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Remove witness directives from crossmp locking VOPs

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These are of limited use since the crossmp vnode locking ops have not
actually used a lock since commit
a2d3554542.  We in fact require that
these operations are always issued with LK_SHARED.  Additionally,
these directives can produce a false positive in certain VV_CROSSLOCK
cases which require upgrading of the covered vnode lock from shared
to exclusive.

While here, replace the runtime check of LK_SHARED with a KASSERT and
expand the check to include LK_NOWAIT, which all callers pass.

Reviewed by:	kib
Tested by:	pho
Differential Revision:	https://reviews.freebsd.org/D35054
This commit is contained in:
Jason A. Harmening 2022-08-05 00:39:04 -05:00
parent 080ef8a418
commit 706f15c5fa
1 changed files with 3 additions and 10 deletions
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13
sys/kern/vfs_lookup.c
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@ -105,21 +105,15 @@ crossmp_vop_lock1(struct vop_lock1_args *ap)
{
struct vnode *vp;
struct lock *lk __diagused;
const char *file __witness_used;
int flags, line __witness_used;
int flags;
vp = ap->a_vp;
lk = vp->v_vnlock;
flags = ap->a_flags;
file = ap->a_file;
line = ap->a_line;
if ((flags & LK_SHARED) == 0)
panic("invalid lock request for crossmp");
KASSERT((flags & (LK_SHARED | LK_NOWAIT)) == (LK_SHARED | LK_NOWAIT),
("%s: invalid lock request 0x%x for crossmp", __func__, flags));
WITNESS_CHECKORDER(&lk->lock_object, LOP_NEWORDER, file, line,
flags & LK_INTERLOCK ? &VI_MTX(vp)->lock_object : NULL);
WITNESS_LOCK(&lk->lock_object, 0, file, line);
if ((flags & LK_INTERLOCK) != 0)
VI_UNLOCK(vp);
LOCK_LOG_LOCK("SLOCK", &lk->lock_object, 0, 0, ap->a_file, ap->a_line);
@ -135,7 +129,6 @@ crossmp_vop_unlock(struct vop_unlock_args *ap)
vp = ap->a_vp;
lk = vp->v_vnlock;
WITNESS_UNLOCK(&lk->lock_object, 0, LOCK_FILE, LOCK_LINE);
LOCK_LOG_LOCK("SUNLOCK", &lk->lock_object, 0, 0, LOCK_FILE,
LOCK_LINE);
return (0);