ccms_state_t
hammer2_inode_lock_upgrade(hammer2_inode_t *ip)
{
return(ccms_thread_lock_upgrade(&ip->topo_cst));
}
/*
* Get the vnode associated with the given inode, allocating the vnode if
* necessary. The vnode will be returned exclusively locked.
*
* The caller must lock the inode (shared or exclusive).
*
* Great care must be taken to avoid deadlocks and vnode acquisition/reclaim
* races.
*/
struct vnode *
hammer2_igetv(hammer2_inode_t *ip, int *errorp)
{
struct vnode *vp;
hammer2_pfsmount_t *pmp;
ccms_state_t ostate;
pmp = ip->pmp;
KKASSERT(pmp != NULL);
*errorp = 0;
for (;;) {
/*
* Attempt to reuse an existing vnode assignment. It is
* possible to race a reclaim so the vget() may fail. The
* inode must be unlocked during the vget() to avoid a
* deadlock against a reclaim.
*/
vp = ip->vp;
if (vp) {
/*
* Inode must be unlocked during the vget() to avoid
* possible deadlocks, vnode is held to prevent
* destruction during the vget(). The vget() can
* still fail if we lost a reclaim race on the vnode.
*/
/* XXX vhold_interlocked(vp);
*/
ccms_thread_unlock(&ip->chain.cst);
/* XXX
if (vget(vp, LK_EXCLUSIVE)) {
vdrop(vp);
ccms_thread_lock(&ip->chain.cst,
CCMS_STATE_EXCLUSIVE);
continue;
}
*/
ccms_thread_lock(&ip->chain.cst, CCMS_STATE_EXCLUSIVE);
/* XX vdrop(vp);
*/
/* vp still locked and ref from vget */
*errorp = 0;
break;
}
/*
* No vnode exists, allocate a new vnode. Beware of
* allocation races. This function will return an
* exclusively locked and referenced vnode.
*/
/* XXX
*errorp = getnewvnode(VT_HAMMER2, pmp->mp, &vp, 0, 0);
if (*errorp) {
vp = NULL;
break;
}
*/
/*
* Lock the inode and check for an allocation race.
*/
ostate = ccms_thread_lock_upgrade(&ip->chain.cst);
if (ip->vp != NULL) {
vp->v_type = VBAD;
/* XXX vx_put(vp); */
ccms_thread_lock_restore(&ip->chain.cst, ostate);
continue;
}
switch (ip->ip_data.type) {
case HAMMER2_OBJTYPE_DIRECTORY:
vp->v_type = VDIR;
break;
case HAMMER2_OBJTYPE_REGFILE:
vp->v_type = VREG;
/* XVFS vinitvmio(vp, ip->ip_data.size,
HAMMER2_LBUFSIZE,
(int)ip->ip_data.size & HAMMER2_LBUFMASK);
*/
break;
case HAMMER2_OBJTYPE_SOFTLINK:
/*
* XXX for now we are using the generic file_read
* and file_write code so we need a buffer cache
* association.
*/
vp->v_type = VLNK;
/* XVFS vinitvmio(vp, ip->ip_data.size,
HAMMER2_LBUFSIZE,
(int)ip->ip_data.size & HAMMER2_LBUFMASK);
*/
break;
/* XXX FIFO */
default:
panic("hammer2: unhandled objtype %d",
ip->ip_data.type);
break;
}
if (ip == pmp->iroot)
/* vsetflags(vp, VROOT); */
vp->v_data = ip;
ip->vp = vp;
hammer2_chain_ref(ip->hmp, &ip->chain); /* vp association */
ccms_thread_lock_restore(&ip->chain.cst, ostate);
break;
}
/*
* Return non-NULL vp and *errorp == 0, or NULL vp and *errorp != 0.
*/
if (hammer2_debug & 0x0002) {
kprintf("igetv vp %p refs %d aux %d\n",
vp, vp->v_sysref.refcnt, vp->v_auxrefs);
}
return (vp);
}
