sysfs: move s_active functions to fs/sysfs/dir.c
These functions are about to receive more complexity and doesn't
really need to be inlined in the first place. Move them from
fs/sysfs/sysfs.h to fs/sysfs/dir.c.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 06dff2c3..f5f0b93 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -20,6 +20,94 @@
static spinlock_t sysfs_ino_lock = SPIN_LOCK_UNLOCKED;
static DEFINE_IDA(sysfs_ino_ida);
+/**
+ * sysfs_get_active - get an active reference to sysfs_dirent
+ * @sd: sysfs_dirent to get an active reference to
+ *
+ * Get an active reference of @sd. This function is noop if @sd
+ * is NULL.
+ *
+ * RETURNS:
+ * Pointer to @sd on success, NULL on failure.
+ */
+struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd)
+{
+ if (sd) {
+ if (unlikely(!down_read_trylock(&sd->s_active)))
+ sd = NULL;
+ }
+ return sd;
+}
+
+/**
+ * sysfs_put_active - put an active reference to sysfs_dirent
+ * @sd: sysfs_dirent to put an active reference to
+ *
+ * Put an active reference to @sd. This function is noop if @sd
+ * is NULL.
+ */
+void sysfs_put_active(struct sysfs_dirent *sd)
+{
+ if (sd)
+ up_read(&sd->s_active);
+}
+
+/**
+ * sysfs_get_active_two - get active references to sysfs_dirent and parent
+ * @sd: sysfs_dirent of interest
+ *
+ * Get active reference to @sd and its parent. Parent's active
+ * reference is grabbed first. This function is noop if @sd is
+ * NULL.
+ *
+ * RETURNS:
+ * Pointer to @sd on success, NULL on failure.
+ */
+struct sysfs_dirent *sysfs_get_active_two(struct sysfs_dirent *sd)
+{
+ if (sd) {
+ if (sd->s_parent && unlikely(!sysfs_get_active(sd->s_parent)))
+ return NULL;
+ if (unlikely(!sysfs_get_active(sd))) {
+ sysfs_put_active(sd->s_parent);
+ return NULL;
+ }
+ }
+ return sd;
+}
+
+/**
+ * sysfs_put_active_two - put active references to sysfs_dirent and parent
+ * @sd: sysfs_dirent of interest
+ *
+ * Put active references to @sd and its parent. This function is
+ * noop if @sd is NULL.
+ */
+void sysfs_put_active_two(struct sysfs_dirent *sd)
+{
+ if (sd) {
+ sysfs_put_active(sd);
+ sysfs_put_active(sd->s_parent);
+ }
+}
+
+/**
+ * sysfs_deactivate - deactivate sysfs_dirent
+ * @sd: sysfs_dirent to deactivate
+ *
+ * Deny new active references and drain existing ones. s_active
+ * will be unlocked when the sysfs_dirent is released.
+ */
+void sysfs_deactivate(struct sysfs_dirent *sd)
+{
+ down_write_nested(&sd->s_active, SYSFS_S_ACTIVE_DEACTIVATE);
+
+ /* s_active will be unlocked by the thread doing the final put
+ * on @sd. Lie to lockdep.
+ */
+ rwsem_release(&sd->s_active.dep_map, 1, _RET_IP_);
+}
+
static int sysfs_alloc_ino(ino_t *pino)
{
int ino, rc;