fusefs: update atime on reads when using cached attributes

When using cached attributes, whether or not the data cache is enabled,
fusefs must update a file's atime whenever it reads from it, so long as
it wasn't mounted with -o noatime.  Update it in-kernel, and flush it to
the server on close or during the next setattr operation.

The downside is that close() will now frequently trigger a FUSE_SETATTR
upcall.  But if you care about performance, you should be using
-o noatime anyway.

Reviewed by:	pfg
Differential Revision: https://reviews.freebsd.org/D33145

(cherry picked from commit 91972cfcddf950d7a9c33df5a9171ada1805a144)

fusefs: fix 32-bit build of the tests after 91972cfcddf

(cherry picked from commit d109559ddbf7afe311c1f1795ece137071406db8)

5 files changed, 33 insertions, 6 deletions

diff --git a/sys/fs/fuse/fuse_internal.c b/sys/fs/fuse/fuse_internal.c
index ffa4a40095b2..403116593bd9 100644
--- a/sys/fs/fuse/fuse_internal.c
+++ b/sys/fs/fuse/fuse_internal.c
@@ -926,6 +926,7 @@ fuse_internal_do_getattr(struct vnode *vp, struct vattr *vap,
 	struct fuse_getattr_in *fgai;
 	struct fuse_attr_out *fao;
 	off_t old_filesize = fvdat->cached_attrs.va_size;
+	struct timespec old_atime = fvdat->cached_attrs.va_atime;
 	struct timespec old_ctime = fvdat->cached_attrs.va_ctime;
 	struct timespec old_mtime = fvdat->cached_attrs.va_mtime;
 	enum vtype vtyp;
@@ -950,6 +951,10 @@ fuse_internal_do_getattr(struct vnode *vp, struct vattr *vap,
 	vtyp = IFTOVT(fao->attr.mode);
 	if (fvdat->flag & FN_SIZECHANGE)
 		fao->attr.size = old_filesize;
+	if (fvdat->flag & FN_ATIMECHANGE) {
+		fao->attr.atime = old_atime.tv_sec;
+		fao->attr.atimensec = old_atime.tv_nsec;
+	}
 	if (fvdat->flag & FN_CTIMECHANGE) {
 		fao->attr.ctime = old_ctime.tv_sec;
 		fao->attr.ctimensec = old_ctime.tv_nsec;
@@ -1209,6 +1214,10 @@ int fuse_internal_setattr(struct vnode *vp, struct vattr *vap,
 		fsai->valid |= FATTR_ATIME;
 		if (vap->va_vaflags & VA_UTIMES_NULL)
 			fsai->valid |= FATTR_ATIME_NOW;
+	} else if (fvdat->flag & FN_ATIMECHANGE) {
+		fsai->atime = fvdat->cached_attrs.va_atime.tv_sec;
+		fsai->atimensec = fvdat->cached_attrs.va_atime.tv_nsec;
+		fsai->valid |= FATTR_ATIME;
 	}
 	if (vap->va_mtime.tv_sec != VNOVAL) {
 		fsai->mtime = vap->va_mtime.tv_sec;
@@ -1257,7 +1266,7 @@ int fuse_internal_setattr(struct vnode *vp, struct vattr *vap,
 	}
 	if (err == 0) {
 		struct fuse_attr_out *fao = (struct fuse_attr_out*)fdi.answ;
-		fuse_vnode_undirty_cached_timestamps(vp);
+		fuse_vnode_undirty_cached_timestamps(vp, true);
 		fuse_internal_cache_attrs(vp, &fao->attr, fao->attr_valid,
 			fao->attr_valid_nsec, NULL, false);
 	}
diff --git a/sys/fs/fuse/fuse_io.c b/sys/fs/fuse/fuse_io.c
index a240217fcc08..78398a990d7d 100644
--- a/sys/fs/fuse/fuse_io.c
+++ b/sys/fs/fuse/fuse_io.c
@@ -236,6 +236,7 @@ fuse_io_dispatch(struct vnode *vp, struct uio *uio, int ioflag,
 
 	switch (uio->uio_rw) {
 	case UIO_READ:
+		fuse_vnode_update(vp, FN_ATIMECHANGE);
 		if (directio) {
 			SDT_PROBE2(fusefs, , io, trace, 1,
 				"direct read of vnode");
@@ -616,7 +617,7 @@ retry:
 	fdisp_destroy(&fdi);
 
 	if (wrote_anything)
-		fuse_vnode_undirty_cached_timestamps(vp);
+		fuse_vnode_undirty_cached_timestamps(vp, false);
 
