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Commit 024f6471 authored by Tejun Heo's avatar Tejun Heo Committed by Greg Kroah-Hartman
Browse files

sysfs, kernfs: introduce kernfs_notify() 



Introduce kernfs interface to wake up poll(2) which takes and returns
sysfs_dirents.

sysfs_notify_dirent() is renamed to kernfs_notify() and sysfs_notify()
is updated so that it doesn't directly grab sysfs_mutex but acquires
the target sysfs_dirents using sysfs_get_dirent().
sysfs_notify_dirent() is reimplemented as a dumb inline wrapper around
kernfs_notify().

This patch doesn't introduce any behavior changes.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent d19b9846

fs/sysfs/file.c

+22 −11
Original line number Diff line number Diff line
@@ -851,7 +851,13 @@ static unsigned int kernfs_file_poll(struct file *filp, poll_table *wait) 
	return DEFAULT_POLLMASK|POLLERR|POLLPRI;

}



void sysfs_notify_dirent(struct sysfs_dirent *sd)

/**

 * kernfs_notify - notify a kernfs file

 * @sd: file to notify

 *

 * Notify @sd such that poll(2) on @sd wakes up.

 */

void kernfs_notify(struct sysfs_dirent *sd)

{

	struct sysfs_open_dirent *od;

	unsigned long flags;
@@ -868,22 +874,27 @@ void sysfs_notify_dirent(struct sysfs_dirent *sd) 


	spin_unlock_irqrestore(&sysfs_open_dirent_lock, flags);

}

EXPORT_SYMBOL_GPL(sysfs_notify_dirent);

EXPORT_SYMBOL_GPL(kernfs_notify);



void sysfs_notify(struct kobject *k, const char *dir, const char *attr)

{

	struct sysfs_dirent *sd = k->sd;



	mutex_lock(&sysfs_mutex);

	struct sysfs_dirent *sd = k->sd, *tmp;



	if (sd && dir)

		sd = sysfs_find_dirent(sd, dir, NULL);

	if (sd && attr)

		sd = sysfs_find_dirent(sd, attr, NULL);

	if (sd)

		sysfs_notify_dirent(sd);

		sd = sysfs_get_dirent(sd, dir);

	else

		sysfs_get(sd);



	mutex_unlock(&sysfs_mutex);

	if (sd && attr) {

		tmp = sysfs_get_dirent(sd, attr);

		sysfs_put(sd);

		sd = tmp;

	}



	if (sd) {

		kernfs_notify(sd);

		sysfs_put(sd);

	}

}

EXPORT_SYMBOL_GPL(sysfs_notify);

include/linux/kernfs.h

+3 −0
Original line number Diff line number Diff line
@@ -84,6 +84,7 @@ int kernfs_rename_ns(struct sysfs_dirent *sd, struct sysfs_dirent *new_parent, 
		     const char *new_name, const void *new_ns);

void kernfs_enable_ns(struct sysfs_dirent *sd);

int kernfs_setattr(struct sysfs_dirent *sd, const struct iattr *iattr);

void kernfs_notify(struct sysfs_dirent *sd);



#else	/* CONFIG_SYSFS */
@@ -120,6 +121,8 @@ static inline int kernfs_setattr(struct sysfs_dirent *sd, 
				 const struct iattr *iattr)

{ return -ENOSYS; }



static inline void kernfs_notify(struct sysfs_dirent *sd) { }



#endif	/* CONFIG_SYSFS */



static inline struct sysfs_dirent *

include/linux/sysfs.h

+5 −4
Original line number Diff line number Diff line
@@ -243,7 +243,6 @@ void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name, 
				  const char *link_name);



void sysfs_notify(struct kobject *kobj, const char *dir, const char *attr);

void sysfs_notify_dirent(struct sysfs_dirent *sd);

struct sysfs_dirent *sysfs_get_dirent_ns(struct sysfs_dirent *parent_sd,

					 const unsigned char *name,

					 const void *ns);
@@ -418,9 +417,6 @@ static inline void sysfs_notify(struct kobject *kobj, const char *dir, 
				const char *attr)

{

}

static inline void sysfs_notify_dirent(struct sysfs_dirent *sd)

{

}

static inline struct sysfs_dirent *

sysfs_get_dirent_ns(struct sysfs_dirent *parent_sd, const unsigned char *name,

		    const void *ns)
@@ -466,4 +462,9 @@ sysfs_get_dirent(struct sysfs_dirent *parent_sd, const unsigned char *name) 
	return sysfs_get_dirent_ns(parent_sd, name, NULL);

}



static inline void sysfs_notify_dirent(struct sysfs_dirent *sd)

{

	kernfs_notify(sd);

}



#endif /* _SYSFS_H_ */