blob: 8188ad131b970d3c49cc32043e28d9c92a98741f [file] [log] [blame]
/* Copyright (c) 2012 Coraid, Inc. See COPYING for GPL terms. */
/*
* aoecmd.c
* Filesystem request handling methods
*/
#include <linux/ata.h>
#include <linux/slab.h>
#include <linux/hdreg.h>
#include <linux/blkdev.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/genhd.h>
#include <linux/moduleparam.h>
#include <linux/workqueue.h>
#include <linux/kthread.h>
#include <net/net_namespace.h>
#include <asm/unaligned.h>
#include <linux/uio.h>
#include "aoe.h"
#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 *);
static int aoe_deadsecs = 60 * 3;
module_param(aoe_deadsecs, int, 0644);
MODULE_PARM_DESC(aoe_deadsecs, "After aoe_deadsecs seconds, give up and fail dev.");
static int aoe_maxout = 64;
module_param(aoe_maxout, int, 0644);
MODULE_PARM_DESC(aoe_maxout,
"Only aoe_maxout outstanding packets for every MAC on eX.Y.");
static wait_queue_head_t ktiowq;
static struct ktstate kts;
/* io completion queue */
static struct {
struct list_head head;
spinlock_t lock;
} iocq;
static struct page *empty_page;
static struct sk_buff *
new_skb(ulong len)
{
struct sk_buff *skb;
skb = alloc_skb(len, GFP_ATOMIC);
if (skb) {
skb_reset_mac_header(skb);
skb_reset_network_header(skb);
skb->protocol = __constant_htons(ETH_P_AOE);
skb_checksum_none_assert(skb);
}
return skb;
}
static struct frame *
getframe_deferred(struct aoedev *d, u32 tag)
{
struct list_head *head, *pos, *nx;
struct frame *f;
head = &d->rexmitq;
list_for_each_safe(pos, nx, head) {
f = list_entry(pos, struct frame, head);
if (f->tag == tag) {
list_del(pos);
return f;
}
}
return NULL;
}
static struct frame *
getframe(struct aoedev *d, u32 tag)
{
struct frame *f;
struct list_head *head, *pos, *nx;
u32 n;
n = tag % NFACTIVE;
head = &d->factive[n];
list_for_each_safe(pos, nx, head) {
f = list_entry(pos, struct frame, head);
if (f->tag == tag) {
list_del(pos);
return f;
}
}
return NULL;
}
/*
* Leave the top bit clear so we have tagspace for userland.
* The bottom 16 bits are the xmit tick for rexmit/rttavg processing.
* This driver reserves tag -1 to mean "unused frame."
*/
static int
newtag(struct aoedev *d)
{
register ulong n;
n = jiffies & 0xffff;
return n |= (++d->lasttag & 0x7fff) << 16;
}
static u32
aoehdr_atainit(struct aoedev *d, struct aoetgt *t, struct aoe_hdr *h)
{
u32 host_tag = newtag(d);
memcpy(h->src, t->ifp->nd->dev_addr, sizeof h->src);
memcpy(h->dst, t->addr, sizeof h->dst);
h->type = __constant_cpu_to_be16(ETH_P_AOE);
h->verfl = AOE_HVER;
h->major = cpu_to_be16(d->aoemajor);
h->minor = d->aoeminor;
h->cmd = AOECMD_ATA;
h->tag = cpu_to_be32(host_tag);
return host_tag;
}
static inline void
put_lba(struct aoe_atahdr *ah, sector_t lba)
{
ah->lba0 = lba;
ah->lba1 = lba >>= 8;
ah->lba2 = lba >>= 8;
ah->lba3 = lba >>= 8;
ah->lba4 = lba >>= 8;
ah->lba5 = lba >>= 8;
}
static struct aoeif *
ifrotate(struct aoetgt *t)
{
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
skb_pool_put(struct aoedev *d, struct sk_buff *skb)
{
__skb_queue_tail(&d->skbpool, skb);
}
static struct sk_buff *
skb_pool_get(struct aoedev *d)
{
struct sk_buff *skb = skb_peek(&d->skbpool);
if (skb && atomic_read(&skb_shinfo(skb)->dataref) == 1) {
__skb_unlink(skb, &d->skbpool);
return skb;
}
if (skb_queue_len(&d->skbpool) < NSKBPOOLMAX &&
(skb = new_skb(ETH_ZLEN)))
return skb;
return NULL;
}
void
aoe_freetframe(struct frame *f)
{
struct aoetgt *t;
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);
}
static struct frame *
newtframe(struct aoedev *d, struct aoetgt *t)
{
struct frame *f;
struct sk_buff *skb;
struct list_head *pos;
if (list_empty(&t->ffree)) {
