summaryrefslogtreecommitdiff
path: root/fs/fuse/acl.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/fuse/acl.c')
-rw-r--r--fs/fuse/acl.c99
1 files changed, 99 insertions, 0 deletions
diff --git a/fs/fuse/acl.c b/fs/fuse/acl.c
new file mode 100644
index 000000000000..ec85765502f1
--- /dev/null
+++ b/fs/fuse/acl.c
@@ -0,0 +1,99 @@
+/*
+ * FUSE: Filesystem in Userspace
+ * Copyright (C) 2016 Canonical Ltd. <seth.forshee@canonical.com>
+ *
+ * This program can be distributed under the terms of the GNU GPL.
+ * See the file COPYING.
+ */
+
+#include "fuse_i.h"
+
+#include <linux/posix_acl.h>
+#include <linux/posix_acl_xattr.h>
+
+struct posix_acl *fuse_get_acl(struct inode *inode, int type)
+{
+ struct fuse_conn *fc = get_fuse_conn(inode);
+ int size;
+ const char *name;
+ void *value = NULL;
+ struct posix_acl *acl;
+
+ if (!fc->posix_acl || fc->no_getxattr)
+ return NULL;
+
+ if (type == ACL_TYPE_ACCESS)
+ name = XATTR_NAME_POSIX_ACL_ACCESS;
+ else if (type == ACL_TYPE_DEFAULT)
+ name = XATTR_NAME_POSIX_ACL_DEFAULT;
+ else
+ return ERR_PTR(-EOPNOTSUPP);
+
+ value = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!value)
+ return ERR_PTR(-ENOMEM);
+ size = fuse_getxattr(inode, name, value, PAGE_SIZE);
+ if (size > 0)
+ acl = posix_acl_from_xattr(&init_user_ns, value, size);
+ else if ((size == 0) || (size == -ENODATA) ||
+ (size == -EOPNOTSUPP && fc->no_getxattr))
+ acl = NULL;
+ else if (size == -ERANGE)
+ acl = ERR_PTR(-E2BIG);
+ else
+ acl = ERR_PTR(size);
+
+ kfree(value);
+ return acl;
+}
+
+int fuse_set_acl(struct inode *inode, struct posix_acl *acl, int type)
+{
+ struct fuse_conn *fc = get_fuse_conn(inode);
+ const char *name;
+ int ret;
+
+ if (!fc->posix_acl || fc->no_setxattr)
+ return -EOPNOTSUPP;
+
+ if (type == ACL_TYPE_ACCESS)
+ name = XATTR_NAME_POSIX_ACL_ACCESS;
+ else if (type == ACL_TYPE_DEFAULT)
+ name = XATTR_NAME_POSIX_ACL_DEFAULT;
+ else
+ return -EINVAL;
+
+ if (acl) {
+ /*
+ * Fuse userspace is responsible for updating access
+ * permissions in the inode, if needed. fuse_setxattr
+ * invalidates the inode attributes, which will force
+ * them to be refreshed the next time they are used,
+ * and it also updates i_ctime.
+ */
+ size_t size = posix_acl_xattr_size(acl->a_count);
+ void *value;
+
+ if (size > PAGE_SIZE)
+ return -E2BIG;
+
+ value = kmalloc(size, GFP_KERNEL);
+ if (!value)
+ return -ENOMEM;
+
+ ret = posix_acl_to_xattr(&init_user_ns, acl, value, size);
+ if (ret < 0) {
+ kfree(value);
+ return ret;
+ }
+
+ ret = fuse_setxattr(inode, name, value, size, 0);
+ kfree(value);
+ } else {
+ ret = fuse_removexattr(inode, name);
+ }
+ forget_all_cached_acls(inode);
+ fuse_invalidate_attr(inode);
+
+ return ret;
+}