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aoe: Convert to immutable biovecs
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Now that we've got a mechanism for immutable biovecs -
bi_iter.bi_bvec_done - we need to convert drivers to use primitives that
respect it instead of using the bvec array directly.

The aoe code no longer has to manually iterate over partial bvecs, so
some struct members go away - other struct members are effectively
renamed:

buf->resid	-> buf->iter.bi_size
buf->sector	-> buf->iter.bi_sector

f->bcnt		-> f->iter.bi_size
f->lba		-> f->iter.bi_sector

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: "Ed L. Cashin" <ecashin@coraid.com>
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Kent Overstreet committed Nov 24, 2013
1 parent 003b5c5 commit feb261e
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Showing 2 changed files with 53 additions and 92 deletions.
10 changes: 2 additions & 8 deletions drivers/block/aoe/aoe.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -100,11 +100,8 @@ enum {

struct buf {
ulong nframesout;
ulong resid;
ulong bv_resid;
sector_t sector;
struct bio *bio;
struct bio_vec *bv;
struct bvec_iter iter;
struct request *rq;
};

Expand All @@ -120,13 +117,10 @@ struct frame {
ulong waited;
ulong waited_total;
struct aoetgt *t; /* parent target I belong to */
sector_t lba;
struct sk_buff *skb; /* command skb freed on module exit */
struct sk_buff *r_skb; /* response skb for async processing */
struct buf *buf;
struct bio_vec *bv;
ulong bcnt;
ulong bv_off;
struct bvec_iter iter;
char flags;
};

Expand Down
135 changes: 51 additions & 84 deletions drivers/block/aoe/aoecmd.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -196,8 +196,7 @@ aoe_freetframe(struct frame *f)

t = f->t;
f->buf = NULL;
f->lba = 0;
f->bv = NULL;
memset(&f->iter, 0, sizeof(f->iter));
f->r_skb = NULL;
f->flags = 0;
list_add(&f->head, &t->ffree);
Expand Down Expand Up @@ -295,21 +294,14 @@ newframe(struct aoedev *d)
}

static void
skb_fillup(struct sk_buff *skb, struct bio_vec *bv, ulong off, ulong cnt)
skb_fillup(struct sk_buff *skb, struct bio *bio, struct bvec_iter iter)
{
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;
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
Expand Down Expand Up @@ -346,12 +338,10 @@ ata_rw_frameinit(struct frame *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);
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 {
Expand All @@ -360,11 +350,11 @@ ata_rw_frameinit(struct frame *f)
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);
skb_fillup(skb, f->buf->bio, f->iter);
ah->aflags |= AOEAFL_WRITE;
skb->len += f->bcnt;
skb->data_len = f->bcnt;
skb->truesize += f->bcnt;
skb->len += f->iter.bi_size;
skb->data_len = f->iter.bi_size;
skb->truesize += f->iter.bi_size;
t->wpkts++;
} else {
t->rpkts++;
Expand All @@ -382,47 +372,29 @@ aoecmd_ata_rw(struct aoedev *d)
struct buf *buf;
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;
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);
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;
buf->sector += bcnt >> 9;

ata_rw_frameinit(f);

skb = skb_clone(f->skb, GFP_ATOMIC);
if (skb) {
Expand Down Expand Up @@ -613,10 +585,7 @@ reassign_frame(struct frame *f)
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->iter = f->iter;
nf->waited = 0;
nf->waited_total = f->waited_total;
nf->sent = f->sent;
Expand Down Expand Up @@ -648,19 +617,19 @@ probe(struct aoetgt *t)
}
f->flags |= FFL_PROBE;
ifrotate(t);
f->bcnt = t->d->maxbcnt ? t->d->maxbcnt : DEFAULTBCNT;
f->iter.bi_size = 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) {
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->bcnt;
skb->data_len = f->bcnt;
skb->truesize += f->bcnt;
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) {
Expand Down Expand Up @@ -929,12 +898,8 @@ bufinit(struct buf *buf, struct request *rq, struct bio *bio)
memset(buf, 0, sizeof(*buf));
buf->rq = rq;
buf->bio = bio;
buf->resid = bio->bi_iter.bi_size;
buf->sector = bio->bi_iter.bi_sector;
buf->iter = bio->bi_iter;
bio_pageinc(bio);
buf->bv = __bio_iovec(bio);
buf->bv_resid = buf->bv->bv_len;
WARN_ON(buf->bv_resid == 0);
}

static struct buf *
Expand Down Expand Up @@ -1119,24 +1084,18 @@ gettgt(struct aoedev *d, char *addr)
}

static void
bvcpy(struct bio_vec *bv, ulong off, struct sk_buff *skb, long cnt)
bvcpy(struct sk_buff *skb, struct bio *bio, struct bvec_iter iter, 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;
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
Expand Down Expand Up @@ -1229,7 +1188,15 @@ noskb: if (buf)
clear_bit(BIO_UPTODATE, &buf->bio->bi_flags);
break;
}
bvcpy(f->bv, f->bv_off, skb, n);
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);
Expand Down Expand Up @@ -1272,7 +1239,7 @@ noskb: if (buf)

aoe_freetframe(f);

if (buf && --buf->nframesout == 0 && buf->resid == 0)
if (buf && --buf->nframesout == 0 && buf->iter.bi_size == 0)
aoe_end_buf(d, buf);

spin_unlock_irq(&d->lock);
Expand Down Expand Up @@ -1727,7 +1694,7 @@ aoe_failbuf(struct aoedev *d, struct buf *buf)
{
if (buf == NULL)
return;
buf->resid = 0;
buf->iter.bi_size = 0;
clear_bit(BIO_UPTODATE, &buf->bio->bi_flags);
if (buf->nframesout == 0)
aoe_end_buf(d, buf);
Expand Down

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