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diff --git a/sys/kern/vfs_default.c b/sys/kern/vfs_default.c
--- a/sys/kern/vfs_default.c
+++ b/sys/kern/vfs_default.c
@@ -1293,91 +1293,86 @@
vop_stdis_text(struct vop_is_text_args *ap)
{
- return (ap->a_vp->v_writecount < 0);
+ return (atomic_load_int(&ap->a_vp->v_writecount) < 0);
}
int
vop_stdset_text(struct vop_set_text_args *ap)
{
struct vnode *vp;
- int error, n;
+ int n;
+ bool gotref;
vp = ap->a_vp;
- /*
- * Avoid the interlock if execs are already present.
- */
n = atomic_load_int(&vp->v_writecount);
for (;;) {
- if (n > -1) {
- break;
- }
- if (atomic_fcmpset_int(&vp->v_writecount, &n, n - 1)) {
- return (0);
+ if (__predict_false(n > 0)) {
+ return (ETXTBSY);
}
- }
- VI_LOCK(vp);
- if (vp->v_writecount > 0) {
- error = ETXTBSY;
- } else {
/*
- * If requested by fs, keep a use reference to the
- * vnode until the last text reference is released.
+ * Transition point, we may need to grab a reference on the vnode.
+ *
+ * Take the ref early As a safety measure against bogus calls
+ * to vop_stdunset_text.
*/
- if ((vn_irflag_read(vp) & VIRF_TEXT_REF) != 0) {
- if (vp->v_writecount == 0) {
- vrefl(vp);
+ if (n == 0) {
+ gotref = false;
+ if ((vn_irflag_read(vp) & VIRF_TEXT_REF) != 0) {
+ vref(vp);
+ gotref = true;
+ }
+ if (atomic_fcmpset_int(&vp->v_writecount, &n, -1)) {
+ return (0);
}
+ if (gotref) {
+ vunref(vp);
+ }
+ continue;
}
- atomic_subtract_int(&vp->v_writecount, 1);
- error = 0;
+ MPASS(n < 0);
+ if (atomic_fcmpset_int(&vp->v_writecount, &n, n - 1)) {
+ return (0);
+ }
}
- VI_UNLOCK(vp);
- return (error);
+ __assert_unreachable();
}
static int
vop_stdunset_text(struct vop_unset_text_args *ap)
{
struct vnode *vp;
- int error, n;
- bool last;
+ int n;
vp = ap->a_vp;
- /*
- * Avoid the interlock if this is not the last exec.
- */
n = atomic_load_int(&vp->v_writecount);
for (;;) {
- if (n >= -1) {
- break;
- }
- if (atomic_fcmpset_int(&vp->v_writecount, &n, n + 1)) {
- return (0);
+ if (__predict_false(n >= 0)) {
+ return (EINVAL);
}
- }
- last = false;
- VI_LOCK(vp);
- if (vp->v_writecount < 0) {
- if ((vn_irflag_read(vp) & VIRF_TEXT_REF) != 0) {
- if (vp->v_writecount == -1) {
- last = true;
+ /*
+ * Transition point, we may need to release a reference on the vnode.
+ */
+ if (n == -1) {
+ if (atomic_fcmpset_int(&vp->v_writecount, &n, 0)) {
+ if ((vn_irflag_read(vp) & VIRF_TEXT_REF) != 0) {
+ vunref(vp);
+ }
+ return (0);
}
+ continue;
}
- atomic_add_int(&vp->v_writecount, 1);
- error = 0;
- } else {
- error = EINVAL;
+ MPASS(n < -1);
+ if (atomic_fcmpset_int(&vp->v_writecount, &n, n + 1)) {
+ return (0);
+ }
}
- VI_UNLOCK(vp);
- if (last)
- vunref(vp);
- return (error);
+ __assert_unreachable();
}
static int __always_inline
@@ -1385,7 +1380,7 @@
{
struct vnode *vp;
struct mount *mp __diagused;
- int error;
+ int n;
vp = ap->a_vp;
@@ -1400,20 +1395,26 @@
}
#endif
- VI_LOCK_FLAGS(vp, MTX_DUPOK);
- if (__predict_false(vp->v_writecount < 0)) {
- error = ETXTBSY;
- } else {
- VNASSERT(vp->v_writecount + ap->a_inc >= 0, vp,
- ("neg writecount increment %d", ap->a_inc));
- if (handle_msync && vp->v_writecount == 0) {
- vlazy(vp);
+ n = atomic_load_int(&vp->v_writecount);
+ for (;;) {
+ if (__predict_false(n < 0)) {
+ return (ETXTBSY);
+ }
+
+ VNASSERT(n + ap->a_inc >= 0, vp,
+ ("neg writecount increment %d + %d = %d", n, ap->a_inc,
+ n + ap->a_inc));
+ if (n == 0) {
+ if (handle_msync) {
+ vlazy(vp);
+ }
+ }
+
+ if (atomic_fcmpset_int(&vp->v_writecount, &n, n + ap->a_inc)) {
+ return (0);
}
- vp->v_writecount += ap->a_inc;
- error = 0;
}
- VI_UNLOCK(vp);
- return (error);
+ __assert_unreachable();
}
int

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