Fix breakage caused by r292373 in ZFS/FUSE/NFS/SMBFS.

With the new VOP_GETPAGES() KPI the "count" argument counts pages already,
and doesn't need to be translated from bytes to pages.

While here make it consistent that *rbehind and *rahead are updated only
if we doesn't return error.

Pointy hat to:	glebius

sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c

@@ -5775,27 +5775,21 @@ zfs_getpages(struct vnode *vp, vm_page_t *m, int count, int *rbehind,
 	off_t startoff, endoff;
 	int i, error;
 	vm_pindex_t reqstart, reqend;
-	int pcount, lsize, reqsize, size;
+	int lsize, reqsize, size;
 
-	if (rbehind)
+	object = m[0]->object;
-		*rbehind = 0;
+	error = 0;
-	if (rahead)
-		*rahead = 0;
 
 	ZFS_ENTER(zfsvfs);
 	ZFS_VERIFY_ZP(zp);
 
-	pcount = OFF_TO_IDX(round_page(count));
-
 	zfs_vmobject_wlock(object);
-	if (m[pcount - 1]->valid != 0 && --pcount == 0) {
+	if (m[count - 1]->valid != 0 && --count == 0) {
 		zfs_vmobject_wunlock(object);
-		ZFS_EXIT(zfsvfs);
+		goto out;
-		return (zfs_vm_pagerret_ok);
 	}
 
-	object = m[0]->object;
+	mlast = m[count - 1];
-	mlast = m[pcount - 1];
 
 	if (IDX_TO_OFF(mlast->pindex) >=
 	    object->un_pager.vnp.vnp_size) {
@@ -5813,10 +5807,9 @@ zfs_getpages(struct vnode *vp, vm_page_t *m, int count, int *rbehind,
 		    IDX_TO_OFF(mlast->pindex);
 	zfs_vmobject_wunlock(object);
 
-	error = 0;
+	for (i = 0; i < count; i++) {
-	for (i = 0; i < pcount; i++) {
 		size = PAGE_SIZE;
-		if (i == pcount - 1)
+		if (i == count - 1)
 			size = lsize;
 		va = zfs_map_page(m[i], &sf);
 		error = dmu_read(os, zp->z_id, IDX_TO_OFF(m[i]->pindex),
@@ -5829,14 +5822,21 @@ zfs_getpages(struct vnode *vp, vm_page_t *m, int count, int *rbehind,
 	}
 
 	zfs_vmobject_wlock(object);
-	for (i = 0; i < pcount; i++)
+	for (i = 0; i < count; i++)
 		m[i]->valid = VM_PAGE_BITS_ALL;
 	zfs_vmobject_wunlock(object);
 
 out:
 	ZFS_ACCESSTIME_STAMP(zfsvfs, zp);
 	ZFS_EXIT(zfsvfs);
-	return (error ? zfs_vm_pagerret_error : zfs_vm_pagerret_ok);
+	if (error == 0) {
+		if (rbehind)
+			*rbehind = 0;
+		if (rahead)
+			*rahead = 0;
+		return (zfs_vm_pagerret_ok);
+	} else
+		return (zfs_vm_pagerret_error);
 }
 
 static int

sys/fs/fuse/fuse_vnops.c

@@ -1752,17 +1752,12 @@ fuse_vnop_getpages(struct vop_getpages_args *ap)
 	td = curthread;			/* XXX */
 	cred = curthread->td_ucred;	/* XXX */
 	pages = ap->a_m;
-	count = ap->a_count;
+	npages = ap->a_count;
-	if (ap->a_rbehind)
-		*ap->a_rbehind = 0;
-	if (ap->a_rahead)
-		*ap->a_rahead = 0;
 
 	if (!fsess_opt_mmap(vnode_mount(vp))) {
 		FS_DEBUG("called on non-cacheable vnode??\n");
 		return (VM_PAGER_ERROR);
 	}
-	npages = btoc(count);
 
 	/*
 	 * If the last page is partially valid, just return it and allow
@@ -1773,13 +1768,8 @@ fuse_vnop_getpages(struct vop_getpages_args *ap)
 	 * but still somewhat disconnected from the kernel?
 	 */
 	VM_OBJECT_WLOCK(vp->v_object);
-	if (pages[npages - 1]->valid != 0) {
+	if (pages[npages - 1]->valid != 0 && --npages == 0)
-		if (--npages == 0) {
+		goto out;
-			VM_OBJECT_WUNLOCK(vp->v_object);
-			return (VM_PAGER_OK);
-		}
-		count = npages << PAGE_SHIFT;
-        }
 	VM_OBJECT_WUNLOCK(vp->v_object);
 
 	/*
@@ -1793,6 +1783,7 @@ fuse_vnop_getpages(struct vop_getpages_args *ap)
 	PCPU_INC(cnt.v_vnodein);
 	PCPU_ADD(cnt.v_vnodepgsin, npages);
 
