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linux/drivers/block/aoe/aoecmd.c
Ed L. Cashin abdbf94d7c aoe: remove unecessary wrapper function 
We can just use skb_mac_header now, and we don't need a wrapper function to
perform the cast.  Instead of requiring the reader to check aoe.h to look
up what an aoe_hdr function does, I'd rather do without it.

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-17 08:42:52 -07:00

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/* Copyright (c) 2006 Coraid, Inc. See COPYING for GPL terms. */
/*
* aoecmd.c
* Filesystem request handling methods
*/
#include <linux/hdreg.h>
#include <linux/blkdev.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/genhd.h>
#include <net/net_namespace.h>
#include <asm/unaligned.h>
#include "aoe.h"
#define TIMERTICK (HZ / 10)
#define MINTIMER (2 * TIMERTICK)
#define MAXTIMER (HZ << 1)
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.");
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->priority = 0;
skb->next = skb->prev = NULL;
/* tell the network layer not to perform IP checksums
* or to get the NIC to do it
*/
skb->ip_summed = CHECKSUM_NONE;
}
return skb;
}
static struct frame *
getframe(struct aoedev *d, int tag)
{
struct frame *f, *e;
f = d->frames;
e = f + d->nframes;
for (; f<e; f++)
if (f->tag == tag)
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 int
aoehdr_atainit(struct aoedev *d, struct aoe_hdr *h)
{
u32 host_tag = newtag(d);
memcpy(h->src, d->ifp->dev_addr, sizeof h->src);
memcpy(h->dst, d->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 void
aoecmd_ata_rw(struct aoedev *d, struct frame *f)
{
struct aoe_hdr *h;
struct aoe_atahdr *ah;
struct buf *buf;
struct sk_buff *skb;
ulong bcnt;
register sector_t sector;
char writebit, extbit;
writebit = 0x10;
extbit = 0x4;
buf = d->inprocess;
sector = buf->sector;
bcnt = buf->bv_resid;
if (bcnt > d->maxbcnt)
bcnt = d->maxbcnt;
/* 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, h);
f->waited = 0;
f->buf = buf;
f->bufaddr = buf->bufaddr;
f->bcnt = bcnt;
f->lba = sector;
/* set up ata header */
ah->scnt = bcnt >> 9;
put_lba(ah, 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_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 {
writebit = 0;
}
ah->cmdstat = WIN_READ | writebit | extbit;
/* mark all tracking fields and load out */
buf->nframesout += 1;
buf->bufaddr += bcnt;
buf->bv_resid -= bcnt;
/* printk(KERN_DEBUG "aoe: bv_resid=%ld\n", buf->bv_resid); */
buf->resid -= bcnt;
buf->sector += bcnt >> 9;
if (buf->resid == 0) {
d->inprocess = NULL;
} else if (buf->bv_resid == 0) {
buf->bv++;
WARN_ON(buf->bv->bv_len == 0);
buf->bv_resid = buf->bv->bv_len;
buf->bufaddr = page_address(buf->bv->bv_page) + buf->bv->bv_offset;
}
skb->dev = d->ifp;
skb = skb_clone(skb, GFP_ATOMIC);
if (skb == NULL)
return;
if (d->sendq_hd)
d->sendq_tl->next = skb;
else
d->sendq_hd = skb;
d->sendq_tl = skb;
}
/* some callers cannot sleep, and they can call this function,
* transmitting the packets later, when interrupts are on
*/
static struct sk_buff *
aoecmd_cfg_pkts(ushort aoemajor, unsigned char aoeminor, struct sk_buff **tail)
{
struct aoe_hdr *h;
struct aoe_cfghdr *ch;
struct sk_buff *skb, *sl, *sl_tail;
struct net_device *ifp;
sl = sl_tail = NULL;
read_lock(&dev_base_lock);
for_each_netdev(&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;
if (sl_tail == NULL)
