vfs: factor out lookup_mountpoint from new_mountpoint

I am shortly going to add a new user of struct mountpoint that
needs to look up existing entries but does not want to create
a struct mountpoint if one does not exist.  Therefore to keep
the code simple and easy to read split out lookup_mountpoint
from new_mountpoint.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/namespace.c b/fs/namespace.c
index 99572dd083361649d937cd49971303357e9fc78e..88fc3f4d77ed10716a7ea3bc7ca4f701b0a995c7 100644 (file)
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -703,11 +703,10 @@ out:
        return is_covered;
 }
 
-static struct mountpoint *new_mountpoint(struct dentry *dentry)
+static struct mountpoint *lookup_mountpoint(struct dentry *dentry)
 {
        struct hlist_head *chain = mp_hash(dentry);
        struct mountpoint *mp;
-       int ret;
 
        hlist_for_each_entry(mp, chain, m_hash) {
                if (mp->m_dentry == dentry) {
@@ -718,6 +717,14 @@ static struct mountpoint *new_mountpoint(struct dentry *dentry)
                        return mp;
                }
        }
+       return NULL;
+}
+
+static struct mountpoint *new_mountpoint(struct dentry *dentry)
+{
+       struct hlist_head *chain = mp_hash(dentry);
+       struct mountpoint *mp;
+       int ret;
 
        mp = kmalloc(sizeof(struct mountpoint), GFP_KERNEL);
        if (!mp)
@@ -1818,7 +1825,9 @@ retry:
        namespace_lock();
        mnt = lookup_mnt(path);
        if (likely(!mnt)) {
-               struct mountpoint *mp = new_mountpoint(dentry);
+               struct mountpoint *mp = lookup_mountpoint(dentry);
+               if (!mp)
+                       mp = new_mountpoint(dentry);
                if (IS_ERR(mp)) {
                        namespace_unlock();
                        mutex_unlock(&dentry->d_inode->i_mutex);