#define MAXIOC (8192) /* default meant to avoid most soft lockups */
static void ktcomplete(struct frame *, struct sk_buff *);
+static int count_targets(struct aoedev *d, int *untainted);
static struct buf *nextbuf(struct aoedev *);
spinlock_t lock;
} iocq;
+static struct page *empty_page;
+
static struct sk_buff *
new_skb(ulong len)
{
t = f->t;
f->buf = NULL;
+ f->lba = 0;
f->bv = NULL;
f->r_skb = NULL;
+ f->flags = 0;
list_add(&f->head, &t->ffree);
}
struct frame *f;
struct aoetgt *t, **tt;
int totout = 0;
+ int use_tainted;
+ int has_untainted;
if (d->targets[0] == NULL) { /* shouldn't happen, but I'm paranoid */
printk(KERN_ERR "aoe: NULL TARGETS!\n");
return NULL;
}
tt = d->tgt; /* last used target */
- for (;;) {
+ for (use_tainted = 0, has_untainted = 0;;) {
tt++;
if (tt >= &d->targets[NTARGETS] || !*tt)
tt = d->targets;
t = *tt;
- totout += t->nout;
+ if (!t->taint) {
+ has_untainted = 1;
+ totout += t->nout;
+ }
if (t->nout < t->maxout
- && t != d->htgt
+ && (use_tainted || !t->taint)
&& t->ifp->nd) {
f = newtframe(d, t);
if (f) {
return f;
}
}
- if (tt == d->tgt) /* we've looped and found nada */
- break;
+ if (tt == d->tgt) { /* we've looped and found nada */
+ if (!use_tainted && !has_untainted)
+ use_tainted = 1;
+ else
+ break;
+ }
}
if (totout == 0) {
d->kicked++;
list_add_tail(&f->head, &d->factive[n]);
}
+static void
+ata_rw_frameinit(struct frame *f)
+{
+ struct aoetgt *t;
+ struct aoe_hdr *h;
+ struct aoe_atahdr *ah;
+ struct sk_buff *skb;
+ char writebit, extbit;
+
+ skb = f->skb;
+ h = (struct aoe_hdr *) skb_mac_header(skb);
+ ah = (struct aoe_atahdr *) (h + 1);
+ skb_put(skb, sizeof(*h) + sizeof(*ah));
+ memset(h, 0, skb->len);
+
+ writebit = 0x10;
+ extbit = 0x4;
+
+ t = f->t;
+ f->tag = aoehdr_atainit(t->d, t, h);
+ fhash(f);
+ t->nout++;
+ f->waited = 0;
+ f->waited_total = 0;
+ if (f->buf)
+ f->lba = f->buf->sector;
+
+ /* set up ata header */
+ ah->scnt = f->bcnt >> 9;
+ put_lba(ah, f->lba);
+ if (t->d->flags & DEVFL_EXT) {
+ ah->aflags |= AOEAFL_EXT;
+ } else {
+ extbit = 0;
+ ah->lba3 &= 0x0f;
+ ah->lba3 |= 0xe0; /* LBA bit + obsolete 0xa0 */
+ }
+ if (f->buf && bio_data_dir(f->buf->bio) == WRITE) {
+ skb_fillup(skb, f->bv, f->bv_off, f->bcnt);
+ ah->aflags |= AOEAFL_WRITE;
+ skb->len += f->bcnt;
+ skb->data_len = f->bcnt;
+ skb->truesize += f->bcnt;
+ t->wpkts++;
+ } else {
+ t->rpkts++;
+ writebit = 0;
+ }
+
+ ah->cmdstat = ATA_CMD_PIO_READ | writebit | extbit;
+ skb->dev = t->ifp->nd;
+}
+
static int
aoecmd_ata_rw(struct aoedev *d)
{
struct frame *f;
- struct aoe_hdr *h;
- struct aoe_atahdr *ah;
struct buf *buf;
struct aoetgt *t;
struct sk_buff *skb;
struct sk_buff_head queue;
ulong bcnt, fbcnt;
- char writebit, extbit;
-
- writebit = 0x10;
- extbit = 0x4;
buf = nextbuf(d);
if (buf == NULL)
} while (fbcnt);
/* initialize the headers & frame */
- skb = f->skb;
- h = (struct aoe_hdr *) skb_mac_header(skb);
- ah = (struct aoe_atahdr *) (h+1);
- skb_put(skb, sizeof *h + sizeof *ah);
- memset(h, 0, skb->len);
- f->tag = aoehdr_atainit(d, t, h);
- fhash(f);
- t->nout++;
- f->waited = 0;
