Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
  [PATCH] get stack footprint of pathname resolution back to relative sanity
  [PATCH] double iput() on failure exit in hugetlb
  [PATCH] double dput() on failure exit in tiny-shmem
  [PATCH] fix up new filp allocators
  [PATCH] check for null vfsmount in dentry_open()
  [PATCH] reiserfs: eliminate private use of struct file in xattr
  [PATCH] sanitize hppfs
  hppfs pass vfsmount to dentry_open()
  [PATCH] restore export of do_kern_mount()

fs/anon_inodes.c

@@ -81,13 +81,10 @@ int anon_inode_getfd(int *pfd, struct inode **pinode, struct file **pfile,
 
 	if (IS_ERR(anon_inode_inode))
 		return -ENODEV;
-	file = get_empty_filp();
-	if (!file)
-		return -ENFILE;
 
 	error = get_unused_fd();
 	if (error < 0)
-		goto err_put_filp;
+		return error;
 	fd = error;
 
 	/*
@@ -114,14 +111,15 @@ int anon_inode_getfd(int *pfd, struct inode **pinode, struct file **pfile,
 	dentry->d_flags &= ~DCACHE_UNHASHED;
 	d_instantiate(dentry, anon_inode_inode);
 
-	file->f_path.mnt = mntget(anon_inode_mnt);
-	file->f_path.dentry = dentry;
+	error = -ENFILE;
+	file = alloc_file(anon_inode_mnt, dentry,
+			  FMODE_READ | FMODE_WRITE, fops);
+	if (!file)
+		goto err_dput;
 	file->f_mapping = anon_inode_inode->i_mapping;
 
 	file->f_pos = 0;
 	file->f_flags = O_RDWR;
-	file->f_op = fops;
-	file->f_mode = FMODE_READ | FMODE_WRITE;
 	file->f_version = 0;
 	file->private_data = priv;
 
@@ -132,10 +130,10 @@ int anon_inode_getfd(int *pfd, struct inode **pinode, struct file **pfile,
 	*pfile = file;
 	return 0;
 
+err_dput:
+	dput(dentry);
 err_put_unused_fd:
 	put_unused_fd(fd);
-err_put_filp:
-	put_filp(file);
 	return error;
 }
 EXPORT_SYMBOL_GPL(anon_inode_getfd);

fs/file_table.c

@@ -83,6 +83,12 @@ int proc_nr_files(ctl_table *table, int write, struct file *filp,
 /* Find an unused file structure and return a pointer to it.
  * Returns NULL, if there are no more free file structures or
  * we run out of memory.
+ *
+ * Be very careful using this.  You are responsible for
+ * getting write access to any mount that you might assign
+ * to this filp, if it is opened for write.  If this is not
+ * done, you will imbalance int the mount's writer count
+ * and a warning at __fput() time.
  */
 struct file *get_empty_filp(void)
 {

fs/hugetlbfs/inode.c

@@ -954,7 +954,7 @@ struct file *hugetlb_file_setup(const char *name, size_t size)
 			FMODE_WRITE | FMODE_READ,
 			&hugetlbfs_file_operations);
 	if (!file)
-		goto out_inode;
+		goto out_dentry; /* inode is already attached */
 
 	return file;
 

fs/namei.c

@@ -106,7 +106,7 @@
  * any extra contention...
  */
 
-static int link_path_walk(const char *name, struct nameidata *nd);
+static int __link_path_walk(const char *name, struct nameidata *nd);
 
 /* In order to reduce some races, while at the same time doing additional
  * checking and hopefully speeding things up, we copy filenames to the
@@ -563,6 +563,37 @@ walk_init_root(const char *name, struct nameidata *nd)
 	return 1;
 }
 
