Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752822Ab2H1Nc3 (ORCPT ); Tue, 28 Aug 2012 09:32:29 -0400 Received: from noserose.net ([66.220.18.76]:35429 "HELO noserose.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752162Ab2H1Nc1 (ORCPT ); Tue, 28 Aug 2012 09:32:27 -0400 Message-Id: <8e733eaf1edf694342bee4708d9ab20b60ddef38.1346158422.git.ecashin@coraid.com> In-Reply-To: References: From: Ed Cashin Date: Sat, 25 Aug 2012 10:39:49 -0400 Subject: [PATCH 05/14] aoe: use packets that work with the smallest-MTU local interface To: Andrew Morton Cc: linux-kernel@vger.kernel.org, ecashin@coraid.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7075 Lines: 299 Users with several network interfaces dedicated to AoE generally do not configure them to support different-sized AoE data payloads on purpose. For a given AoE target, there will be a set of local network interfaces that can reach it. Using only the payload that will fit in the smallest-sized MTU of all those local interfaces greatly simplifies the driver, especially in failure scenarios. Signed-off-by: Ed Cashin --- drivers/block/aoe/aoe.h | 7 +- drivers/block/aoe/aoecmd.c | 151 ++++++++++++++++++++++++-------------------- 2 files changed, 87 insertions(+), 71 deletions(-) diff --git a/drivers/block/aoe/aoe.h b/drivers/block/aoe/aoe.h index d0087de1..ffded64 100644 --- a/drivers/block/aoe/aoe.h +++ b/drivers/block/aoe/aoe.h @@ -125,9 +125,8 @@ struct frame { struct aoeif { struct net_device *nd; - unsigned char lost; - unsigned char lostjumbo; - ushort maxbcnt; + ulong lost; + int bcnt; }; struct aoetgt { @@ -144,6 +143,7 @@ struct aoetgt { u16 useme; ulong falloc; ulong lastwadj; /* last window adjustment */ + int minbcnt; int wpkts, rpkts; }; @@ -172,6 +172,7 @@ struct aoedev { struct bio *nxbio; struct request *rq; } ip; + ulong maxbcnt; struct aoetgt *targets[NTARGETS]; struct aoetgt **tgt; /* target in use when working */ struct aoetgt *htgt; /* target needing rexmit assistance */ diff --git a/drivers/block/aoe/aoecmd.c b/drivers/block/aoe/aoecmd.c index 5cc4d3a..cf196ed 100644 --- a/drivers/block/aoe/aoecmd.c +++ b/drivers/block/aoe/aoecmd.c @@ -118,16 +118,18 @@ put_lba(struct aoe_atahdr *ah, sector_t lba) ah->lba5 = lba >>= 8; } -static void +static struct aoeif * ifrotate(struct aoetgt *t) { - t->ifp++; - if (t->ifp >= &t->ifs[NAOEIFS] || t->ifp->nd == NULL) - t->ifp = t->ifs; - if (t->ifp->nd == NULL) { - printk(KERN_INFO "aoe: no interface to rotate to\n"); - BUG(); - } + struct aoeif *ifp; + + ifp = t->ifp; + ifp++; + if (ifp >= &t->ifs[NAOEIFS] || ifp->nd == NULL) + ifp = t->ifs; + if (ifp->nd == NULL) + return NULL; + return t->ifp = ifp; } static void @@ -231,8 +233,8 @@ newframe(struct aoedev *d) && t->ifp->nd) { f = newtframe(d, t); if (f) { - d->tgt = tt; ifrotate(t); + d->tgt = tt; return f; } } @@ -299,7 +301,7 @@ aoecmd_ata_rw(struct aoedev *d) return 0; t = *d->tgt; bv = buf->bv; - bcnt = t->ifp->maxbcnt; + bcnt = d->maxbcnt; if (bcnt == 0) bcnt = DEFAULTBCNT; if (bcnt > buf->resid) @@ -430,9 +432,14 @@ resend(struct aoedev *d, struct frame *f) u32 n; t = f->t; - ifrotate(t); n = newtag(t); skb = f->skb; + if (ifrotate(t) == NULL) { + /* probably can't happen, but set it up to fail anyway */ + pr_info("aoe: resend: no interfaces to rotate to.