- f->waited_total = 0;
f->buf = buf;
f->bcnt = bcnt;
- f->lba = buf->sector;
-
- /* set up ata header */
- ah->scnt = bcnt >> 9;
- put_lba(ah, buf->sector);
- if (d->flags & DEVFL_EXT) {
- ah->aflags |= AOEAFL_EXT;
- } else {
- extbit = 0;
- ah->lba3 &= 0x0f;
- ah->lba3 |= 0xe0; /* LBA bit + obsolete 0xa0 */
- }
- if (bio_data_dir(buf->bio) == WRITE) {
- skb_fillup(skb, f->bv, f->bv_off, bcnt);
- ah->aflags |= AOEAFL_WRITE;
- skb->len += bcnt;
- skb->data_len = bcnt;
- skb->truesize += bcnt;
- t->wpkts++;
- } else {
- t->rpkts++;
- writebit = 0;
- }
-
- ah->cmdstat = ATA_CMD_PIO_READ | writebit | extbit;
+ ata_rw_frameinit(f);
/* mark all tracking fields and load out */
buf->nframesout += 1;
buf->sector += bcnt >> 9;
- skb->dev = t->ifp->nd;
- skb = skb_clone(skb, GFP_ATOMIC);
+ skb = skb_clone(f->skb, GFP_ATOMIC);
if (skb) {
do_gettimeofday(&f->sent);
f->sent_jiffs = (u32) jiffies;
h = (struct aoe_hdr *) skb_mac_header(skb);
ah = (struct aoe_atahdr *) (h+1);
- snprintf(buf, sizeof buf,
- "%15s e%ld.%d oldtag=%08x@%08lx newtag=%08x s=%pm d=%pm nout=%d\n",
- "retransmit", d->aoemajor, d->aoeminor, f->tag, jiffies, n,
- h->src, h->dst, t->nout);
- aoechr_error(buf);
+ if (!(f->flags & FFL_PROBE)) {
+ snprintf(buf, sizeof(buf),
+ "%15s e%ld.%d oldtag=%08x@%08lx newtag=%08x s=%pm d=%pm nout=%d\n",
+ "retransmit", d->aoemajor, d->aoeminor,
+ f->tag, jiffies, n,
+ h->src, h->dst, t->nout);
+ aoechr_error(buf);
+ }
f->tag = n;
fhash(f);
}
static struct frame *
-reassign_frame(struct list_head *pos)
+reassign_frame(struct frame *f)
{
- struct frame *f;
struct frame *nf;
struct sk_buff *skb;
- f = list_entry(pos, struct frame, head);
nf = newframe(f->t->d);
if (!nf)
return NULL;
-
- list_del(pos);
+ if (nf->t == f->t) {
+ aoe_freetframe(nf);
+ return NULL;
+ }
skb = nf->skb;
nf->skb = f->skb;
nf->sent = f->sent;
nf->sent_jiffs = f->sent_jiffs;
f->skb = skb;
- aoe_freetframe(f);
- f->t->nout--;
- nf->t->nout++;
return nf;
}
-static int
-sthtith(struct aoedev *d)
+static void
+probe(struct aoetgt *t)
{
- struct frame *f, *nf;
- struct list_head *nx, *pos, *head;
- struct aoetgt *ht = d->htgt;
- int i;
+ struct aoedev *d;
+ struct frame *f;
+ struct sk_buff *skb;
+ struct sk_buff_head queue;
+ size_t n, m;
+ int frag;
- /* look through the active and pending retransmit frames */
- for (i = 0; i < NFACTIVE; i++) {
- head = &d->factive[i];
- list_for_each_safe(pos, nx, head) {
- f = list_entry(pos, struct frame, head);
- if (f->t != ht)
- continue;
- nf = reassign_frame(pos);
- if (!nf)
- return 0;
- resend(d, nf);
- }
+ d = t->d;
+ f = newtframe(d, t);
+ if (!f) {
+ pr_err("%s %pm for e%ld.%d: %s\n",
+ "aoe: cannot probe remote address",
+ t->addr,
+ (long) d->aoemajor, d->aoeminor,
+ "no frame available");
+ return;
}
- head = &d->rexmitq;
- list_for_each_safe(pos, nx, head) {
- f = list_entry(pos, struct frame, head);
- if (f->t != ht)
- continue;
- nf = reassign_frame(pos);
- if (!nf)
- return 0;
- resend(d, nf);
+ f->flags |= FFL_PROBE;
+ ifrotate(t);
+ f->bcnt = t->d->maxbcnt ? t->d->maxbcnt : DEFAULTBCNT;
+ ata_rw_frameinit(f);
