linux/drivers/block/aoe/aoecmd.c
David Rientjes 668f9abbd4 mm: close PageTail race
Commit bf6bddf192 ("mm: introduce compaction and migration for
ballooned pages") introduces page_count(page) into memory compaction
which dereferences page->first_page if PageTail(page).

This results in a very rare NULL pointer dereference on the
aforementioned page_count(page).  Indeed, anything that does
compound_head(), including page_count() is susceptible to racing with
prep_compound_page() and seeing a NULL or dangling page->first_page
pointer.

This patch uses Andrea's implementation of compound_trans_head() that
deals with such a race and makes it the default compound_head()
implementation.  This includes a read memory barrier that ensures that
if PageTail(head) is true that we return a head page that is neither
NULL nor dangling.  The patch then adds a store memory barrier to
prep_compound_page() to ensure page->first_page is set.

This is the safest way to ensure we see the head page that we are
expecting, PageTail(page) is already in the unlikely() path and the
memory barriers are unfortunately required.

Hugetlbfs is the exception, we don't enforce a store memory barrier
during init since no race is possible.

Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Holger Kiehl <Holger.Kiehl@dwd.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: Rafael Aquini <aquini@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-03-04 07:55:47 -08:00

1827 lines
37 KiB
C

/* Copyright (c) 2013 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.");
/* The number of online cpus during module initialization gives us a
* convenient heuristic cap on the parallelism used for ktio threads
* doing I/O completion. It is not important that the cap equal the
* actual number of running CPUs at any given time, but because of CPU
* hotplug, we take care to use ncpus instead of using
* num_online_cpus() after module initialization.
*/
static int ncpus;
/* mutex lock used for synchronization while thread spawning */
static DEFINE_MUTEX(ktio_spawn_lock);
static wait_queue_head_t *ktiowq;
static struct ktstate *kts;
/* io completion queue */
struct iocq_ktio {
struct list_head head;
spinlock_t lock;
};
static struct iocq_ktio *iocq;
static struct page *empty_page;
static struct sk_buff *
new_skb(ulong len)
{
struct sk_buff *skb;
skb = alloc_skb(len + MAX_HEADER, GFP_ATOMIC);
if (skb) {
skb_reserve(skb, MAX_HEADER);
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;
memset(&f->iter, 0, sizeof(f->iter));
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 *bio, struct bvec_iter iter)
{
int frag = 0;
struct bio_vec bv;
__bio_for_each_segment(bv, bio, iter, iter)
skb_fill_page_desc(skb, frag++, bv.bv_page,
bv.bv_offset, bv.bv_len);
}
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;
/* set up ata header */
ah->scnt = f->iter.bi_size >> 9;
put_lba(ah, f->iter.bi_sector);
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->buf->bio, f->iter);
ah->aflags |= AOEAFL_WRITE;
skb->len += f->iter.bi_size;
skb->data_len = f->iter.bi_size;
skb->truesize += f->iter.bi_size;
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 sk_buff *skb;
struct sk_buff_head queue;
buf = nextbuf(d);
if (buf == NULL)
return 0;
f = newframe(d);
if (f == NULL)
return 0;
/* initialize the headers & frame */
f->buf = buf;
f->iter = buf->iter;
f->iter.bi_size = min_t(unsigned long,
d->maxbcnt ?: DEFAULTBCNT,
f->iter.bi_size);
bio_advance_iter(buf->bio, &buf->iter, f->iter.bi_size);
if (!buf->iter.bi_size)
d->ip.buf = NULL;
/* mark all tracking fields and load out */
buf->nframesout += 1;
ata_rw_frameinit(f);
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 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);
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->iter = f->iter;
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->iter.bi_size = t->d->maxbcnt ? t->d->maxbcnt : DEFAULTBCNT;
ata_rw_frameinit(f);
skb = f->skb;
for (frag = 0, n = f->iter.bi_size; 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->iter.bi_size;
skb->data_len = f->iter.bi_size;
skb->truesize += f->iter.bi_size;
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;
struct bvec_iter iter;
bio_for_each_segment(bv, bio, iter) {
/* Non-zero page count for non-head members of
* compound pages is no longer allowed by the kernel.
*/
page = compound_head(bv.bv_page);
