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

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
......@@ -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);
......
......@@ -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 *
......
......@@ -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_ */
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