if (t->falloc >= NSKBPOOLMAX*2)
return NULL;
f = kcalloc(1, sizeof(*f), GFP_ATOMIC);
if (f == NULL)
return NULL;
t->falloc++;
f->t = t;
} else {
pos = t->ffree.next;
list_del(pos);
f = list_entry(pos, struct frame, head);
}
skb = f->skb;
if (skb == NULL) {
f->skb = skb = new_skb(ETH_ZLEN);
if (!skb) {
bail: aoe_freetframe(f);
return NULL;
}
}
if (atomic_read(&skb_shinfo(skb)->dataref) != 1) {
skb = skb_pool_get(d);
if (skb == NULL)
goto bail;
skb_pool_put(d, f->skb);
f->skb = skb;
}
skb->truesize -= skb->data_len;
skb_shinfo(skb)->nr_frags = skb->data_len = 0;
skb_trim(skb, 0);
return f;
}
static struct frame *
newframe(struct aoedev *d)
{
struct frame *f;
struct aoetgt *t, **tt;
int totout = 0;
int use_tainted;
int has_untainted;
if (!d->targets || !d->targets[0]) {
printk(KERN_ERR "aoe: NULL TARGETS!\n");
return NULL;
}
tt = d->tgt; /* last used target */
for (use_tainted = 0, has_untainted = 0;;) {
tt++;
if (tt >= &d->targets[d->ntargets] || !*tt)
tt = d->targets;
t = *tt;
if (!t->taint) {
has_untainted = 1;
totout += t->nout;
}
if (t->nout < t->maxout
&& (use_tainted || !t->taint)
&& t->ifp->nd) {
f = newtframe(d, t);
if (f) {
ifrotate(t);
d->tgt = tt;
return f;
}
}
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++;
d->flags |= DEVFL_KICKME;
}
return NULL;
}
static void
skb_fillup(struct sk_buff *skb, struct bio_vec *bv, ulong off, ulong cnt)
{
int frag = 0;
ulong fcnt;
loop:
fcnt = bv->bv_len - (off - bv->bv_offset);
if (fcnt > cnt)
fcnt = cnt;
skb_fill_page_desc(skb, frag++, bv->bv_page, off, fcnt);
cnt -= fcnt;
if (cnt <= 0)
return;
bv++;
off = bv->bv_offset;
goto loop;
}
static void
fhash(struct frame *f)
{
struct aoedev *d = f->t->d;
u32 n;
n = f->tag % NFACTIVE;
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 buf *buf;
struct aoetgt *t;
struct sk_buff *skb;
struct sk_buff_head queue;
ulong bcnt, fbcnt;
buf = nextbuf(d);
if (buf == NULL)
return 0;
f = newframe(d);
if (f == NULL)
return 0;
t = *d->tgt;
bcnt = d->maxbcnt;
if (bcnt == 0)
bcnt = DEFAULTBCNT;
if (bcnt > buf->resid)
bcnt = buf->resid;
fbcnt = bcnt;
f->bv = buf->bv;
f->bv_off = f->bv->bv_offset + (f->bv->bv_len - buf->bv_resid);
do {
if (fbcnt < buf->bv_resid) {
buf->bv_resid -= fbcnt;
buf->resid -= fbcnt;
break;
}
fbcnt -= buf->bv_resid;
buf->resid -= buf->bv_resid;
if (buf->resid == 0) {
d->ip.buf = NULL;
break;
}
buf->bv++;
buf->bv_resid = buf->bv->bv_len;
WARN_ON(buf->bv_resid == 0);
} while (fbcnt);
/* initialize the headers & frame */
f->buf = buf;
f->bcnt = bcnt;
ata_rw_frameinit(f);
/* mark all tracking fields and load out */
buf->nframesout += 1;
buf->sector += bcnt >> 9;
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);
}
return 1;
}
/* some callers cannot sleep, and they can call this function,
* transmitting the packets later, when interrupts are on
*/
static void
aoecmd_cfg_pkts(ushort aoemajor, unsigned char aoeminor, struct sk_buff_head *queue)
{
struct aoe_hdr *h;
struct aoe_cfghdr *ch;
struct sk_buff *skb;
struct net_device *ifp;
rcu_read_lock();
for_each_netdev_rcu(&init_net, ifp) {
dev_hold(ifp);
if (!is_aoe_netif(ifp))
goto cont;
skb = new_skb(sizeof *h + sizeof *ch);
if (skb == NULL) {
printk(KERN_INFO "aoe: skb alloc failure\n");
goto cont;
}
skb_put(skb, sizeof *h + sizeof *ch);
skb->dev = ifp;
__skb_queue_tail(queue, skb);
h = (struct aoe_hdr *) skb_mac_header(skb);
memset(h, 0, sizeof *h + sizeof *ch);
memset(h->dst, 0xff, sizeof h->dst);
memcpy(h->src, ifp->dev_addr, sizeof h->src);
h->type = __constant_cpu_to_be16(ETH_P_AOE);
h->verfl = AOE_HVER;
h->major = cpu_to_be16(aoemajor);
h->minor = aoeminor;
h->cmd = AOECMD_CFG;
cont:
dev_put(ifp);
}
rcu_read_unlock();
