[PATCH 12/23] block: Convert drivers to immutable biovecs

From: Kent Overstreet
Date: Tue Oct 29 2013 - 16:23:47 EST

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.

Signed-off-by: Kent Overstreet <kmo@xxxxxxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: NeilBrown <neilb@xxxxxxx>
Cc: Alasdair Kergon <agk@xxxxxxxxxx>
Cc: dm-devel@xxxxxxxxxx
---
drivers/block/umem.c | 50 ++++++++++++++++++++++--------------------------
drivers/md/dm-crypt.c | 49 +++++++++++++++++------------------------------
drivers/md/dm-io.c | 31 ++++++++++++++++--------------
drivers/md/dm-raid1.c | 8 ++++----
drivers/md/dm-verity.c | 52 ++++++++++++++------------------------------------
fs/bio.c | 14 +++++++++++---
include/linux/dm-io.h | 4 ++--
7 files changed, 89 insertions(+), 119 deletions(-)

diff --git a/drivers/block/umem.c b/drivers/block/umem.c
index dab4f1a..4cf81b5 100644
--- a/drivers/block/umem.c
+++ b/drivers/block/umem.c
@@ -108,8 +108,7 @@ struct cardinfo {
* have been written
*/
struct bio *bio, *currentbio, **biotail;
- int current_idx;
- sector_t current_sector;
+ struct bvec_iter current_iter;

struct request_queue *queue;

@@ -118,7 +117,7 @@ struct cardinfo {
struct mm_dma_desc *desc;
int cnt, headcnt;
struct bio *bio, **biotail;
- int idx;
+ struct bvec_iter iter;
} mm_pages[2];
#define DESC_PER_PAGE ((PAGE_SIZE*2)/sizeof(struct mm_dma_desc))

@@ -344,16 +343,13 @@ static int add_bio(struct cardinfo *card)
dma_addr_t dma_handle;
int offset;
struct bio *bio;
- struct bio_vec *vec;
- int idx;
+ struct bio_vec vec;
int rw;
- int len;

bio = card->currentbio;
if (!bio && card->bio) {
card->currentbio = card->bio;
- card->current_idx = card->bio->bi_iter.bi_idx;
- card->current_sector = card->bio->bi_iter.bi_sector;
+ card->current_iter = card->bio->bi_iter;
card->bio = card->bio->bi_next;
if (card->bio == NULL)
card->biotail = &card->bio;
@@ -362,18 +358,17 @@ static int add_bio(struct cardinfo *card)
}
if (!bio)
return 0;
- idx = card->current_idx;

rw = bio_rw(bio);
if (card->mm_pages[card->Ready].cnt >= DESC_PER_PAGE)
return 0;

- vec = bio_iovec_idx(bio, idx);
- len = vec->bv_len;
+ vec = bio_iter_iovec(bio, card->current_iter);
+
dma_handle = pci_map_page(card->dev,
- vec->bv_page,
- vec->bv_offset,
- len,
+ vec.bv_page,
+ vec.bv_offset,
+ vec.bv_len,
(rw == READ) ?
PCI_DMA_FROMDEVICE : PCI_DMA_TODEVICE);

@@ -381,7 +376,7 @@ static int add_bio(struct cardinfo *card)
desc = &p->desc[p->cnt];
p->cnt++;
if (p->bio == NULL)
- p->idx = idx;
+ p->iter = card->current_iter;
if ((p->biotail) != &bio->bi_next) {
*(p->biotail) = bio;
p->biotail = &(bio->bi_next);
@@ -391,8 +386,8 @@ static int add_bio(struct cardinfo *card)
desc->data_dma_handle = dma_handle;

desc->pci_addr = cpu_to_le64((u64)desc->data_dma_handle);
- desc->local_addr = cpu_to_le64(card->current_sector << 9);
- desc->transfer_size = cpu_to_le32(len);
+ desc->local_addr = cpu_to_le64(card->current_iter.bi_sector << 9);
+ desc->transfer_size = cpu_to_le32(vec.bv_len);
offset = (((char *)&desc->sem_control_bits) - ((char *)p->desc));
desc->sem_addr = cpu_to_le64((u64)(p->page_dma+offset));
desc->zero1 = desc->zero2 = 0;
@@ -407,10 +402,9 @@ static int add_bio(struct cardinfo *card)
desc->control_bits |= cpu_to_le32(DMASCR_TRANSFER_READ);
desc->sem_control_bits = desc->control_bits;

