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vfs: stop handling VI_OWEINACT in vget

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vget is almost always called with LK_SHARED, meaning the flag (if present) is
almost guaranteed to get cleared. Stop handling it in the first place and
instead let the thread which wanted to do inactive handle the bumepd usecount.

Reviewed by:	jeff
Tested by:	pho
Differential Revision:	https://reviews.freebsd.org/D23184
This commit is contained in:
Mateusz Guzik 2020-01-24 07:45:59 +00:00
parent 74c4b7cc60
commit d93762b94d
2 changed files with 36 additions and 55 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

83
sys/kern/vfs_subr.c
View File

@ -2860,7 +2860,7 @@ vget(struct vnode *vp, int flags, struct thread *td)
int
vget_finish(struct vnode *vp, int flags, enum vgetstate vs)
{
int error, oweinact;
int error;
VNASSERT((flags & LK_TYPE_MASK) != 0, vp,
("%s: invalid lock operation", __func__));
@ -2887,8 +2887,6 @@ vget_finish(struct vnode *vp, int flags, enum vgetstate vs)
}
if (vs == VGET_USECOUNT) {
VNASSERT((vp->v_iflag & VI_OWEINACT) == 0, vp,
("%s: vnode with usecount and VI_OWEINACT set", __func__));
return (0);
}
@ -2904,9 +2902,6 @@ vget_finish(struct vnode *vp, int flags, enum vgetstate vs)
#else
refcount_release(&vp->v_holdcnt);
#endif
VNODE_REFCOUNT_FENCE_ACQ();
VNASSERT((vp->v_iflag & VI_OWEINACT) == 0, vp,
("%s: vnode with usecount and VI_OWEINACT set", __func__));
return (0);
}
@ -2930,25 +2925,11 @@ vget_finish(struct vnode *vp, int flags, enum vgetstate vs)
#else
refcount_release(&vp->v_holdcnt);
#endif
VNODE_REFCOUNT_FENCE_ACQ();
VNASSERT((vp->v_iflag & VI_OWEINACT) == 0, vp,
("%s: vnode with usecount and VI_OWEINACT set",
__func__));
VI_UNLOCK(vp);
return (0);
}
if ((vp->v_iflag & VI_OWEINACT) == 0) {
oweinact = 0;
} else {
oweinact = 1;
vp->v_iflag &= ~VI_OWEINACT;
VNODE_REFCOUNT_FENCE_REL();
}
v_incr_devcount(vp);
refcount_acquire(&vp->v_usecount);
if (oweinact && VOP_ISLOCKED(vp) == LK_EXCLUSIVE &&
(flags & LK_NOWAIT) == 0)
vinactive(vp);
VI_UNLOCK(vp);
return (0);
}
@ -2967,8 +2948,6 @@ vref(struct vnode *vp)
VNODE_REFCOUNT_FENCE_ACQ();
VNASSERT(vp->v_holdcnt > 0, vp,
("%s: active vnode not held", __func__));
VNASSERT((vp->v_iflag & VI_OWEINACT) == 0, vp,
("%s: vnode with usecount and VI_OWEINACT set", __func__));
return;
}
VI_LOCK(vp);
@ -2986,15 +2965,9 @@ vrefl(struct vnode *vp)
VNODE_REFCOUNT_FENCE_ACQ();
VNASSERT(vp->v_holdcnt > 0, vp,
("%s: active vnode not held", __func__));
VNASSERT((vp->v_iflag & VI_OWEINACT) == 0, vp,
("%s: vnode with usecount and VI_OWEINACT set", __func__));
return;
}
vholdl(vp);
if ((vp->v_iflag & VI_OWEINACT) != 0) {
vp->v_iflag &= ~VI_OWEINACT;
VNODE_REFCOUNT_FENCE_REL();
}
v_incr_devcount(vp);
refcount_acquire(&vp->v_usecount);
}
@ -3052,8 +3025,8 @@ vdefer_inactive(struct vnode *vp)
{
ASSERT_VI_LOCKED(vp, __func__);
VNASSERT(vp->v_iflag & VI_OWEINACT, vp,
("%s: vnode without VI_OWEINACT", __func__));
VNASSERT(vp->v_holdcnt > 0, vp,
("%s: vnode without hold count", __func__));
