Add post-VOP hooks for VOP_DELETEEXTATTR() and VOP_SETEXTATTR() and use

these to trigger a NOTE_ATTRIB EVFILT_VNODE kevent when the extended
attributes of a vnode are changed.

Note that OS X already implements this behavior.

Reviewed by:	rwatson
MFC after:	2 weeks

3 files changed, 22 insertions, 0 deletions

diff --git a/sys/kern/vfs_subr.c b/sys/kern/vfs_subr.c
index 2872f77..544b1cc 100644
--- a/sys/kern/vfs_subr.c
+++ b/sys/kern/vfs_subr.c
@@ -4033,6 +4033,15 @@ vop_create_post(void *ap, int rc)
 }
 
 void
+vop_deleteextattr_post(void *ap, int rc)
+{
+	struct vop_setattr_args *a = ap;
+
+	if (!rc)
+		VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB);
+}
+
+void
 vop_link_post(void *ap, int rc)
 {
 	struct vop_link_args *a = ap;
@@ -4114,6 +4123,15 @@ vop_setattr_post(void *ap, int rc)
 }
 
 void
+vop_setextattr_post(void *ap, int rc)
+{
+	struct vop_setattr_args *a = ap;
+
+	if (!rc)
+		VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB);
+}
+
+void
 vop_symlink_post(void *ap, int rc)
 {
 	struct vop_symlink_args *a = ap;
diff --git a/sys/kern/vnode_if.src b/sys/kern/vnode_if.src
index 6f24d17..334ce16 100644
--- a/sys/kern/vnode_if.src
+++ b/sys/kern/vnode_if.src
@@ -569,6 +569,7 @@ vop_openextattr {
 
 
 %% deleteextattr	vp	E E E
+%! deleteextattr	post	vop_deleteextattr_post
 
 vop_deleteextattr {
 	IN struct vnode *vp;
@@ -580,6 +581,7 @@ vop_deleteextattr {
 
 
 %% setextattr	vp	E E E
+%! setextattr	post	vop_setextattr_post
 
 vop_setextattr {
 	IN struct vnode *vp;
diff --git a/sys/sys/vnode.h b/sys/sys/vnode.h
index 7382336..7f364ad 100644
--- a/sys/sys/vnode.h
+++ b/sys/sys/vnode.h
@@ -705,6 +705,7 @@ int	vop_panic(struct vop_generic_args *ap);
 
 /* These are called from within the actual VOPS. */
 void	vop_create_post(void *a, int rc);
+void	vop_deleteextattr_post(void *a, int rc);
 void	vop_link_post(void *a, int rc);
 void	vop_lock_pre(void *a);
 void	vop_lock_post(void *a, int rc);
@@ -717,6 +718,7 @@ void	vop_rename_post(void *a, int rc);
 void	vop_rename_pre(void *a);
 void	vop_rmdir_post(void *a, int rc);
 void	vop_setattr_post(void *a, int rc);
+void	vop_setextattr_post(void *a, int rc);
 void	vop_strategy_pre(void *a);
 void	vop_symlink_post(void *a, int rc);
 void	vop_unlock_post(void *a, int rc);