}
static void
resend(struct aoedev *d, struct frame *f)
{
struct sk_buff *skb;
struct sk_buff_head queue;
struct aoe_hdr *h;
struct aoe_atahdr *ah;
struct aoetgt *t;
char buf[128];
u32 n;
t = f->t;
n = newtag(d);
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);
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);
h->tag = cpu_to_be32(n);
memcpy(h->dst, t->addr, sizeof h->dst);
memcpy(h->src, t->ifp->nd->dev_addr, sizeof h->src);
skb->dev = t->ifp->nd;
skb = skb_clone(skb, GFP_ATOMIC);
if (skb == NULL)
return;
do_gettimeofday(&f->sent);
f->sent_jiffs = (u32) jiffies;
__skb_queue_head_init(&queue);
__skb_queue_tail(&queue, skb);
aoenet_xmit(&queue);
}
static int
tsince_hr(struct frame *f)
{
struct timeval now;
int n;
do_gettimeofday(&now);
n = now.tv_usec - f->sent.tv_usec;
n += (now.tv_sec - f->sent.tv_sec) * USEC_PER_SEC;
if (n < 0)
n = -n;
/* For relatively long periods, use jiffies to avoid
* discrepancies caused by updates to the system time.
*
* On system with HZ of 1000, 32-bits is over 49 days
* worth of jiffies, or over 71 minutes worth of usecs.
*
* Jiffies overflow is handled by subtraction of unsigned ints:
* (gdb) print (unsigned) 2 - (unsigned) 0xfffffffe
* $3 = 4
* (gdb)
*/
if (n > USEC_PER_SEC / 4) {
n = ((u32) jiffies) - f->sent_jiffs;
n *= USEC_PER_SEC / HZ;
}
return n;
}
static int
tsince(u32 tag)
{
int n;
n = jiffies & 0xffff;
n -= tag & 0xffff;
if (n < 0)
n += 1<<16;
return jiffies_to_usecs(n + 1);
}
static struct aoeif *
getif(struct aoetgt *t, struct net_device *nd)
{
struct aoeif *p, *e;
p = t->ifs;
e = p + NAOEIFS;
for (; p < e; p++)
if (p->nd == nd)
return p;
return NULL;
}
static void
ejectif(struct aoetgt *t, struct aoeif *ifp)
{
struct aoeif *e;
struct net_device *nd;
ulong n;
nd = ifp->nd;
e = t->ifs + NAOEIFS - 1;
n = (e - ifp) * sizeof *ifp;
memmove(ifp, ifp+1, n);
e->nd = NULL;
dev_put(nd);
}
static struct frame *
reassign_frame(struct frame *f)
{
struct frame *nf;
struct sk_buff *skb;
nf = newframe(f->t->d);
if (!nf)
return NULL;
if (nf->t == f->t) {
aoe_freetframe(nf);
return NULL;
}
skb = nf->skb;
nf->skb = f->skb;
nf->buf = f->buf;
nf->bcnt = f->bcnt;
nf->lba = f->lba;
nf->bv = f->bv;
nf->bv_off = f->bv_off;
nf->waited = 0;
nf->waited_total = f->waited_total;
nf->sent = f->sent;
nf->sent_jiffs = f->sent_jiffs;
f->skb = skb;
return nf;
}
static void
probe(struct aoetgt *t)
{
struct aoedev *d;
struct frame *f;
struct sk_buff *skb;
struct sk_buff_head queue;
size_t n, m;
int frag;
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;
}
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);
}
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
rexmit_deferred(struct aoedev *d)
{
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;
resend(d, f);
}
}
/* 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)
{
struct aoedev *d;
struct aoetgt *t;
struct aoeif *ifp;
struct frame *f;
struct list_head *head, *pos, *nx;
LIST_HEAD(flist);
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 = rto(d);
utgts = count_targets(d, NULL);
if (d->flags & DEVFL_TKILL) {
spin_unlock_irqrestore(&d->lock, flags);
return;
}
/* collect all frames to rexmit into flist */
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 (tsince_hr(f) < timeout)
break; /* end of expired frames */
/* move to flist for later processing */
list_move_tail(pos, &flist);
}
}
/* process expired frames */
while (!list_empty(&flist)) {
pos = flist.next;
f = list_entry(pos, struct frame, head);
since = tsince_hr(f);
n = f->waited_total + since;
n /= USEC_PER_SEC;
if (aoe_deadsecs
&& n > aoe_deadsecs
&& !(f->flags & FFL_PROBE)) {
/* Waited too long. Device failure.