- card->current_sector += (len >> 9);
- idx++;
- card->current_idx = idx;
- if (idx >= bio->bi_vcnt)
+
+ bio_advance_iter(bio, &card->current_iter, vec.bv_len);
+ if (!card->current_iter.bi_size)
card->currentbio = NULL;

return 1;
@@ -439,23 +433,25 @@ static void process_page(unsigned long data)
struct mm_dma_desc *desc = &page->desc[page->headcnt];
int control = le32_to_cpu(desc->sem_control_bits);
int last = 0;
- int idx;
+ struct bio_vec vec;

if (!(control & DMASCR_DMA_COMPLETE)) {
control = dma_status;
last = 1;
}
+
page->headcnt++;
- idx = page->idx;
- page->idx++;
- if (page->idx >= bio->bi_vcnt) {
+ vec = bio_iter_iovec(bio, page->iter);
+ bio_advance_iter(bio, &page->iter, vec.bv_len);
+
+ if (!page->iter.bi_size) {
page->bio = bio->bi_next;
if (page->bio)
- page->idx = page->bio->bi_iter.bi_idx;
+ page->iter = page->bio->bi_iter;
}

pci_unmap_page(card->dev, desc->data_dma_handle,
- bio_iovec_idx(bio, idx)->bv_len,
+ vec.bv_len,
(control & DMASCR_TRANSFER_READ) ?
PCI_DMA_TODEVICE : PCI_DMA_FROMDEVICE);
if (control & DMASCR_HARD_ERROR) {
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 3e8dd65..4db7e48 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -38,10 +38,8 @@ struct convert_context {
struct completion restart;
struct bio *bio_in;
struct bio *bio_out;
- unsigned int offset_in;
- unsigned int offset_out;
- unsigned int idx_in;
- unsigned int idx_out;
+ struct bvec_iter iter_in;
+ struct bvec_iter iter_out;
sector_t cc_sector;
atomic_t cc_pending;
};
@@ -650,10 +648,10 @@ static void crypt_convert_init(struct crypt_config *cc,
{
ctx->bio_in = bio_in;
ctx->bio_out = bio_out;
- ctx->offset_in = 0;
- ctx->offset_out = 0;
- ctx->idx_in = bio_in ? bio_in->bi_iter.bi_idx : 0;
- ctx->idx_out = bio_out ? bio_out->bi_iter.bi_idx : 0;
+ if (bio_in)
+ ctx->iter_in = bio_in->bi_iter;
+ if (bio_out)
+ ctx->iter_out = bio_out->bi_iter;
ctx->cc_sector = sector + cc->iv_offset;
init_completion(&ctx->restart);
}
@@ -681,8 +679,8 @@ static int crypt_convert_block(struct crypt_config *cc,
struct convert_context *ctx,
struct ablkcipher_request *req)
{
- struct bio_vec *bv_in = bio_iovec_idx(ctx->bio_in, ctx->idx_in);
- struct bio_vec *bv_out = bio_iovec_idx(ctx->bio_out, ctx->idx_out);
+ struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in);
+ struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out);
struct dm_crypt_request *dmreq;
u8 *iv;
int r;
@@ -693,24 +691,15 @@ static int crypt_convert_block(struct crypt_config *cc,
dmreq->iv_sector = ctx->cc_sector;
dmreq->ctx = ctx;
sg_init_table(&dmreq->sg_in, 1);
- sg_set_page(&dmreq->sg_in, bv_in->bv_page, 1 << SECTOR_SHIFT,
- bv_in->bv_offset + ctx->offset_in);
+ sg_set_page(&dmreq->sg_in, bv_in.bv_page, 1 << SECTOR_SHIFT,
+ bv_in.bv_offset);

sg_init_table(&dmreq->sg_out, 1);
- sg_set_page(&dmreq->sg_out, bv_out->bv_page, 1 << SECTOR_SHIFT,
- bv_out->bv_offset + ctx->offset_out);
+ sg_set_page(&dmreq->sg_out, bv_out.bv_page, 1 << SECTOR_SHIFT,
+ bv_out.bv_offset);