sl_tail = 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;
skb->next = sl;
sl = skb;
cont:
dev_put(ifp);
}
read_unlock(&dev_base_lock);
if (tail != NULL)
*tail = sl_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;
skb_trim(f->skb, 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)
{
struct frame *f;
struct buf *buf;
if (d->flags & DEVFL_PAUSE) {
if (!aoedev_isbusy(d))
d->sendq_hd = aoecmd_cfg_pkts(d->aoemajor,
d->aoeminor, &d->sendq_tl);
return;
}
loop:
f = freeframe(d);
if (f == NULL)
return;
if (d->inprocess == NULL) {
if (list_empty(&d->bufq))
return;
buf = container_of(d->bufq.next, struct buf, bufs);
list_del(d->bufq.next);
/*printk(KERN_DEBUG "aoe: bi_size=%ld\n", buf->bio->bi_size); */
d->inprocess = buf;
}
aoecmd_ata_rw(d, f);
goto loop;
}
static void
rexmit(struct aoedev *d, struct frame *f)
{
struct sk_buff *skb;
struct aoe_hdr *h;
struct aoe_atahdr *ah;
char buf[128];
u32 n;
n = newtag(d);
snprintf(buf, sizeof buf,
"%15s e%ld.%ld oldtag=%08x@%08lx newtag=%08x\n",
"retransmit",
d->aoemajor, d->aoeminor, f->tag, jiffies, n);
aoechr_error(buf);
skb = f->skb;
h = (struct aoe_hdr *) skb_mac_header(skb);
ah = (struct aoe_atahdr *) (h+1);
f->tag = n;
h->tag = cpu_to_be32(n);
memcpy(h->dst, d->addr, sizeof h->dst);
memcpy(h->src, d->ifp->dev_addr, sizeof h->src);
n = DEFAULTBCNT / 512;
if (ah->scnt > n) {
ah->scnt = n;
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) {
printk(KERN_INFO "aoe: 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 = skb_clone(skb, GFP_ATOMIC);
if (skb == NULL)
return;
if (d->sendq_hd)
d->sendq_tl->next = skb;
else
d->sendq_hd = skb;
d->sendq_tl = skb;
}
static int
tsince(int tag)
{
int n;
n = jiffies & 0xffff;
n -= tag & 0xffff;
if (n < 0)
n += 1<<16;
return n;
}
static void
rexmit_timer(ulong vp)
{
struct aoedev *d;
struct frame *f, *e;
struct sk_buff *sl;
register long timeout;
ulong flags, n;
d = (struct aoedev *) vp;
sl = NULL;
/* timeout is always ~150% of the moving average */
timeout = d->rttavg;
timeout += timeout >> 1;
spin_lock_irqsave(&d->lock, flags);
if (d->flags & DEVFL_TKILL) {
spin_unlock_irqrestore(&d->lock, flags);
return;
}
f = d->frames;
e = f + d->nframes;
for (; f<e; f++) {
if (f->tag != FREETAG && tsince(f->tag) >= timeout) {
n = f->waited += timeout;
n /= HZ;
if (n > aoe_deadsecs) { /* waited too long for response */
aoedev_downdev(d);
break;
}
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;
if (sl) {
n = d->rttavg <<= 1;
if (n > MAXTIMER)
d->rttavg = MAXTIMER;
}
d->timer.expires = jiffies + TIMERTICK;
add_timer(&d->timer);
spin_unlock_irqrestore(&d->lock, flags);
aoenet_xmit(sl);
}
/* 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);
if (d->flags & DEVFL_GDALLOC)
aoeblk_gdalloc(d);
if (d->flags & DEVFL_NEWSIZE) {
struct block_device *bd;
unsigned long flags;
u64 ssize;
ssize = d->gd->capacity;
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_irqsave(&d->lock, flags);
d->flags |= DEVFL_UP;
d->flags &= ~DEVFL_NEWSIZE;
spin_unlock_irqrestore(&d->lock, flags);
}
}
static void
ataid_complete(struct aoedev *d, unsigned char *id)
{
u64 ssize;
u16 n;
/* word 83: command set supported */
n = le16_to_cpu(get_unaligned((__le16 *) &id[83<<1]));
/* word 86: command set/feature enabled */
n |= le16_to_cpu(get_unaligned((__le16 *) &id[86<<1]));
if (n & (1<<10)) { /* bit 10: LBA 48 */
d->flags |= DEVFL_EXT;
/* word 100: number lba48 sectors */