+ skb = f->skb;
+ for (frag = 0, n = f->bcnt; n > 0; ++frag, n -= m) {
+ if (n < PAGE_SIZE)
+ m = n;
+ else
+ m = PAGE_SIZE;
+ skb_fill_page_desc(skb, frag, empty_page, 0, m);
}
- /* 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;
+ skb->len += f->bcnt;
+ skb->data_len = f->bcnt;
+ skb->truesize += f->bcnt;
+
+ skb = skb_clone(f->skb, GFP_ATOMIC);
+ if (skb) {
+ do_gettimeofday(&f->sent);
+ f->sent_jiffs = (u32) jiffies;
+ __skb_queue_head_init(&queue);
+ __skb_queue_tail(&queue, skb);
+ aoenet_xmit(&queue);
+ }
+}
+
+static long
+rto(struct aoedev *d)
+{
+ long t;
+
+ t = 2 * d->rttavg >> RTTSCALE;
+ t += 8 * d->rttdev >> RTTDSCALE;
+ if (t == 0)
+ t = 1;
+
+ return t;
}
static void
{
struct aoetgt *t;
struct frame *f;
+ struct frame *nf;
struct list_head *pos, *nx, *head;
int since;
+ int untainted;
+
+ count_targets(d, &untainted);
head = &d->rexmitq;
list_for_each_safe(pos, nx, head) {
f = list_entry(pos, struct frame, head);
t = f->t;
+ if (t->taint) {
+ if (!(f->flags & FFL_PROBE)) {
+ nf = reassign_frame(f);
+ if (nf) {
+ if (t->nout_probes == 0
+ && untainted > 0) {
+ probe(t);
+ t->nout_probes++;
+ }
+ list_replace(&f->head, &nf->head);
+ pos = &nf->head;
+ aoe_freetframe(f);
+ f = nf;
+ t = f->t;
+ }
+ } else if (untainted < 1) {
+ /* don't probe w/o other untainted aoetgts */
+ goto stop_probe;
+ } else if (tsince_hr(f) < t->taint * rto(d)) {
+ /* reprobe slowly when taint is high */
+ continue;
+ }
+ } else if (f->flags & FFL_PROBE) {
+stop_probe: /* don't probe untainted aoetgts */
+ list_del(pos);
+ aoe_freetframe(f);
+ /* leaving d->kicked, because this is routine */
+ f->t->d->flags |= DEVFL_KICKME;
+ continue;
+ }
if (t->nout >= t->maxout)
continue;
list_del(pos);
t->nout++;
+ if (f->flags & FFL_PROBE)
+ t->nout_probes++;
since = tsince_hr(f);
f->waited += since;
f->waited_total += since;
}
}
+/* An aoetgt accumulates demerits quickly, and successful
+ * probing redeems the aoetgt slowly.
+ */
+static void
+scorn(struct aoetgt *t)
+{
+ int n;
+
+ n = t->taint++;
+ t->taint += t->taint * 2;
+ if (n > t->taint)
+ t->taint = n;
+ if (t->taint > MAX_TAINT)
+ t->taint = MAX_TAINT;
+}
+
+static int
+count_targets(struct aoedev *d, int *untainted)
+{
+ int i, good;
+
+ for (i = good = 0; i < d->ntargets && d->targets[i]; ++i)
+ if (d->targets[i]->taint == 0)
+ good++;
+
+ if (untainted)
+ *untainted = good;
+ return i;
+}
+
static void
rexmit_timer(ulong vp)
{
register long timeout;
ulong flags, n;
int i;
+ int utgts; /* number of aoetgt descriptors (not slots) */
int since;
d = (struct aoedev *) vp;
spin_lock_irqsave(&d->lock, flags);
/* timeout based on observed timings and variations */
- timeout = 2 * d->rttavg >> RTTSCALE;
- timeout += 8 * d->rttdev >> RTTDSCALE;
- if (timeout == 0)
- timeout = 1;
+ timeout = rto(d);
+
+ utgts = count_targets(d, NULL);
if (d->flags & DEVFL_TKILL) {
spin_unlock_irqrestore(&d->lock, flags);
since = tsince_hr(f);
n = f->waited_total + since;
n /= USEC_PER_SEC;
- if (n > aoe_deadsecs) {
+ if (n > aoe_deadsecs && !(f->flags & FFL_PROBE)) {
/* Waited too long. Device failure.