if (VN_IS_DOOMED(vp)) {
vdropl(vp);
return;
@ -3063,6 +3036,11 @@ vdefer_inactive(struct vnode *vp)
vdropl(vp);
return;
}
if (vp->v_usecount > 0) {
vp->v_iflag &= ~VI_OWEINACT;
vdropl(vp);
return;
}
vlazy(vp);
vp->v_iflag |= VI_DEFINACT;
VI_UNLOCK(vp);
@ -3070,11 +3048,10 @@ vdefer_inactive(struct vnode *vp)
}
static void
vdefer_inactive_cond(struct vnode *vp)
vdefer_inactive_unlocked(struct vnode *vp)
{
VI_LOCK(vp);
VNASSERT(vp->v_holdcnt > 0, vp, ("vnode without hold count"));
if ((vp->v_iflag & VI_OWEINACT) == 0) {
vdropl(vp);
return;
@ -3173,15 +3150,12 @@ vputx(struct vnode *vp, enum vputx_op func)
VNASSERT(vp->v_usecount == 0 || (vp->v_iflag & VI_OWEINACT) == 0, vp,
("vnode with usecount and VI_OWEINACT set"));
if (error == 0) {
if (vp->v_iflag & VI_OWEINACT)
vinactive(vp);
vinactive(vp);
if (func != VPUTX_VUNREF)
VOP_UNLOCK(vp);
vdropl(vp);
} else if (vp->v_iflag & VI_OWEINACT) {
vdefer_inactive(vp);
} else {
vdropl(vp);
vdefer_inactive(vp);
}
return;
out:
@ -3442,11 +3416,9 @@ vdropl(struct vnode *vp)
/*
* Call VOP_INACTIVE on the vnode and manage the DOINGINACT and OWEINACT
* flags. DOINGINACT prevents us from recursing in calls to vinactive.
* OWEINACT tracks whether a vnode missed a call to inactive due to a
* failed lock upgrade.
*/
void
vinactive(struct vnode *vp)
static void
vinactivef(struct vnode *vp)
{
struct vm_object *obj;
@ -3481,6 +3453,25 @@ vinactive(struct vnode *vp)
vp->v_iflag &= ~VI_DOINGINACT;
}
void
vinactive(struct vnode *vp)
{
ASSERT_VOP_ELOCKED(vp, "vinactive");
ASSERT_VI_LOCKED(vp, "vinactive");
CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
if ((vp->v_iflag & VI_OWEINACT) == 0)
return;
if (vp->v_iflag & VI_DOINGINACT)
return;
if (vp->v_usecount > 0) {
vp->v_iflag &= ~VI_OWEINACT;
return;
}
vinactivef(vp);
}
/*
* Remove any vnodes in the vnode table belonging to mount point mp.
*
@ -3779,8 +3770,7 @@ vgonel(struct vnode *vp)
VOP_CLOSE(vp, FNONBLOCK, NOCRED, td);
if (oweinact || active) {
VI_LOCK(vp);
if ((vp->v_iflag & VI_DOINGINACT) == 0)
vinactive(vp);
vinactivef(vp);
VI_UNLOCK(vp);
}
if (vp->v_type == VSOCK)
@ -4530,13 +4520,12 @@ vfs_deferred_inactive(struct vnode *vp, int lkflags)
}
if (vn_lock(vp, lkflags) == 0) {
VI_LOCK(vp);
if ((vp->v_iflag & (VI_OWEINACT | VI_DOINGINACT)) == VI_OWEINACT)
vinactive(vp);
vinactive(vp);
VOP_UNLOCK(vp);
vdropl(vp);
return;
}
vdefer_inactive_cond(vp);
vdefer_inactive_unlocked(vp);
}
static int
@ -4636,7 +4625,7 @@ vfs_periodic_msync_inactive(struct mount *mp, int flags)
vdrop(vp);
} else {
if (seen_defer)
vdefer_inactive_cond(vp);
vdefer_inactive_unlocked(vp);
}
}
}

8
sys/ufs/ffs/ffs_snapshot.c
View File

@ -2583,15 +2583,7 @@ process_deferred_inactive(struct mount *mp)
UFS_INODE_SET_FLAG(ip, IN_MODIFIED);
}
VI_LOCK(vp);
if ((vp->v_iflag & VI_OWEINACT) == 0 || vp->v_usecount > 0) {
VI_UNLOCK(vp);
VOP_UNLOCK(vp);
vdrop(vp);
continue;
}
vinactive(vp);
VNASSERT((vp->v_iflag & VI_OWEINACT) == 0, vp,
("process_deferred_inactive: got VI_OWEINACT"));
VI_UNLOCK(vp);
VOP_UNLOCK(vp);
vdrop(vp);