tidy up namei.c a bit

locking/unlocking for rcu walk taken to a couple of inline helpers

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 21 insertions, 18 deletions

diff --git a/fs/namei.c b/fs/namei.c
index d4d15bbc8af7..2ccc35c4dc24 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -427,6 +427,18 @@ EXPORT_SYMBOL(path_put);
  * to restart the path walk from the beginning in ref-walk mode.
  */
 
+static inline void lock_rcu_walk(void)
+{
+        br_read_lock(&vfsmount_lock);
+        rcu_read_lock();
+}
+
+static inline void unlock_rcu_walk(void)
+{
+        rcu_read_unlock();
+        br_read_unlock(&vfsmount_lock);
+}
+
 /**
  * unlazy_walk - try to switch to ref-walk mode.
  * @nd: nameidata pathwalk data
@@ -480,8 +492,7 @@ static int unlazy_walk(struct nameidata *nd, struct dentry *dentry)
         }
         mntget(nd->path.mnt);
 
-        rcu_read_unlock();
-        br_read_unlock(&vfsmount_lock);
+        unlock_rcu_walk();
         nd->flags &= ~LOOKUP_RCU;
         return 0;
 
@@ -522,15 +533,13 @@ static int complete_walk(struct nameidata *nd)
                 spin_lock(&dentry->d_lock);
                 if (unlikely(!__d_rcu_to_refcount(dentry, nd->seq))) {
                         spin_unlock(&dentry->d_lock);
-                        rcu_read_unlock();
-                        br_read_unlock(&vfsmount_lock);
+                        unlock_rcu_walk();
                         return -ECHILD;
                 }
                 BUG_ON(nd->inode != dentry->d_inode);
                 spin_unlock(&dentry->d_lock);
                 mntget(nd->path.mnt);
-                rcu_read_unlock();
-                br_read_unlock(&vfsmount_lock);
+                unlock_rcu_walk();
         }
 
         if (likely(!(nd->flags & LOOKUP_JUMPED)))
@@ -985,8 +994,7 @@ failed:
         nd->flags &= ~LOOKUP_RCU;
         if (!(nd->flags & LOOKUP_ROOT))
                 nd->root.mnt = NULL;
-        rcu_read_unlock();
-        br_read_unlock(&vfsmount_lock);
+        unlock_rcu_walk();
         return -ECHILD;
 }
 
@@ -1323,8 +1331,7 @@ static void terminate_walk(struct nameidata *nd)
                 nd->flags &= ~LOOKUP_RCU;
                 if (!(nd->flags & LOOKUP_ROOT))
                         nd->root.mnt = NULL;
-                rcu_read_unlock();
-                br_read_unlock(&vfsmount_lock);
+                unlock_rcu_walk();
         }
 }
 
@@ -1691,8 +1698,7 @@ static int path_init(int dfd, const char *name, unsigned int flags,
                 nd->path = nd->root;
                 nd->inode = inode;
                 if (flags & LOOKUP_RCU) {
-                        br_read_lock(&vfsmount_lock);
-                        rcu_read_lock();
+                        lock_rcu_walk();
                         nd->seq = __read_seqcount_begin(&nd->path.dentry->d_seq);
                 } else {
                         path_get(&nd->path);
@@ -1704,8 +1710,7 @@ static int path_init(int dfd, const char *name, unsigned int flags,
 
         if (*name=='/') {
                 if (flags & LOOKUP_RCU) {
-                        br_read_lock(&vfsmount_lock);
-                        rcu_read_lock();
+                        lock_rcu_walk();
                         set_root_rcu(nd);
                 } else {
                         set_root(nd);
@@ -1717,8 +1722,7 @@ static int path_init(int dfd, const char *name, unsigned int flags,
                         struct fs_struct *fs = current->fs;
                         unsigned seq;
 
-                        br_read_lock(&vfsmount_lock);
-                        rcu_read_lock();
+                        lock_rcu_walk();
 
                         do {
                                 seq = read_seqcount_begin(&fs->seq);
@@ -1753,8 +1757,7 @@ static int path_init(int dfd, const char *name, unsigned int flags,
                         if (fput_needed)
                                 *fp = file;
                         nd->seq = __read_seqcount_begin(&nd->path.dentry->d_seq);
-                        br_read_lock(&vfsmount_lock);
-                        rcu_read_lock();
+                        lock_rcu_walk();
                 } else {
                         path_get(&file->f_path);
                         fput_light(file, fput_needed);