git: bc4430dc203e - main - vfs: Add event notification points

From: Mark Johnston <markj_at_FreeBSD.org>
Date: Fri, 04 Jul 2025 14:55:56 UTC
The branch main has been updated by markj:

URL: https://cgit.FreeBSD.org/src/commit/?id=bc4430dc203ed7b6765fb5df041bf545c50f859b

commit bc4430dc203ed7b6765fb5df041bf545c50f859b
Author:     Mark Johnston <markj@FreeBSD.org>
AuthorDate: 2025-07-03 20:10:35 +0000
Commit:     Mark Johnston <markj@FreeBSD.org>
CommitDate: 2025-07-04 14:42:33 +0000

    vfs: Add event notification points
    
    The INOTIFY macro and its variants check if the vnode is being watched,
    and if so, calls into a slow path which adds an event to one or more
    inotify descriptors.  Most of these events correspond to EVFILT_VNODE
    events as well, and are added to VOP *_post hooks.
    
    Reviewed by:    kib
    MFC after:      3 months
    Sponsored by:   Klara, Inc.
    Differential Revision:  https://reviews.freebsd.org/D50315
---
 sys/kern/kern_sendfile.c |  4 ++-
 sys/kern/vfs_subr.c      | 86 +++++++++++++++++++++++++++++++++++++++++-------
 sys/kern/vfs_vnops.c     |  4 +++
 sys/kern/vnode_if.src    |  3 ++
 sys/sys/vnode.h          | 12 +++++--
 5 files changed, 94 insertions(+), 15 deletions(-)

diff --git a/sys/kern/kern_sendfile.c b/sys/kern/kern_sendfile.c
index 17b53208157a..35b258e68701 100644
--- a/sys/kern/kern_sendfile.c
+++ b/sys/kern/kern_sendfile.c
@@ -27,12 +27,12 @@
  * SUCH DAMAGE.
  */
 
-#include <sys/cdefs.h>
 #include "opt_kern_tls.h"
 
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/capsicum.h>
+#include <sys/inotify.h>
 #include <sys/kernel.h>
 #include <sys/lock.h>
 #include <sys/ktls.h>
@@ -1246,6 +1246,8 @@ out:
 	 */
 	if (error == 0) {
 		td->td_retval[0] = 0;
+		if (sbytes > 0 && vp != NULL)
+			INOTIFY(vp, IN_ACCESS);
 	}
 	if (sent != NULL) {
 		(*sent) = sbytes;
diff --git a/sys/kern/vfs_subr.c b/sys/kern/vfs_subr.c
index fdc86e8ef90c..877931721da4 100644
--- a/sys/kern/vfs_subr.c
+++ b/sys/kern/vfs_subr.c
@@ -56,6 +56,7 @@
 #include <sys/extattr.h>
 #include <sys/file.h>
 #include <sys/fcntl.h>
+#include <sys/inotify.h>
 #include <sys/jail.h>
 #include <sys/kdb.h>
 #include <sys/kernel.h>
@@ -6057,6 +6058,28 @@ vop_need_inactive_debugpost(void *ap, int rc)
 }
 #endif
 
+void
+vop_allocate_post(void *ap, int rc)
+{
+	struct vop_allocate_args *a;
+
+	a = ap;
+	if (rc == 0)
+		INOTIFY(a->a_vp, IN_MODIFY);
+}
+
+void
+vop_copy_file_range_post(void *ap, int rc)
+{
+	struct vop_copy_file_range_args *a;
+
+	a = ap;
+	if (rc == 0) {
+		INOTIFY(a->a_invp, IN_ACCESS);
+		INOTIFY(a->a_outvp, IN_MODIFY);
+	}
+}
+
 void
 vop_create_pre(void *ap)
 {
@@ -6077,8 +6100,20 @@ vop_create_post(void *ap, int rc)
 	a = ap;
 	dvp = a->a_dvp;
 	vn_seqc_write_end(dvp);
-	if (!rc)
+	if (!rc) {
 		VFS_KNOTE_LOCKED(dvp, NOTE_WRITE);
+		INOTIFY_NAME(*a->a_vpp, dvp, a->a_cnp, IN_CREATE);
+	}
+}
+
+void
+vop_deallocate_post(void *ap, int rc)
+{
+	struct vop_deallocate_args *a;
+
+	a = ap;
+	if (rc == 0)
+		INOTIFY(a->a_vp, IN_MODIFY);
 }
 
