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Commit 8a5e02a0 authored by Bart Van Assche's avatar Bart Van Assche Committed by Greg Kroah-Hartman
Browse files

scsi: sysfs: Introduce sysfs_{un,}break_active_protection() 



commit 2afc9166f79b8f6da5f347f48515215ceee4ae37 upstream.

Introduce these two functions and export them such that the next patch
can add calls to these functions from the SCSI core.

Signed-off-by: default avatarBart Van Assche <bart.vanassche@wdc.com>
Acked-by: default avatarTejun Heo <tj@kernel.org>
Acked-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent a6b728be

fs/sysfs/file.c

+44 −0
Original line number Diff line number Diff line
@@ -407,6 +407,50 @@ int sysfs_chmod_file(struct kobject *kobj, const struct attribute *attr, 
}

EXPORT_SYMBOL_GPL(sysfs_chmod_file);



/**

 * sysfs_break_active_protection - break "active" protection

 * @kobj: The kernel object @attr is associated with.

 * @attr: The attribute to break the "active" protection for.

 *

 * With sysfs, just like kernfs, deletion of an attribute is postponed until

 * all active .show() and .store() callbacks have finished unless this function

 * is called. Hence this function is useful in methods that implement self

 * deletion.

 */

struct kernfs_node *sysfs_break_active_protection(struct kobject *kobj,

						  const struct attribute *attr)

{

	struct kernfs_node *kn;



	kobject_get(kobj);

	kn = kernfs_find_and_get(kobj->sd, attr->name);

	if (kn)

		kernfs_break_active_protection(kn);

	return kn;

}

EXPORT_SYMBOL_GPL(sysfs_break_active_protection);



/**

 * sysfs_unbreak_active_protection - restore "active" protection

 * @kn: Pointer returned by sysfs_break_active_protection().

 *

 * Undo the effects of sysfs_break_active_protection(). Since this function

 * calls kernfs_put() on the kernfs node that corresponds to the 'attr'

 * argument passed to sysfs_break_active_protection() that attribute may have

 * been removed between the sysfs_break_active_protection() and

 * sysfs_unbreak_active_protection() calls, it is not safe to access @kn after

 * this function has returned.

 */

void sysfs_unbreak_active_protection(struct kernfs_node *kn)

{

	struct kobject *kobj = kn->parent->priv;



	kernfs_unbreak_active_protection(kn);

	kernfs_put(kn);

	kobject_put(kobj);

}

EXPORT_SYMBOL_GPL(sysfs_unbreak_active_protection);



/**

 * sysfs_remove_file_ns - remove an object attribute with a custom ns tag

 * @kobj: object we're acting for

include/linux/sysfs.h

+14 −0
Original line number Diff line number Diff line
@@ -238,6 +238,9 @@ int __must_check sysfs_create_files(struct kobject *kobj, 
				   const struct attribute **attr);

int __must_check sysfs_chmod_file(struct kobject *kobj,

				  const struct attribute *attr, umode_t mode);

struct kernfs_node *sysfs_break_active_protection(struct kobject *kobj,

						  const struct attribute *attr);

void sysfs_unbreak_active_protection(struct kernfs_node *kn);

void sysfs_remove_file_ns(struct kobject *kobj, const struct attribute *attr,

			  const void *ns);

bool sysfs_remove_file_self(struct kobject *kobj, const struct attribute *attr);
@@ -351,6 +354,17 @@ static inline int sysfs_chmod_file(struct kobject *kobj, 
	return 0;

}



static inline struct kernfs_node *

sysfs_break_active_protection(struct kobject *kobj,

			      const struct attribute *attr)

{

	return NULL;

}



static inline void sysfs_unbreak_active_protection(struct kernfs_node *kn)

{

}



static inline void sysfs_remove_file_ns(struct kobject *kobj,

					const struct attribute *attr,

					const void *ns)