[PATCH] ufs: little directory lookup optimization

This patch make little optimization of ufs_find_entry like "ext2" does.  Save
number of page and reuse it again in the next call.
Signed-off-by: Evgeniy Dushistov <dushistov@mail.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

fs/ufs/dir.c

@@ -252,6 +252,7 @@ struct ufs_dir_entry *ufs_find_entry(struct inode *dir, struct dentry *dentry,
 	unsigned long start, n;
 	unsigned long npages = ufs_dir_pages(dir);
 	struct page *page = NULL;
+	struct ufs_inode_info *ui = UFS_I(dir);
 	struct ufs_dir_entry *de;
 
 	UFSD("ENTER, dir_ino %lu, name %s, namlen %u\n", dir->i_ino, name, namelen);
@@ -262,8 +263,8 @@ struct ufs_dir_entry *ufs_find_entry(struct inode *dir, struct dentry *dentry,
 	/* OFFSET_CACHE */
 	*res_page = NULL;
 
-	/* start = ei->i_dir_start_lookup; */
-	start = 0;
+	start = ui->i_dir_start_lookup;
+
 	if (start >= npages)
 		start = 0;
 	n = start;
@@ -295,7 +296,7 @@ struct ufs_dir_entry *ufs_find_entry(struct inode *dir, struct dentry *dentry,
 
 found:
 	*res_page = page;
-	/* ei->i_dir_start_lookup = n; */
+	ui->i_dir_start_lookup = n;
 	return de;
 }
 

fs/ufs/ialloc.c

@@ -264,6 +264,7 @@ struct inode * ufs_new_inode(struct inode * dir, int mode)
 	ufsi->i_shadow = 0;
 	ufsi->i_osync = 0;
 	ufsi->i_oeftflag = 0;
+	ufsi->i_dir_start_lookup = 0;
 	memset(&ufsi->i_u1, 0, sizeof(ufsi->i_u1));
 
 	insert_inode_hash(inode);

fs/ufs/inode.c

@@ -628,12 +628,12 @@ void ufs_read_inode (struct inode * inode)
 	ufsi->i_shadow = fs32_to_cpu(sb, ufs_inode->ui_u3.ui_sun.ui_shadow);
 	ufsi->i_oeftflag = fs32_to_cpu(sb, ufs_inode->ui_u3.ui_sun.ui_oeftflag);
 	ufsi->i_lastfrag = (inode->i_size + uspi->s_fsize - 1) >> uspi->s_fshift;
+	ufsi->i_dir_start_lookup = 0;
 	
 	if (S_ISCHR(mode) || S_ISBLK(mode) || inode->i_blocks) {
 		for (i = 0; i < (UFS_NDADDR + UFS_NINDIR); i++)
 			ufsi->i_u1.i_data[i] = ufs_inode->ui_u2.ui_addr.ui_db[i];
-	}
-	else {
+	} else {
 		for (i = 0; i < (UFS_NDADDR + UFS_NINDIR) * 4; i++)
 			ufsi->i_u1.i_symlink[i] = ufs_inode->ui_u2.ui_symlink[i];
 	}

include/linux/ufs_fs_i.h

@@ -27,6 +27,7 @@ struct ufs_inode_info {
 	__u32	i_oeftflag;
 	__u16	i_osync;
 	__u32	i_lastfrag;
+	__u32   i_dir_start_lookup;
 	struct inode vfs_inode;
 };