 void
@@ -6123,8 +6158,10 @@ vop_deleteextattr_post(void *ap, int rc)
 	a = ap;
 	vp = a->a_vp;
 	vn_seqc_write_end(vp);
-	if (!rc)
+	if (!rc) {
 		VFS_KNOTE_LOCKED(a->a_vp, NOTE_ATTRIB);
+		INOTIFY(vp, IN_ATTRIB);
+	}
 }
 
 void
@@ -6154,6 +6191,8 @@ vop_link_post(void *ap, int rc)
 	if (!rc) {
 		VFS_KNOTE_LOCKED(vp, NOTE_LINK);
 		VFS_KNOTE_LOCKED(tdvp, NOTE_WRITE);
+		INOTIFY_NAME(vp, tdvp, a->a_cnp, _IN_ATTRIB_LINKCOUNT);
+		INOTIFY_NAME(vp, tdvp, a->a_cnp, IN_CREATE);
 	}
 }
 
@@ -6177,8 +6216,10 @@ vop_mkdir_post(void *ap, int rc)
 	a = ap;
 	dvp = a->a_dvp;
 	vn_seqc_write_end(dvp);
-	if (!rc)
+	if (!rc) {
 		VFS_KNOTE_LOCKED(dvp, NOTE_WRITE | NOTE_LINK);
+		INOTIFY_NAME(*a->a_vpp, dvp, a->a_cnp, IN_CREATE);
+	}
 }
 
 #ifdef DEBUG_VFS_LOCKS
@@ -6213,8 +6254,10 @@ vop_mknod_post(void *ap, int rc)
 	a = ap;
 	dvp = a->a_dvp;
 	vn_seqc_write_end(dvp);
-	if (!rc)
+	if (!rc) {
 		VFS_KNOTE_LOCKED(dvp, NOTE_WRITE);
+		INOTIFY_NAME(*a->a_vpp, dvp, a->a_cnp, IN_CREATE);
+	}
 }
 
 void
@@ -6226,8 +6269,10 @@ vop_reclaim_post(void *ap, int rc)
 	a = ap;
 	vp = a->a_vp;
 	ASSERT_VOP_IN_SEQC(vp);
-	if (!rc)
+	if (!rc) {
 		VFS_KNOTE_LOCKED(vp, NOTE_REVOKE);
+		INOTIFY_REVOKE(vp);
+	}
 }
 
 void
@@ -6258,6 +6303,8 @@ vop_remove_post(void *ap, int rc)
 	if (!rc) {
 		VFS_KNOTE_LOCKED(dvp, NOTE_WRITE);
 		VFS_KNOTE_LOCKED(vp, NOTE_DELETE);
+		INOTIFY_NAME(vp, dvp, a->a_cnp, _IN_ATTRIB_LINKCOUNT);
+		INOTIFY_NAME(vp, dvp, a->a_cnp, IN_DELETE);
 	}
 }
 
