/* $OpenBSD: softraid_aoe.c,v 1.33 2013/06/11 16:42:13 deraadt Exp $ */ /* * Copyright (c) 2008 Ted Unangst * Copyright (c) 2008 Marco Peereboom * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ #include "bio.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* AOE initiator functions. */ int sr_aoe_create(struct sr_discipline *, struct bioc_createraid *, int, int64_t); int sr_aoe_assemble(struct sr_discipline *, struct bioc_createraid *, int, void *); int sr_aoe_alloc_resources(struct sr_discipline *); void sr_aoe_free_resources(struct sr_discipline *); int sr_aoe_rw(struct sr_workunit *); /* AOE target functions. */ int sr_aoe_server_create(struct sr_discipline *, struct bioc_createraid *, int, int64_t); int sr_aoe_server_assemble(struct sr_discipline *, struct bioc_createraid *, int, void *); int sr_aoe_server_alloc_resources(struct sr_discipline *); void sr_aoe_server_free_resources(struct sr_discipline *); int sr_aoe_server_start(struct sr_discipline *); void sr_aoe_request_done(struct aoe_req *, struct aoe_packet *); void sr_aoe_input(struct aoe_handler *, struct mbuf *); void sr_aoe_setup(struct aoe_handler *, struct mbuf *); void sr_aoe_timeout(void *); /* Discipline initialisation. */ void sr_aoe_discipline_init(struct sr_discipline *sd) { /* Fill out discipline members. */ sd->sd_type = SR_MD_AOE_INIT; strlcpy(sd->sd_name, "AOE INIT", sizeof(sd->sd_name)); sd->sd_capabilities = SR_CAP_SYSTEM_DISK; sd->sd_max_wu = SR_RAIDAOE_NOWU; /* Setup discipline specific function pointers. */ sd->sd_alloc_resources = sr_aoe_alloc_resources; sd->sd_assemble = sr_aoe_assemble; sd->sd_create = sr_aoe_create; sd->sd_free_resources = sr_aoe_free_resources; sd->sd_scsi_rw = sr_aoe_rw; sd->sd_scsi_intr = NULL; } void sr_aoe_server_discipline_init(struct sr_discipline *sd) { /* Fill out discipline members. */ sd->sd_type = SR_MD_AOE_TARG; strlcpy(sd->sd_name, "AOE TARG", sizeof(sd->sd_name)); sd->sd_capabilities = 0; sd->sd_max_wu = SR_RAIDAOE_NOWU; /* Setup discipline specific function pointers. */ sd->sd_alloc_resources = sr_aoe_server_alloc_resources; sd->sd_assemble = sr_aoe_server_assemble; sd->sd_create = sr_aoe_server_create; sd->sd_free_resources = sr_aoe_server_free_resources; sd->sd_scsi_inquiry = NULL; sd->sd_scsi_read_cap = NULL; sd->sd_scsi_tur = NULL; sd->sd_scsi_req_sense = NULL; sd->sd_scsi_start_stop = NULL; sd->sd_scsi_sync = NULL; sd->sd_scsi_rw = NULL; sd->sd_scsi_intr = NULL; sd->sd_set_chunk_state = NULL; sd->sd_set_vol_state = NULL; sd->sd_start_discipline = sr_aoe_server_start; } /* AOE initiator */ int sr_aoe_create(struct sr_discipline *sd, struct bioc_createraid *bc, int no_chunk, int64_t coerced_size) { if (no_chunk != 1) { sr_error(sd->sd_sc, "%s requires exactly one chunk", sd->sd_name); return EINVAL; } sd->sd_max_ccb_per_wu = no_chunk; return 0; } int sr_aoe_assemble(struct sr_discipline *sd, struct bioc_createraid *bc, int no_chunk, void *data) { struct ifnet *ifp; struct aoe_handler *ah; struct sr_aoe_config sri; int rv, s; #if 0 struct mbuf *m; struct ether_header *eh; struct aoe_packet *ap; int rv; #endif if (!