Commit 9255782f authored by Sourabh Jain's avatar Sourabh Jain Committed by Michael Ellerman
Browse files

sysfs: Wrap __compat_only_sysfs_link_entry_to_kobj function to change the symlink name 



The __compat_only_sysfs_link_entry_to_kobj function creates a symlink
to a kobject but doesn't provide an option to change the symlink file
name.

This patch adds a wrapper function compat_only_sysfs_link_entry_to_kobj
that extends the __compat_only_sysfs_link_entry_to_kobj functionality
which allows function caller to customize the symlink name.

Signed-off-by: default avatarSourabh Jain <sourabhjain@linux.ibm.com>
[mpe: Fix compile error when CONFIG_SYSFS=n]
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191211160910.21656-3-sourabhjain@linux.ibm.com
parent f52153ab

fs/sysfs/group.c

+25 −3
Original line number Diff line number Diff line
@@ -424,6 +424,25 @@ EXPORT_SYMBOL_GPL(sysfs_remove_link_from_group); 
int __compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj,

				      struct kobject *target_kobj,

				      const char *target_name)

{

	return compat_only_sysfs_link_entry_to_kobj(kobj, target_kobj,

						    target_name, NULL);

}

EXPORT_SYMBOL_GPL(__compat_only_sysfs_link_entry_to_kobj);



/**

 * compat_only_sysfs_link_entry_to_kobj - add a symlink to a kobject pointing

 * to a group or an attribute

 * @kobj:		The kobject containing the group.

 * @target_kobj:	The target kobject.

 * @target_name:	The name of the target group or attribute.

 * @symlink_name:	The name of the symlink file (target_name will be

 *			considered if symlink_name is NULL).

 */

int compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj,

					 struct kobject *target_kobj,

					 const char *target_name,

					 const char *symlink_name)

{

	struct kernfs_node *target;

	struct kernfs_node *entry;
@@ -448,12 +467,15 @@ int __compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj, 
		return -ENOENT;

	}



	link = kernfs_create_link(kobj->sd, target_name, entry);

	if (!symlink_name)

		symlink_name = target_name;



	link = kernfs_create_link(kobj->sd, symlink_name, entry);

	if (PTR_ERR(link) == -EEXIST)

		sysfs_warn_dup(kobj->sd, target_name);

		sysfs_warn_dup(kobj->sd, symlink_name);



	kernfs_put(entry);

	kernfs_put(target);

	return PTR_ERR_OR_ZERO(link);

}

EXPORT_SYMBOL_GPL(__compat_only_sysfs_link_entry_to_kobj);
 
EXPORT_SYMBOL_GPL(compat_only_sysfs_link_entry_to_kobj);

include/linux/sysfs.h

+12 −0
Original line number Diff line number Diff line
@@ -300,6 +300,10 @@ void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name, 
int __compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj,

				      struct kobject *target_kobj,

				      const char *target_name);

int compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj,

					 struct kobject *target_kobj,

					 const char *target_name,

					 const char *symlink_name);



void sysfs_notify(struct kobject *kobj, const char *dir, const char *attr);
@@ -508,6 +512,14 @@ static inline int __compat_only_sysfs_link_entry_to_kobj( 
	return 0;

}



static inline int compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj,

						       struct kobject *target_kobj,

						       const char *target_name,

						       const char *symlink_name)

{

	return 0;

}



static inline void sysfs_notify(struct kobject *kobj, const char *dir,

				const char *attr)

{

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