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>
diff --git a/fs/namei.c b/fs/namei.c
index d4d15bb..2ccc35c 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -427,6 +427,18 @@
* 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 @@
}
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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);