From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001
From: André Fabian Silva Delgado <emulatorman@parabola.nu>
Date: Wed, 5 Aug 2015 17:04:01 -0300
Subject: Initial import

---
 fs/btrfs/acl.c | 166 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 166 insertions(+)
 create mode 100644 fs/btrfs/acl.c

(limited to 'fs/btrfs/acl.c')

diff --git a/fs/btrfs/acl.c b/fs/btrfs/acl.c
new file mode 100644
index 000000000..9a0124a95
--- /dev/null
+++ b/fs/btrfs/acl.c
@@ -0,0 +1,166 @@
+/*
+ * Copyright (C) 2007 Red Hat.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/fs.h>
+#include <linux/string.h>
+#include <linux/xattr.h>
+#include <linux/posix_acl_xattr.h>
+#include <linux/posix_acl.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+
+#include "ctree.h"
+#include "btrfs_inode.h"
+#include "xattr.h"
+
+struct posix_acl *btrfs_get_acl(struct inode *inode, int type)
+{
+	int size;
+	const char *name;
+	char *value = NULL;
+	struct posix_acl *acl;
+
+	switch (type) {
+	case ACL_TYPE_ACCESS:
+		name = POSIX_ACL_XATTR_ACCESS;
+		break;
+	case ACL_TYPE_DEFAULT:
+		name = POSIX_ACL_XATTR_DEFAULT;
+		break;
+	default:
+		BUG();
+	}
+
+	size = __btrfs_getxattr(inode, name, "", 0);
+	if (size > 0) {
+		value = kzalloc(size, GFP_NOFS);
+		if (!value)
+			return ERR_PTR(-ENOMEM);
+		size = __btrfs_getxattr(inode, name, value, size);
+	}
+	if (size > 0) {
+		acl = posix_acl_from_xattr(&init_user_ns, value, size);
+	} else if (size == -ENOENT || size == -ENODATA || size == 0) {
+		/* FIXME, who returns -ENOENT?  I think nobody */
+		acl = NULL;
+	} else {
+		acl = ERR_PTR(-EIO);
+	}
+	kfree(value);
+
+	if (!IS_ERR(acl))
+		set_cached_acl(inode, type, acl);
+
+	return acl;
+}
+
+/*
+ * Needs to be called with fs_mutex held
+ */
+static int __btrfs_set_acl(struct btrfs_trans_handle *trans,
+			 struct inode *inode, struct posix_acl *acl, int type)
+{
+	int ret, size = 0;
+	const char *name;
+	char *value = NULL;
+
+	switch (type) {
+	case ACL_TYPE_ACCESS:
+		name = POSIX_ACL_XATTR_ACCESS;
+		if (acl) {
+			ret = posix_acl_equiv_mode(acl, &inode->i_mode);
+			if (ret < 0)
+				return ret;
+			if (ret == 0)
+				acl = NULL;
+		}
+		ret = 0;
+		break;
+	case ACL_TYPE_DEFAULT:
+		if (!S_ISDIR(inode->i_mode))
+			return acl ? -EINVAL : 0;
+		name = POSIX_ACL_XATTR_DEFAULT;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (acl) {
+		size = posix_acl_xattr_size(acl->a_count);
+		value = kmalloc(size, GFP_NOFS);
+		if (!value) {
+			ret = -ENOMEM;
+			goto out;
+		}
+
+		ret = posix_acl_to_xattr(&init_user_ns, acl, value, size);
+		if (ret < 0)
+			goto out;
+	}
+
+	ret = __btrfs_setxattr(trans, inode, name, value, size, 0);
+out:
+	kfree(value);
+
+	if (!ret)
+		set_cached_acl(inode, type, acl);
+
+	return ret;
+}
+
+int btrfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
+{
+	return __btrfs_set_acl(NULL, inode, acl, type);
+}
+
+/*
+ * btrfs_init_acl is already generally called under fs_mutex, so the locking
+ * stuff has been fixed to work with that.  If the locking stuff changes, we
+ * need to re-evaluate the acl locking stuff.
+ */
+int btrfs_init_acl(struct btrfs_trans_handle *trans,
+		   struct inode *inode, struct inode *dir)
+{
+	struct posix_acl *default_acl, *acl;
+	int ret = 0;
+
+	/* this happens with subvols */
+	if (!dir)
+		return 0;
+
+	ret = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
+	if (ret)
+		return ret;
+
+	if (default_acl) {
+		ret = __btrfs_set_acl(trans, inode, default_acl,
+				      ACL_TYPE_DEFAULT);
+		posix_acl_release(default_acl);
+	}
+
+	if (acl) {
+		if (!ret)
+			ret = __btrfs_set_acl(trans, inode, acl,
+					      ACL_TYPE_ACCESS);
+		posix_acl_release(acl);
+	}
+
+	if (!default_acl && !acl)
+		cache_no_acl(inode);
+	return ret;
+}
-- 
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