atomic_inc(&page->_count);
}
}
static void
bio_pagedec(struct bio *bio)
{
struct page *page;
struct bio_vec bv;
struct bvec_iter iter;
bio_for_each_segment(bv, bio, iter) {
page = compound_head(bv.bv_page);
atomic_dec(&page->_count);
}
}
static void
bufinit(struct buf *buf, struct request *rq, struct bio *bio)
{
memset(buf, 0, sizeof(*buf));
buf->rq = rq;
buf->bio = bio;
buf->iter = bio->bi_iter;
bio_pageinc(bio);
}
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 sk_buff *skb, struct bio *bio, struct bvec_iter iter, long cnt)
{
int soff = 0;
struct bio_vec bv;
iter.bi_size = cnt;
__bio_for_each_segment(bv, bio, iter, iter) {
char *p = page_address(bv.bv_page) + bv.bv_offset;
skb_copy_bits(skb, soff, p, bv.bv_len);
soff += bv.bv_len;
}
}
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_iter.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;
}
if (n > f->iter.bi_size) {
pr_err_ratelimited("%s e%ld.%d. bytes=%ld need=%u\n",
"aoe: too-large data size in read from",
(long) d->aoemajor, d->aoeminor,
n, f->iter.bi_size);
clear_bit(BIO_UPTODATE, &buf->bio->bi_flags);
break;
}
bvcpy(skb, f->buf->bio, f->iter, 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->iter.bi_size == 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(int id)
{
struct frame *f;
struct list_head *pos;
int i;
int actual_id;
for (i = 0; ; ++i) {
if (i == MAXIOC)
return 1;
if (list_empty(&iocq[id].head))
return 0;
pos = iocq[id].head.next;
list_del(pos);
f = list_entry(pos, struct frame, head);
spin_unlock_irq(&iocq[id].lock);
ktiocomplete(f);
/* Figure out if extra threads are required. */
actual_id = f->t->d->aoeminor % ncpus;
if (!kts[actual_id].active) {
BUG_ON(id != 0);
mutex_lock(&ktio_spawn_lock);
if (!kts[actual_id].active
&& aoe_ktstart(&kts[actual_id]) == 0)
kts[actual_id].active = 1;
mutex_unlock(&ktio_spawn_lock);
}
spin_lock_irq(&iocq[id].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(k->id);
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, "%s", 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)
{
int id;
ulong flags;
f->r_skb = skb;
id = f->t->d->aoeminor % ncpus;
spin_lock_irqsave(&iocq[id].lock, flags);
if (!kts[id].active) {
spin_unlock_irqrestore(&iocq[id].lock, flags);
/* The thread with id has not been spawned yet,
* so delegate the work to the main thread and
* try spawning a new thread.
*/
id = 0;
spin_lock_irqsave(&iocq[id].lock, flags);
}
list_add_tail(&f->head, &iocq[id].head);
spin_unlock_irqrestore(&iocq[id].lock, flags);
wake_up(&ktiowq[id]);
}
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->iter.bi_size = 0;
clear_bit(BIO_UPTODATE, &buf->bio->bi_flags);
if (buf->nframesout == 0)
aoe_end_buf(d, buf);
}
void
aoe_flush_iocq(void)
{
int i;
for (i = 0; i < ncpus; i++) {
if (kts[i].active)
aoe_flush_iocq_by_index(i);
}
}
void
aoe_flush_iocq_by_index(int id)
{
struct frame *f;
struct aoedev *d;
LIST_HEAD(flist);
struct list_head *pos;
struct sk_buff *skb;
ulong flags;
spin_lock_irqsave(&iocq[id].lock, flags);
list_splice_init(&iocq[id].head, &flist);
spin_unlock_irqrestore(&iocq[id].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;
int i;
int ret;
/* 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);
ncpus = num_online_cpus();
iocq = kcalloc(ncpus, sizeof(struct iocq_ktio), GFP_KERNEL);
if (!iocq)
return -ENOMEM;
kts = kcalloc(ncpus, sizeof(struct ktstate), GFP_KERNEL);
if (!kts) {
ret = -ENOMEM;
goto kts_fail;
}
ktiowq = kcalloc(ncpus, sizeof(wait_queue_head_t), GFP_KERNEL);
if (!ktiowq) {
ret = -ENOMEM;
goto ktiowq_fail;
}
mutex_init(&ktio_spawn_lock);
for (i = 0; i < ncpus; i++) {
INIT_LIST_HEAD(&iocq[i].head);
spin_lock_init(&iocq[i].lock);
init_waitqueue_head(&ktiowq[i]);
snprintf(kts[i].name, sizeof(kts[i].name), "aoe_ktio%d", i);
kts[i].fn = ktio;
kts[i].waitq = &ktiowq[i];
kts[i].lock = &iocq[i].lock;
kts[i].id = i;
kts[i].active = 0;
}
kts[0].active = 1;
if (aoe_ktstart(&kts[0])) {
ret = -ENOMEM;
goto ktstart_fail;
}
return 0;
ktstart_fail:
kfree(ktiowq);
ktiowq_fail:
kfree(kts);
kts_fail:
kfree(iocq);
return ret;
}
void
aoecmd_exit(void)
{
int i;
for (i = 0; i < ncpus; i++)
if (kts[i].active)
aoe_ktstop(&kts[i]);
aoe_flush_iocq();
/* Free up the iocq and thread speicific configuration
* allocated during startup.
*/
kfree(iocq);
kfree(kts);
kfree(ktiowq);
free_page((unsigned long) page_address(empty_page));
empty_page = NULL;
}