Btrfs: Implement ACLs setting and getting

ACLs are stored but not used for permission checks (yet)

Signed-off-by: Chris Mason <chris.mason@oracle.com>

fs/btrfs/acl.c

@@ -22,53 +22,68 @@
 #include <linux/posix_acl_xattr.h>
 #include "ctree.h"
 #include "xattr.h"
+static int btrfs_xattr_set_acl(struct inode *inode, int type,
+			       const void *value, size_t size)
+{
+	int ret = 0;
+	struct posix_acl *acl;
 
-/*
- * FIXME: At this point this is all place holder stuff, we just return
- * -EOPNOTSUPP so cp won't complain when it tries to copy over a file with an
- *  acl on it.
- */
+	if (!is_owner_or_cap(inode))
+		return -EPERM;
+	if (value) {
+		acl = posix_acl_from_xattr(value, size);
+		if (acl == NULL) {
+			value = NULL;
+			size = 0;
+		} else if (IS_ERR(acl)) {
+			ret = PTR_ERR(acl);
+		} else {
+			ret = posix_acl_valid(acl);
+			posix_acl_release(acl);
+		}
+		if (ret)
+			return ret;
+	}
+	return btrfs_xattr_set(inode, type, "", value, size, 0);
+}
 
+static int btrfs_xattr_get_acl(struct inode *inode, int type,
+			       void *value, size_t size)
+{
+	return btrfs_xattr_get(inode, type, "", value, size);
+}
 static int btrfs_xattr_acl_access_get(struct inode *inode, const char *name,
 				      void *value, size_t size)
 {
-	/*
-	return btrfs_xattr_get(inode, BTRFS_XATTR_INDEX_POSIX_ACL_ACCESS, name,
-			       value, size);
-	*/
-	return -EOPNOTSUPP;
+	if (*name != '\0')
+	       return -EINVAL;
+	return btrfs_xattr_get_acl(inode, BTRFS_XATTR_INDEX_POSIX_ACL_ACCESS,
+				   value, size);
 }
-
 static int btrfs_xattr_acl_access_set(struct inode *inode, const char *name,
 				      const void *value, size_t size, int flags)
 {
-	/*
-	return btrfs_xattr_set(inode, BTRFS_XATTR_INDEX_POSIX_ACL_ACCESS, name,
-			       value, size, flags);
-	*/
-	return -EOPNOTSUPP;
+	if (*name != '\0')
+	       return -EINVAL;
+	return btrfs_xattr_set_acl(inode, BTRFS_XATTR_INDEX_POSIX_ACL_ACCESS,
+				   value, size);
 }
-
 static int btrfs_xattr_acl_default_get(struct inode *inode, const char *name,
 				       void *value, size_t size)
 {
-	/*
-	return btrfs_xattr_get(inode, BTRFS_XATTR_INDEX_POSIX_ACL_DEFAULT,
-			       name, value, size);
-	*/
-	return -EOPNOTSUPP;
+	if (*name != '\0')
+	       return -EINVAL;
+	return btrfs_xattr_get_acl(inode, BTRFS_XATTR_INDEX_POSIX_ACL_DEFAULT,
+				   value, size);
 }
-
 static int btrfs_xattr_acl_default_set(struct inode *inode, const char *name,
 				       const void *value, size_t size, int flags)
 {
-	/*
-	return btrfs_xattr_set(inode, BTRFS_XATTR_INDEX_POSIX_ACL_DEFAULT,
-			       name, value, size, flags);
-	*/
-	return -EOPNOTSUPP;
+	if (*name != '\0')
+	       return -EINVAL;
+	return btrfs_xattr_set_acl(inode, BTRFS_XATTR_INDEX_POSIX_ACL_DEFAULT,
+				   value, size);
 }
-
 struct xattr_handler btrfs_xattr_acl_default_handler = {
 	.prefix = POSIX_ACL_XATTR_DEFAULT,
 	.list	= btrfs_xattr_generic_list,

fs/btrfs/dir-item.c

@@ -76,6 +76,9 @@ int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans,
 	path = btrfs_alloc_path();
 	if (!path)
 		return -ENOMEM;
+	if (name_len + data_len + sizeof(struct btrfs_dir_item) >
+	    BTRFS_LEAF_DATA_SIZE(root) - sizeof(struct btrfs_item))
+		return -ENOSPC;
 
 	data_size = sizeof(*dir_item) + name_len + data_len;
 	dir_item = insert_with_overflow(trans, root, path, &key, data_size,

fs/btrfs/xattr.c

@@ -141,11 +141,6 @@ ssize_t btrfs_xattr_get(struct inode *inode, int name_index,
 
 	if (!handler)
 		return -EOPNOTSUPP;
-
-	/* just in case... */
-	if (*attr_name == '\0')
-		return -EINVAL;
-
 	name = get_name(attr_name, name_index);
 	if (!name)
 		return -ENOMEM;
@@ -201,14 +196,8 @@ int btrfs_xattr_set(struct inode *inode, int name_index,
 	struct xattr_handler *handler = btrfs_xattr_handler(name_index);
 	char *name;
 	int ret = 0, mod = 0;
-
 	if (!handler)
 		return -EOPNOTSUPP;
-
-	/* just in case... */
-	if (*attr_name == '\0')
-		return -EINVAL;
-
 	name = get_name(attr_name, name_index);
 	if (!name)
 		return -ENOMEM;
@@ -454,15 +443,18 @@ static int btrfs_xattr_##name##_get(struct inode *inode,		\
 				    const char *name, void *value,	\
 				    size_t size)			\
 {									\
+	if (*name == '\0')						\
+		return -EINVAL;						\
 	return btrfs_xattr_get(inode, index, name, value, size);	\
 }									\
 static int btrfs_xattr_##name##_set(struct inode *inode,		\
 				    const char *name, const void *value,\
 				    size_t size, int flags)		\
 {									\
+	if (*name == '\0')						\
+		return -EINVAL;						\
 	return btrfs_xattr_set(inode, index, name, value, size, flags);	\
 }									\
-
 BTRFS_XATTR_SETGET_FUNCS(security, BTRFS_XATTR_INDEX_SECURITY);
 BTRFS_XATTR_SETGET_FUNCS(system, BTRFS_XATTR_INDEX_SYSTEM);
 BTRFS_XATTR_SETGET_FUNCS(user, BTRFS_XATTR_INDEX_USER);