The patch titled
Subject: aoe: use packets that work with the smallest-MTU local interface
has been added to the -mm tree. Its filename is
aoe-use-packets-that-work-with-the-smallest-mtu-local-interface.patch
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------------------------------------------------------
From: Ed Cashin <ecashin@xxxxxxxxxx>
Subject: aoe: use packets that work with the smallest-MTU local interface
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 <ecashin@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/block/aoe/aoe.h | 7 -
drivers/block/aoe/aoecmd.c | 151 +++++++++++++++++++----------------
2 files changed, 87 insertions(+), 71 deletions(-)
diff -puN drivers/block/aoe/aoe.h~aoe-use-packets-that-work-with-the-smallest-mtu-local-interface drivers/block/aoe/aoe.h
--- a/drivers/block/aoe/aoe.h~aoe-use-packets-that-work-with-the-smallest-mtu-local-interface
+++ a/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 -puN drivers/block/aoe/aoecmd.c~aoe-use-packets-that-work-with-the-smallest-mtu-local-interface drivers/block/aoe/aoecmd.c
--- a/drivers/block/aoe/aoecmd.c~aoe-use-packets-that-work-with-the-smallest-mtu-local-interface
+++ a/drivers/block/aoe/aoecmd.c
@@ -118,16 +118,18 @@ put_lba(struct aoe_atahdr *ah, sector_t
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_devic
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, ulo
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
_
Patches currently in -mm which might be from ecashin@xxxxxxxxxx are
aoe-for-performance-support-larger-packet-payloads.patch
aoe-kernel-thread-handles-i-o-completions-for-simple-locking.patch
aoe-become-i-o-request-queue-handler-for-increased-user-control.patch
aoe-use-a-kernel-thread-for-transmissions.patch
aoe-use-packets-that-work-with-the-smallest-mtu-local-interface.patch
aoe-failover-remote-interface-based-on-aoe_deadsecs-parameter.patch
aoe-do-revalidation-steps-in-order.patch
aoe-disallow-unsupported-aoe-minor-addresses.patch
aoe-associate-frames-with-the-aoe-storage-target.patch
aoe-increase-net_device-reference-count-while-using-it.patch
aoe-remove-unused-code-and-add-cosmetic-improvements.patch
aoe-update-internal-version-number-to-49.patch
aoe-update-copyright-year-in-touched-files.patch
aoe-update-documentation-with-new-url-and-vm-settings-reference.patch
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