* Hang all frames on first hash bucket for downdev
* to clean up.
*/
list_splice(&flist, &d->factive[0]);
aoedev_downdev(d);
goto out;
}
t = f->t;
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;
}
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->blkq) {
d->flags &= ~DEVFL_KICKME;
d->blkq->request_fn(d->blkq);
}
d->timer.expires = jiffies + TIMERTICK;
add_timer(&d->timer);
spin_unlock_irqrestore(&d->lock, flags);
}
static unsigned long
rqbiocnt(struct request *r)
{
struct bio *bio;
unsigned long n = 0;
__rq_for_each_bio(bio, r)
n++;
return n;
}
/* This can be removed if we are certain that no users of the block
* layer will ever use zero-count pages in bios. Otherwise we have to
* protect against the put_page sometimes done by the network layer.
*
* See http://oss.sgi.com/archives/xfs/2007-01/msg00594.html for
* discussion.
*
* We cannot use get_page in the workaround, because it insists on a
* positive page count as a precondition. So we use _count directly.
*/
static void
bio_pageinc(struct bio *bio)
{
struct bio_vec *bv;
struct page *page;
int i;
bio_for_each_segment(bv, bio, i) {
page = bv->bv_page;
/* Non-zero page count for non-head members of
* compound pages is no longer allowed by the kernel,
* but this has never been seen here.
*/
if (unlikely(PageCompound(page)))
if (compound_trans_head(page) != page) {
pr_crit("page tail used for block I/O\n");
BUG();
}
atomic_inc(&page->_count);
}
}
static void
bio_pagedec(struct bio *bio)
{
struct bio_vec *bv;
int i;
bio_for_each_segment(bv, bio, i)
atomic_dec(&bv->bv_page->_count);
}
static void
bufinit(struct buf *buf, struct request *rq, struct bio *bio)
{
struct bio_vec *bv;
memset(buf, 0, sizeof(*buf));
buf->rq = rq;
buf->bio = bio;
buf->resid = bio->bi_size;
buf->sector = bio->bi_sector;
bio_pageinc(bio);
buf->bv = bio_iovec(bio);
buf->bv_resid = bv->bv_len;
WARN_ON(buf->bv_resid == 0);
}
static struct buf *
nextbuf(struct aoedev *d)
{
struct request *rq;
struct request_queue *q;
struct buf *buf;
struct bio *bio;
q = d->blkq;
if (q == NULL)
return NULL; /* initializing */
if (d->ip.buf)
return d->ip.buf;
rq = d->ip.rq;
if (rq == NULL) {
rq = blk_peek_request(q);
if (rq == NULL)
return NULL;
blk_start_request(rq);
d->ip.rq = rq;
d->ip.nxbio = rq->bio;
rq->special = (void *) rqbiocnt(rq);
}
buf = mempool_alloc(d->bufpool, GFP_ATOMIC);
if (buf == NULL) {
pr_err("aoe: nextbuf: unable to mempool_alloc!\n");
return NULL;
}
bio = d->ip.nxbio;
bufinit(buf, rq, bio);
bio = bio->bi_next;
d->ip.nxbio = bio;
if (bio == NULL)
d->ip.rq = NULL;
return d->ip.buf = buf;
}
/* enters with d->lock held */
void
aoecmd_work(struct aoedev *d)
{
rexmit_deferred(d);
while (aoecmd_ata_rw(d))
;
}
/* this function performs work that has been deferred until sleeping is OK
*/
void
aoecmd_sleepwork(struct work_struct *work)