+/*
+ * Wrapper to retry pathname resolution whenever the underlying
+ * file system returns an ESTALE.
+ *
+ * Retry the whole path once, forcing real lookup requests
+ * instead of relying on the dcache.
+ */
+static __always_inline int link_path_walk(const char *name, struct nameidata *nd)
+{
+	struct path save = nd->path;
+	int result;
+
+	/* make sure the stuff we saved doesn't go away */
+	dget(save.dentry);
+	mntget(save.mnt);
+
+	result = __link_path_walk(name, nd);
+	if (result == -ESTALE) {
+		/* nd->path had been dropped */
+		nd->path = save;
+		dget(nd->path.dentry);
+		mntget(nd->path.mnt);
+		nd->flags |= LOOKUP_REVAL;
+		result = __link_path_walk(name, nd);
+	}
+
+	path_put(&save);
+
+	return result;
+}
+
 static __always_inline int __vfs_follow_link(struct nameidata *nd, const char *link)
 {
 	int res = 0;
@@ -1020,36 +1051,6 @@ return_err:
 	return err;
 }
 
-/*
- * Wrapper to retry pathname resolution whenever the underlying
- * file system returns an ESTALE.
- *
- * Retry the whole path once, forcing real lookup requests
- * instead of relying on the dcache.
- */
-static int link_path_walk(const char *name, struct nameidata *nd)
-{
-	struct nameidata save = *nd;
-	int result;
-
-	/* make sure the stuff we saved doesn't go away */
-	dget(save.path.dentry);
-	mntget(save.path.mnt);
-
-	result = __link_path_walk(name, nd);
-	if (result == -ESTALE) {
-		*nd = save;
-		dget(nd->path.dentry);
-		mntget(nd->path.mnt);
-		nd->flags |= LOOKUP_REVAL;
-		result = __link_path_walk(name, nd);
-	}
-
-	path_put(&save.path);
-
-	return result;
-}
-
 static int path_walk(const char *name, struct nameidata *nd)
 {
 	current->total_link_count = 0;

fs/open.c

@@ -903,6 +903,18 @@ struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags)
 	int error;
 	struct file *f;
 
+	/*
+	 * We must always pass in a valid mount pointer.   Historically
+	 * callers got away with not passing it, but we must enforce this at
+	 * the earliest possible point now to avoid strange problems deep in the
+	 * filesystem stack.
+	 */
+	if (!mnt) {
+		printk(KERN_WARNING "%s called with NULL vfsmount\n", __func__);
+		dump_stack();
+		return ERR_PTR(-EINVAL);
+	}
+
 	error = -ENFILE;
 	f = get_empty_filp();
 	if (f == NULL) {

fs/pipe.c

@@ -957,13 +957,10 @@ struct file *create_write_pipe(void)
 	struct dentry *dentry;
 	struct qstr name = { .name = "" };
 
-	f = get_empty_filp();
-	if (!f)
-		return ERR_PTR(-ENFILE);
 	err = -ENFILE;
 	inode = get_pipe_inode();
 	if (!inode)
-		goto err_file;
+		goto err;
 
 	err = -ENOMEM;
 	dentry = d_alloc(pipe_mnt->mnt_sb->s_root, &name);
@@ -978,22 +975,24 @@ struct file *create_write_pipe(void)
 	 */
 	dentry->d_flags &= ~DCACHE_UNHASHED;
 	d_instantiate(dentry, inode);
-	f->f_path.mnt = mntget(pipe_mnt);
-	f->f_path.dentry = dentry;
+
+	err = -ENFILE;
+	f = alloc_file(pipe_mnt, dentry, FMODE_WRITE, &write_pipe_fops);
+	if (!f)
+		goto err_dentry;
 	f->f_mapping = inode->i_mapping;
 
 	f->f_flags = O_WRONLY;
-	f->f_op = &write_pipe_fops;
-	f->f_mode = FMODE_WRITE;
 	f->f_version = 0;
 
 	return f;
 
