Commit 4f51dc5e authored by Ed L. Cashin's avatar Ed L. Cashin Committed by Greg Kroah-Hartman
Browse files

aoe: zero copy write 2 of 2 



Avoid memory copy on writes.
(This patch follows patch 4.)

Signed-off-by: default avatar"Ed L. Cashin" <ecashin@coraid.com>
Acked-by: default avatarAlan Cox <alan@redhat.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent dced3a05

drivers/block/aoe/aoe.h

+1 −0
Original line number Diff line number Diff line
@@ -84,6 +84,7 @@ enum { 
	DEVFL_PAUSE = (1<<5),

	DEVFL_NEWSIZE = (1<<6),	/* need to update dev size in block layer */

	DEVFL_MAXBCNT = (1<<7), /* d->maxbcnt is not changeable */

	DEVFL_KICKME = (1<<8),



	BUFFL_FAIL = 1,

};

drivers/block/aoe/aoecmd.c

+62 −20
Original line number Diff line number Diff line
@@ -120,7 +120,7 @@ aoecmd_ata_rw(struct aoedev *d, struct frame *f) 
	h = (struct aoe_hdr *) skb->mac.raw;

	ah = (struct aoe_atahdr *) (h+1);

	skb->len = sizeof *h + sizeof *ah;

	memset(h, 0, skb->len);

	memset(h, 0, ETH_ZLEN);

	f->tag = aoehdr_atainit(d, h);

	f->waited = 0;

	f->buf = buf;
@@ -143,8 +143,9 @@ aoecmd_ata_rw(struct aoedev *d, struct frame *f) 
		skb_fill_page_desc(skb, 0, virt_to_page(f->bufaddr),

			offset_in_page(f->bufaddr), bcnt);

		ah->aflags |= AOEAFL_WRITE;

		skb->len += bcnt;

		skb->data_len = bcnt;

	} else {

		skb_shinfo(skb)->nr_frags = 0;

		skb->len = ETH_ZLEN;

		writebit = 0;

	}
@@ -167,8 +168,9 @@ aoecmd_ata_rw(struct aoedev *d, struct frame *f) 
	}



	skb->dev = d->ifp;

	skb_get(skb);

	skb->next = NULL;

	skb = skb_clone(skb, GFP_ATOMIC);

	if (skb == NULL)

		return;

	if (d->sendq_hd)

		d->sendq_tl->next = skb;

	else
@@ -224,6 +226,29 @@ aoecmd_cfg_pkts(ushort aoemajor, unsigned char aoeminor, struct sk_buff **tail) 
	return sl;

}



static struct frame *

freeframe(struct aoedev *d)

{

	struct frame *f, *e;

	int n = 0;



	f = d->frames;

	e = f + d->nframes;

	for (; f<e; f++) {

		if (f->tag != FREETAG)

			continue;

		if (atomic_read(&skb_shinfo(f->skb)->dataref) == 1) {

			skb_shinfo(f->skb)->nr_frags = f->skb->data_len = 0;

			return f;

		}

		n++;

	}

	if (n == d->nframes)	/* wait for network layer */

		d->flags |= DEVFL_KICKME;



	return NULL;

}



/* enters with d->lock held */

void

aoecmd_work(struct aoedev *d)
@@ -239,7 +264,7 @@ aoecmd_work(struct aoedev *d) 
	}



loop:

	f = getframe(d, FREETAG);

	f = freeframe(d);

	if (f == NULL)

		return;

	if (d->inprocess == NULL) {
@@ -282,20 +307,25 @@ rexmit(struct aoedev *d, struct frame *f) 
	n = DEFAULTBCNT / 512;

	if (ah->scnt > n) {

		ah->scnt = n;

		if (ah->aflags & AOEAFL_WRITE)

		if (ah->aflags & AOEAFL_WRITE) {

			skb_fill_page_desc(skb, 0, virt_to_page(f->bufaddr),

				offset_in_page(f->bufaddr), DEFAULTBCNT);

			skb->len = sizeof *h + sizeof *ah + DEFAULTBCNT;

			skb->data_len = DEFAULTBCNT;

		}

		if (++d->lostjumbo > (d->nframes << 1))

		if (d->maxbcnt != DEFAULTBCNT) {

			iprintk("too many lost jumbo - using 1KB frames.\n");

			iprintk("e%ld.%ld: too many lost jumbo on %s - using 1KB frames.\n",

				d->aoemajor, d->aoeminor, d->ifp->name);

			d->maxbcnt = DEFAULTBCNT;

			d->flags |= DEVFL_MAXBCNT;

