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Staging: hv: Get rid of the forward declaration for blkvsc_do_request()
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Get rid of the forward declaration for blkvsc_do_request() by moving the
code around.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Abhishek Kane <v-abkane@microsoft.com>
Signed-off-by: Hank Janssen <hjanssen@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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K. Y. Srinivasan authored and Greg Kroah-Hartman committed Apr 25, 2011
1 parent 2c77407 commit 8f8e57a
Showing 1 changed file with 193 additions and 177 deletions.
370 changes: 193 additions & 177 deletions drivers/staging/hv/blkvsc_drv.c
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Original file line number Diff line number Diff line change
Expand Up @@ -118,6 +118,12 @@ static const struct hv_guid g_blk_device_type = {
}
};

/*
* There is a circular dependency involving blkvsc_request_completion()
* and blkvsc_do_request().
*/
static void blkvsc_request_completion(struct hv_storvsc_request *request);

static int blk_vsc_on_device_add(struct hv_device *device,
void *additional_info)
{
Expand Down Expand Up @@ -947,12 +953,196 @@ static int blkvsc_do_inquiry(struct block_device_context *blkdev)
return 0;
}


/*
* We break the request into 1 or more blkvsc_requests and submit
* them. If we cant submit them all, we put them on the
* pending_list. The blkvsc_request() will work on the pending_list.
*/
static int blkvsc_do_request(struct block_device_context *blkdev,
struct request *req)
{
struct bio *bio = NULL;
struct bio_vec *bvec = NULL;
struct bio_vec *prev_bvec = NULL;
struct blkvsc_request *blkvsc_req = NULL;
struct blkvsc_request *tmp;
int databuf_idx = 0;
int seg_idx = 0;
sector_t start_sector;
unsigned long num_sectors = 0;
int ret = 0;
int pending = 0;
struct blkvsc_request_group *group = NULL;

DPRINT_DBG(BLKVSC_DRV, "blkdev %p req %p sect %lu\n", blkdev, req,
(unsigned long)blk_rq_pos(req));

/* Create a group to tie req to list of blkvsc_reqs */
group = kmem_cache_zalloc(blkdev->request_pool, GFP_ATOMIC);
if (!group)
return -ENOMEM;

INIT_LIST_HEAD(&group->blkvsc_req_list);
group->outstanding = group->status = 0;

start_sector = blk_rq_pos(req);

/* foreach bio in the request */
if (req->bio) {
for (bio = req->bio; bio; bio = bio->bi_next) {
/*
* Map this bio into an existing or new storvsc request
*/
bio_for_each_segment(bvec, bio, seg_idx) {
DPRINT_DBG(BLKVSC_DRV, "bio_for_each_segment() "
"- req %p bio %p bvec %p seg_idx %d "
"databuf_idx %d\n", req, bio, bvec,
seg_idx, databuf_idx);

/* Get a new storvsc request */
/* 1st-time */
if ((!blkvsc_req) ||
(databuf_idx >= MAX_MULTIPAGE_BUFFER_COUNT)
/* hole at the begin of page */
|| (bvec->bv_offset != 0) ||
/* hold at the end of page */
(prev_bvec &&
(prev_bvec->bv_len != PAGE_SIZE))) {
/* submit the prev one */
if (blkvsc_req) {
blkvsc_req->sector_start =
start_sector;
sector_div(
blkvsc_req->sector_start,
(blkdev->sector_size >> 9));

blkvsc_req->sector_count =
num_sectors /
(blkdev->sector_size >> 9);
blkvsc_init_rw(blkvsc_req);
}

/*
* Create new blkvsc_req to represent
* the current bvec
*/
blkvsc_req =
kmem_cache_zalloc(
blkdev->request_pool, GFP_ATOMIC);
if (!blkvsc_req) {
/* free up everything */
list_for_each_entry_safe(
blkvsc_req, tmp,
&group->blkvsc_req_list,
req_entry) {
list_del(
&blkvsc_req->req_entry);
kmem_cache_free(
blkdev->request_pool,
blkvsc_req);
}

kmem_cache_free(
blkdev->request_pool, group);
return -ENOMEM;
}

memset(blkvsc_req, 0,
sizeof(struct blkvsc_request));

blkvsc_req->dev = blkdev;
blkvsc_req->req = req;
blkvsc_req->request.
data_buffer.offset
= bvec->bv_offset;
blkvsc_req->request.
data_buffer.len = 0;