ssize = le64_to_cpu(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 = le32_to_cpu(get_unaligned((__le32 *) &id[60<<1]));
/* NOTE: obsolete in ATA 6 */
d->geo.cylinders = le16_to_cpu(get_unaligned((__le16 *) &id[54<<1]));
d->geo.heads = le16_to_cpu(get_unaligned((__le16 *) &id[55<<1]));
d->geo.sectors = le16_to_cpu(get_unaligned((__le16 *) &id[56<<1]));
}
if (d->ssize != ssize)
printk(KERN_INFO "aoe: %012llx e%lu.%lu v%04x has %llu sectors\n",
(unsigned long long)mac_addr(d->addr),
d->aoemajor, d->aoeminor,
d->fw_ver, (long long)ssize);
d->ssize = ssize;
d->geo.start = 0;
if (d->gd != NULL) {
d->gd->capacity = ssize;
d->flags |= DEVFL_NEWSIZE;
} else {
if (d->flags & DEVFL_GDALLOC) {
printk(KERN_ERR "aoe: can't schedule work for e%lu.%lu, %s\n",
d->aoemajor, d->aoeminor,
"it's already on! This shouldn't happen.\n");
return;
}
d->flags |= DEVFL_GDALLOC;
}
schedule_work(&d->work);
}
static void
calc_rttavg(struct aoedev *d, int rtt)
{
register long n;
n = rtt;
if (n < 0) {
n = -rtt;
if (n < MINTIMER)
n = MINTIMER;
else if (n > MAXTIMER)
n = MAXTIMER;
d->mintimer += (n - d->mintimer) >> 1;
} else if (n < d->mintimer)
n = d->mintimer;
else if (n > MAXTIMER)
n = MAXTIMER;
/* g == .25; cf. Congestion Avoidance and Control, Jacobson & Karels; 1988 */
n -= d->rttavg;
d->rttavg += n >> 2;
}
void
aoecmd_ata_rsp(struct sk_buff *skb)
{
struct aoedev *d;
struct aoe_hdr *hin, *hout;
struct aoe_atahdr *ahin, *ahout;
struct frame *f;
struct buf *buf;
struct sk_buff *sl;
register long n;
ulong flags;
char ebuf[128];
u16 aoemajor;
hin = (struct aoe_hdr *) skb_mac_header(skb);
aoemajor = be16_to_cpu(get_unaligned(&hin->major));
d = aoedev_by_aoeaddr(aoemajor, hin->minor);
if (d == NULL) {
snprintf(ebuf, sizeof ebuf, "aoecmd_ata_rsp: ata response "
"for unknown device %d.%d\n",
aoemajor, hin->minor);
aoechr_error(ebuf);
return;
}
spin_lock_irqsave(&d->lock, flags);
n = be32_to_cpu(get_unaligned(&hin->tag));
f = getframe(d, n);
if (f == NULL) {
calc_rttavg(d, -tsince(n));
spin_unlock_irqrestore(&d->lock, flags);
snprintf(ebuf, sizeof ebuf,
"%15s e%d.%d tag=%08x@%08lx\n",
"unexpected rsp",
be16_to_cpu(get_unaligned(&hin->major)),
hin->minor,
be32_to_cpu(get_unaligned(&hin->tag)),
jiffies);
aoechr_error(ebuf);
return;
}
calc_rttavg(d, tsince(f->tag));
ahin = (struct aoe_atahdr *) (hin+1);
hout = (struct aoe_hdr *) skb_mac_header(f->skb);
ahout = (struct aoe_atahdr *) (hout+1);
buf = f->buf;
if (ahout->cmdstat == WIN_IDENTIFY)
d->flags &= ~DEVFL_PAUSE;
if (ahin->cmdstat & 0xa9) { /* these bits cleared on success */
printk(KERN_ERR
"aoe: ata error cmd=%2.2Xh stat=%2.2Xh from e%ld.%ld\n",
ahout->cmdstat, ahin->cmdstat,
d->aoemajor, d->aoeminor);
if (buf)
buf->flags |= BUFFL_FAIL;
} else {
n = ahout->scnt << 9;
switch (ahout->cmdstat) {
case WIN_READ:
case WIN_READ_EXT:
if (skb->len - sizeof *hin - sizeof *ahin < n) {
printk(KERN_ERR
"aoe: runt data size in read. skb->len=%d\n",
skb->len);
/* fail frame f? just returning will rexmit. */
spin_unlock_irqrestore(&d->lock, flags);
return;
}
memcpy(f->bufaddr, ahin+1, n);
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(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 = skb_clone(skb, GFP_ATOMIC);
spin_unlock_irqrestore(&d->lock, flags);
if (skb)
aoenet_xmit(skb);
return;
}
if (n > DEFAULTBCNT)
d->lostjumbo = 0;
break;
case WIN_IDENTIFY:
if (skb->len - sizeof *hin - sizeof *ahin < 512) {
