xattr handlers: Pass handler to operations instead of flags

The xattr_handler operations are currently all passed a file system
specific flags value which the operations can use to disambiguate between
different handlers; some file systems use that to distinguish the xattr
namespace, for example.  In some oprations, it would be useful to also have
access to the handler prefix.  To allow that, pass a pointer to the handler
to operations instead of the flags value alone.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/posix_acl.c b/fs/posix_acl.c
index 2fdca61..4adde1e 100644
--- a/fs/posix_acl.c
+++ b/fs/posix_acl.c
@@ -762,8 +762,9 @@
 EXPORT_SYMBOL (posix_acl_to_xattr);
 
 static int
-posix_acl_xattr_get(struct dentry *dentry, const char *name,
-		void *value, size_t size, int type)
+posix_acl_xattr_get(const struct xattr_handler *handler,
+		    struct dentry *dentry, const char *name,
+		    void *value, size_t size)
 {
 	struct posix_acl *acl;
 	int error;
@@ -775,7 +776,7 @@
 	if (d_is_symlink(dentry))
 		return -EOPNOTSUPP;
 
-	acl = get_acl(d_backing_inode(dentry), type);
+	acl = get_acl(d_backing_inode(dentry), handler->flags);
 	if (IS_ERR(acl))
 		return PTR_ERR(acl);
 	if (acl == NULL)
@@ -788,8 +789,9 @@
 }
 
 static int
-posix_acl_xattr_set(struct dentry *dentry, const char *name,
-		const void *value, size_t size, int flags, int type)
+posix_acl_xattr_set(const struct xattr_handler *handler,
+		    struct dentry *dentry, const char *name,
+		    const void *value, size_t size, int flags)
 {
 	struct inode *inode = d_backing_inode(dentry);
 	struct posix_acl *acl = NULL;
@@ -802,7 +804,7 @@
 	if (!inode->i_op->set_acl)
 		return -EOPNOTSUPP;
 
-	if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode))
+	if (handler->flags == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode))
 		return value ? -EACCES : 0;
 	if (!inode_owner_or_capable(inode))
 		return -EPERM;
@@ -819,27 +821,23 @@
 		}
 	}
 
-	ret = inode->i_op->set_acl(inode, acl, type);
+	ret = inode->i_op->set_acl(inode, acl, handler->flags);
 out:
 	posix_acl_release(acl);
 	return ret;
 }
 
 static size_t
-posix_acl_xattr_list(struct dentry *dentry, char *list, size_t list_size,
-		const char *name, size_t name_len, int type)
+posix_acl_xattr_list(const struct xattr_handler *handler,
+		     struct dentry *dentry, char *list, size_t list_size,
+		     const char *name, size_t name_len)
 {
-	const char *xname;
+	const char *xname = handler->prefix;
 	size_t size;
 
 	if (!IS_POSIXACL(d_backing_inode(dentry)))
 		return 0;
 
-	if (type == ACL_TYPE_ACCESS)
-		xname = POSIX_ACL_XATTR_ACCESS;
-	else
-		xname = POSIX_ACL_XATTR_DEFAULT;
-
 	size = strlen(xname) + 1;
 	if (list && size <= list_size)
 		memcpy(list, xname, size);