static bd_xfer_impl_t *
bd_xfer_alloc(bd_t *bd, struct buf *bp, int (*func)(void *, bd_xfer_t *),
int kmflag)
{
bd_xfer_impl_t *xi;
int rv = 0;
int status;
unsigned dir;
int (*cb)(caddr_t);
size_t len;
uint32_t shift;
if (kmflag == KM_SLEEP) {
cb = DDI_DMA_SLEEP;
} else {
cb = DDI_DMA_DONTWAIT;
}
xi = kmem_cache_alloc(bd->d_cache, kmflag);
if (xi == NULL) {
bioerror(bp, ENOMEM);
return (NULL);
}
ASSERT(bp);
xi->i_bp = bp;
xi->i_func = func;
xi->i_blkno = bp->b_lblkno;
if (bp->b_bcount == 0) {
xi->i_len = 0;
xi->i_nblks = 0;
xi->i_kaddr = NULL;
xi->i_resid = 0;
xi->i_num_win = 0;
goto done;
}
if (bp->b_flags & B_READ) {
dir = DDI_DMA_READ;
xi->i_func = bd->d_ops.o_read;
} else {
dir = DDI_DMA_WRITE;
xi->i_func = bd->d_ops.o_write;
}
shift = bd->d_blkshift;
xi->i_blkshift = shift;
if (!bd->d_use_dma) {
bp_mapin(bp);
rv = 0;
xi->i_offset = 0;
xi->i_num_win =
(bp->b_bcount + (bd->d_maxxfer - 1)) / bd->d_maxxfer;
xi->i_cur_win = 0;
xi->i_len = min(bp->b_bcount, bd->d_maxxfer);
xi->i_nblks = xi->i_len >> shift;
xi->i_kaddr = bp->b_un.b_addr;
xi->i_resid = bp->b_bcount;
} else {
/* ARGSUSED */
static struct scsi_pkt *
emul64_scsi_init_pkt(struct scsi_address *ap, struct scsi_pkt *pkt,
struct buf *bp, int cmdlen, int statuslen, int tgtlen,
int flags, int (*callback)(), caddr_t arg)
{
struct emul64 *emul64 = ADDR2EMUL64(ap);
struct emul64_cmd *sp;
ASSERT(callback == NULL_FUNC || callback == SLEEP_FUNC);
/*
* First step of emul64_scsi_init_pkt: pkt allocation
*/
if (pkt == NULL) {
pkt = scsi_hba_pkt_alloc(emul64->emul64_dip, ap, cmdlen,
statuslen,
tgtlen, sizeof (struct emul64_cmd), callback, arg);
if (pkt == NULL) {
cmn_err(CE_WARN, "emul64_scsi_init_pkt: "
"scsi_hba_pkt_alloc failed");
return (NULL);
}
sp = PKT2CMD(pkt);
/*
* Initialize the new pkt - we redundantly initialize
* all the fields for illustrative purposes.
*/
sp->cmd_pkt = pkt;
sp->cmd_flags = 0;
sp->cmd_scblen = statuslen;
sp->cmd_cdblen = cmdlen;
sp->cmd_emul64 = emul64;
pkt->pkt_address = *ap;
pkt->pkt_comp = (void (*)())NULL;
pkt->pkt_flags = 0;
pkt->pkt_time = 0;
pkt->pkt_resid = 0;
pkt->pkt_statistics = 0;
pkt->pkt_reason = 0;
} else {
sp = PKT2CMD(pkt);
}
/*
* Second step of emul64_scsi_init_pkt: dma allocation/move
*/
if (bp && bp->b_bcount != 0) {
if (bp->b_flags & B_READ) {
sp->cmd_flags &= ~CFLAG_DMASEND;
} else {
sp->cmd_flags |= CFLAG_DMASEND;
}
bp_mapin(bp);
sp->cmd_addr = (unsigned char *) bp->b_un.b_addr;
sp->cmd_count = bp->b_bcount;
pkt->pkt_resid = 0;
}
return (pkt);
}
int
zvol_strategy(buf_t *bp)
{
zvol_state_t *zv = ddi_get_soft_state(zvol_state, getminor(bp->b_edev));
uint64_t off, volsize;
size_t size, resid;
char *addr;
objset_t *os;
int error = 0;
int sync;
int reading;
int txg_sync_needed = B_FALSE;
if (zv == NULL) {
bioerror(bp, ENXIO);
biodone(bp);
return (0);
}
if (getminor(bp->b_edev) == 0) {
bioerror(bp, EINVAL);
biodone(bp);
return (0);
}
if (zv->zv_readonly && !(bp->b_flags & B_READ)) {
bioerror(bp, EROFS);
biodone(bp);
return (0);
}
off = ldbtob(bp->b_blkno);
volsize = zv->zv_volsize;
os = zv->zv_objset;
ASSERT(os != NULL);
sync = !(bp->b_flags & B_ASYNC) && !(zil_disable);
bp_mapin(bp);
addr = bp->b_un.b_addr;
resid = bp->b_bcount;
/*
* There must be no buffer changes when doing a dmu_sync() because
* we can't change the data whilst calculating the checksum.
* A better approach than a per zvol rwlock would be to lock ranges.
*/
reading = bp->b_flags & B_READ;
if (reading || resid <= zvol_immediate_write_sz)
rw_enter(&zv->zv_dslock, RW_READER);
else
rw_enter(&zv->zv_dslock, RW_WRITER);
while (resid != 0 && off < volsize) {
size = MIN(resid, 1UL << 20); /* cap at 1MB per tx */
if (size > volsize - off) /* don't write past the end */
size = volsize - off;
if (reading) {
error = dmu_read(os, ZVOL_OBJ, off, size, addr);
} else {
dmu_tx_t *tx = dmu_tx_create(os);
dmu_tx_hold_write(tx, ZVOL_OBJ, off, size);
error = dmu_tx_assign(tx, TXG_WAIT);
if (error) {
dmu_tx_abort(tx);
} else {
dmu_write(os, ZVOL_OBJ, off, size, addr, tx);
if (sync) {
/* use the ZIL to commit this write */
if (zvol_log_write(zv, tx, off, size,
addr) != 0) {
txg_sync_needed = B_TRUE;
}
}
dmu_tx_commit(tx);
}
}
if (error)
break;
off += size;
addr += size;
resid -= size;
}
rw_exit(&zv->zv_dslock);
if ((bp->b_resid = resid) == bp->b_bcount)
bioerror(bp, off > volsize ? EINVAL : error);
biodone(bp);
if (sync) {
if (txg_sync_needed)
txg_wait_synced(dmu_objset_pool(os), 0);
else
zil_commit(zv->zv_zilog, UINT64_MAX, 0);
}
return (0);
}