/* Try to discard pages, in order to recycle a vcache entry.
*
* We also make some sanity checks: ref count, open count, held locks.
*
* We also do some non-VM-related chores, such as releasing the cred pointer
* (for AIX and Solaris) and releasing the gnode (for AIX).
*
* Locking: afs_xvcache lock is held. If it is dropped and re-acquired,
* *slept should be set to warn the caller.
*
* Formerly, afs_xvcache was dropped and re-acquired for Solaris, but now it
* is not dropped and re-acquired for any platform. It may be that *slept is
* therefore obsolescent.
*
*/
int
osi_VM_FlushVCache(struct vcache *avc, int *slept)
{
struct vnode *vp;
int code;
vp = AFSTOV(avc);
if (!VI_TRYLOCK(vp))
return EBUSY;
code = osi_fbsd_checkinuse(avc);
if (code) {
VI_UNLOCK(vp);
return code;
}
/* must hold the vnode before calling cache_purge()
* This code largely copied from vfs_subr.c:vlrureclaim() */
vholdl(vp);
VI_UNLOCK(vp);
AFS_GUNLOCK();
cache_purge(vp);
AFS_GLOCK();
vdrop(vp);
return 0;
}
int
osi_TryEvictVCache(struct vcache *avc, int *slept, int defersleep)
{
struct vnode *vp;
int code;
vp = AFSTOV(avc);
if (!VI_TRYLOCK(vp))
return 0;
code = osi_fbsd_checkinuse(avc);
if (code != 0) {
VI_UNLOCK(vp);
return 0;
}
if ((vp->v_iflag & VI_DOOMED) != 0) {
VI_UNLOCK(vp);
return 1;
}
/* must hold the vnode before calling vgone()
* This code largely copied from vfs_subr.c:vlrureclaim() */
vholdl(vp);
AFS_GUNLOCK();
*slept = 1;
/* use the interlock while locking, so no one else can DOOM this */
ma_vn_lock(vp, LK_INTERLOCK|LK_EXCLUSIVE|LK_RETRY, curthread);
vgone(vp);
MA_VOP_UNLOCK(vp, 0, curthread);
vdrop(vp);
AFS_GLOCK();
return 1;
}
/* Try to discard pages, in order to recycle a vcache entry.
*
* We also make some sanity checks: ref count, open count, held locks.
*
* We also do some non-VM-related chores, such as releasing the cred pointer
* (for AIX and Solaris) and releasing the gnode (for AIX).
*
* Locking: afs_xvcache lock is held. If it is dropped and re-acquired,
* *slept should be set to warn the caller.
*
* Formerly, afs_xvcache was dropped and re-acquired for Solaris, but now it
* is not dropped and re-acquired for any platform. It may be that *slept is
* therefore obsolescent.
*
*/
int
osi_VM_FlushVCache(struct vcache *avc, int *slept)
{
struct vm_object *obj;
struct vnode *vp = AFSTOV(avc);
if (!VI_TRYLOCK(vp)) /* need interlock to check usecount */
return EBUSY;
if (vp->v_usecount > 0) {
VI_UNLOCK(vp);
return EBUSY;
}
/* XXX
* The value of avc->opens here came to be, at some point,
* typically -1. This was caused by incorrectly performing afs_close
* processing on vnodes being recycled */
if (avc->opens) {
VI_UNLOCK(vp);
return EBUSY;
}
/* if a lock is held, give up */
if (CheckLock(&avc->lock)) {
VI_UNLOCK(vp);
return EBUSY;
}
if ((vp->v_iflag & VI_DOOMED) != 0) {
VI_UNLOCK(vp);
return (0);
}
/* must hold the vnode before calling vgone()
* This code largely copied from vfs_subr.c:vlrureclaim() */
vholdl(vp);
AFS_GUNLOCK();
*slept = 1;
/* use the interlock while locking, so no one else can DOOM this */
ilock_vnode(vp);
vgone(vp);
unlock_vnode(vp);
vdrop(vp);
AFS_GLOCK();
return 0;
}