+	count = npages << PAGE_SHIFT;
 	iov.iov_base = (caddr_t)kva;
 	iov.iov_len = count;
 	uio.uio_iov = &iov;
@@ -1852,8 +1843,13 @@ fuse_vnop_getpages(struct vop_getpages_args *ap)
 		}
 	}
 	fuse_vm_page_unlock_queues();
+out:
 	VM_OBJECT_WUNLOCK(vp->v_object);
-	return 0;
+	if (ap->a_rbehind)
+		*ap->a_rbehind = 0;
+	if (ap->a_rahead)
+		*ap->a_rahead = 0;
+	return (VM_PAGER_OK);
 }
 
 /*

sys/fs/nfsclient/nfs_clbio.c

@@ -100,11 +100,7 @@ ncl_getpages(struct vop_getpages_args *ap)
 	cred = curthread->td_ucred;		/* XXX */
 	nmp = VFSTONFS(vp->v_mount);
 	pages = ap->a_m;
-	count = ap->a_count;
+	npages = ap->a_count;
-	if (ap->a_rbehind)
-		*ap->a_rbehind = 0;
-	if (ap->a_rahead)
-		*ap->a_rahead = 0;
 
 	if ((object = vp->v_object) == NULL) {
 		ncl_printf("nfs_getpages: called with non-merged cache vnode??\n");
@@ -130,8 +126,6 @@ ncl_getpages(struct vop_getpages_args *ap)
 	} else
 		mtx_unlock(&nmp->nm_mtx);
 
-	npages = btoc(count);
-
 	/*
 	 * If the requested page is partially valid, just return it and
 	 * allow the pager to zero-out the blanks.  Partially valid pages
@@ -140,13 +134,8 @@ ncl_getpages(struct vop_getpages_args *ap)
 	 * XXXGL: is that true for NFS, where short read can occur???
 	 */
 	VM_OBJECT_WLOCK(object);
-	if (pages[npages - 1]->valid != 0) {
+	if (pages[npages - 1]->valid != 0 && --npages == 0)
-		if (--npages == 0) {
+		goto out;
-			VM_OBJECT_WUNLOCK(object);
-			return (VM_PAGER_OK);
-		}
-		count = npages << PAGE_SHIFT;
-	}
 	VM_OBJECT_WUNLOCK(object);
 
 	/*
@@ -160,6 +149,7 @@ ncl_getpages(struct vop_getpages_args *ap)
 	PCPU_INC(cnt.v_vnodein);
 	PCPU_ADD(cnt.v_vnodepgsin, npages);
 
+	count = npages << PAGE_SHIFT;
 	iov.iov_base = (caddr_t) kva;
 	iov.iov_len = count;
 	uio.uio_iov = &iov;
@@ -221,8 +211,13 @@ ncl_getpages(struct vop_getpages_args *ap)
 			;
 		}
 	}
+out:
 	VM_OBJECT_WUNLOCK(object);
-	return (0);
+	if (ap->a_rbehind)
+		*ap->a_rbehind = 0;
+	if (ap->a_rahead)
+		*ap->a_rahead = 0;
+	return (VM_PAGER_OK);
 }
 
 /*

sys/fs/smbfs/smbfs_io.c

@@ -449,12 +449,7 @@ smbfs_getpages(ap)
 	np = VTOSMB(vp);
 	smp = VFSTOSMBFS(vp->v_mount);
 	pages = ap->a_m;
-	count = ap->a_count;
+	npages = ap->a_count;
-	npages = btoc(count);
-	if (ap->a_rbehind)
-		*ap->a_rbehind = 0;
-	if (ap->a_rahead)
-		*ap->a_rahead = 0;
 
 	/*
 	 * If the requested page is partially valid, just return it and
@@ -464,13 +459,8 @@ smbfs_getpages(ap)
 	 * XXXGL: is that true for SMB filesystem?
 	 */
 	VM_OBJECT_WLOCK(object);
-	if (pages[npages - 1]->valid != 0) {
+	if (pages[npages - 1]->valid != 0 && --npages == 0)
-		if (--npages == 0) {
+		goto out;
-			VM_OBJECT_WUNLOCK(object);
-			return (VM_PAGER_OK);
-		}
-		count = npages << PAGE_SHIFT;
-	}
 	VM_OBJECT_WUNLOCK(object);
 
 	scred = smbfs_malloc_scred();
@@ -483,6 +473,7 @@ smbfs_getpages(ap)
 	PCPU_INC(cnt.v_vnodein);
 	PCPU_ADD(cnt.v_vnodepgsin, npages);
 
+	count = npages << PAGE_SHIFT;
 	iov.iov_base = (caddr_t) kva;
 	iov.iov_len = count;
 	uio.uio_iov = &iov;
@@ -536,8 +527,13 @@ smbfs_getpages(ap)
 			;
 		}
 	}
+out:
 	VM_OBJECT_WUNLOCK(object);
-	return 0;
+	if (ap->a_rbehind)
+		*ap->a_rbehind = 0;
+	if (ap->a_rahead)
+		*ap->a_rahead = 0;
+	return (VM_PAGER_OK);
 #endif /* SMBFS_RWGENERIC */
 }