+ err_dentry:
+	dput(dentry);
  err_inode:
 	free_pipe_info(inode);
 	iput(inode);
- err_file:
-	put_filp(f);
+ err:
 	return ERR_PTR(err);
 }
 

fs/reiserfs/xattr.c

@@ -191,28 +191,11 @@ static struct dentry *get_xa_file_dentry(const struct inode *inode,
 	dput(xadir);
 	if (err)
 		xafile = ERR_PTR(err);
-	return xafile;
-}
-
-/* Opens a file pointer to the attribute associated with inode */
-static struct file *open_xa_file(const struct inode *inode, const char *name,
-				 int flags)
-{
-	struct dentry *xafile;
-	struct file *fp;
-
-	xafile = get_xa_file_dentry(inode, name, flags);
-	if (IS_ERR(xafile))
-		return ERR_PTR(PTR_ERR(xafile));
 	else if (!xafile->d_inode) {
 		dput(xafile);
-		return ERR_PTR(-ENODATA);
+		xafile = ERR_PTR(-ENODATA);
 	}
-
-	fp = dentry_open(xafile, NULL, O_RDWR);
-	/* dentry_open dputs the dentry if it fails */
-
-	return fp;
+	return xafile;
 }
 
 /*
@@ -228,9 +211,8 @@ static struct file *open_xa_file(const struct inode *inode, const char *name,
  * we're called with i_mutex held, so there are no worries about the directory
  * changing underneath us.
  */
-static int __xattr_readdir(struct file *filp, void *dirent, filldir_t filldir)
+static int __xattr_readdir(struct inode *inode, void *dirent, filldir_t filldir)
 {
-	struct inode *inode = filp->f_path.dentry->d_inode;
 	struct cpu_key pos_key;	/* key of current position in the directory (key of directory entry) */
 	INITIALIZE_PATH(path_to_entry);
 	struct buffer_head *bh;
@@ -374,23 +356,16 @@ static int __xattr_readdir(struct file *filp, void *dirent, filldir_t filldir)
  *
  */
 static
-int xattr_readdir(struct file *file, filldir_t filler, void *buf)
+int xattr_readdir(struct inode *inode, filldir_t filler, void *buf)
 {
-	struct inode *inode = file->f_path.dentry->d_inode;
-	int res = -ENOTDIR;
-	if (!file->f_op || !file->f_op->readdir)
-		goto out;
+	int res = -ENOENT;
 	mutex_lock_nested(&inode->i_mutex, I_MUTEX_XATTR);
-//        down(&inode->i_zombie);
-	res = -ENOENT;
 	if (!IS_DEADDIR(inode)) {
 		lock_kernel();
-		res = __xattr_readdir(file, buf, filler);
+		res = __xattr_readdir(inode, buf, filler);
 		unlock_kernel();
 	}
-//        up(&inode->i_zombie);
 	mutex_unlock(&inode->i_mutex);
-      out:
 	return res;
 }
 
@@ -442,7 +417,7 @@ reiserfs_xattr_set(struct inode *inode, const char *name, const void *buffer,
 		   size_t buffer_size, int flags)
 {
 	int err = 0;
-	struct file *fp;
+	struct dentry *dentry;
 	struct page *page;
 	char *data;
 	struct address_space *mapping;
@@ -460,18 +435,18 @@ reiserfs_xattr_set(struct inode *inode, const char *name, const void *buffer,
 		xahash = xattr_hash(buffer, buffer_size);
 
       open_file:
-	fp = open_xa_file(inode, name, flags);
-	if (IS_ERR(fp)) {
-		err = PTR_ERR(fp);
+	dentry = get_xa_file_dentry(inode, name, flags);
+	if (IS_ERR(dentry)) {
+		err = PTR_ERR(dentry);
 		goto out;
 	}
 
-	xinode = fp->f_path.dentry->d_inode;
+	xinode = dentry->d_inode;
 	REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
 
