d/freebsd-skq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

nullfs: reduce areas protected by vnode interlock in null_lock

Browse Source 
Similarly to the other routine stop taking the interlock for the lower
vnode. The interlock for nullfs vnode is still taken to ensure
stability of ->v_data.

Reviewed by:	kib
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D21480
This commit is contained in:
Mateusz Guzik 2019-09-01 02:52:00 +00:00
parent 32287ea72b
commit e0f4540a2a
1 changed files with 10 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
sys/fs/nullfs/null_vnops.c
View File

@ -638,16 +638,16 @@ static int
null_lock(struct vop_lock1_args *ap)
{
struct vnode *vp = ap->a_vp;
int flags = ap->a_flags;
int flags;
struct null_node *nn;
struct vnode *lvp;
int error;
if ((flags & LK_INTERLOCK) == 0) {
if ((ap->a_flags & LK_INTERLOCK) == 0)
VI_LOCK(vp);
ap->a_flags = flags |= LK_INTERLOCK;
}
else
ap->a_flags &= ~LK_INTERLOCK;
flags = ap->a_flags;
nn = VTONULL(vp);
/*
* If we're still active we must ask the lower layer to
@ -655,8 +655,6 @@ null_lock(struct vop_lock1_args *ap)
* vop lock.
*/
if (nn != NULL && (lvp = NULLVPTOLOWERVP(vp)) != NULL) {
VI_LOCK_FLAGS(lvp, MTX_DUPOK);
VI_UNLOCK(vp);
/*
* We have to hold the vnode here to solve a potential
* reclaim race. If we're forcibly vgone'd while we
@ -669,6 +667,7 @@ null_lock(struct vop_lock1_args *ap)
* here.
*/
vholdnz(lvp);
VI_UNLOCK(vp);
error = VOP_LOCK(lvp, flags);
/*
@ -678,7 +677,7 @@ null_lock(struct vop_lock1_args *ap)
* case by reacquiring correct lock in requested mode.
*/
if (VTONULL(vp) == NULL && error == 0) {
ap->a_flags &= ~(LK_TYPE_MASK | LK_INTERLOCK);
ap->a_flags &= ~LK_TYPE_MASK;
switch (flags & LK_TYPE_MASK) {
case LK_SHARED:
ap->a_flags |= LK_SHARED;
@ -695,8 +694,10 @@ null_lock(struct vop_lock1_args *ap)
error = vop_stdlock(ap);
}
vdrop(lvp);
} else
} else {
VI_UNLOCK(vp);
error = vop_stdlock(ap);
}
return (error);
}