- ctx->offset_in += 1 << SECTOR_SHIFT;
- if (ctx->offset_in >= bv_in->bv_len) {
- ctx->offset_in = 0;
- ctx->idx_in++;
- }
-
- ctx->offset_out += 1 << SECTOR_SHIFT;
- if (ctx->offset_out >= bv_out->bv_len) {
- ctx->offset_out = 0;
- ctx->idx_out++;
- }
+ bio_advance_iter(ctx->bio_in, &ctx->iter_in, 1 << SECTOR_SHIFT);
+ bio_advance_iter(ctx->bio_out, &ctx->iter_out, 1 << SECTOR_SHIFT);

if (cc->iv_gen_ops) {
r = cc->iv_gen_ops->generator(cc, iv, dmreq);
@@ -761,8 +750,7 @@ static int crypt_convert(struct crypt_config *cc,

atomic_set(&ctx->cc_pending, 1);

- while(ctx->idx_in < ctx->bio_in->bi_vcnt &&
- ctx->idx_out < ctx->bio_out->bi_vcnt) {
+ while (ctx->iter_in.bi_size && ctx->iter_out.bi_size) {

crypt_alloc_req(cc, ctx);

@@ -1031,7 +1019,7 @@ static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async)
}

/* crypt_convert should have filled the clone bio */
- BUG_ON(io->ctx.idx_out < clone->bi_vcnt);
+ BUG_ON(io->ctx.iter_out.bi_size);

clone->bi_iter.bi_sector = cc->start + io->sector;

@@ -1070,7 +1058,7 @@ static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
}

io->ctx.bio_out = clone;
- io->ctx.idx_out = 0;
+ io->ctx.iter_out = clone->bi_iter;

remaining -= clone->bi_iter.bi_size;
sector += bio_sectors(clone);
@@ -1114,8 +1102,7 @@ static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
crypt_inc_pending(new_io);
crypt_convert_init(cc, &new_io->ctx, NULL,
io->base_bio, sector);
- new_io->ctx.idx_in = io->ctx.idx_in;
- new_io->ctx.offset_in = io->ctx.offset_in;
+ new_io->ctx.iter_in = io->ctx.iter_in;

/*
* Fragments after the first use the base_io
diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c
index 01558b0..b2b8a10 100644
--- a/drivers/md/dm-io.c
+++ b/drivers/md/dm-io.c
@@ -201,26 +201,29 @@ static void list_dp_init(struct dpages *dp, struct page_list *pl, unsigned offse
/*
* Functions for getting the pages from a bvec.
*/
-static void bvec_get_page(struct dpages *dp,
+static void bio_get_page(struct dpages *dp,
struct page **p, unsigned long *len, unsigned *offset)
{
- struct bio_vec *bvec = (struct bio_vec *) dp->context_ptr;
- *p = bvec->bv_page;
- *len = bvec->bv_len;
- *offset = bvec->bv_offset;
+ struct bio *bio = dp->context_ptr;
+ struct bio_vec bvec = bio_iovec(bio);
+ *p = bvec.bv_page;
+ *len = bvec.bv_len;
+ *offset = bvec.bv_offset;
}

-static void bvec_next_page(struct dpages *dp)
+static void bio_next_page(struct dpages *dp)
{
- struct bio_vec *bvec = (struct bio_vec *) dp->context_ptr;
- dp->context_ptr = bvec + 1;
+ struct bio *bio = dp->context_ptr;
+ struct bio_vec bvec = bio_iovec(bio);
+
+ bio_advance(bio, bvec.bv_len);
}