{
struct aoedev *d = container_of(work, struct aoedev, work);
struct block_device *bd;
u64 ssize;
if (d->flags & DEVFL_GDALLOC)
aoeblk_gdalloc(d);
if (d->flags & DEVFL_NEWSIZE) {
ssize = get_capacity(d->gd);
bd = bdget_disk(d->gd, 0);
if (bd) {
mutex_lock(&bd->bd_inode->i_mutex);
i_size_write(bd->bd_inode, (loff_t)ssize<<9);
mutex_unlock(&bd->bd_inode->i_mutex);
bdput(bd);
}
spin_lock_irq(&d->lock);
d->flags |= DEVFL_UP;
d->flags &= ~DEVFL_NEWSIZE;
spin_unlock_irq(&d->lock);
}
}
static void
ata_ident_fixstring(u16 *id, int ns)
{
u16 s;
while (ns-- > 0) {
s = *id;
*id++ = s >> 8 | s << 8;
}
}
static void
ataid_complete(struct aoedev *d, struct aoetgt *t, unsigned char *id)
{
u64 ssize;
u16 n;
/* word 83: command set supported */
n = get_unaligned_le16(&id[83 << 1]);
/* word 86: command set/feature enabled */
n |= get_unaligned_le16(&id[86 << 1]);
if (n & (1<<10)) { /* bit 10: LBA 48 */
d->flags |= DEVFL_EXT;
/* word 100: number lba48 sectors */
ssize = get_unaligned_le64(&id[100 << 1]);
/* set as in ide-disk.c:init_idedisk_capacity */
d->geo.cylinders = ssize;
d->geo.cylinders /= (255 * 63);
d->geo.heads = 255;
d->geo.sectors = 63;
} else {
d->flags &= ~DEVFL_EXT;
/* number lba28 sectors */
ssize = get_unaligned_le32(&id[60 << 1]);
/* NOTE: obsolete in ATA 6 */
d->geo.cylinders = get_unaligned_le16(&id[54 << 1]);
d->geo.heads = get_unaligned_le16(&id[55 << 1]);
d->geo.sectors = get_unaligned_le16(&id[56 << 1]);
}
ata_ident_fixstring((u16 *) &id[10<<1], 10); /* serial */
ata_ident_fixstring((u16 *) &id[23<<1], 4); /* firmware */
ata_ident_fixstring((u16 *) &id[27<<1], 20); /* model */
memcpy(d->ident, id, sizeof(d->ident));
if (d->ssize != ssize)
printk(KERN_INFO
"aoe: %pm e%ld.%d v%04x has %llu sectors\n",
t->addr,
d->aoemajor, d->aoeminor,
d->fw_ver, (long long)ssize);
d->ssize = ssize;
d->geo.start = 0;
if (d->flags & (DEVFL_GDALLOC|DEVFL_NEWSIZE))
return;
if (d->gd != NULL) {
set_capacity(d->gd, ssize);
d->flags |= DEVFL_NEWSIZE;
} else
d->flags |= DEVFL_GDALLOC;
schedule_work(&d->work);
}
static void
calc_rttavg(struct aoedev *d, struct aoetgt *t, int rtt)
{
register long n;
n = rtt;
/* cf. Congestion Avoidance and Control, Jacobson & Karels, 1988 */
n -= d->rttavg >> RTTSCALE;
d->rttavg += n;
if (n < 0)
n = -n;
n -= d->rttdev >> RTTDSCALE;
d->rttdev += n;
if (!t || t->maxout >= t->nframes)
return;
if (t->maxout < t->ssthresh)
t->maxout += 1;
else if (t->nout == t->maxout && t->next_cwnd-- == 0) {
t->maxout += 1;
t->next_cwnd = t->maxout;
}
}
static struct aoetgt *
gettgt(struct aoedev *d, char *addr)
{
struct aoetgt **t, **e;
t = d->targets;
e = t + d->ntargets;
for (; t < e && *t; t++)
if (memcmp((*t)->addr, addr, sizeof((*t)->addr)) == 0)
return *t;
return NULL;
}
static void
bvcpy(struct bio_vec *bv, ulong off, struct sk_buff *skb, long cnt)
{