(bc->bc_opaque_flags & BIOC_SOIN)) return (EINVAL); if (bc->bc_opaque_size != sizeof(sri)) return (EINVAL); if ((rv = copyin(bc->bc_opaque, &sri, sizeof(sri)))) return (rv); sri.nic[sizeof(sri.nic) - 1] = 0; sd->sd_max_ccb_per_wu = sd->sd_meta->ssdi.ssd_chunk_no; ifp = ifunit(sri.nic); if (!ifp) return (EINVAL); ah = malloc(sizeof(*ah), M_DEVBUF, M_WAITOK | M_ZERO); ah->ifp = ifp; ah->major = sri.shelf; ah->minor = sri.slot; ah->fn = (workq_fn)sr_aoe_input; TAILQ_INIT(&ah->reqs); s = splnet(); TAILQ_INSERT_TAIL(&aoe_handlers, ah, next); splx(s); sd->mds.mdd_aoe.sra_ah = ah; sd->mds.mdd_aoe.sra_eaddr = sri.dsteaddr; #if 0 MGETHDR(m, M_WAIT, MT_HEADER); eh = mtod(m, struct ether_header *); memcpy(eh->ether_dhost, sd->mds.mdd_aoe.sra_eaddr, 6); memcpy(eh->ether_shost, ((struct arpcom *)ifp)->ac_enaddr, 6); eh->ether_type = htons(ETHERTYPE_AOE); ap = (struct aoe_packet *)&eh[1]; ap->vers = 1; ap->flags = 0; ap->error = 0; ap->major = sri.shelf; ap->minor = sri.slot; ap->command = 1; ap->tag = 0; ap->buffercnt = 0; ap->firmwarevers = 0; ap->configsectorcnt = 0; ap->serververs = 0; ap->ccmd = 0; ap->configstringlen = 0; m->m_pkthdr.len = m->m_len = AOE_CFGHDRLEN; s = splnet(); IFQ_ENQUEUE(&ifp->if_snd, m, NULL, rv); if ((ifp->if_flags & IFF_OACTIVE) == 0) (*ifp->if_start)(ifp); rv = tsleep(ah, PRIBIO|PCATCH, "aoesetup", 30 * hz); splx(s); if (rv) { s = splnet(); TAILQ_REMOVE(&aoe_handlers, ah, next); splx(s); free(ah, M_DEVBUF); return rv; } #endif return 0; } void sr_aoe_setup(struct aoe_handler *ah, struct mbuf *m) { struct aoe_packet *ap; int s; ap = mtod(m, struct aoe_packet *); if (ap->command != 1) goto out; if (ap->tag != 0) goto out; s = splnet(); ah->fn = (workq_fn)sr_aoe_input; wakeup(ah); splx(s); out: m_freem(m); } int sr_aoe_alloc_resources(struct sr_discipline *sd) { DNPRINTF(SR_D_DIS, "%s: sr_aoe_alloc_resources\n", DEVNAME(sd->sd_sc)); sr_wu_alloc(sd); sr_ccb_alloc(sd); return 0; } void sr_aoe_free_resources(struct sr_discipline *sd) { struct aoe_handler *ah; int s; DNPRINTF(SR_D_DIS, "%s: sr_aoe_free_resources\n", DEVNAME(sd->sd_sc)); ah = sd->mds.mdd_aoe.sra_ah; if (ah) { s = splnet(); TAILQ_REMOVE(&aoe_handlers, ah, next); splx(s); free(ah, M_DEVBUF); } if (sd->sd_meta) free(sd->sd_meta, M_DEVBUF); sr_wu_free(sd); sr_ccb_free(sd); } int sr_send_aoe_chunk(struct sr_workunit *wu, daddr_t blk, int i); int sr_send_aoe_chunk(struct sr_workunit *wu, daddr_t blk, int i) { struct sr_discipline *sd = wu->swu_dis; struct scsi_xfer *xs = wu->swu_xs; int s; daddr_t fragblk; struct mbuf *m; struct ether_header *eh; struct aoe_packet *ap; struct ifnet *ifp; struct aoe_handler *ah; struct aoe_req *ar; int tag, rv; int fragsize; const int aoe_frags = 2; fragblk = blk + aoe_frags * i; fragsize = aoe_frags * 512; if (fragblk + aoe_frags - 1 > wu->swu_blk_end) { fragsize = (wu->swu_blk_end - fragblk + 1) * 512; } tag = ++sd->mds.mdd_aoe.sra_tag; ah = sd->mds.mdd_aoe.sra_ah; ar = malloc(sizeof(*ar), M_DEVBUF, M_NOWAIT); if (!ar) { splx(s); return ENOMEM; } ar->v = wu; ar->tag = tag; ar->len = fragsize; timeout_set(&ar->to, sr_aoe_timeout, ar); TAILQ_INSERT_TAIL(&ah->reqs, ar, next); splx(s); ifp = ah->ifp; MGETHDR(m, M_DONTWAIT, MT_HEADER); if (xs->flags & SCSI_DATA_OUT && m) { MCLGET(m, M_DONTWAIT); if (!(m->m_flags & M_EXT)) { m_freem(m); m = NULL; } } if (!m) { s = splbio(); TAILQ_REMOVE(&ah->reqs, ar, next); splx(s); free(ar, M_DEVBUF); return ENOMEM; } eh = mtod(m, struct ether_header *); memcpy(eh->ether_dhost, &sd->mds.mdd_aoe.sra_eaddr, ETHER_ADDR_LEN); memcpy(eh->ether_shost, ((struct arpcom *)ifp)->ac_enaddr, ETHER_ADDR_LEN); eh->ether_type = htons(ETHERTYPE_AOE); ap = (struct aoe_packet *)&eh[1]; ap->vers = 1; ap->flags = 0; ap->error = 0; ap->major = ah->major; ap->minor = ah->minor; ap->command = 0; ap->tag = tag; ap->aflags = 0; /* AOE_EXTENDED; */ if (xs->flags & SCSI_DATA_OUT) { ap->aflags |= AOE_WRITE; ap->cmd = AOE_WRITE; memcpy(ap->data, xs->data + (aoe_frags * i * 512), fragsize); } else { ap->cmd = AOE_READ; } ap->feature = 0; ap->sectorcnt = fragsize / 512; AOE_BLK2HDR(fragblk, ap); m->m_pkthdr.len = m->m_len = AOE_CMDHDRLEN + fragsize; s = splnet(); IFQ_ENQUEUE(&ifp->if_snd, m, NULL, rv); if ((ifp->if_flags & IFF_OACTIVE) == 0) (*ifp->if_start)(ifp); if (rv == 0) timeout_add_sec(&ar->to, 10); splx(s); if (rv) { s = splbio(); TAILQ_REMOVE(&ah->reqs, ar, next); splx(s); free(ar, M_DEVBUF); } return rv; } int sr_aoe_rw(struct sr_workunit *wu) { struct sr_discipline *sd = wu->swu_dis; struct scsi_xfer *xs = wu->swu_xs; struct sr_chunk *scp; daddr_t blk; int s, ios, rt; int rv, i; const int aoe_frags = 2; printf("%s: sr_aoe_rw 0x%02x\n", DEVNAME(sd->sd_sc), xs->cmd->opcode); return (1); DNPRINTF(SR_D_DIS, "%s: sr_aoe_rw 0x%02x\n", DEVNAME(sd->sd_sc), xs->cmd->opcode); /* blk and scsi error will be handled by sr_validate_io */ if (sr_validate_io(wu, &blk, "sr_aoe_rw")) goto bad; /* add 1 to get the inclusive amount, then some more for rounding */ ios = (wu->swu_blk_end - wu->swu_blk_start + 1 + (aoe_frags - 1)) / aoe_frags; wu->swu_io_count = ios; if (xs->flags & SCSI_POLL) panic("can't AOE poll"); s = splbio(); for (i = 0; i < ios; i++) { if (xs->flags & SCSI_DATA_IN) { rt = 0; ragain: scp = sd->sd_vol.sv_chunks[0]; switch (scp->src_meta.scm_status) { case