* Hang all frames on first hash bucket for downdev
* to clean up.
}
t = f->t;
- if (n > aoe_deadsecs/2)
- d->htgt = t; /* see if another target can help */
+ n = f->waited + since;
+ n /= USEC_PER_SEC;
+ if (aoe_deadsecs && utgts > 0
+ && (n > aoe_deadsecs / utgts || n > HARD_SCORN_SECS))
+ scorn(t); /* avoid this target */
if (t->maxout != 1) {
t->ssthresh = t->maxout / 2;
t->maxout = 1;
}
- ifp = getif(t, f->skb->dev);
- if (ifp && ++ifp->lost > (t->nframes << 1)
- && (ifp != t->ifs || t->ifs[1].nd)) {
- ejectif(t, ifp);
- ifp = NULL;
+ if (f->flags & FFL_PROBE) {
+ t->nout_probes--;
+ } else {
+ ifp = getif(t, f->skb->dev);
+ if (ifp && ++ifp->lost > (t->nframes << 1)
+ && (ifp != t->ifs || t->ifs[1].nd)) {
+ ejectif(t, ifp);
+ ifp = NULL;
+ }
}
list_move_tail(pos, &d->rexmitq);
t->nout--;
rexmit_deferred(d);
out:
- if ((d->flags & DEVFL_KICKME || d->htgt) && d->blkq) {
+ if ((d->flags & DEVFL_KICKME) && d->blkq) {
d->flags &= ~DEVFL_KICKME;
d->blkq->request_fn(d->blkq);
}
void
aoecmd_work(struct aoedev *d)
{
- if (d->htgt && !sthtith(d))
- return;
rexmit_deferred(d);
while (aoecmd_ata_rw(d))
;
struct aoeif *ifp;
struct aoedev *d;
long n;
+ int untainted;
if (f == NULL)
return;
t = f->t;
d = t->d;
+ skb = f->r_skb;
+ buf = f->buf;
+ if (f->flags & FFL_PROBE)
+ goto out;
+ if (!skb) /* just fail the buf. */
+ goto noskb;
hout = (struct aoe_hdr *) skb_mac_header(f->skb);
ahout = (struct aoe_atahdr *) (hout+1);
- buf = f->buf;
- skb = f->r_skb;
- if (skb == NULL)
- goto noskb; /* just fail the buf. */
hin = (struct aoe_hdr *) skb->data;
skb_pull(skb, sizeof(*hin));
d->aoemajor, d->aoeminor);
noskb: if (buf)
clear_bit(BIO_UPTODATE, &buf->bio->bi_flags);
- goto badrsp;
+ goto out;
}
n = ahout->scnt << 9;
ifp = getif(t, skb->dev);
if (ifp)
ifp->lost = 0;
- if (d->htgt == t) /* I'll help myself, thank you. */
- d->htgt = NULL;
spin_unlock_irq(&d->lock);
break;
case ATA_CMD_ID_ATA:
be16_to_cpu(get_unaligned(&hin->major)),
hin->minor);
}
-badrsp:
+out:
spin_lock_irq(&d->lock);
+ if (t->taint > 0
+ && --t->taint > 0
+ && t->nout_probes == 0) {
+ count_targets(d, &untainted);
+ if (untainted > 0) {
+ probe(t);
+ t->nout_probes++;
+ }
+ }
aoe_freetframe(f);
if (f) {
calc_rttavg(d, f->t, tsince_hr(f));
f->t->nout--;
+ if (f->flags & FFL_PROBE)
+ f->t->nout_probes--;
} else {
f = getframe_deferred(d, n);
if (f) {
memcpy(t->addr, addr, sizeof t->addr);
t->ifp = t->ifs;
aoecmd_wreset(t);
+ t->maxout = t->nframes / 2;
INIT_LIST_HEAD(&t->ffree);
return *tt = t;
}
int __init
aoecmd_init(void)
{
+ void *p;
+
+ /* get_zeroed_page returns page with ref count 1 */
+ p = (void *) get_zeroed_page(GFP_KERNEL | __GFP_REPEAT);
+ if (!p)
+ return -ENOMEM;
+ empty_page = virt_to_page(p);
+
INIT_LIST_HEAD(&iocq.head);
spin_lock_init(&iocq.lock);
init_waitqueue_head(&ktiowq);
{
aoe_ktstop(&kts);
aoe_flush_iocq();
+
+ free_page((unsigned long) page_address(empty_page));
+ empty_page = NULL;
}
projects / users / willy / pagecache.git / commitdiff