/* Add to the group */
blkvsc_req->group = group;
blkvsc_req->group->outstanding++;
list_add_tail(&blkvsc_req->req_entry,
&blkvsc_req->group->blkvsc_req_list);

start_sector += num_sectors;
num_sectors = 0;
databuf_idx = 0;
}

/*
* Add the curr bvec/segment to the curr
* blkvsc_req
*/
blkvsc_req->request.data_buffer.
pfn_array[databuf_idx]
= page_to_pfn(bvec->bv_page);
blkvsc_req->request.data_buffer.len
+= bvec->bv_len;

prev_bvec = bvec;

databuf_idx++;
num_sectors += bvec->bv_len >> 9;

} /* bio_for_each_segment */

} /* rq_for_each_bio */
}

/* Handle the last one */
if (blkvsc_req) {
DPRINT_DBG(BLKVSC_DRV, "blkdev %p req %p group %p count %d\n",
blkdev, req, blkvsc_req->group,
blkvsc_req->group->outstanding);

blkvsc_req->sector_start = start_sector;
sector_div(blkvsc_req->sector_start,
(blkdev->sector_size >> 9));

blkvsc_req->sector_count = num_sectors /
(blkdev->sector_size >> 9);

blkvsc_init_rw(blkvsc_req);
}

list_for_each_entry(blkvsc_req, &group->blkvsc_req_list, req_entry) {
if (pending) {
DPRINT_DBG(BLKVSC_DRV, "adding blkvsc_req to "
"pending_list - blkvsc_req %p start_sect %lu"
" sect_count %ld (%lu %ld)\n", blkvsc_req,
(unsigned long)blkvsc_req->sector_start,
blkvsc_req->sector_count,
(unsigned long)start_sector,
(unsigned long)num_sectors);

list_add_tail(&blkvsc_req->pend_entry,
&blkdev->pending_list);
} else {
ret = blkvsc_submit_request(blkvsc_req,
blkvsc_request_completion);
if (ret == -1) {
pending = 1;
list_add_tail(&blkvsc_req->pend_entry,
&blkdev->pending_list);
}

DPRINT_DBG(BLKVSC_DRV, "submitted blkvsc_req %p "
"start_sect %lu sect_count %ld (%lu %ld) "
"ret %d\n", blkvsc_req,
(unsigned long)blkvsc_req->sector_start,
blkvsc_req->sector_count,
(unsigned long)start_sector,
num_sectors, ret);
}
}

return pending;
}

/* Static decl */
static int blkvsc_probe(struct device *dev);
static void blkvsc_request(struct request_queue *queue);
static void blkvsc_request_completion(struct hv_storvsc_request *request);
static int blkvsc_do_request(struct block_device_context *blkdev,
struct request *req);
static int blkvsc_do_pending_reqs(struct block_device_context *blkdev);

static int blkvsc_ringbuffer_size = BLKVSC_RING_BUFFER_SIZE;
Expand Down Expand Up @@ -1207,180 +1397,6 @@ static int blkvsc_probe(struct device *device)
return ret;
}

/*
* We break the request into 1 or more blkvsc_requests and submit
* them. If we can't submit them all, we put them on the
* pending_list. The blkvsc_request() will work on the pending_list.
*/
static int blkvsc_do_request(struct block_device_context *blkdev,
struct request *req)
{
struct bio *bio = NULL;
struct bio_vec *bvec = NULL;
struct bio_vec *prev_bvec = NULL;
struct blkvsc_request *blkvsc_req = NULL;
struct blkvsc_request *tmp;
int databuf_idx = 0;
int seg_idx = 0;
sector_t start_sector;
unsigned long num_sectors = 0;
int ret = 0;
int pending = 0;
struct blkvsc_request_group *group = NULL;

DPRINT_DBG(BLKVSC_DRV, "blkdev %p req %p sect %lu\n", blkdev, req,
(unsigned long)blk_rq_pos(req));

/* Create a group to tie req to list of blkvsc_reqs */
group = kmem_cache_zalloc(blkdev->request_pool, GFP_ATOMIC);
if (!group)
return -ENOMEM;

INIT_LIST_HEAD(&group->blkvsc_req_list);
group->outstanding = group->status = 0;

start_sector = blk_rq_pos(req);