BIOC_SDONLINE: case BIOC_SDSCRUB: break; case BIOC_SDOFFLINE: case BIOC_SDREBUILD: case BIOC_SDHOTSPARE: if (rt++ < sd->sd_meta->ssdi.ssd_chunk_no) goto ragain; /* FALLTHROUGH */ default: /* volume offline */ printf("%s: is offline, can't read\n", DEVNAME(sd->sd_sc)); goto bad; } } else { scp = sd->sd_vol.sv_chunks[0]; switch (scp->src_meta.scm_status) { case BIOC_SDONLINE: case BIOC_SDSCRUB: case BIOC_SDREBUILD: break; case BIOC_SDHOTSPARE: /* should never happen */ case BIOC_SDOFFLINE: wu->swu_io_count--; goto bad; default: goto bad; } } rv = sr_send_aoe_chunk(wu, blk, i); if (rv) { return rv; } } return (0); bad: /* wu is unwound by sr_wu_put */ return (1); } void sr_aoe_request_done(struct aoe_req *ar, struct aoe_packet *ap) { struct sr_discipline *sd; struct scsi_xfer *xs; struct sr_workunit *wu; daddr_t blk, offset; int len, s; wu = ar->v; sd = wu->swu_dis; xs = wu->swu_xs; if (!ap || ap->flags & AOE_F_ERROR) { wu->swu_ios_failed++; } else { wu->swu_ios_succeeded++; len = ar->len; /* XXX check against sector count */ if (xs->flags & SCSI_DATA_IN) { AOE_HDR2BLK(ap, blk); /* XXX bounds checking */ offset = (wu->swu_blk_start - blk) * 512; memcpy(xs->data + offset, ap->data, len); } } wu->swu_ios_complete++; s = splbio(); if (wu->swu_ios_complete == wu->swu_io_count) { if (wu->swu_ios_failed == wu->swu_ios_complete) xs->error = XS_DRIVER_STUFFUP; else xs->error = XS_NOERROR; sr_scsi_done(sd, xs); } splx(s); free(ar, M_DEVBUF); } void sr_aoe_input(struct aoe_handler *ah, struct mbuf *m) { struct aoe_packet *ap; struct aoe_req *ar; int tag; int s; ap = mtod(m, struct aoe_packet *); tag = ap->tag; s = splnet(); TAILQ_FOREACH(ar, &ah->reqs, next) { if (ar->tag == tag) { timeout_del(&ar->to); TAILQ_REMOVE(&ah->reqs, ar, next); break; } } splx(s); if (!ar) goto out; ap = mtod(m, struct aoe_packet *); sr_aoe_request_done(ar, ap); out: m_freem(m); } void sr_aoe_timeout(void *v) { struct aoe_req *ar = v; struct sr_discipline *sd; struct scsi_xfer *xs; struct aoe_handler *ah; struct sr_workunit *wu; int s; wu = ar->v; sd = wu->swu_dis; xs = wu->swu_xs; ah = sd->mds.mdd_aoe.sra_ah; s = splnet(); TAILQ_REMOVE(&ah->reqs, ar, next); splx(s); sr_aoe_request_done(ar, NULL); } /* AOE target */ void sr_aoe_server(struct aoe_handler *, struct mbuf *); void sr_aoe_server_create_thread(void *); void sr_aoe_server_thread(void *); int sr_aoe_server_create(struct sr_discipline *sd, struct bioc_createraid *bc, int no_chunk, int64_t coerced_size) { if (no_chunk != 1) { sr_error(sd->sd_sc, "%s requires exactly one chunk", sd->sd_name); return EINVAL; } sd->sd_meta->ssdi.ssd_size = coerced_size; strlcpy(sd->sd_name, "AOE TARG", sizeof(sd->sd_name)); sd->sd_max_ccb_per_wu = no_chunk; return 0; } int sr_aoe_server_assemble(struct sr_discipline *sd, struct bioc_createraid *bc, int no_chunk, void *data) { sd->sd_max_ccb_per_wu = sd->sd_meta->ssdi.ssd_chunk_no; return 0; } int sr_aoe_server_alloc_resources(struct sr_discipline *sd) { int s, rv = EINVAL; unsigned char slot; unsigned short shelf; const char *nic; struct aoe_handler *ah; struct ifnet *ifp; DNPRINTF(SR_D_DIS, "%s: sr_aoe_server_alloc_resources\n", DEVNAME(sd->sd_sc)); /* setup runtime values */ /* XXX where do these come from */ slot = 3; shelf = 4; nic = "re0"; ifp = ifunit(nic); if (!ifp) { printf("%s: sr_aoe_server_alloc_resources: illegal interface " "%s\n", DEVNAME(sd->sd_sc), nic); return (EINVAL); } shelf = htons(shelf); ah = malloc(sizeof(*ah), M_DEVBUF, M_WAITOK | M_ZERO); ah->ifp = ifp; ah->major = shelf; ah->minor = slot; ah->fn = (workq_fn)sr_aoe_server; TAILQ_INIT(&ah->reqs); s = splnet(); TAILQ_INSERT_TAIL(&aoe_handlers, ah, next); splx(s); sd->mds.mdd_aoe.sra_ah = ah; memset(&sd->mds.mdd_aoe.sra_eaddr, 0xff, sizeof(sd->mds.mdd_aoe.sra_eaddr)); sd->mds.mdd_aoe.sra_ifp = ifp; if (sr_wu_alloc(sd)) goto bad; if (sr_ccb_alloc(sd)) goto bad; rv = 0; bad: return (rv); } void sr_aoe_server_free_resources(struct sr_discipline *sd) { int s; DNPRINTF(SR_D_DIS, "%s: sr_aoe_server_free_resources\n", DEVNAME(sd->sd_sc)); s = splnet(); if (sd->mds.mdd_aoe.sra_ah) { TAILQ_REMOVE(&aoe_handlers, sd->mds.mdd_aoe.sra_ah, next); free(sd->mds.mdd_aoe.sra_ah, M_DEVBUF); } splx(s); sr_wu_free(sd); sr_ccb_free(sd); } int sr_aoe_server_start(struct sr_discipline *sd) { kthread_create_deferred(sr_aoe_server_create_thread, sd); return (0); } void sr_aoe_server_create_thread(void *arg) { struct sr_discipline *sd = arg; if (kthread_create(sr_aoe_server_thread, arg, NULL, DEVNAME(sd->sd_sc)) != 0) { printf("%s: unable to create AOE thread\n", DEVNAME(sd->sd_sc)); /* XXX unwind */ return; } } void sr_aoe_server_thread(void *arg) { struct sr_discipline *sd = arg; struct ifnet *ifp; struct aoe_handler *ah; struct aoe_req *ar; struct aoe_packet *rp, *ap; struct mbuf *m, *m2; struct ether_header *eh; struct buf buf; daddr_t blk; int len; int rv, s; /* sanity */ if (!sd) return; ah = sd->mds.mdd_aoe.sra_ah; if (ah == NULL) return; ifp = sd->mds.mdd_aoe.sra_ifp; if (ifp == NULL) return; printf("%s: AOE target: %s exported via: %s\n", DEVNAME(sd->sd_sc), sd->sd_meta->ssd_devname, ifp->if_xname); while (1) { s = splnet(); resleep: rv = tsleep(ah, PCATCH | PRIBIO, "aoe targ", 0); if (rv) { splx(s); break; } ar = TAILQ_FIRST(&ah->reqs); if (!ar) { goto resleep; } TAILQ_REMOVE(&ah->reqs, ar, next); splx(s); m2 = ar->v; rp = mtod(m2, struct aoe_packet *); if (rp->command) { continue; } if (rp->aflags & AOE_AF_WRITE) { MGETHDR(m, M_DONTWAIT, MT_HEADER); if (!m) continue; len = rp->sectorcnt * 512; eh = mtod(m, struct ether_header *); memcpy(eh->ether_dhost, &sd->mds.mdd_aoe.sra_eaddr, ETHER_ADDR_LEN); memcpy(eh->ether_shost, ((struct arpcom *)ifp)->ac_enaddr, ETHER_ADDR_LEN); eh->ether_type = htons(ETHERTYPE_AOE); ap = (struct aoe_packet *)&eh[1]; AOE_HDR2BLK(ap, blk); bzero(&buf, sizeof(buf)); buf.b_blkno = blk; buf.b_flags = B_WRITE | B_PHYS; buf.b_bcount = len; buf.b_bufsize = len; buf.b_resid = len; buf.b_data = rp->data; buf.b_error = 0; buf.b_proc = curproc; buf.b_dev = sd->sd_vol.sv_chunks[0]->src_dev_mm; buf.b_vp = sd->sd_vol.sv_chunks[0]->src_vn; if ((buf.b_flags & B_READ) == 0) buf.b_vp->v_numoutput++; LIST_INIT(&buf.b_dep); s = splbio(); VOP_STRATEGY(&buf); biowait(&buf); splx(s); ap->vers = 1; ap->flags = AOE_F_RESP; ap->error = 0; ap->major = rp->major; ap->minor = rp->minor; ap->command = 1; ap->tag = rp->tag; ap->aflags = rp->aflags; ap->feature = 0; ap->sectorcnt = len / 512; ap->cmd = AOE_WRITE; ap->lba0 = 0; ap->lba1 = 0; ap->lba2 = 0; ap->lba3 = 0; ap->lba4 = 0; ap->lba5 = 0; ap->reserved = 0; m->m_pkthdr.len = m->m_len = AOE_CMDHDRLEN; s = splnet(); IFQ_ENQUEUE(&ifp->if_snd, m, NULL, rv); if ((ifp->if_flags & IFF_OACTIVE) == 0) (*ifp->if_start)(ifp); splx(s); } else { MGETHDR(m, M_DONTWAIT, MT_HEADER); if (m) { MCLGET(m, M_DONTWAIT); if (!(m->m_flags & M_EXT)) { m_freem(m); m = NULL; } } if (!m) continue; len = rp->sectorcnt * 512; eh = mtod(m, struct ether_header *); memcpy(eh->ether_dhost, &sd->mds.mdd_aoe.sra_eaddr, ETHER_ADDR_LEN); memcpy(eh->ether_shost, ((struct arpcom *)ifp)->ac_enaddr, ETHER_ADDR_LEN); eh->ether_type = htons(ETHERTYPE_AOE); ap = (struct aoe_packet *)&eh[1]; AOE_HDR2BLK(ap, blk); memset(&buf, 0, sizeof buf); buf.b_blkno = blk; buf.b_flags = B_WRITE | B_PHYS; buf.b_bcount = len; buf.b_bufsize = len; buf.b_resid = len; buf.b_data = ap->data; buf.b_error = 0; buf.b_proc = curproc; buf.b_dev = sd->sd_vol.sv_chunks[0]->src_dev_mm; buf.b_vp = sd->sd_vol.sv_chunks[0]->src_vn; if ((buf.b_flags & B_READ) == 0) buf.b_vp->v_numoutput++; LIST_INIT(&buf.b_dep); s = splbio(); VOP_STRATEGY(&buf); biowait(&buf); splx(s); ap->vers = 1; ap->flags = AOE_F_RESP; ap->error = 0; ap->major = rp->major; ap->minor = rp->minor; ap->command = 1; ap->tag = rp->tag; ap->aflags = rp->aflags; ap->feature = 0; ap->sectorcnt = len / 512; ap->cmd = AOE_READ; ap->lba0 = 0; ap->lba1 = 0; ap->lba2 = 0; ap->lba3 = 0; ap->lba4 = 0; ap->lba5 = 0; ap->reserved = 0; m->m_pkthdr.len = m->m_len = AOE_CMDHDRLEN; s = splnet(); IFQ_ENQUEUE(&ifp->if_snd, m, NULL, rv); if ((ifp->if_flags & IFF_OACTIVE) == 0) (*ifp->if_start)(ifp); splx(s); } } } void sr_aoe_server(struct aoe_handler *ah, struct mbuf *m) { struct aoe_req *ar; int s; ar = malloc(sizeof *ar, M_DEVBUF, M_NOWAIT); if (!ar) { /* XXX warning? */ m_freem(m); return; } ar->v = m; s = splnet(); TAILQ_INSERT_TAIL(&ah->reqs, ar, next); wakeup(ah); splx(s); }