ulong fcnt;
char *p;
int soff = 0;
loop:
fcnt = bv->bv_len - (off - bv->bv_offset);
if (fcnt > cnt)
fcnt = cnt;
p = page_address(bv->bv_page) + off;
skb_copy_bits(skb, soff, p, fcnt);
soff += fcnt;
cnt -= fcnt;
if (cnt <= 0)
return;
bv++;
off = bv->bv_offset;
goto loop;
}
void
aoe_end_request(struct aoedev *d, struct request *rq, int fastfail)
{
struct bio *bio;
int bok;
struct request_queue *q;
q = d->blkq;
if (rq == d->ip.rq)
d->ip.rq = NULL;
do {
bio = rq->bio;
bok = !fastfail && test_bit(BIO_UPTODATE, &bio->bi_flags);
} while (__blk_end_request(rq, bok ? 0 : -EIO, bio->bi_size));
/* cf. http://lkml.org/lkml/2006/10/31/28 */
if (!fastfail)
__blk_run_queue(q);
}
static void
aoe_end_buf(struct aoedev *d, struct buf *buf)
{
struct request *rq;
unsigned long n;
if (buf == d->ip.buf)
d->ip.buf = NULL;
rq = buf->rq;
bio_pagedec(buf->bio);
mempool_free(buf, d->bufpool);
n = (unsigned long) rq->special;
rq->special = (void *) --n;
if (n == 0)
aoe_end_request(d, rq, 0);
}
static void
ktiocomplete(struct frame *f)
{
struct aoe_hdr *hin, *hout;
struct aoe_atahdr *ahin, *ahout;
struct buf *buf;
struct sk_buff *skb;
struct aoetgt *t;
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);
hin = (struct aoe_hdr *) skb->data;
skb_pull(skb, sizeof(*hin));
ahin = (struct aoe_atahdr *) skb->data;
skb_pull(skb, sizeof(*ahin));
if (ahin->cmdstat & 0xa9) { /* these bits cleared on success */
pr_err("aoe: ata error cmd=%2.2Xh stat=%2.2Xh from e%ld.%d\n",
ahout->cmdstat, ahin->cmdstat,
d->aoemajor, d->aoeminor);
noskb: if (buf)
clear_bit(BIO_UPTODATE, &buf->bio->bi_flags);
goto out;
}
n = ahout->scnt << 9;
switch (ahout->cmdstat) {
case ATA_CMD_PIO_READ:
case ATA_CMD_PIO_READ_EXT:
if (skb->len < n) {
pr_err("%s e%ld.%d. skb->len=%d need=%ld\n",
"aoe: runt data size in read from",
(long) d->aoemajor, d->aoeminor,
skb->len, n);
clear_bit(BIO_UPTODATE, &buf->bio->bi_flags);
break;
}
bvcpy(f->bv, f->bv_off, skb, n);
case ATA_CMD_PIO_WRITE:
case ATA_CMD_PIO_WRITE_EXT:
spin_lock_irq(&d->lock);
ifp = getif(t, skb->dev);
if (ifp)
ifp->lost = 0;
spin_unlock_irq(&d->lock);
break;
case ATA_CMD_ID_ATA:
if (skb->len < 512) {
pr_info("%s e%ld.%d. skb->len=%d need=512\n",
"aoe: runt data size in ataid from",
(long) d->aoemajor, d->aoeminor,
skb->len);
break;
}
if (skb_linearize(skb))
break;
spin_lock_irq(&d->lock);
ataid_complete(d, t, skb->data);
spin_unlock_irq(&d->lock);
break;
default:
pr_info("aoe: unrecognized ata command %2.2Xh for %d.%d\n",
ahout->cmdstat,
be16_to_cpu(get_unaligned(&hin->major)),
hin->minor);
}
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 (buf && --buf->nframesout == 0 && buf->resid == 0)
aoe_end_buf(d, buf);
spin_unlock_irq(&d->lock);
aoedev_put(d);
dev_kfree_skb(skb);
}
/* Enters with iocq.lock held.
* Returns true iff responses needing processing remain.
