Kill cached_lookup() and real_lookup()

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

diff --git a/fs/namei.c b/fs/namei.c
index b2b22f2..020bb08 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -412,26 +412,6 @@ do_revalidate(struct dentry *dentry, struct nameidata *nd)
 }
 
 /*
- * Internal lookup() using the new generic dcache.
- * SMP-safe
- */
-static struct dentry * cached_lookup(struct dentry * parent, struct qstr * name, struct nameidata *nd)
-{
-       struct dentry * dentry = __d_lookup(parent, name);
-
-       /* lockess __d_lookup may fail due to concurrent d_move() 
-        * in some unrelated directory, so try with d_lookup
-        */
-       if (!dentry)
-               dentry = d_lookup(parent, name);
-
-       if (dentry && dentry->d_op && dentry->d_op->d_revalidate)
-               dentry = do_revalidate(dentry, nd);
-
-       return dentry;
-}
-
-/*
  * Short-cut version of permission(), for calling by
  * path_walk(), when dcache lock is held.  Combines parts
  * of permission() and generic_permission(), and tests ONLY for
@@ -463,70 +443,6 @@ ok:
        return security_inode_permission(inode, MAY_EXEC);
 }
 
-/*
- * This is called when everything else fails, and we actually have
- * to go to the low-level filesystem to find out what we should do..
- *
- * We get the directory semaphore, and after getting that we also
- * make sure that nobody added the entry to the dcache in the meantime..
- * SMP-safe
- */
-static struct dentry * real_lookup(struct dentry * parent, struct qstr * name, struct nameidata *nd)
-{
-       struct dentry * result;
-       struct inode *dir = parent->d_inode;
-
-       mutex_lock(&dir->i_mutex);
-       /*
-        * First re-do the cached lookup just in case it was created
-        * while we waited for the directory semaphore..
-        *
-        * FIXME! This could use version numbering or similar to
-        * avoid unnecessary cache lookups.
-        *
-        * The "dcache_lock" is purely to protect the RCU list walker
-        * from concurrent renames at this point (we mustn't get false
-        * negatives from the RCU list walk here, unlike the optimistic
-        * fast walk).
-        *
-        * so doing d_lookup() (with seqlock), instead of lockfree __d_lookup
-        */
-       result = d_lookup(parent, name);
-       if (!result) {
-               struct dentry *dentry;
-
-               /* Don't create child dentry for a dead directory. */
-               result = ERR_PTR(-ENOENT);
-               if (IS_DEADDIR(dir))
-                       goto out_unlock;
-
-               dentry = d_alloc(parent, name);
-               result = ERR_PTR(-ENOMEM);
-               if (dentry) {
-                       result = dir->i_op->lookup(dir, dentry, nd);
-                       if (result)
-                               dput(dentry);
-                       else
-                               result = dentry;
-               }
-out_unlock:
-               mutex_unlock(&dir->i_mutex);
-               return result;
-       }
-
-       /*
-        * Uhhuh! Nasty case: the cache was re-populated while
-        * we waited on the semaphore. Need to revalidate.
-        */
-       mutex_unlock(&dir->i_mutex);
-       if (result->d_op && result->d_op->d_revalidate) {
-               result = do_revalidate(result, nd);
-               if (!result)
-                       result = ERR_PTR(-ENOENT);
-       }
-       return result;
-}
-
 static __always_inline void set_root(struct nameidata *nd)
 {
        if (!nd->root.mnt) {
@@ -767,7 +683,8 @@ static int do_lookup(struct nameidata *nd, struct qstr *name,
                     struct path *path)
 {
        struct vfsmount *mnt = nd->path.mnt;
-       struct dentry *dentry;
+       struct dentry *dentry, *parent;
+       struct inode *dir;
        /*
         * See if the low-level filesystem might want
         * to use its own hash..
@@ -790,7 +707,59 @@ done:
        return 0;
 
 need_lookup:
-       dentry = real_lookup(nd->path.dentry, name, nd);
+       parent = nd->path.dentry;
+       dir = parent->d_inode;
+
+       mutex_lock(&dir->i_mutex);
+       /*
+        * First re-do the cached lookup just in case it was created
+        * while we waited for the directory semaphore..
+        *
+        * FIXME! This could use version numbering or similar to
+        * avoid unnecessary cache lookups.
+        *
+        * The "dcache_lock" is purely to protect the RCU list walker
+        * from concurrent renames at this point (we mustn't get false
+        * negatives from the RCU list walk here, unlike the optimistic
+        * fast walk).
+        *
+        * so doing d_lookup() (with seqlock), instead of lockfree __d_lookup
+        */
+       dentry = d_lookup(parent, name);
+       if (!dentry) {
+               struct dentry *new;
+
+               /* Don't create child dentry for a dead directory. */
+               dentry = ERR_PTR(-ENOENT);
+               if (IS_DEADDIR(dir))
+                       goto out_unlock;
+
+               new = d_alloc(parent, name);
+               dentry = ERR_PTR(-ENOMEM);
+               if (new) {
+                       dentry = dir->i_op->lookup(dir, new, nd);
+                       if (dentry)
+                               dput(new);
+                       else
+                               dentry = new;
+               }
+out_unlock:
+               mutex_unlock(&dir->i_mutex);
+               if (IS_ERR(dentry))
+                       goto fail;
+               goto done;
+       }
+
+       /*
+        * Uhhuh! Nasty case: the cache was re-populated while
+        * we waited on the semaphore. Need to revalidate.
+        */
+       mutex_unlock(&dir->i_mutex);
+       if (dentry->d_op && dentry->d_op->d_revalidate) {
+               dentry = do_revalidate(dentry, nd);
+               if (!dentry)
+                       dentry = ERR_PTR(-ENOENT);
+       }
        if (IS_ERR(dentry))
                goto fail;
        goto done;
@@ -1144,7 +1113,17 @@ static struct dentry *__lookup_hash(struct qstr *name,
                        goto out;
        }
 
-       dentry = cached_lookup(base, name, nd);
+       dentry = __d_lookup(base, name);
+
+       /* lockess __d_lookup may fail due to concurrent d_move()
+        * in some unrelated directory, so try with d_lookup
+        */
+       if (!dentry)
+               dentry = d_lookup(base, name);
+
+       if (dentry && dentry->d_op && dentry->d_op->d_revalidate)
+               dentry = do_revalidate(dentry, nd);
+
        if (!dentry) {
                struct dentry *new;