@@ -6289,6 +6336,8 @@ vop_rename_post(void *ap, int rc)
 		VFS_KNOTE_UNLOCKED(a->a_fvp, NOTE_RENAME);
 		if (a->a_tvp)
 			VFS_KNOTE_UNLOCKED(a->a_tvp, NOTE_DELETE);
+		INOTIFY_MOVE(a->a_fvp, a->a_fdvp, a->a_fcnp, a->a_tvp,
+		    a->a_tdvp, a->a_tcnp);
 	}
 	if (a->a_tdvp != a->a_fdvp)
 		vdrop(a->a_fdvp);
@@ -6328,6 +6377,7 @@ vop_rmdir_post(void *ap, int rc)
 		vp->v_vflag |= VV_UNLINKED;
 		VFS_KNOTE_LOCKED(dvp, NOTE_WRITE | NOTE_LINK);
 		VFS_KNOTE_LOCKED(vp, NOTE_DELETE);
+		INOTIFY_NAME(vp, dvp, a->a_cnp, IN_DELETE);
 	}
 }
 
@@ -6351,8 +6401,10 @@ vop_setattr_post(void *ap, int rc)
 	a = ap;
 	vp = a->a_vp;
 	vn_seqc_write_end(vp);
-	if (!rc)
+	if (!rc) {
 		VFS_KNOTE_LOCKED(vp, NOTE_ATTRIB);
+		INOTIFY(vp, IN_ATTRIB);
+	}
 }
 
 void
@@ -6397,8 +6449,10 @@ vop_setextattr_post(void *ap, int rc)
 	a = ap;
 	vp = a->a_vp;
 	vn_seqc_write_end(vp);
-	if (!rc)
+	if (!rc) {
 		VFS_KNOTE_LOCKED(vp, NOTE_ATTRIB);
+		INOTIFY(vp, IN_ATTRIB);
+	}
 }
 
 void
@@ -6421,8 +6475,10 @@ vop_symlink_post(void *ap, int rc)
 	a = ap;
 	dvp = a->a_dvp;
 	vn_seqc_write_end(dvp);
-	if (!rc)
+	if (!rc) {
 		VFS_KNOTE_LOCKED(dvp, NOTE_WRITE);
+		INOTIFY_NAME(*a->a_vpp, dvp, a->a_cnp, IN_CREATE);
+	}
 }
 
 void
@@ -6430,8 +6486,10 @@ vop_open_post(void *ap, int rc)
 {
 	struct vop_open_args *a = ap;
 
-	if (!rc)
+	if (!rc) {
 		VFS_KNOTE_LOCKED(a->a_vp, NOTE_OPEN);
+		INOTIFY(a->a_vp, IN_OPEN);
+	}
 }
 
 void
@@ -6443,6 +6501,8 @@ vop_close_post(void *ap, int rc)
 	    !VN_IS_DOOMED(a->a_vp))) {
 		VFS_KNOTE_LOCKED(a->a_vp, (a->a_fflag & FWRITE) != 0 ?
 		    NOTE_CLOSE_WRITE : NOTE_CLOSE);
+		INOTIFY(a->a_vp, (a->a_fflag & FWRITE) != 0 ?
+		    IN_CLOSE_WRITE : IN_CLOSE_NOWRITE);
 	}
 }
 
@@ -6451,8 +6511,10 @@ vop_read_post(void *ap, int rc)
 {
 	struct vop_read_args *a = ap;
 
-	if (!rc)
+	if (!rc) {
 		VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ);
+		INOTIFY(a->a_vp, IN_ACCESS);
+	}
 }
 
 void
@@ -6469,8 +6531,10 @@ vop_readdir_post(void *ap, int rc)
 {
 	struct vop_readdir_args *a = ap;
 
-	if (!rc)
+	if (!rc) {
 		VFS_KNOTE_LOCKED(a->a_vp, NOTE_READ);
+		INOTIFY(a->a_vp, IN_ACCESS);
+	}
 }
 
 static struct knlist fs_knlist;
diff --git a/sys/kern/vfs_vnops.c b/sys/kern/vfs_vnops.c
index 2d743eacd1f0..6451c9e07a60 100644
--- a/sys/kern/vfs_vnops.c
+++ b/sys/kern/vfs_vnops.c
@@ -52,6 +52,7 @@
 #include <sys/fcntl.h>
 #include <sys/file.h>
 #include <sys/filio.h>
+#include <sys/inotify.h>
 #include <sys/ktr.h>
 #include <sys/ktrace.h>
 #include <sys/limits.h>
@@ -485,6 +486,7 @@ vn_open_vnode(struct vnode *vp, int fmode, struct ucred *cred,
 		if (vp->v_type != VFIFO && vp->v_type != VSOCK &&
 		    VOP_ACCESS(vp, VREAD, cred, td) == 0)
 			fp->f_flag |= FKQALLOWED;
+		INOTIFY(vp, IN_OPEN);
 		return (0);
 	}
 