/* foreach bio in the request */
if (req->bio) {
for (bio = req->bio; bio; bio = bio->bi_next) {
/*
* Map this bio into an existing or new storvsc request
*/
bio_for_each_segment(bvec, bio, seg_idx) {
DPRINT_DBG(BLKVSC_DRV, "bio_for_each_segment() "
"- req %p bio %p bvec %p seg_idx %d "
"databuf_idx %d\n", req, bio, bvec,
seg_idx, databuf_idx);

/* Get a new storvsc request */
/* 1st-time */
if ((!blkvsc_req) ||
(databuf_idx >= MAX_MULTIPAGE_BUFFER_COUNT)
/* hole at the begin of page */
|| (bvec->bv_offset != 0) ||
/* hold at the end of page */
(prev_bvec &&
(prev_bvec->bv_len != PAGE_SIZE))) {
/* submit the prev one */
if (blkvsc_req) {
blkvsc_req->sector_start = start_sector;
sector_div(blkvsc_req->sector_start, (blkdev->sector_size >> 9));

blkvsc_req->sector_count = num_sectors / (blkdev->sector_size >> 9);
blkvsc_init_rw(blkvsc_req);
}

/*
* Create new blkvsc_req to represent
* the current bvec
*/
blkvsc_req =
kmem_cache_zalloc(
blkdev->request_pool, GFP_ATOMIC);
if (!blkvsc_req) {
/* free up everything */
list_for_each_entry_safe(
blkvsc_req, tmp,
&group->blkvsc_req_list,
req_entry) {
list_del(&blkvsc_req->req_entry);
kmem_cache_free(blkdev->request_pool, blkvsc_req);
}

kmem_cache_free(blkdev->request_pool, group);
return -ENOMEM;
}

memset(blkvsc_req, 0,
sizeof(struct blkvsc_request));

blkvsc_req->dev = blkdev;
blkvsc_req->req = req;
blkvsc_req->request.
data_buffer.offset
= bvec->bv_offset;
blkvsc_req->request.
data_buffer.len = 0;

/* Add to the group */
blkvsc_req->group = group;
blkvsc_req->group->outstanding++;
list_add_tail(&blkvsc_req->req_entry,
&blkvsc_req->group->blkvsc_req_list);

start_sector += num_sectors;
num_sectors = 0;
databuf_idx = 0;
}

/* Add the curr bvec/segment to the curr blkvsc_req */
blkvsc_req->request.data_buffer.
pfn_array[databuf_idx]
= page_to_pfn(bvec->bv_page);
blkvsc_req->request.data_buffer.len
+= bvec->bv_len;

prev_bvec = bvec;

databuf_idx++;
num_sectors += bvec->bv_len >> 9;

} /* bio_for_each_segment */

} /* rq_for_each_bio */
}

/* Handle the last one */
if (blkvsc_req) {
DPRINT_DBG(BLKVSC_DRV, "blkdev %p req %p group %p count %d\n",
blkdev, req, blkvsc_req->group,
blkvsc_req->group->outstanding);

blkvsc_req->sector_start = start_sector;
sector_div(blkvsc_req->sector_start,
(blkdev->sector_size >> 9));

blkvsc_req->sector_count = num_sectors /
(blkdev->sector_size >> 9);

blkvsc_init_rw(blkvsc_req);
}

list_for_each_entry(blkvsc_req, &group->blkvsc_req_list, req_entry) {
if (pending) {
DPRINT_DBG(BLKVSC_DRV, "adding blkvsc_req to "
"pending_list - blkvsc_req %p start_sect %lu"
" sect_count %ld (%lu %ld)\n", blkvsc_req,
(unsigned long)blkvsc_req->sector_start,
blkvsc_req->sector_count,
(unsigned long)start_sector,
(unsigned long)num_sectors);

list_add_tail(&blkvsc_req->pend_entry,
&blkdev->pending_list);
} else {
ret = blkvsc_submit_request(blkvsc_req,
blkvsc_request_completion);
if (ret == -1) {
pending = 1;
list_add_tail(&blkvsc_req->pend_entry,
&blkdev->pending_list);
}

DPRINT_DBG(BLKVSC_DRV, "submitted blkvsc_req %p "
"start_sect %lu sect_count %ld (%lu %ld) "
"ret %d\n", blkvsc_req,
(unsigned long)blkvsc_req->sector_start,
blkvsc_req->sector_count,
(unsigned long)start_sector,
num_sectors, ret);
}
}

return pending;
}

static void blkvsc_request_completion(struct hv_storvsc_request *request)
{
struct blkvsc_request *blkvsc_req =
Expand Down

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