		}

	}



	skb->dev = d->ifp;

	skb_get(skb);

	skb->next = NULL;

	skb = skb_clone(skb, GFP_ATOMIC);

	if (skb == NULL)

		return;

	if (d->sendq_hd)

		d->sendq_tl->next = skb;

	else
@@ -350,6 +380,10 @@ rexmit_timer(ulong vp) 
			rexmit(d, f);

		}

	}

	if (d->flags & DEVFL_KICKME) {

		d->flags &= ~DEVFL_KICKME;

		aoecmd_work(d);

	}



	sl = d->sendq_hd;

	d->sendq_hd = d->sendq_tl = NULL;
@@ -552,23 +586,27 @@ aoecmd_ata_rsp(struct sk_buff *skb) 
		case WIN_WRITE:

		case WIN_WRITE_EXT:

			if (f->bcnt -= n) {

				skb = f->skb;

				f->bufaddr += n;

				put_lba(ahout, f->lba += ahout->scnt);

				n = f->bcnt;

				if (n > DEFAULTBCNT)

					n = DEFAULTBCNT;

				ahout->scnt = n >> 9;

				if (ahout->aflags & AOEAFL_WRITE)

					skb_fill_page_desc(f->skb, 0,

				if (ahout->aflags & AOEAFL_WRITE) {

					skb_fill_page_desc(skb, 0,

						virt_to_page(f->bufaddr),

						offset_in_page(f->bufaddr), n);

					skb->len = sizeof *hout + sizeof *ahout + n;

					skb->data_len = n;

				}

				f->tag = newtag(d);

				hout->tag = cpu_to_be32(f->tag);

				skb->dev = d->ifp;

				skb_get(f->skb);

				f->skb->next = NULL;

				skb = skb_clone(skb, GFP_ATOMIC);

				spin_unlock_irqrestore(&d->lock, flags);

				aoenet_xmit(f->skb);

				if (skb)

					aoenet_xmit(skb);

				return;

			}

			if (n > DEFAULTBCNT)
@@ -642,7 +680,7 @@ aoecmd_ata_id(struct aoedev *d) 
	struct frame *f;

	struct sk_buff *skb;



	f = getframe(d, FREETAG);

	f = freeframe(d);

	if (f == NULL) {

		eprintk("can't get a frame. This shouldn't happen.\n");

		return NULL;
@@ -652,8 +690,8 @@ aoecmd_ata_id(struct aoedev *d) 
	skb = f->skb;

	h = (struct aoe_hdr *) skb->mac.raw;

	ah = (struct aoe_atahdr *) (h+1);

	skb->len = sizeof *h + sizeof *ah;

	memset(h, 0, skb->len);

	skb->len = ETH_ZLEN;

	memset(h, 0, ETH_ZLEN);

	f->tag = aoehdr_atainit(d, h);

	f->waited = 0;
@@ -663,12 +701,11 @@ aoecmd_ata_id(struct aoedev *d) 
	ah->lba3 = 0xa0;



	skb->dev = d->ifp;

	skb_get(skb);



	d->rttavg = MAXTIMER;

	d->timer.function = rexmit_timer;



	return skb;

	return skb_clone(skb, GFP_ATOMIC);

}

 

void
@@ -724,7 +761,12 @@ aoecmd_cfg_rsp(struct sk_buff *skb) 
		n /= 512;

		if (n > ch->scnt)

			n = ch->scnt;

		d->maxbcnt = n ? n * 512 : DEFAULTBCNT;

		n = n ? n * 512 : DEFAULTBCNT;

		if (n != d->maxbcnt) {

			iprintk("e%ld.%ld: setting %d byte data frames on %s\n",

				d->aoemajor, d->aoeminor, n, d->ifp->name);

			d->maxbcnt = n;

		}

	}



	/* don't change users' perspective */

drivers/block/aoe/aoedev.c

+1 −0
Original line number Diff line number Diff line
@@ -121,6 +121,7 @@ aoedev_downdev(struct aoedev *d) 
			mempool_free(buf, d->bufpool);

			bio_endio(bio, bio->bi_size, -EIO);

		}

		skb_shinfo(f->skb)->nr_frags = f->skb->data_len = 0;

	}

	d->inprocess = NULL;