@@ -1747,6 +1749,8 @@ vn_truncate_locked(struct vnode *vp, off_t length, bool sync,
 			vattr.va_vaflags |= VA_SYNC;
 		error = VOP_SETATTR(vp, &vattr, cred);
 		VOP_ADD_WRITECOUNT_CHECKED(vp, -1);
+		if (error == 0)
+			INOTIFY(vp, IN_MODIFY);
 	}
 	return (error);
 }
diff --git a/sys/kern/vnode_if.src b/sys/kern/vnode_if.src
index 9651d655f887..38138a4af921 100644
--- a/sys/kern/vnode_if.src
+++ b/sys/kern/vnode_if.src
@@ -702,6 +702,7 @@ vop_vptocnp {
 
 
 %% allocate	vp	E E E
+%! allocate	post	vop_allocate_post
 
 vop_allocate {
 	IN struct vnode *vp;
@@ -786,6 +787,7 @@ vop_fdatasync {
 
 %% copy_file_range	invp	U U U
 %% copy_file_range	outvp	U U U
+%! copy_file_range	post	vop_copy_file_range_post
 
 vop_copy_file_range {
 	IN struct vnode *invp;
@@ -810,6 +812,7 @@ vop_vput_pair {
 
 
 %% deallocate	vp	L L L
+%! deallocate	post	vop_deallocate_post
 
 vop_deallocate {
 	IN struct vnode *vp;
diff --git a/sys/sys/vnode.h b/sys/sys/vnode.h
index c6a03edacff0..3ed469bdce6d 100644
--- a/sys/sys/vnode.h
+++ b/sys/sys/vnode.h
@@ -918,9 +918,12 @@ int	dead_read(struct vop_read_args *ap);
 int	dead_write(struct vop_write_args *ap);
 
 /* These are called from within the actual VOPS. */
+void	vop_allocate_post(void *a, int rc);
+void	vop_copy_file_range_post(void *ap, int rc);
 void	vop_close_post(void *a, int rc);
 void	vop_create_pre(void *a);
 void	vop_create_post(void *a, int rc);
+void	vop_deallocate_post(void *a, int rc);
 void	vop_whiteout_pre(void *a);
 void	vop_whiteout_post(void *a, int rc);
 void	vop_deleteextattr_pre(void *a);
@@ -1028,9 +1031,12 @@ void	vop_rename_fail(struct vop_rename_args *ap);
 
 #define VOP_WRITE_POST(ap, ret)						\
 	noffset = (ap)->a_uio->uio_offset;				\
-	if (noffset > ooffset && !VN_KNLIST_EMPTY((ap)->a_vp)) {	\
-		VFS_KNOTE_LOCKED((ap)->a_vp, NOTE_WRITE			\
-		    | (noffset > osize ? NOTE_EXTEND : 0));		\
+	if (noffset > ooffset) {					\
+		if (VN_KNLIST_EMPTY((ap)->a_vp)) {			\
+			VFS_KNOTE_LOCKED((ap)->a_vp, NOTE_WRITE |	\
+			    (noffset > osize ? NOTE_EXTEND : 0));	\
+		}							\
+		INOTIFY((ap)->a_vp, IN_MODIFY);				\
 	}
 
 #define VOP_LOCK(vp, flags) VOP_LOCK1(vp, flags, __FILE__, __LINE__)