 	/* we need to copy it off.. */
 	if (xinode->i_nlink > 1) {
-		fput(fp);
+		dput(dentry);
 		err = reiserfs_xattr_del(inode, name);
 		if (err < 0)
 			goto out;
@@ -485,7 +460,7 @@ reiserfs_xattr_set(struct inode *inode, const char *name, const void *buffer,
 	newattrs.ia_size = buffer_size;
 	newattrs.ia_valid = ATTR_SIZE | ATTR_CTIME;
 	mutex_lock_nested(&xinode->i_mutex, I_MUTEX_XATTR);
-	err = notify_change(fp->f_path.dentry, &newattrs);
+	err = notify_change(dentry, &newattrs);
 	if (err)
 		goto out_filp;
 
@@ -518,13 +493,12 @@ reiserfs_xattr_set(struct inode *inode, const char *name, const void *buffer,
 			rxh->h_hash = cpu_to_le32(xahash);
 		}
 
-		err = reiserfs_prepare_write(fp, page, page_offset,
+		err = reiserfs_prepare_write(NULL, page, page_offset,
 					    page_offset + chunk + skip);
 		if (!err) {
 			if (buffer)
 				memcpy(data + skip, buffer + buffer_pos, chunk);
-			err =
-			    reiserfs_commit_write(fp, page, page_offset,
+			err = reiserfs_commit_write(NULL, page, page_offset,
 						    page_offset + chunk +
 						    skip);
 		}
@@ -548,7 +522,7 @@ reiserfs_xattr_set(struct inode *inode, const char *name, const void *buffer,
 
       out_filp:
 	mutex_unlock(&xinode->i_mutex);
-	fput(fp);
+	dput(dentry);
 
       out:
 	return err;
@@ -562,7 +536,7 @@ reiserfs_xattr_get(const struct inode *inode, const char *name, void *buffer,
 		   size_t buffer_size)
 {
 	ssize_t err = 0;
-	struct file *fp;
+	struct dentry *dentry;
 	size_t isize;
 	size_t file_pos = 0;
 	size_t buffer_pos = 0;
@@ -578,13 +552,13 @@ reiserfs_xattr_get(const struct inode *inode, const char *name, void *buffer,
 	if (get_inode_sd_version(inode) == STAT_DATA_V1)
 		return -EOPNOTSUPP;
 
-	fp = open_xa_file(inode, name, FL_READONLY);
-	if (IS_ERR(fp)) {
-		err = PTR_ERR(fp);
+	dentry = get_xa_file_dentry(inode, name, FL_READONLY);
+	if (IS_ERR(dentry)) {
+		err = PTR_ERR(dentry);
 		goto out;
 	}
 
-	xinode = fp->f_path.dentry->d_inode;
+	xinode = dentry->d_inode;
 	isize = xinode->i_size;
 	REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
 
@@ -652,7 +626,7 @@ reiserfs_xattr_get(const struct inode *inode, const char *name, void *buffer,
 	}
 
       out_dput:
-	fput(fp);
+	dput(dentry);
 
       out:
 	return err;
@@ -742,7 +716,6 @@ reiserfs_delete_xattrs_filler(void *buf, const char *name, int namelen,
 /* This is called w/ inode->i_mutex downed */
 int reiserfs_delete_xattrs(struct inode *inode)
 {
-	struct file *fp;
 	struct dentry *dir, *root;
 	int err = 0;
 
@@ -763,15 +736,8 @@ int reiserfs_delete_xattrs(struct inode *inode)
 		return 0;
 	}
 
-	fp = dentry_open(dir, NULL, O_RDWR);
-	if (IS_ERR(fp)) {
-		err = PTR_ERR(fp);
-		/* dentry_open dputs the dentry if it fails */
-		goto out;
-	}
-
 	lock_kernel();
-	err = xattr_readdir(fp, reiserfs_delete_xattrs_filler, dir);
+	err = xattr_readdir(dir->d_inode, reiserfs_delete_xattrs_filler, dir);
 	if (err) {
 		unlock_kernel();
 		goto out_dir;
@@ -791,7 +757,7 @@ int reiserfs_delete_xattrs(struct inode *inode)
 	unlock_kernel();
 
       out_dir:
-	fput(fp);
+	dput(dir);
 
       out:
 	if (!err)
@@ -833,7 +799,6 @@ reiserfs_chown_xattrs_filler(void *buf, const char *name, int namelen,
 
 int reiserfs_chown_xattrs(struct inode *inode, struct iattr *attrs)
 {
-	struct file *fp;
 	struct dentry *dir;
 	int err = 0;
 	struct reiserfs_chown_buf buf;
@@ -857,13 +822,6 @@ int reiserfs_chown_xattrs(struct inode *inode, struct iattr *attrs)
 		goto out;
 	}
 