printk(KERN_INFO
"aoe: runt data size in ataid. skb->len=%d\n",
skb->len);
spin_unlock_irqrestore(&d->lock, flags);
return;
}
ataid_complete(d, (char *) (ahin+1));
break;
default:
printk(KERN_INFO
"aoe: unrecognized ata command %2.2Xh for %d.%d\n",
ahout->cmdstat,
be16_to_cpu(get_unaligned(&hin->major)),
hin->minor);
}
}
if (buf) {
buf->nframesout -= 1;
if (buf->nframesout == 0 && buf->resid == 0) {
unsigned long duration = jiffies - buf->start_time;
unsigned long n_sect = buf->bio->bi_size >> 9;
struct gendisk *disk = d->gd;
const int rw = bio_data_dir(buf->bio);
disk_stat_inc(disk, ios[rw]);
disk_stat_add(disk, ticks[rw], duration);
disk_stat_add(disk, sectors[rw], n_sect);
disk_stat_add(disk, io_ticks, duration);
n = (buf->flags & BUFFL_FAIL) ? -EIO : 0;
bio_endio(buf->bio, n);
mempool_free(buf, d->bufpool);
}
}
f->buf = NULL;
f->tag = FREETAG;
aoecmd_work(d);
sl = d->sendq_hd;
d->sendq_hd = d->sendq_tl = NULL;
spin_unlock_irqrestore(&d->lock, flags);
aoenet_xmit(sl);
}
void
aoecmd_cfg(ushort aoemajor, unsigned char aoeminor)
{
struct sk_buff *sl;
sl = aoecmd_cfg_pkts(aoemajor, aoeminor, NULL);
aoenet_xmit(sl);
}
/*
* Since we only call this in one place (and it only prepares one frame)
* we just return the skb. Usually we'd chain it up to the aoedev sendq.
*/
static struct sk_buff *
aoecmd_ata_id(struct aoedev *d)
{
struct aoe_hdr *h;
struct aoe_atahdr *ah;
struct frame *f;
struct sk_buff *skb;
f = freeframe(d);
if (f == NULL) {
printk(KERN_ERR "aoe: can't get a frame. This shouldn't happen.\n");
return NULL;
}
/* 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, h);
f->waited = 0;
/* set up ata header */
ah->scnt = 1;
ah->cmdstat = WIN_IDENTIFY;
ah->lba3 = 0xa0;
skb->dev = d->ifp;
d->rttavg = MAXTIMER;
d->timer.function = rexmit_timer;
return skb_clone(skb, GFP_ATOMIC);
}
void
aoecmd_cfg_rsp(struct sk_buff *skb)
{
struct aoedev *d;
struct aoe_hdr *h;
struct aoe_cfghdr *ch;
ulong flags, sysminor, aoemajor;
struct sk_buff *sl;
enum { MAXFRAMES = 16 };
u16 n;
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 = be16_to_cpu(get_unaligned(&h->major));
if (aoemajor == 0xfff) {
printk(KERN_ERR "aoe: Warning: shelf address is all ones. "
"Check shelf dip switches.\n");
return;
}
sysminor = SYSMINOR(aoemajor, h->minor);
if (sysminor * AOE_PARTITIONS + AOE_PARTITIONS > MINORMASK) {
printk(KERN_INFO "aoe: e%ld.%d: minor number too large\n",
aoemajor, (int) h->minor);
return;
}
n = be16_to_cpu(ch->bufcnt);
if (n > MAXFRAMES) /* keep it reasonable */
n = MAXFRAMES;
d = aoedev_by_sysminor_m(sysminor, n);
if (d == NULL) {
printk(KERN_INFO "aoe: device sysminor_m failure\n");
return;
}
spin_lock_irqsave(&d->lock, flags);
/* permit device to migrate mac and network interface */
d->ifp = skb->dev;
memcpy(d->addr, h->src, sizeof d->addr);
if (!(d->flags & DEVFL_MAXBCNT)) {
n = d->ifp->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 != d->maxbcnt) {
printk(KERN_INFO
"aoe: 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 */
if (d->nopen && !(d->flags & DEVFL_PAUSE)) {
spin_unlock_irqrestore(&d->lock, flags);
return;
}
d->flags |= DEVFL_PAUSE; /* force pause */
d->mintimer = MINTIMER;
d->fw_ver = be16_to_cpu(ch->fwver);
/* check for already outstanding ataid */
sl = aoedev_isbusy(d) == 0 ? aoecmd_ata_id(d) : NULL;
spin_unlock_irqrestore(&d->lock, flags);
aoenet_xmit(sl);
}
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