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-rw-r--r--kernel/fs/btrfs/acl.c166
1 files changed, 166 insertions, 0 deletions
diff --git a/kernel/fs/btrfs/acl.c b/kernel/fs/btrfs/acl.c
new file mode 100644
index 000000000..9a0124a95
--- /dev/null
+++ b/kernel/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;
+}