-	fp = dentry_open(dir, NULL, O_RDWR);
-	if (IS_ERR(fp)) {
-		err = PTR_ERR(fp);
-		/* dentry_open dputs the dentry if it fails */
-		goto out;
-	}
-
 	lock_kernel();
 
 	attrs->ia_valid &= (ATTR_UID | ATTR_GID | ATTR_CTIME);
@@ -871,7 +829,7 @@ int reiserfs_chown_xattrs(struct inode *inode, struct iattr *attrs)
 	buf.attrs = attrs;
 	buf.inode = inode;
 
-	err = xattr_readdir(fp, reiserfs_chown_xattrs_filler, &buf);
+	err = xattr_readdir(dir->d_inode, reiserfs_chown_xattrs_filler, &buf);
 	if (err) {
 		unlock_kernel();
 		goto out_dir;
@@ -881,7 +839,7 @@ int reiserfs_chown_xattrs(struct inode *inode, struct iattr *attrs)
 	unlock_kernel();
 
       out_dir:
-	fput(fp);
+	dput(dir);
 
       out:
 	attrs->ia_valid = ia_valid;
@@ -1029,7 +987,6 @@ reiserfs_listxattr_filler(void *buf, const char *name, int namelen,
  */
 ssize_t reiserfs_listxattr(struct dentry * dentry, char *buffer, size_t size)
 {
-	struct file *fp;
 	struct dentry *dir;
 	int err = 0;
 	struct reiserfs_listxattr_buf buf;
@@ -1052,13 +1009,6 @@ ssize_t reiserfs_listxattr(struct dentry * dentry, char *buffer, size_t size)
 		goto out;
 	}
 
-	fp = dentry_open(dir, NULL, O_RDWR);
-	if (IS_ERR(fp)) {
-		err = PTR_ERR(fp);
-		/* dentry_open dputs the dentry if it fails */
-		goto out;
-	}
-
 	buf.r_buf = buffer;
 	buf.r_size = buffer ? size : 0;
 	buf.r_pos = 0;
@@ -1066,7 +1016,7 @@ ssize_t reiserfs_listxattr(struct dentry * dentry, char *buffer, size_t size)
 
 	REISERFS_I(dentry->d_inode)->i_flags |= i_has_xattr_dir;
 
-	err = xattr_readdir(fp, reiserfs_listxattr_filler, &buf);
+	err = xattr_readdir(dir->d_inode, reiserfs_listxattr_filler, &buf);
 	if (err)
 		goto out_dir;
 
@@ -1076,7 +1026,7 @@ ssize_t reiserfs_listxattr(struct dentry * dentry, char *buffer, size_t size)
 		err = buf.r_pos;
 
       out_dir:
-	fput(fp);
+	dput(dir);
 
       out:
 	reiserfs_read_unlock_xattr_i(dentry->d_inode);

fs/super.c

@@ -945,6 +945,7 @@ do_kern_mount(const char *fstype, int flags, const char *name, void *data)
 	put_filesystem(type);
 	return mnt;
 }
+EXPORT_SYMBOL_GPL(do_kern_mount);
 
 struct vfsmount *kern_mount_data(struct file_system_type *type, void *data)
 {

mm/tiny-shmem.c

@@ -88,6 +88,8 @@ struct file *shmem_file_setup(char *name, loff_t size, unsigned long flags)
 
 close_file:
 	put_filp(file);
+	return ERR_PTR(error);
+
 put_dentry:
 	dput(dentry);
 put_memory: