Kill cached_lookup() and real_lookup()

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

1 files changed, 66 insertions, 87 deletions

diff --git a/fs/namei.c b/fs/namei.c
index b2b22f244180..020bb082d0b9 100644
--- 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;