vn_delayed_setsize(): post-commit review' changes

Handle doomed vnodes after LK_RETRY.
Rename the flag from VI_DELAYEDSSZ to VI_DELAYED_SETSIZE.
Change signature of vn_lock_delayed_setsize() to take flatten values
list instead of vop args structure.
__predict_true() for VI_DELAYED_SETSIZE not set.
Minor editings like removing tautological assert, and sorting items.

Noted by:	markj
Fixes:	45117ffcd533ddf995f654db60b10899ae8370ec
Reviewed by:	markj, rmacklem
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D55681

4 files changed, 35 insertions, 37 deletions

diff --git a/sys/fs/deadfs/dead_vnops.c b/sys/fs/deadfs/dead_vnops.c
index b6d6fa55d221..c793ef2ebf4d 100644
--- a/sys/fs/deadfs/dead_vnops.c
+++ b/sys/fs/deadfs/dead_vnops.c
@@ -55,6 +55,9 @@ struct vop_vector dead_vnodeops = {
 	.vop_bmap =		VOP_EBADF,
 	.vop_close =		dead_close,
 	.vop_create =		VOP_PANIC,
+	.vop_delayed_setsize =	VOP_NULL,
+	.vop_fplookup_symlink =	VOP_EOPNOTSUPP,
+	.vop_fplookup_vexec =	VOP_EOPNOTSUPP,
 	.vop_getattr =		VOP_EBADF,
 	.vop_getwritemount =	dead_getwritemount,
 	.vop_inactive =		VOP_NULL,
@@ -78,9 +81,6 @@ struct vop_vector dead_vnodeops = {
 	.vop_vptocnp =		VOP_EBADF,
 	.vop_unset_text =	dead_unset_text,
 	.vop_write =		dead_write,
-	.vop_fplookup_vexec =	VOP_EOPNOTSUPP,
-	.vop_fplookup_symlink =	VOP_EOPNOTSUPP,
-	.vop_delayed_setsize =	VOP_NULL,
 };
 VFS_VOP_VECTOR_REGISTER(dead_vnodeops);
 
diff --git a/sys/fs/nfsclient/nfs_clport.c b/sys/fs/nfsclient/nfs_clport.c
index 1156e1738703..cf163adc02de 100644
--- a/sys/fs/nfsclient/nfs_clport.c
+++ b/sys/fs/nfsclient/nfs_clport.c
@@ -646,7 +646,7 @@ ncl_pager_setsize(struct vnode *vp, u_quad_t *nsizep)
 		    (curthread->td_pflags2 & TDP2_SBPAGES) == 0)
 			setnsize = true;
 		else
-			vn_delay_setsize(vp);
+			vn_delayed_setsize(vp);
 	}
 	if (nsizep == NULL) {
 		NFSUNLOCKNODE(np);
diff --git a/sys/kern/vfs_vnops.c b/sys/kern/vfs_vnops.c
index 24efdf4ac0d5..ea8f8437b743 100644
--- a/sys/kern/vfs_vnops.c
+++ b/sys/kern/vfs_vnops.c
@@ -1960,25 +1960,25 @@ _vn_lock_fallback(struct vnode *vp, int flags, const char *file, int line,
 }
 
 static int
-vn_lock_delayed_setsize(struct vop_lock1_args *ap)
+vn_lock_delayed_setsize(struct vnode *vp, int flags, const char *file, int line)
 {
-	struct vnode *vp;
+	struct vop_lock1_args ap;
 	int error, lktype;
 	bool onfault;
 
