centos man page for inode_permission

INODE_PERMISSION(9)						   The Linux VFS					       INODE_PERMISSION(9)

NAME
       inode_permission - Check for access rights to a given inode

SYNOPSIS
       int inode_permission(struct inode * inode, int mask);

ARGUMENTS
       inode
	   Inode to check permission on

       mask
	   Right to check for (MAY_READ, MAY_WRITE, MAY_EXEC)

DESCRIPTION
       Check for read/write/execute permissions on an inode. We use fs[ug]id for this, letting us set arbitrary permissions for filesystem access
       without changing the "normal" UIDs which are used for other things.

       When checking for MAY_APPEND, MAY_WRITE must also be set in mask.

COPYRIGHT
Kernel Hackers Manual 3.10					     June 2014						       INODE_PERMISSION(9)