summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorTejun Heo <tj@kernel.org>2013-11-28 19:54:27 (GMT)
committerPawel Osmialowski <p.osmialowsk@mcdsrvbld02.digital.local>2015-03-27 13:37:30 (GMT)
commitcf98677723fb0e42fa2b41a370bf85332bd3c750 (patch)
treefe039a314b02737fe6e350a5e8e5cfce4e4efdde
parentea72c71344e75459493113b7d264f5973ebdcfb8 (diff)
downloadlinux-3.10-cf98677723fb0e42fa2b41a370bf85332bd3c750.zip
linux-3.10-cf98677723fb0e42fa2b41a370bf85332bd3c750.tar.gz
linux-3.10-cf98677723fb0e42fa2b41a370bf85332bd3c750.tar.bz2
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: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--fs/sysfs/file.c33
-rw-r--r--include/linux/kernfs.h3
-rw-r--r--include/linux/sysfs.h9
3 files changed, 30 insertions, 15 deletions
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index ef89b3c..9370743 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -852,7 +852,13 @@ 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;
@@ -869,22 +875,27 @@ 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);
diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h
index ba993eb..f20796e 100644
--- a/include/linux/kernfs.h
+++ b/include/linux/kernfs.h
@@ -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 *
diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h
index 6bd10c9d..b440f93 100644
--- a/include/linux/sysfs.h
+++ b/include/linux/sysfs.h
@@ -196,7 +196,6 @@ 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);
@@ -360,9 +359,6 @@ 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)
@@ -408,4 +404,9 @@ 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_ */