) {

		sysfs_put(sd);



	return rc;

		return ERR_PTR(rc);

	}

	return sd;

}



int sysfs_add_file(struct sysfs_dirent *dir_sd, const struct attribute *attr,

include/linux/kernfs.h

+18 −0
Original line number Diff line number Diff line
@@ -64,6 +64,11 @@ struct kernfs_ops { 
struct sysfs_dirent *kernfs_create_dir_ns(struct sysfs_dirent *parent,

					  const char *name, void *priv,

					  const void *ns);

struct sysfs_dirent *kernfs_create_file_ns(struct sysfs_dirent *parent,

					   const char *name,

					   umode_t mode, loff_t size,

					   const struct kernfs_ops *ops,

					   void *priv, const void *ns);

struct sysfs_dirent *kernfs_create_link(struct sysfs_dirent *parent,

					const char *name,

					struct sysfs_dirent *target);
@@ -82,6 +87,12 @@ kernfs_create_dir_ns(struct sysfs_dirent *parent, const char *name, void *priv, 
		     const void *ns)

{ return ERR_PTR(-ENOSYS); }



static inline struct sysfs_dirent *

kernfs_create_file_ns(struct sysfs_dirent *parent, const char *name,

		      umode_t mode, loff_t size, const struct kernfs_ops *ops,

		      void *priv, const void *ns)

{ return ERR_PTR(-ENOSYS); }



static inline struct sysfs_dirent *

kernfs_create_link(struct sysfs_dirent *parent, const char *name,

		   struct sysfs_dirent *target)
@@ -112,6 +123,13 @@ kernfs_create_dir(struct sysfs_dirent *parent, const char *name, void *priv) 
	return kernfs_create_dir_ns(parent, name, priv, NULL);

}



static inline struct sysfs_dirent *

kernfs_create_file(struct sysfs_dirent *parent, const char *name, umode_t mode,

		   loff_t size, const struct kernfs_ops *ops, void *priv)

{

	return kernfs_create_file_ns(parent, name, mode, size, ops, priv, NULL);

}



static inline int kernfs_remove_by_name(struct sysfs_dirent *parent,

					const char *name)

{