*/
static int
ktio(void)
{
struct frame *f;
struct list_head *pos;
int i;
for (i = 0; ; ++i) {
if (i == MAXIOC)
return 1;
if (list_empty(&iocq.head))
return 0;
pos = iocq.head.next;
list_del(pos);
spin_unlock_irq(&iocq.lock);
f = list_entry(pos, struct frame, head);
ktiocomplete(f);
spin_lock_irq(&iocq.lock);
}
}
static int
kthread(void *vp)
{
struct ktstate *k;
DECLARE_WAITQUEUE(wait, current);
int more;
k = vp;
current->flags |= PF_NOFREEZE;
set_user_nice(current, -10);
complete(&k->rendez); /* tell spawner we're running */
do {
spin_lock_irq(k->lock);
more = k->fn();
if (!more) {
add_wait_queue(k->waitq, &wait);
__set_current_state(TASK_INTERRUPTIBLE);
}
spin_unlock_irq(k->lock);
if (!more) {
schedule();
remove_wait_queue(k->waitq, &wait);
} else
cond_resched();
} while (!kthread_should_stop());
complete(&k->rendez); /* tell spawner we're stopping */
return 0;
}
void
aoe_ktstop(struct ktstate *k)
{
kthread_stop(k->task);
wait_for_completion(&k->rendez);
}
int
aoe_ktstart(struct ktstate *k)
{
struct task_struct *task;
init_completion(&k->rendez);
task = kthread_run(kthread, k, k->name);
if (task == NULL || IS_ERR(task))
return -ENOMEM;
k->task = task;
wait_for_completion(&k->rendez); /* allow kthread to start */
init_completion(&k->rendez); /* for waiting for exit later */
return 0;
}
/* pass it off to kthreads for processing */
static void
ktcomplete(struct frame *f, struct sk_buff *skb)
{
ulong flags;
f->r_skb = skb;
spin_lock_irqsave(&iocq.lock, flags);
list_add_tail(&f->head, &iocq.head);
spin_unlock_irqrestore(&iocq.lock, flags);
wake_up(&ktiowq);
}
struct sk_buff *
aoecmd_ata_rsp(struct sk_buff *skb)
{
struct aoedev *d;
struct aoe_hdr *h;
struct frame *f;
u32 n;
ulong flags;
char ebuf[128];
u16 aoemajor;
h = (struct aoe_hdr *) skb->data;
aoemajor = be16_to_cpu(get_unaligned(&h->major));
d = aoedev_by_aoeaddr(aoemajor, h->minor, 0);
if (d == NULL) {
snprintf(ebuf, sizeof ebuf, "aoecmd_ata_rsp: ata response "
"for unknown device %d.%d\n",
aoemajor, h->minor);
aoechr_error(ebuf);
return skb;
}
spin_lock_irqsave(&d->lock, flags);
n = be32_to_cpu(get_unaligned(&h->tag));
f = getframe(d, n);
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) {
calc_rttavg(d, NULL, tsince_hr(f));
} else {
calc_rttavg(d, NULL, tsince(n));
spin_unlock_irqrestore(&d->lock, flags);
aoedev_put(d);
snprintf(ebuf, sizeof(ebuf),
"%15s e%d.%d tag=%08x@%08lx s=%pm d=%pm\n",
"unexpected rsp",
get_unaligned_be16(&h->major),
h->minor,
get_unaligned_be32(&h->tag),
jiffies,
h->src,
h->dst);
aoechr_error(ebuf);
return skb;
}
}
aoecmd_work(d);
spin_unlock_irqrestore(&d->lock, flags);
ktcomplete(f, skb);
/*
* Note here that we do not perform an aoedev_put, as we are
* leaving this reference for the ktio to release.
*/
return NULL;
}
void
aoecmd_cfg(ushort aoemajor, unsigned char aoeminor)
{
struct sk_buff_head queue;
__skb_queue_head_init(&queue);
aoecmd_cfg_pkts(aoemajor, aoeminor, &queue);
aoenet_xmit(&queue);
}
struct sk_buff *
aoecmd_ata_id(struct aoedev *d)
{
struct aoe_hdr *h;
struct aoe_atahdr *ah;
struct frame *f;
struct sk_buff *skb;
struct aoetgt *t;
f = newframe(d);
if (f == NULL)
return NULL;
t = *d->tgt;
/* 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;
/* set up ata header */
ah->scnt = 1;
ah->cmdstat = ATA_CMD_ID_ATA;
ah->lba3 = 0xa0;
skb->dev = t->ifp->nd;
d->rttavg = RTTAVG_INIT;
d->rttdev = RTTDEV_INIT;
d->timer.function = rexmit_timer;
skb = skb_clone(skb, GFP_ATOMIC);
if (skb) {
do_gettimeofday(&f->sent);
f->sent_jiffs = (u32) jiffies;
}
return skb;
}
static struct aoetgt **
grow_targets(struct aoedev *d)
{
ulong oldn, newn;
struct aoetgt **tt;
oldn = d->ntargets;
newn = oldn * 2;
tt = kcalloc(newn, sizeof(*d->targets), GFP_ATOMIC);
if (!tt)
return NULL;
memmove(tt, d->targets, sizeof(*d->targets) * oldn);
d->tgt = tt + (d->tgt - d->targets);
kfree(d->targets);
d->targets = tt;
d->ntargets = newn;
return &d->targets[oldn];
}
static struct aoetgt *
addtgt(struct aoedev *d, char *addr, ulong nframes)
{
struct aoetgt *t, **tt, **te;
tt = d->targets;
te = tt + d->ntargets;
for (; tt < te && *tt; tt++)
;
if (tt == te) {
tt = grow_targets(d);
if (!tt)
goto nomem;
}
t = kzalloc(sizeof(*t), GFP_ATOMIC);
if (!t)
goto nomem;
t->nframes = nframes;
t->d = d;
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;
nomem:
pr_info("aoe: cannot allocate memory to add target\n");
return NULL;
}
static void
setdbcnt(struct aoedev *d)
{
struct aoetgt **t, **e;
int bcnt = 0;
t = d->targets;
e = t + d->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;
}
dev_hold(nd);
p->nd = nd;
p->bcnt = bcnt;
}
t->minbcnt = minbcnt;
setdbcnt(d);
}
void
aoecmd_cfg_rsp(struct sk_buff *skb)
{
struct aoedev *d;
struct aoe_hdr *h;
struct aoe_cfghdr *ch;
struct aoetgt *t;
ulong flags, aoemajor;
struct sk_buff *sl;
struct sk_buff_head queue;
u16 n;
sl = NULL;
h = (struct aoe_hdr *) skb_mac_header(skb);
ch = (struct aoe_cfghdr *) (h+1);
/*
* Enough people have their dip switches set backwards to
* warrant a loud message for this special case.
