NFS: The fact that readdirplus calls now create dentries from within readdir

     calls renders nfs_cached_lookup() obsolete.
Signed-off-by: Trond Myklebust <trond.myklebust@fys.uio.no>

fs/nfs/dir.c

@@ -40,8 +40,6 @@
 static int nfs_opendir(struct inode *, struct file *);
 static int nfs_readdir(struct file *, void *, filldir_t);
 static struct dentry *nfs_lookup(struct inode *, struct dentry *, struct nameidata *);
-static int nfs_cached_lookup(struct inode *, struct dentry *,
-				struct nfs_fh *, struct nfs_fattr *);
 static int nfs_create(struct inode *, struct dentry *, int, struct nameidata *);
 static int nfs_mkdir(struct inode *, struct dentry *, int);
 static int nfs_rmdir(struct inode *, struct dentry *);
@@ -613,24 +611,10 @@ static int nfs_lookup_revalidate(struct dentry * dentry, struct nameidata *nd)
 		goto out_valid;
 	}
 
-	/*
-	 * Note: we're not holding inode->i_sem and so may be racing with
-	 * operations that change the directory. We therefore save the
-	 * change attribute *before* we do the RPC call.
-	 */
-	verifier = nfs_save_change_attribute(dir);
-	error = nfs_cached_lookup(dir, dentry, &fhandle, &fattr);
-	if (!error) {
-		if (nfs_compare_fh(NFS_FH(inode), &fhandle))
-			goto out_bad;
-		if (nfs_lookup_verify_inode(inode, isopen))
-			goto out_zap_parent;
-		goto out_valid_renew;
-	}
-
 	if (NFS_STALE(inode))
 		goto out_bad;
 
+	verifier = nfs_save_change_attribute(dir);
 	error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, &fhandle, &fattr);
 	if (error)
 		goto out_bad;
@@ -639,7 +623,6 @@ static int nfs_lookup_revalidate(struct dentry * dentry, struct nameidata *nd)
 	if ((error = nfs_refresh_inode(inode, &fattr)) != 0)
 		goto out_bad;
 
- out_valid_renew:
 	nfs_renew_times(dentry);
 	nfs_set_verifier(dentry, verifier);
  out_valid:
@@ -744,15 +727,11 @@ static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, stru
 	if (nfs_is_exclusive_create(dir, nd))
 		goto no_entry;
 
-	error = nfs_cached_lookup(dir, dentry, &fhandle, &fattr);
-	if (error != 0) {
-		error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name,
-				&fhandle, &fattr);
-		if (error == -ENOENT)
-			goto no_entry;
-		if (error != 0)
-			goto out_unlock;
-	}
+	error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, &fhandle, &fattr);
+	if (error == -ENOENT)
+		goto no_entry;
+	if (error != 0)
+		goto out_unlock;
 	error = -EACCES;
 	inode = nfs_fhget(dentry->d_sb, &fhandle, &fattr);
 	if (!inode)
@@ -947,85 +926,6 @@ static struct dentry *nfs_readdir_lookup(nfs_readdir_descriptor_t *desc)
 	return dentry;
 }
 
-static inline
-int find_dirent_name(nfs_readdir_descriptor_t *desc, struct page *page, struct dentry *dentry)
-{
-	struct nfs_entry *entry = desc->entry;
-	int		 status;
-
-	while((status = dir_decode(desc)) == 0) {
-		if (entry->len != dentry->d_name.len)
-			continue;
-		if (memcmp(entry->name, dentry->d_name.name, entry->len))
-			continue;
-		if (!(entry->fattr->valid & NFS_ATTR_FATTR))
-			continue;
-		break;
-	}
-	return status;
-}
-
-/*
- * Use the cached Readdirplus results in order to avoid a LOOKUP call
- * whenever we believe that the parent directory has not changed.
- *
- * We assume that any file creation/rename changes the directory mtime.
- * As this results in a page cache invalidation whenever it occurs,
- * we don't require any other tests for cache coherency.
- */
-static
-int nfs_cached_lookup(struct inode *dir, struct dentry *dentry,
-			struct nfs_fh *fh, struct nfs_fattr *fattr)
-{
-	nfs_readdir_descriptor_t desc;
-	struct nfs_server *server;
-	struct nfs_entry entry;
-	struct page *page;
-	unsigned long timestamp;
-	int res;
-
-	if (!NFS_USE_READDIRPLUS(dir))
-		return -ENOENT;
-	server = NFS_SERVER(dir);
-	/* Don't use readdirplus unless the cache is stable */
-	if ((server->flags & NFS_MOUNT_NOAC) != 0
-			|| nfs_caches_unstable(dir)
-			|| nfs_attribute_timeout(dir))
-		return -ENOENT;
-	if ((NFS_FLAGS(dir) & (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA)) != 0)
-		return -ENOENT;
-	timestamp = NFS_I(dir)->readdir_timestamp;
-
-	entry.fh = fh;
-	entry.fattr = fattr;
-
-	desc.decode = NFS_PROTO(dir)->decode_dirent;
-	desc.entry = &entry;
-	desc.page_index = 0;
-	desc.plus = 1;
-
-	for(;(page = find_get_page(dir->i_mapping, desc.page_index)); desc.page_index++) {
-
-		res = -EIO;
-		if (PageUptodate(page)) {
-			void * kaddr = kmap_atomic(page, KM_USER0);
-			desc.ptr = kaddr;
-			res = find_dirent_name(&desc, page, dentry);
-			kunmap_atomic(kaddr, KM_USER0);
-		}
-		page_cache_release(page);
-
-		if (res == 0)
-			goto out_found;
-		if (res != -EAGAIN)
-			break;
-	}
-	return -ENOENT;
- out_found:
-	fattr->timestamp = timestamp;
-	return 0;
-}
-
 /*
  * Code common to create, mkdir, and mknod.
  */