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Commit 7cb32942 authored by Eric W. Biederman's avatar Eric W. Biederman Committed by Greg Kroah-Hartman
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sysfs: Implement sysfs_rename_link 



Because of rename ordering problems we occassionally give false
warnings about invalid sysfs operations.  So using sysfs_rename
create a sysfs_rename_link function that doesn't need strange
workarounds.

Cc: Benjamin Thery <benjamin.thery@bull.net>
Cc: Daniel Lezcano <dlezcano@fr.ibm.com>
Acked-by: default avatarSerge Hallyn <serue@us.ibm.com>
Acked-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarEric W. Biederman <ebiederm@aristanetworks.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 19c38b63

fs/sysfs/symlink.c

+38 −0
Original line number Diff line number Diff line
@@ -123,6 +123,44 @@ void sysfs_remove_link(struct kobject * kobj, const char * name) 
	sysfs_hash_and_remove(parent_sd, name);

}



/**

 *	sysfs_rename_link - rename symlink in object's directory.

 *	@kobj:	object we're acting for.

 *	@targ:	object we're pointing to.

 *	@old:	previous name of the symlink.

 *	@new:	new name of the symlink.

 *

 *	A helper function for the common rename symlink idiom.

 */

int sysfs_rename_link(struct kobject *kobj, struct kobject *targ,

			const char *old, const char *new)

{

	struct sysfs_dirent *parent_sd, *sd = NULL;

	int result;



	if (!kobj)

		parent_sd = &sysfs_root;

	else

		parent_sd = kobj->sd;



	result = -ENOENT;

	sd = sysfs_get_dirent(parent_sd, old);

	if (!sd)

		goto out;



	result = -EINVAL;

	if (sysfs_type(sd) != SYSFS_KOBJ_LINK)

		goto out;

	if (sd->s_symlink.target_sd->s_dir.kobj != targ)

		goto out;



	result = sysfs_rename(sd, parent_sd, new);



out:

	sysfs_put(sd);

	return result;

}



static int sysfs_get_target_path(struct sysfs_dirent *parent_sd,

				 struct sysfs_dirent *target_sd, char *path)

{

include/linux/sysfs.h

+9 −0
Original line number Diff line number Diff line
@@ -151,6 +151,9 @@ int __must_check sysfs_create_link_nowarn(struct kobject *kobj, 
					  const char *name);

void sysfs_remove_link(struct kobject *kobj, const char *name);



int sysfs_rename_link(struct kobject *kobj, struct kobject *target,

			const char *old_name, const char *new_name);



int __must_check sysfs_create_group(struct kobject *kobj,

				    const struct attribute_group *grp);

int sysfs_update_group(struct kobject *kobj,
@@ -255,6 +258,12 @@ static inline void sysfs_remove_link(struct kobject *kobj, const char *name) 
{

}



static inline int sysfs_rename_link(struct kobject *k, struct kobject *t,

				    const char *old_name, const char *new_name)

{

	return 0;

}



static inline int sysfs_create_group(struct kobject *kobj,

				     const struct attribute_group *grp)

{