 	return (err);
 }
diff --git a/sys/fs/fuse/fuse_node.c b/sys/fs/fuse/fuse_node.c
index c8982c5a48a1..f74de2faa702 100644
--- a/sys/fs/fuse/fuse_node.c
+++ b/sys/fs/fuse/fuse_node.c
@@ -474,11 +474,13 @@ fuse_vnode_size(struct vnode *vp, off_t *filesize, struct ucred *cred,
 }
 
 void
-fuse_vnode_undirty_cached_timestamps(struct vnode *vp)
+fuse_vnode_undirty_cached_timestamps(struct vnode *vp, bool atime)
 {
 	struct fuse_vnode_data *fvdat = VTOFUD(vp);
 
 	fvdat->flag &= ~(FN_MTIMECHANGE | FN_CTIMECHANGE);
+	if (atime)
+		fvdat->flag &= ~FN_ATIMECHANGE;
 }
 
 /* Update a fuse file's cached timestamps */
@@ -486,7 +488,8 @@ void
 fuse_vnode_update(struct vnode *vp, int flags)
 {
 	struct fuse_vnode_data *fvdat = VTOFUD(vp);
-	struct fuse_data *data = fuse_get_mpdata(vnode_mount(vp));
+	struct mount *mp = vnode_mount(vp);
+	struct fuse_data *data = fuse_get_mpdata(mp);
 	struct timespec ts;
 
 	vfs_timestamp(&ts);
@@ -494,6 +497,11 @@ fuse_vnode_update(struct vnode *vp, int flags)
 	if (data->time_gran > 1)
 		ts.tv_nsec = rounddown(ts.tv_nsec, data->time_gran);
 
+	if (mp->mnt_flag & MNT_NOATIME)
+		flags &= ~FN_ATIMECHANGE;
+
+	if (flags & FN_ATIMECHANGE)
+		fvdat->cached_attrs.va_atime = ts;
 	if (flags & FN_MTIMECHANGE)
 		fvdat->cached_attrs.va_mtime = ts;
 	if (flags & FN_CTIMECHANGE)
diff --git a/sys/fs/fuse/fuse_node.h b/sys/fs/fuse/fuse_node.h
index 8f69ef9a08f3..3a33c57001dc 100644
--- a/sys/fs/fuse/fuse_node.h
+++ b/sys/fs/fuse/fuse_node.h
@@ -91,6 +91,7 @@
  */
 #define	FN_MTIMECHANGE		0x00000800
 #define	FN_CTIMECHANGE		0x00001000
+#define	FN_ATIMECHANGE		0x00002000
 
 struct fuse_vnode_data {
 	/** self **/
@@ -201,7 +202,7 @@ int fuse_vnode_savesize(struct vnode *vp, struct ucred *cred, pid_t pid);
 
 int fuse_vnode_setsize(struct vnode *vp, off_t newsize, bool from_server);
 
-void fuse_vnode_undirty_cached_timestamps(struct vnode *vp);
+void fuse_vnode_undirty_cached_timestamps(struct vnode *vp, bool atime);
 
 void fuse_vnode_update(struct vnode *vp, int flags);
 
diff --git a/sys/fs/fuse/fuse_vnops.c b/sys/fs/fuse/fuse_vnops.c
index 5630eeeb9e65..d0f4cae302c1 100644
--- a/sys/fs/fuse/fuse_vnops.c
+++ b/sys/fs/fuse/fuse_vnops.c
@@ -613,6 +613,7 @@ fuse_vnop_close(struct vop_close_args *ap)
 	int fflag = ap->a_fflag;
 	struct thread *td = ap->a_td;
 	pid_t pid = td->td_proc->p_pid;
+	struct fuse_vnode_data *fvdat = VTOFUD(vp);
 	int err = 0;
 
 	if (fuse_isdeadfs(vp))
@@ -623,8 +624,15 @@ fuse_vnop_close(struct vop_close_args *ap)
 		return 0;
 
 	err = fuse_flush(vp, cred, pid, fflag);
+	if (err == 0 && (fvdat->flag & FN_ATIMECHANGE)) {
+		struct vattr vap;
+
+		VATTR_NULL(&vap);
+		vap.va_atime = fvdat->cached_attrs.va_atime;
+		err = fuse_internal_setattr(vp, &vap, td, NULL);
+	}
 	/* TODO: close the file handle, if we're sure it's no longer used */
-	if ((VTOFUD(vp)->flag & FN_SIZECHANGE) != 0) {
+	if ((fvdat->flag & FN_SIZECHANGE) != 0) {
 		fuse_vnode_savesize(vp, cred, td->td_proc->p_pid);
 	}
 	return err;