static int
cgd_diskstart(device_t dev, struct buf *bp)
{
struct cgd_softc *cs = device_private(dev);
struct dk_softc *dksc = &cs->sc_dksc;
struct buf *nbp;
void * addr;
void * newaddr;
daddr_t bn;
struct vnode *vp;
DPRINTF_FOLLOW(("cgd_diskstart(%p, %p)\n", dksc, bp));
bn = bp->b_rawblkno;
/*
* We attempt to allocate all of our resources up front, so that
* we can fail quickly if they are unavailable.
*/
nbp = getiobuf(cs->sc_tvn, false);
if (nbp == NULL)
return EAGAIN;
/*
* If we are writing, then we need to encrypt the outgoing
* block into a new block of memory.
*/
newaddr = addr = bp->b_data;
if ((bp->b_flags & B_READ) == 0) {
newaddr = cgd_getdata(dksc, bp->b_bcount);
if (!newaddr) {
putiobuf(nbp);
return EAGAIN;
}
cgd_cipher(cs, newaddr, addr, bp->b_bcount, bn,
DEV_BSIZE, CGD_CIPHER_ENCRYPT);
}
nbp->b_data = newaddr;
nbp->b_flags = bp->b_flags;
nbp->b_oflags = bp->b_oflags;
nbp->b_cflags = bp->b_cflags;
nbp->b_iodone = cgdiodone;
nbp->b_proc = bp->b_proc;
nbp->b_blkno = bn;
nbp->b_bcount = bp->b_bcount;
nbp->b_private = bp;
BIO_COPYPRIO(nbp, bp);
if ((nbp->b_flags & B_READ) == 0) {
vp = nbp->b_vp;
mutex_enter(vp->v_interlock);
vp->v_numoutput++;
mutex_exit(vp->v_interlock);
}
VOP_STRATEGY(cs->sc_tvn, nbp);
return 0;
}
static void
vndthread(void *arg)
{
struct vnd_softc *vnd = arg;
int s;
/* Determine whether we can *use* VOP_BMAP and VOP_STRATEGY to
* directly access the backing vnode. If we can, use these two
* operations to avoid messing with the local buffer cache.
* Otherwise fall back to regular VOP_READ/VOP_WRITE operations
* which are guaranteed to work with any file system. */
if ((vnd->sc_flags & VNF_USE_VN_RDWR) == 0 &&
! vnode_has_strategy(vnd))
vnd->sc_flags |= VNF_USE_VN_RDWR;
#ifdef DEBUG
if (vnddebug & VDB_INIT)
printf("vndthread: vp %p, %s\n", vnd->sc_vp,
(vnd->sc_flags & VNF_USE_VN_RDWR) == 0 ?
"using bmap/strategy operations" :
"using read/write operations");
#endif
s = splbio();
vnd->sc_flags |= VNF_KTHREAD;
wakeup(&vnd->sc_kthread);
/*
* Dequeue requests and serve them depending on the available
* vnode operations.
*/
while ((vnd->sc_flags & VNF_VUNCONF) == 0) {
struct vndxfer *vnx;
int flags;
struct buf *obp;
struct buf *bp;
obp = bufq_get(vnd->sc_tab);
if (obp == NULL) {
tsleep(&vnd->sc_tab, PRIBIO, "vndbp", 0);
continue;
};
if ((vnd->sc_flags & VNF_USE_VN_RDWR)) {
KASSERT(vnd->sc_pending > 0 &&
vnd->sc_pending <= VND_MAXPENDING(vnd));
if (vnd->sc_pending-- == VND_MAXPENDING(vnd))
wakeup(&vnd->sc_pending);
}
splx(s);
flags = obp->b_flags;
#ifdef DEBUG
if (vnddebug & VDB_FOLLOW)
printf("vndthread(%p)\n", obp);
#endif
if (vnd->sc_vp->v_mount == NULL) {
obp->b_error = ENXIO;
goto done;
}
#ifdef VND_COMPRESSION
/* handle a compressed read */
if ((flags & B_READ) != 0 && (vnd->sc_flags & VNF_COMP)) {
off_t bn;
/* Convert to a byte offset within the file. */
bn = obp->b_rawblkno *
vnd->sc_dkdev.dk_label->d_secsize;
compstrategy(obp, bn);
goto done;
}
#endif /* VND_COMPRESSION */
/*
* Allocate a header for this transfer and link it to the
* buffer
*/
s = splbio();
vnx = VND_GETXFER(vnd);
splx(s);
vnx->vx_vnd = vnd;
s = splbio();
while (vnd->sc_active >= vnd->sc_maxactive) {
tsleep(&vnd->sc_tab, PRIBIO, "vndac", 0);
}
vnd->sc_active++;
splx(s);
/* Instrumentation. */
disk_busy(&vnd->sc_dkdev);
bp = &vnx->vx_buf;
buf_init(bp);
bp->b_flags = (obp->b_flags & B_READ);
bp->b_oflags = obp->b_oflags;
bp->b_cflags = obp->b_cflags;
bp->b_iodone = vndiodone;
bp->b_private = obp;
bp->b_vp = vnd->sc_vp;
bp->b_objlock = bp->b_vp->v_interlock;
bp->b_data = obp->b_data;
bp->b_bcount = obp->b_bcount;
BIO_COPYPRIO(bp, obp);
/* Handle the request using the appropriate operations. */
if ((vnd->sc_flags & VNF_USE_VN_RDWR) == 0)
handle_with_strategy(vnd, obp, bp);
else
handle_with_rdwr(vnd, obp, bp);
s = splbio();
continue;
done:
biodone(obp);
s = splbio();
}
vnd->sc_flags &= (~VNF_KTHREAD | VNF_VUNCONF);
wakeup(&vnd->sc_kthread);
splx(s);
kthread_exit(0);
}