-static void bvec_dp_init(struct dpages *dp, struct bio_vec *bvec)
+static void bio_dp_init(struct dpages *dp, struct bio *bio)
{
- dp->get_page = bvec_get_page;
- dp->next_page = bvec_next_page;
- dp->context_ptr = bvec;
+ dp->get_page = bio_get_page;
+ dp->next_page = bio_next_page;
+ dp->context_ptr = bio;
}

/*
@@ -457,8 +460,8 @@ static int dp_init(struct dm_io_request *io_req, struct dpages *dp,
list_dp_init(dp, io_req->mem.ptr.pl, io_req->mem.offset);
break;

- case DM_IO_BVEC:
- bvec_dp_init(dp, io_req->mem.ptr.bvec);
+ case DM_IO_BIO:
+ bio_dp_init(dp, io_req->mem.ptr.bio);
break;

case DM_IO_VMA:
diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c
index 9f6d8e6..f284e0b 100644
--- a/drivers/md/dm-raid1.c
+++ b/drivers/md/dm-raid1.c
@@ -526,8 +526,8 @@ static void read_async_bio(struct mirror *m, struct bio *bio)
struct dm_io_region io;
struct dm_io_request io_req = {
.bi_rw = READ,
- .mem.type = DM_IO_BVEC,
- .mem.ptr.bvec = bio->bi_io_vec + bio->bi_iter.bi_idx,
+ .mem.type = DM_IO_BIO,
+ .mem.ptr.bio = bio,
.notify.fn = read_callback,
.notify.context = bio,
.client = m->ms->io_client,
@@ -629,8 +629,8 @@ static void do_write(struct mirror_set *ms, struct bio *bio)
struct mirror *m;
struct dm_io_request io_req = {
.bi_rw = WRITE | (bio->bi_rw & WRITE_FLUSH_FUA),
- .mem.type = DM_IO_BVEC,
- .mem.ptr.bvec = bio->bi_io_vec + bio->bi_iter.bi_idx,
+ .mem.type = DM_IO_BIO,
+ .mem.ptr.bio = bio,
.notify.fn = write_callback,
.notify.context = bio,
.client = ms->io_client,
diff --git a/drivers/md/dm-verity.c b/drivers/md/dm-verity.c
index 5392135..ac35e95 100644
--- a/drivers/md/dm-verity.c
+++ b/drivers/md/dm-verity.c
@@ -73,15 +73,10 @@ struct dm_verity_io {
sector_t block;
unsigned n_blocks;

- /* saved bio vector */
- struct bio_vec *io_vec;
- unsigned io_vec_size;
+ struct bvec_iter iter;

struct work_struct work;

- /* A space for short vectors; longer vectors are allocated separately. */
- struct bio_vec io_vec_inline[DM_VERITY_IO_VEC_INLINE];
-
/*
* Three variably-size fields follow this struct:
*
@@ -284,9 +279,10 @@ release_ret_r:
static int verity_verify_io(struct dm_verity_io *io)
{
struct dm_verity *v = io->v;
+ struct bio *bio = dm_bio_from_per_bio_data(io,
+ v->ti->per_bio_data_size);
unsigned b;
int i;
- unsigned vector = 0, offset = 0;

for (b = 0; b < io->n_blocks; b++) {
struct shash_desc *desc;
@@ -336,31 +332,22 @@ test_block_hash:
}

todo = 1 << v->data_dev_block_bits;
- do {
- struct bio_vec *bv;
+ while (io->iter.bi_size) {
u8 *page;
- unsigned len;
-
- BUG_ON(vector >= io->io_vec_size);
- bv = &io->io_vec[vector];
- page = kmap_atomic(bv->bv_page);
- len = bv->bv_len - offset;
- if (likely(len >= todo))
- len = todo;
- r = crypto_shash_update(desc,
- page + bv->bv_offset + offset, len);
+ struct bio_vec bv = bio_iter_iovec(bio, io->iter);
+
+ page = kmap_atomic(bv.bv_page);
+ r = crypto_shash_update(desc, page + bv.bv_offset,
+ bv.bv_len);
kunmap_atomic(page);
+
if (r < 0) {
DMERR("crypto_shash_update failed: %d", r);
return r;
}
- offset += len;
- if (likely(offset == bv->bv_len)) {
- offset = 0;
- vector++;
- }
- todo -= len;
- } while (todo);
+
+ bio_advance_iter(bio, &io->iter, bv.bv_len);
+ }

