Re: [PATCH] sanitize lookup_hash prototype

[Christoph Hellwig <hch@lst.de>]

On Sat, Oct 29, 2005 at 01:40:30AM +0200, Christoph Hellwig wrote:
> ->permission and ->lookup have a struct nameidata * argument these
> days to pass down lookup intents.  Unfortunately some callers of
> lookup_hash don't actually pass this one down.  For lookup_one_len()
> we don't have a struct nameidata to pass down, but as this function
> is a library function only used by filesystem code this is an acceptable
> limitation.  All other callers should pass down the nameidata, so this
> patch changes the lookup_hash interface to only take a struct nameidata
> argument and derives the other two arguments to __lookup_hash from it.
> All callers already have the nameidata argument available so this is not
> a problem.
> 
> At the same time I'd like to deprecate the lookup_hash interface as
> there are better exported interfaces for filesystem usage.  Before it
> can actually be removed I need to fix up rpc_pipefs.

Sorry, the last patch was actually missing one hook in rpc_pipe.c, this
one is correct:


Signed-off-by: Christoph Hellwig <hch@lst.de>

Index: linux-2.6/fs/namei.c
===================================================================
--- linux-2.6.orig/fs/namei.c	2005-10-29 04:14:44.000000000 +0200
+++ linux-2.6/fs/namei.c	2005-10-29 17:55:21.000000000 +0200
@@ -1173,9 +1173,9 @@
 	return dentry;
 }
 
-struct dentry * lookup_hash(struct qstr *name, struct dentry * base)
+struct dentry * lookup_hash(struct nameidata *nd)
 {
-	return __lookup_hash(name, base, NULL);
+	return __lookup_hash(&nd->last, nd->dentry, nd);
 }
 
 /* SMP-safe */
@@ -1199,7 +1199,7 @@
 	}
 	this.hash = end_name_hash(hash);
 
-	return lookup_hash(&this, base);
+	return __lookup_hash(&this, base, NULL);
 access:
 	return ERR_PTR(-EACCES);
 }
@@ -1538,7 +1538,7 @@
 	dir = nd->dentry;
 	nd->flags &= ~LOOKUP_PARENT;
 	down(&dir->d_inode->i_sem);
-	path.dentry = __lookup_hash(&nd->last, nd->dentry, nd);
+	path.dentry = lookup_hash(nd);
 	path.mnt = nd->mnt;
 
 do_last:
@@ -1640,7 +1640,7 @@
 	}
 	dir = nd->dentry;
 	down(&dir->d_inode->i_sem);
-	path.dentry = __lookup_hash(&nd->last, nd->dentry, nd);
+	path.dentry = lookup_hash(nd);
 	path.mnt = nd->mnt;
 	__putname(nd->last.name);
 	goto do_last;
@@ -1672,7 +1672,7 @@
 	/*
 	 * Do the final lookup.
 	 */
-	dentry = lookup_hash(&nd->last, nd->dentry);
+	dentry = lookup_hash(nd);
 	if (IS_ERR(dentry))
 		goto fail;
 
@@ -1907,7 +1907,7 @@
 			goto exit1;
 	}
 	down(&nd.dentry->d_inode->i_sem);
-	dentry = lookup_hash(&nd.last, nd.dentry);
+	dentry = lookup_hash(&nd);
 	error = PTR_ERR(dentry);
 	if (!IS_ERR(dentry)) {
 		error = vfs_rmdir(nd.dentry->d_inode, dentry);
@@ -1976,7 +1976,7 @@
 	if (nd.last_type != LAST_NORM)
 		goto exit1;
 	down(&nd.dentry->d_inode->i_sem);
-	dentry = lookup_hash(&nd.last, nd.dentry);
+	dentry = lookup_hash(&nd);
 	error = PTR_ERR(dentry);
 	if (!IS_ERR(dentry)) {
 		/* Why not before? Because we want correct error value */
@@ -2319,7 +2319,7 @@
 
 	trap = lock_rename(new_dir, old_dir);
 
-	old_dentry = lookup_hash(&oldnd.last, old_dir);
+	old_dentry = lookup_hash(&oldnd);
 	error = PTR_ERR(old_dentry);
 	if (IS_ERR(old_dentry))
 		goto exit3;
@@ -2339,7 +2339,7 @@
 	error = -EINVAL;
 	if (old_dentry == trap)
 		goto exit4;
-	new_dentry = lookup_hash(&newnd.last, new_dir);
+	new_dentry = lookup_hash(&newnd);
 	error = PTR_ERR(new_dentry);
 	if (IS_ERR(new_dentry))
 		goto exit4;
Index: linux-2.6/include/linux/namei.h
===================================================================
--- linux-2.6.orig/include/linux/namei.h	2005-10-29 04:14:44.000000000 +0200
+++ linux-2.6/include/linux/namei.h	2005-10-29 04:14:46.000000000 +0200
@@ -74,7 +74,7 @@
 extern void release_open_intent(struct nameidata *);
 
 extern struct dentry * lookup_one_len(const char *, struct dentry *, int);
-extern struct dentry * lookup_hash(struct qstr *, struct dentry *);
+extern struct dentry * lookup_hash(struct nameidata *);
 
 extern int follow_down(struct vfsmount **, struct dentry **);
 extern int follow_up(struct vfsmount **, struct dentry **);
Index: linux-2.6/net/sunrpc/rpc_pipe.c
===================================================================
--- linux-2.6.orig/net/sunrpc/rpc_pipe.c	2005-10-29 04:14:44.000000000 +0200
+++ linux-2.6/net/sunrpc/rpc_pipe.c	2005-10-29 18:46:22.000000000 +0200
@@ -603,7 +603,7 @@
 		return ERR_PTR(error);
 	dir = nd->dentry->d_inode;
 	down(&dir->i_sem);
-	dentry = lookup_hash(&nd->last, nd->dentry);
+	dentry = lookup_hash(nd);
 	if (IS_ERR(dentry))
 		goto out_err;
 	if (dentry->d_inode) {
@@ -665,7 +665,7 @@
 		return error;
 	dir = nd.dentry->d_inode;
 	down(&dir->i_sem);
-	dentry = lookup_hash(&nd.last, nd.dentry);
+	dentry = lookup_hash(&nd);
 	if (IS_ERR(dentry)) {
 		error = PTR_ERR(dentry);
 		goto out_release;
@@ -726,7 +726,7 @@
 		return error;
 	dir = nd.dentry->d_inode;
 	down(&dir->i_sem);
-	dentry = lookup_hash(&nd.last, nd.dentry);
+	dentry = lookup_hash(&nd);
 	if (IS_ERR(dentry)) {
 		error = PTR_ERR(dentry);
 		goto out_release;
Index: linux-2.6/Documentation/feature-removal-schedule.txt
===================================================================
--- linux-2.6.orig/Documentation/feature-removal-schedule.txt	2005-10-29 04:14:44.000000000 +0200
+++ linux-2.6/Documentation/feature-removal-schedule.txt	2005-10-29 04:14:46.000000000 +0200
@@ -95,3 +95,10 @@
 	to link against API-compatible library on top of libnfnetlink_queue 
 	instead of the current 'libipq'.
 Who:	Harald Welte <laforge@netfilter.org>
+
+---------------------------
+
+What:	EXPORT_SYMBOL(lookup_hash)
+When:	January 2006
+Why:	Too low-level interface.  Use lookup_one_len or lookup_create instead.
+Who:	Christoph Hellwig <hch@lst.de>