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Subject[PATCH v2 16/26] pktcdvd: use bio_copy_data()
Date
Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: Jiri Kosina <jkosina@suse.cz>
---
drivers/block/pktcdvd.c | 79 ++++++++-----------------------------------------
1 file changed, 12 insertions(+), 67 deletions(-)

diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index 0824627..1079a77 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -948,31 +948,6 @@ static int pkt_set_segment_merging(struct pktcdvd_device *pd, struct request_que
}

/*
- * Copy CD_FRAMESIZE bytes from src_bio into a destination page
- */
-static void pkt_copy_bio_data(struct bio *src_bio, int seg, int offs, struct page *dst_page, int dst_offs)
-{
- unsigned int copy_size = CD_FRAMESIZE;
-
- while (copy_size > 0) {
- struct bio_vec *src_bvl = bio_iovec_idx(src_bio, seg);
- void *vfrom = kmap_atomic(src_bvl->bv_page) +
- src_bvl->bv_offset + offs;
- void *vto = page_address(dst_page) + dst_offs;
- int len = min_t(int, copy_size, src_bvl->bv_len - offs);
-
- BUG_ON(len < 0);
- memcpy(vto, vfrom, len);
- kunmap_atomic(vfrom);
-
- seg++;
- offs = 0;
- dst_offs += len;
- copy_size -= len;
- }
-}
-
-/*
* Copy all data for this packet to pkt->pages[], so that
* a) The number of required segments for the write bio is minimized, which
* is necessary for some scsi controllers.
@@ -1325,55 +1300,35 @@ try_next_bio:
*/
static void pkt_start_write(struct pktcdvd_device *pd, struct packet_data *pkt)
{
- struct bio *bio;
int f;
- int frames_write;
struct bio_vec *bvec = pkt->w_bio->bi_io_vec;

+ bio_reset(pkt->w_bio);
+ pkt->w_bio->bi_sector = pkt->sector;
+ pkt->w_bio->bi_bdev = pd->bdev;
+ pkt->w_bio->bi_end_io = pkt_end_io_packet_write;
+ pkt->w_bio->bi_private = pkt;
+
+ /* XXX: locking? */
for (f = 0; f < pkt->frames; f++) {
bvec[f].bv_page = pkt->pages[(f * CD_FRAMESIZE) / PAGE_SIZE];
bvec[f].bv_offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
+ if (!bio_add_page(pkt->w_bio, bvec[f].bv_page, CD_FRAMESIZE, bvec[f].bv_offset))
+ BUG();
}
+ VPRINTK(DRIVER_NAME": vcnt=%d\n", pkt->w_bio->bi_vcnt);

/*
* Fill-in bvec with data from orig_bios.
*/
- frames_write = 0;
spin_lock(&pkt->lock);
- bio_list_for_each(bio, &pkt->orig_bios) {
- int segment = bio->bi_idx;
- int src_offs = 0;
- int first_frame = (bio->bi_sector - pkt->sector) / (CD_FRAMESIZE >> 9);
- int num_frames = bio->bi_size / CD_FRAMESIZE;
- BUG_ON(first_frame < 0);
- BUG_ON(first_frame + num_frames > pkt->frames);
- for (f = first_frame; f < first_frame + num_frames; f++) {
- struct bio_vec *src_bvl = bio_iovec_idx(bio, segment);
-
- while (src_offs >= src_bvl->bv_len) {
- src_offs -= src_bvl->bv_len;
- segment++;
- BUG_ON(segment >= bio->bi_vcnt);
- src_bvl = bio_iovec_idx(bio, segment);
- }
+ bio_copy_data(pkt->w_bio, pkt->orig_bios.head);

- if (src_bvl->bv_len - src_offs >= CD_FRAMESIZE) {
- bvec[f].bv_page = src_bvl->bv_page;
- bvec[f].bv_offset = src_bvl->bv_offset + src_offs;
- } else {
- pkt_copy_bio_data(bio, segment, src_offs,
- bvec[f].bv_page, bvec[f].bv_offset);
- }
- src_offs += CD_FRAMESIZE;
- frames_write++;
- }
- }
pkt_set_state(pkt, PACKET_WRITE_WAIT_STATE);
spin_unlock(&pkt->lock);

VPRINTK("pkt_start_write: Writing %d frames for zone %llx\n",
- frames_write, (unsigned long long)pkt->sector);
- BUG_ON(frames_write != pkt->write_size);
+ pkt->write_size, (unsigned long long)pkt->sector);

if (test_bit(PACKET_MERGE_SEGS, &pd->flags) || (pkt->write_size < pkt->frames)) {
pkt_make_local_copy(pkt, bvec);
@@ -1383,16 +1338,6 @@ static void pkt_start_write(struct pktcdvd_device *pd, struct packet_data *pkt)
}

/* Start the write request */
- bio_reset(pkt->w_bio);
- pkt->w_bio->bi_sector = pkt->sector;
- pkt->w_bio->bi_bdev = pd->bdev;
- pkt->w_bio->bi_end_io = pkt_end_io_packet_write;
- pkt->w_bio->bi_private = pkt;
- for (f = 0; f < pkt->frames; f++)
- if (!bio_add_page(pkt->w_bio, bvec[f].bv_page, CD_FRAMESIZE, bvec[f].bv_offset))
- BUG();
- VPRINTK(DRIVER_NAME": vcnt=%d\n", pkt->w_bio->bi_vcnt);
-
atomic_set(&pkt->io_wait, 1);
pkt->w_bio->bi_rw = WRITE;
pkt_queue_bio(pd, pkt->w_bio);
--
1.7.12


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