*/
aoemajor = get_unaligned_be16(&h->major);
if (aoemajor == 0xfff) {
printk(KERN_ERR "aoe: Warning: shelf address is all ones. "
"Check shelf dip switches.\n");
return;
}
if (aoemajor == 0xffff) {
pr_info("aoe: e%ld.%d: broadcast shelf number invalid\n",
aoemajor, (int) h->minor);
return;
}
if (h->minor == 0xff) {
pr_info("aoe: e%ld.%d: broadcast slot number invalid\n",
aoemajor, (int) h->minor);
return;
}
n = be16_to_cpu(ch->bufcnt);
if (n > aoe_maxout) /* keep it reasonable */
n = aoe_maxout;
d = aoedev_by_aoeaddr(aoemajor, h->minor, 1);
if (d == NULL) {
pr_info("aoe: device allocation failure\n");
return;
}
spin_lock_irqsave(&d->lock, flags);
t = gettgt(d, h->src);
if (t) {
t->nframes = n;
if (n < t->maxout)
aoecmd_wreset(t);
} else {
t = addtgt(d, h->src, n);
if (!t)
goto bail;
}
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) {
d->fw_ver = be16_to_cpu(ch->fwver);
sl = aoecmd_ata_id(d);
}
bail:
spin_unlock_irqrestore(&d->lock, flags);
aoedev_put(d);
if (sl) {
__skb_queue_head_init(&queue);
__skb_queue_tail(&queue, sl);
aoenet_xmit(&queue);
}
}
void
aoecmd_wreset(struct aoetgt *t)
{
t->maxout = 1;
t->ssthresh = t->nframes / 2;
t->next_cwnd = t->nframes;
}
void
aoecmd_cleanslate(struct aoedev *d)
{
struct aoetgt **t, **te;
d->rttavg = RTTAVG_INIT;
d->rttdev = RTTDEV_INIT;
d->maxbcnt = 0;
t = d->targets;
te = t + d->ntargets;
for (; t < te && *t; t++)
aoecmd_wreset(*t);
}
void
aoe_failbuf(struct aoedev *d, struct buf *buf)
{
if (buf == NULL)
return;
buf->resid = 0;
clear_bit(BIO_UPTODATE, &buf->bio->bi_flags);
if (buf->nframesout == 0)
aoe_end_buf(d, buf);
}
void
aoe_flush_iocq(void)
{
struct frame *f;
struct aoedev *d;
LIST_HEAD(flist);
struct list_head *pos;
struct sk_buff *skb;
ulong flags;
spin_lock_irqsave(&iocq.lock, flags);
list_splice_init(&iocq.head, &flist);
spin_unlock_irqrestore(&iocq.lock, flags);
while (!list_empty(&flist)) {
pos = flist.next;
list_del(pos);
f = list_entry(pos, struct frame, head);
d = f->t->d;
skb = f->r_skb;
spin_lock_irqsave(&d->lock, flags);
if (f->buf) {
f->buf->nframesout--;
aoe_failbuf(d, f->buf);
}
aoe_freetframe(f);
spin_unlock_irqrestore(&d->lock, flags);
dev_kfree_skb(skb);
aoedev_put(d);
}
}
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);
kts.name = "aoe_ktio";
kts.fn = ktio;
kts.waitq = &ktiowq;
kts.lock = &iocq.lock;
return aoe_ktstart(&kts);
}
void
aoecmd_exit(void)
{
aoe_ktstop(&kts);
aoe_flush_iocq();
free_page((unsigned long) page_address(empty_page));
empty_page = NULL;
}