freebsd man page for vop_setattr

VOP_ATTRIB(9)						   BSD Kernel Developer's Manual					     VOP_ATTRIB(9)

NAME
     VOP_GETATTR, VOP_SETATTR -- get and set attributes on a file or directory

SYNOPSIS
     #include <sys/param.h>
     #include <sys/vnode.h>

     int
     VOP_GETATTR(struct vnode *vp, struct vattr *vap, struct ucred *cred);

     int
     VOP_SETATTR(struct vnode *vp, struct vattr *vap, struct ucred *cred);

DESCRIPTION
     These entry points manipulate various attributes of a file or directory, including file permissions, owner, group, size, access time and mod-
     ification time.

     The arguments are:

     vp    The vnode of the file.

     vap   The attributes of the file.

     cred  The user credentials of the calling process.

     Attributes which are not being modified by VOP_SETATTR() should be set to the value VNOVAL; VATTR_NULL() may be used to clear all the values,
     and should generally be used to reset the contents of *vap prior to setting specific values.

LOCKS
     VOP_GETATTR() expects the vnode to be locked on entry and will leave the vnode locked on return.  The lock type can be either shared or
     exclusive.

     VOP_SETATTR() expects the vnode to be locked on entry and will leave the vnode locked on return.  The lock type must be exclusive.

RETURN VALUES
     VOP_GETATTR() returns 0 if it was able to retrieve the attribute data via *vap, otherwise an appropriate error is returned.  VOP_SETATTR()
     returns zero if the attributes were changed successfully, otherwise an appropriate error is returned.

ERRORS
     [EPERM]		The file is immutable.

     [EACCES]		The caller does not have permission to modify the file or directory attributes.

     [EROFS]		The file system is read-only.

SEE ALSO
     VFS(9), vnode(9), VOP_ACCESS(9)

AUTHORS
     This manual page was written by Doug Rabson.

BSD
								  August 29, 2008							       BSD