[PATCH 17/22] Staging: hv: Get rid of the forward declaration for blkvsc_do_request()

K. Y. Srinivasan
2011-04-06T22:38:01Z

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>
---
drivers/staging/hv/blkvsc_drv.c | 370 ++++++++++++++++++++-------------------
1 files changed, 193 insertions(+), 177 deletions(-)

diff --git a/drivers/staging/hv/blkvsc_drv.c b/drivers/staging/hv/blkvsc_drv.c
index f7bf42f..9d4fcbd 100644
--- a/drivers/staging/hv/blkvsc_drv.c
+++ b/drivers/staging/hv/blkvsc_drv.c
@@ -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)
{
@@ -955,12 +961,196 @@ 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;
@@ -1216,180 +1406,6 @@ Cleanup:
return ret;
}

-/*
- * 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 void blkvsc_request_completion(struct hv_storvsc_request *request)
{
struct blkvsc_request *blkvsc_req =
--
1.7.4.1