-	vp = ap->a_vp;
-	lktype = ap->a_flags & LK_TYPE_MASK;
+	ASSERT_VOP_LOCKED(vp, "vn_lock_delayed_setsize");
+	lktype = flags & LK_TYPE_MASK;
 	if (vp->v_op == &dead_vnodeops)
 		return (0);
 	VI_LOCK(vp);
-	if ((vp->v_iflag & VI_DELAYEDSSZ) == 0 || (lktype != LK_SHARED &&
+	if ((vp->v_iflag & VI_DELAYED_SETSIZE) == 0 || (lktype != LK_SHARED &&
 	    lktype != LK_EXCLUSIVE && lktype != LK_UPGRADE &&
 	    lktype != LK_TRYUPGRADE)) {
 		VI_UNLOCK(vp);
 		return (0);
 	}
-	onfault = (ap->a_flags & LK_EATTR_MASK) == LK_NOWAIT &&
-	    (ap->a_flags & LK_INIT_MASK) == LK_CANRECURSE &&
+	onfault = (flags & LK_EATTR_MASK) == LK_NOWAIT &&
+	    (flags & LK_INIT_MASK) == LK_CANRECURSE &&
 	    (lktype == LK_SHARED || lktype == LK_EXCLUSIVE);
 	if (onfault && vp->v_vnlock->lk_recurse == 0) {
 		/*
@@ -1990,35 +1990,38 @@ vn_lock_delayed_setsize(struct vop_lock1_args *ap)
 		VOP_UNLOCK(vp);
 		return (EBUSY);
 	}
-	if ((ap->a_flags & LK_NOWAIT) != 0 ||
+	if ((flags & LK_NOWAIT) != 0 ||
 	    (lktype == LK_SHARED && vp->v_vnlock->lk_recurse > 0)) {
 		VI_UNLOCK(vp);
 		return (0);
 	}
 	if (lktype == LK_SHARED) {
 		VOP_UNLOCK(vp);
-		ap->a_flags &= ~LK_TYPE_MASK;
-		ap->a_flags |= LK_EXCLUSIVE | LK_INTERLOCK;
-		error = VOP_LOCK1_APV(&default_vnodeops, ap);
+		ap.a_gen.a_desc = &vop_lock1_desc;
+		ap.a_vp = vp;
+		ap.a_flags = (flags & ~LK_TYPE_MASK) | LK_EXCLUSIVE |
+		    LK_INTERLOCK;
+		ap.a_file = file;
+		ap.a_line = line;
+		error = VOP_LOCK1_APV(&default_vnodeops, &ap);
 		if (error != 0 || vp->v_op == &dead_vnodeops)
 			return (error);
 		if (vp->v_data == NULL)
 			goto downgrade;
-		MPASS(vp->v_data != NULL);
 		VI_LOCK(vp);
-		if ((vp->v_iflag & VI_DELAYEDSSZ) == 0) {
+		if ((vp->v_iflag & VI_DELAYED_SETSIZE) == 0) {
 			VI_UNLOCK(vp);
 			goto downgrade;
 		}
 	}
-	vp->v_iflag &= ~VI_DELAYEDSSZ;
+	vn_clear_delayed_setsize_locked(vp);
 	VI_UNLOCK(vp);
 	VOP_DELAYED_SETSIZE(vp);
 downgrade:
 	if (lktype == LK_SHARED) {
-		ap->a_flags &= ~(LK_TYPE_MASK | LK_INTERLOCK);
-		ap->a_flags |= LK_DOWNGRADE;
-		(void)VOP_LOCK1_APV(&default_vnodeops, ap);
+		ap.a_flags &= ~(LK_TYPE_MASK | LK_INTERLOCK);
+		ap.a_flags |= LK_DOWNGRADE;
+		(void)VOP_LOCK1_APV(&default_vnodeops, &ap);
 	}
 	return (0);
 }
@@ -2026,7 +2029,6 @@ downgrade:
 int
 _vn_lock(struct vnode *vp, int flags, const char *file, int line)
 {
-	struct vop_lock1_args ap;
 	int error;
 
 	VNASSERT((flags & LK_TYPE_MASK) != 0, vp,
@@ -2034,15 +2036,11 @@ _vn_lock(struct vnode *vp, int flags, const char *file, int line)
 	VNPASS(vp->v_holdcnt > 0, vp);
 	error = VOP_LOCK1(vp, flags, file, line);
 	if (__predict_false(error != 0 || VN_IS_DOOMED(vp)))
-		return (_vn_lock_fallback(vp, flags, file, line, error));
-	if (__predict_false((vp->v_iflag & VI_DELAYEDSSZ) == 0))
-		return (0);
-	ap.a_gen.a_desc = &vop_lock1_desc;
-	ap.a_vp = vp;
-	ap.a_flags = flags;
-	ap.a_file = file;
-	ap.a_line = line;
-	return (vn_lock_delayed_setsize(&ap));
+		error = _vn_lock_fallback(vp, flags, file, line, error);
+	if (error != 0 || __predict_true((atomic_load_short(&vp->v_iflag) &
+	    VI_DELAYED_SETSIZE) == 0))
+		return (error);
+	return (vn_lock_delayed_setsize(vp, flags, file, line));
 }
 
 /*
diff --git a/sys/sys/vnode.h b/sys/sys/vnode.h
index 36e10fd8d8b7..3fd2c770cda1 100644
--- a/sys/sys/vnode.h
+++ b/sys/sys/vnode.h
@@ -268,7 +268,7 @@ _Static_assert(sizeof(struct vnode) <= 448, "vnode size crosses 448 bytes");
 #define	VI_DEFINACT	0x0010	/* deferred inactive */
 #define	VI_FOPENING	0x0020	/* In open, with opening process having the
 				   first right to advlock file */
-#define	VI_DELAYEDSSZ	0x0040	/* Delayed setsize */
+#define	VI_DELAYED_SETSIZE 0x0040	/* Delayed setsize */
 
 #define	VV_ROOT		0x0001	/* root of its filesystem */
 #define	VV_ISTTY	0x0002	/* vnode represents a tty */
@@ -1253,17 +1253,17 @@ vn_get_state(struct vnode *vp)
 })
 
 static inline void
-vn_delay_setsize_locked(struct vnode *vp)
+vn_delayed_setsize_locked(struct vnode *vp)
 {
 	ASSERT_VI_LOCKED(vp, "delayed_setsize");
-	vp->v_iflag |= VI_DELAYEDSSZ;
+	vp->v_iflag |= VI_DELAYED_SETSIZE;
 }
 
 static inline void
-vn_delay_setsize(struct vnode *vp)
+vn_delayed_setsize(struct vnode *vp)
 {
 	VI_LOCK(vp);
-	vn_delay_setsize_locked(vp);
+	vn_delayed_setsize_locked(vp);
 	VI_UNLOCK(vp);
 }
 
@@ -1271,7 +1271,7 @@ static inline void
 vn_clear_delayed_setsize_locked(struct vnode *vp)
 {
 	ASSERT_VI_LOCKED(vp, "delayed_setsize");
-	vp->v_iflag &= ~VI_DELAYEDSSZ;
+	vp->v_iflag &= ~VI_DELAYED_SETSIZE;
 }
 
 static inline void