[PATCH] ufs: directory and page cache: from blocks to pages

Change function in fs/ufs/dir.c and fs/ufs/namei.c to work with pages
instead of straight work with blocks.  It fixed such bugs:

* for i in `seq 1 1000`; do touch $i; done - crash system
* mkdir create directory without "." and ".." entries
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/namei.c

 /*
  * linux/fs/ufs/namei.c
  *
+ * Migration to usage of "page cache" on May 2006 by
+ * Evgeniy Dushistov <dushistov@mail.ru> based on ext2 code base.
+ *
  * Copyright (C) 1998
  * Daniel Pirkl <daniel.pirkl@email.cz>
  * Charles University, Faculty of Mathematics and Physics
@@ -28,7 +31,6 @@
 #include <linux/fs.h>
 #include <linux/ufs_fs.h>
 #include <linux/smp_lock.h>
-#include <linux/buffer_head.h>
 #include "swab.h"	/* will go away - see comment in mknod() */
 #include "util.h"
 
@@ -232,19 +234,18 @@ static int ufs_mkdir(struct inode * dir, struct dentry * dentry, int mode)
 	goto out;
 }
 
-static int ufs_unlink(struct inode * dir, struct dentry *dentry)
+static int ufs_unlink(struct inode *dir, struct dentry *dentry)
 {
 	struct inode * inode = dentry->d_inode;
-	struct buffer_head * bh;
-	struct ufs_dir_entry * de;
+	struct ufs_dir_entry *de;
+	struct page *page;
 	int err = -ENOENT;
 
-	lock_kernel();
-	de = ufs_find_entry (dentry, &bh);
+	de = ufs_find_entry(dir, dentry, &page);
 	if (!de)
 		goto out;
 
-	err = ufs_delete_entry (dir, de, bh);
+	err = ufs_delete_entry(dir, de, page);
 	if (err)
 		goto out;
 
@@ -252,7 +253,6 @@ static int ufs_unlink(struct inode * dir, struct dentry *dentry)
 	inode_dec_link_count(inode);
 	err = 0;
 out:
-	unlock_kernel();
 	return err;
 }
 
@@ -274,42 +274,42 @@ static int ufs_rmdir (struct inode * dir, struct dentry *dentry)
 	return err;
 }
 
-static int ufs_rename (struct inode * old_dir, struct dentry * old_dentry,
-	struct inode * new_dir,	struct dentry * new_dentry )
+static int ufs_rename(struct inode *old_dir, struct dentry *old_dentry,
+		      struct inode *new_dir, struct dentry *new_dentry)
 {
 	struct inode *old_inode = old_dentry->d_inode;
 	struct inode *new_inode = new_dentry->d_inode;
-	struct buffer_head *dir_bh = NULL;
-	struct ufs_dir_entry *dir_de = NULL;
-	struct buffer_head *old_bh;
+	struct page *dir_page = NULL;
+	struct ufs_dir_entry * dir_de = NULL;
+	struct page *old_page;
 	struct ufs_dir_entry *old_de;
 	int err = -ENOENT;
 
-	lock_kernel();
-	old_de = ufs_find_entry (old_dentry, &old_bh);
+	old_de = ufs_find_entry(old_dir, old_dentry, &old_page);
 	if (!old_de)
 		goto out;
 
 	if (S_ISDIR(old_inode->i_mode)) {
 		err = -EIO;
-		dir_de = ufs_dotdot(old_inode, &dir_bh);
+		dir_de = ufs_dotdot(old_inode, &dir_page);
 		if (!dir_de)
 			goto out_old;
 	}
 
 	if (new_inode) {
-		struct buffer_head *new_bh;
+		struct page *new_page;
 		struct ufs_dir_entry *new_de;
 
 		err = -ENOTEMPTY;
-		if (dir_de && !ufs_empty_dir (new_inode))
+		if (dir_de && !ufs_empty_dir(new_inode))
 			goto out_dir;
+
 		err = -ENOENT;
-		new_de = ufs_find_entry (new_dentry, &new_bh);
+		new_de = ufs_find_entry(new_dir, new_dentry, &new_page);
 		if (!new_de)
 			goto out_dir;
 		inode_inc_link_count(old_inode);
-		ufs_set_link(new_dir, new_de, new_bh, old_inode);
+		ufs_set_link(new_dir, new_de, new_page, old_inode);
 		new_inode->i_ctime = CURRENT_TIME_SEC;
 		if (dir_de)
 			new_inode->i_nlink--;
@@ -330,24 +330,32 @@ static int ufs_rename (struct inode * old_dir, struct dentry * old_dentry,
 			inode_inc_link_count(new_dir);
 	}
 
-	ufs_delete_entry (old_dir, old_de, old_bh);
+	/*
+	 * Like most other Unix systems, set the ctime for inodes on a
+ 	 * rename.
+	 * inode_dec_link_count() will mark the inode dirty.
+	 */
+	old_inode->i_ctime = CURRENT_TIME_SEC;
 
+	ufs_delete_entry(old_dir, old_de, old_page);
 	inode_dec_link_count(old_inode);
 
 	if (dir_de) {
-		ufs_set_link(old_inode, dir_de, dir_bh, new_dir);
+		ufs_set_link(old_inode, dir_de, dir_page, new_dir);
 		inode_dec_link_count(old_dir);
 	}
-	unlock_kernel();
 	return 0;
 
+
 out_dir:
-	if (dir_de)
-		brelse(dir_bh);
+	if (dir_de) {
+		kunmap(dir_page);
+		page_cache_release(dir_page);
+	}
 out_old:
-	brelse (old_bh);
+	kunmap(old_page);
+	page_cache_release(old_page);
 out:
-	unlock_kernel();
 	return err;
 }
 

include/linux/ufs_fs.h

@@ -887,11 +887,12 @@ extern struct inode_operations ufs_dir_inode_operations;
 extern int ufs_add_link (struct dentry *, struct inode *);
 extern ino_t ufs_inode_by_name(struct inode *, struct dentry *);
 extern int ufs_make_empty(struct inode *, struct inode *);
-extern struct ufs_dir_entry * ufs_find_entry (struct dentry *, struct buffer_head **);
-extern int ufs_delete_entry (struct inode *, struct ufs_dir_entry *, struct buffer_head *);
+extern struct ufs_dir_entry *ufs_find_entry(struct inode *, struct dentry *, struct page **);
+extern int ufs_delete_entry(struct inode *, struct ufs_dir_entry *, struct page *);
 extern int ufs_empty_dir (struct inode *);
-extern struct ufs_dir_entry * ufs_dotdot (struct inode *, struct buffer_head **);
-extern void ufs_set_link(struct inode *, struct ufs_dir_entry *, struct buffer_head *, struct inode *);
+extern struct ufs_dir_entry *ufs_dotdot(struct inode *, struct page **);
+extern void ufs_set_link(struct inode *dir, struct ufs_dir_entry *de,
+			 struct page *page, struct inode *inode);
 
 /* file.c */
 extern struct inode_operations ufs_file_inode_operations;