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authorTejun Heo <tj@kernel.org>2013-11-28 23:54:27 +0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-11-30 05:48:14 +0400
commit024f647117d697165aaadf3f1af1343b7000149a (patch)
tree79dcad5d6babfe359c443093fe7e5bed84322ef7 /fs/sysfs/file.c
parentd19b9846df64d8845be682b6318bd1aee246cf60 (diff)
downloadlinux-024f647117d697165aaadf3f1af1343b7000149a.tar.xz
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>
Diffstat (limited to 'fs/sysfs/file.c')
-rw-r--r--fs/sysfs/file.c33
1 files changed, 22 insertions, 11 deletions
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index 74e3478d9cb4..a68cbef3a674 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -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);