[PATCH 1/3] proc: introduce proc_sys_evict_inode()

[Oleg Nesterov]

Preparation. Shift the sysctl_head_put() code from proc_evict_inode()
into the new trivial helper, make sysctl_head_put() static.

---
 fs/proc/inode.c       |    8 ++------
 fs/proc/internal.h    |    4 ++--
 fs/proc/proc_sysctl.c |   13 ++++++++++++-
 3 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/fs/proc/inode.c b/fs/proc/inode.c
index 0adbc02..9f6715a 100644
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -31,7 +31,6 @@
 static void proc_evict_inode(struct inode *inode)
 {
 	struct proc_dir_entry *de;
-	struct ctl_table_header *head;
 	const struct proc_ns_operations *ns_ops;
 	void *ns;
 
@@ -45,11 +44,8 @@ static void proc_evict_inode(struct inode *inode)
 	de = PROC_I(inode)->pde;
 	if (de)
 		pde_put(de);
-	head = PROC_I(inode)->sysctl;
-	if (head) {
-		RCU_INIT_POINTER(PROC_I(inode)->sysctl, NULL);
-		sysctl_head_put(head);
-	}
+
+	proc_sys_evict_inode(inode);
 	/* Release any associated namespace */
 	ns_ops = PROC_I(inode)->ns.ns_ops;
 	ns = PROC_I(inode)->ns.ns;
diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index 78784cd..7ce3262 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -238,10 +238,10 @@ extern int proc_setup_self(struct super_block *);
  */
 #ifdef CONFIG_PROC_SYSCTL
 extern int proc_sys_init(void);
-extern void sysctl_head_put(struct ctl_table_header *);
+extern void proc_sys_evict_inode(struct inode *inode);
 #else
 static inline void proc_sys_init(void) { }
-static inline void sysctl_head_put(struct ctl_table_header *head) { }
+static inline void proc_sys_evict_inode(struct inode *inode) { }
 #endif
 
 /*
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index 7129046..2fa67e7 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -256,7 +256,7 @@ static void sysctl_head_get(struct ctl_table_header *head)
 	spin_unlock(&sysctl_lock);
 }
 
-void sysctl_head_put(struct ctl_table_header *head)
+static void sysctl_head_put(struct ctl_table_header *head)
 {
 	spin_lock(&sysctl_lock);
 	if (!--head->count)
@@ -264,6 +264,17 @@ void sysctl_head_put(struct ctl_table_header *head)
 	spin_unlock(&sysctl_lock);
 }
 
+void proc_sys_evict_inode(struct inode *inode)
+{
+	struct ctl_table_header *head;
+
+	head = PROC_I(inode)->sysctl;
+	if (head) {
+		RCU_INIT_POINTER(PROC_I(inode)->sysctl, NULL);
+		sysctl_head_put(head);
+	}
+}
+
 static struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
 {
 	BUG_ON(!head);
-- 
1.5.5.1