\n"); + ktcomplete(f, NULL); + return; + } h = (struct aoe_hdr *) skb_mac_header(skb); ah = (struct aoe_atahdr *) (h+1); @@ -482,21 +489,6 @@ getif(struct aoetgt *t, struct net_device *nd) return NULL; } -static struct aoeif * -addif(struct aoetgt *t, struct net_device *nd) -{ - struct aoeif *p; - - p = getif(t, NULL); - if (!p) - return NULL; - p->nd = nd; - p->maxbcnt = DEFAULTBCNT; - p->lost = 0; - p->lostjumbo = 0; - return p; -} - static void ejectif(struct aoetgt *t, struct aoeif *ifp) { @@ -545,7 +537,11 @@ sthtith(struct aoedev *d) resend(d, nf); } } - /* he's clean, he's useless. take away his interfaces */ + /* We've cleaned up the outstanding so take away his + * interfaces so he won't be used. We should remove him from + * the target array here, but cleaning up a target is + * involved. PUNT! + */ memset(ht->ifs, 0, sizeof ht->ifs); d->htgt = NULL; return 1; @@ -1014,11 +1010,8 @@ noskb: if (buf) case ATA_CMD_PIO_WRITE_EXT: spin_lock_irq(&d->lock); ifp = getif(t, skb->dev); - if (ifp) { + if (ifp) ifp->lost = 0; - if (n > DEFAULTBCNT) - ifp->lostjumbo = 0; - } if (d->htgt == t) /* I'll help myself, thank you. */ d->htgt = NULL; spin_unlock_irq(&d->lock); @@ -1292,6 +1285,56 @@ addtgt(struct aoedev *d, char *addr, ulong nframes) return *tt = t; } +static void +setdbcnt(struct aoedev *d) +{ + struct aoetgt **t, **e; + int bcnt = 0; + + t = d->targets; + e = t + NTARGETS; + for (; t < e && *t; t++) + if (bcnt == 0 || bcnt > (*t)->minbcnt) + bcnt = (*t)->minbcnt; + if (bcnt != d->maxbcnt) { + d->maxbcnt = bcnt; + pr_info("aoe: e%ld.%d: setting %d byte data frames\n", + d->aoemajor, d->aoeminor, bcnt); + } +} + +static void +setifbcnt(struct aoetgt *t, struct net_device *nd, int bcnt) +{ + struct aoedev *d; + struct aoeif *p, *e; + int minbcnt; + + d = t->d; + minbcnt = bcnt; + p = t->ifs; + e = p + NAOEIFS; + for (; p < e; p++) { + if (p->nd == NULL) + break; /* end of the valid interfaces */ + if (p->nd == nd) { + p->bcnt = bcnt; /* we're updating */ + nd = NULL; + } else if (minbcnt > p->bcnt) + minbcnt = p->bcnt; /* find the min interface */ + } + if (nd) { + if (p == e) { + pr_err("aoe: device setifbcnt failure; too many interfaces.\n"); + return; + } + p->nd = nd; + p->bcnt = bcnt; + } + t->minbcnt = minbcnt; + setdbcnt(d); +} + void aoecmd_cfg_rsp(struct sk_buff *skb) { @@ -1299,7 +1342,6 @@ aoecmd_cfg_rsp(struct sk_buff *skb) struct aoe_hdr *h; struct aoe_cfghdr *ch; struct aoetgt *t; - struct aoeif *ifp; ulong flags, sysminor, aoemajor; struct sk_buff *sl; struct sk_buff_head queue; @@ -1345,32 +1387,13 @@ aoecmd_cfg_rsp(struct sk_buff *skb) if (!t) goto bail; } - ifp = getif(t, skb->dev); - if (!ifp) { - ifp = addif(t, skb->dev); - if (!ifp) { - printk(KERN_INFO - "aoe: device addif failure; " - "too many interfaces?\n"); - goto bail; - } - } - if (ifp->maxbcnt) { - n = ifp->nd->mtu; - n -= sizeof (struct aoe_hdr) + sizeof (struct aoe_atahdr); - n /= 512; - if (n > ch->scnt) - n = ch->scnt; - n = n ? n * 512 : DEFAULTBCNT; - if (n != ifp->maxbcnt) { - printk(KERN_INFO - "aoe: e%ld.%d: setting %d%s%s:%pm\n", - d->aoemajor, d->aoeminor, n, - " byte data frames on ", ifp->nd->name, - t->addr); - ifp->maxbcnt = n; - } - } + n = skb->dev->mtu; + n -= sizeof(struct aoe_hdr) + sizeof(struct aoe_atahdr); + n /= 512; + if (n > ch->scnt) + n = ch->scnt; + n = n ? n * 512 : DEFAULTBCNT; + setifbcnt(t, skb->dev, n); /* don't change users' perspective */ if (d->nopen == 0) { @@ -1391,22 +1414,14 @@ void aoecmd_cleanslate(struct aoedev *d) { struct aoetgt **t, **te; - struct aoeif *p, *e; d->mintimer = MINTIMER; + d->maxbcnt = 0; t = d->targets; te = t + NTARGETS; - for (; t < te && *t; t++) { + for (; t < te && *t; t++) (*t)->maxout = (*t)->nframes; - p = (*t)->ifs; - e = p + NAOEIFS; - for (; p < e; p++) { - p->lostjumbo = 0; - p->lost = 0; - p->maxbcnt = DEFAULTBCNT; - } - } } void -- 1.7.2.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/