if (!v->version) {
r = crypto_shash_update(desc, v->salt, v->salt_size);
@@ -383,8 +370,6 @@ test_block_hash:
return -EIO;
}
}
- BUG_ON(vector != io->io_vec_size);
- BUG_ON(offset);

return 0;
}
@@ -400,9 +385,6 @@ static void verity_finish_io(struct dm_verity_io *io, int error)
bio->bi_end_io = io->orig_bi_end_io;
bio->bi_private = io->orig_bi_private;

- if (io->io_vec != io->io_vec_inline)
- mempool_free(io->io_vec, v->vec_mempool);
-
bio_endio(bio, error);
}

@@ -519,13 +501,7 @@ static int verity_map(struct dm_target *ti, struct bio *bio)

bio->bi_end_io = verity_end_io;
bio->bi_private = io;
- io->io_vec_size = bio_segments(bio);
- if (io->io_vec_size < DM_VERITY_IO_VEC_INLINE)
- io->io_vec = io->io_vec_inline;
- else
- io->io_vec = mempool_alloc(v->vec_mempool, GFP_NOIO);
- memcpy(io->io_vec, __bio_iovec(bio),
- io->io_vec_size * sizeof(struct bio_vec));
+ io->iter = bio->bi_iter;

verity_submit_prefetch(v, io);

diff --git a/fs/bio.c b/fs/bio.c
index 8c118d0..ff5195d 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -525,8 +525,17 @@ EXPORT_SYMBOL(bio_phys_segments);
*/
void __bio_clone(struct bio *bio, struct bio *bio_src)
{
- memcpy(bio->bi_io_vec, bio_src->bi_io_vec,
- bio_src->bi_max_vecs * sizeof(struct bio_vec));
+ if (bio_is_rw(bio_src)) {
+ struct bio_vec bv;
+ struct bvec_iter iter;
+
+ bio_for_each_segment(bv, bio_src, iter)
+ bio->bi_io_vec[bio->bi_vcnt++] = bv;
+ } else if (bio_has_data(bio_src)) {
+ memcpy(bio->bi_io_vec, bio_src->bi_io_vec,
+ bio_src->bi_max_vecs * sizeof(struct bio_vec));
+ bio->bi_vcnt = bio_src->bi_vcnt;
+ }

/*
* most users will be overriding ->bi_bdev with a new target,
@@ -535,7 +544,6 @@ void __bio_clone(struct bio *bio, struct bio *bio_src)
bio->bi_bdev = bio_src->bi_bdev;
bio->bi_flags |= 1 << BIO_CLONED;
bio->bi_rw = bio_src->bi_rw;
- bio->bi_vcnt = bio_src->bi_vcnt;
bio->bi_iter = bio_src->bi_iter;
}
EXPORT_SYMBOL(__bio_clone);
diff --git a/include/linux/dm-io.h b/include/linux/dm-io.h
index f4b0aa3..a68cbe5 100644
--- a/include/linux/dm-io.h
+++ b/include/linux/dm-io.h
@@ -29,7 +29,7 @@ typedef void (*io_notify_fn)(unsigned long error, void *context);

enum dm_io_mem_type {
DM_IO_PAGE_LIST,/* Page list */
- DM_IO_BVEC, /* Bio vector */
+ DM_IO_BIO, /* Bio vector */
DM_IO_VMA, /* Virtual memory area */
DM_IO_KMEM, /* Kernel memory */
};
@@ -41,7 +41,7 @@ struct dm_io_memory {

union {
struct page_list *pl;
- struct bio_vec *bvec;
+ struct bio *bio;
void *vma;
void *addr;
} ptr;
--
1.8.4.rc3

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