diff options
| -rw-r--r-- | drivers/xen/blkback/blkback.c | 45 |
1 files changed, 23 insertions, 22 deletions
diff --git a/drivers/xen/blkback/blkback.c b/drivers/xen/blkback/blkback.c index 464f2e0b5a61..3c10499d61a7 100644 --- a/drivers/xen/blkback/blkback.c +++ b/drivers/xen/blkback/blkback.c @@ -421,7 +421,8 @@ static void dispatch_rw_block_io(struct blkif_st *blkif, } seg[BLKIF_MAX_SEGMENTS_PER_REQUEST]; unsigned int nseg; struct bio *bio = NULL; - int ret, i; + struct bio *biolist[BLKIF_MAX_SEGMENTS_PER_REQUEST]; + int ret, i, nbio = 0; int operation; struct blk_plug plug; struct request_queue *q; @@ -529,14 +530,7 @@ static void dispatch_rw_block_io(struct blkif_st *blkif, goto fail_flush; } - /* Get a reference count for the disk queue and start sending I/O */ - blk_get_queue(q); - blk_start_plug(&plug); - - /* We set it one so that the last submit_bio does not have to call - * atomic_inc. - */ - atomic_set(&pending_req->pendcnt, 1); + /* This corresponding blkif_put is done in __end_block_io_op */ blkif_get(blkif); for (i = 0; i < nseg; i++) { @@ -552,12 +546,8 @@ static void dispatch_rw_block_io(struct blkif_st *blkif, blkbk->pending_page(pending_req, i), seg[i].nsec << 9, seg[i].buf & ~PAGE_MASK) == 0)) { - if (bio) { - atomic_inc(&pending_req->pendcnt); - submit_bio(operation, bio); - } - bio = bio_alloc(GFP_KERNEL, nseg-i); + bio = biolist[nbio++] = bio_alloc(GFP_KERNEL, nseg-i); if (unlikely(bio == NULL)) goto fail_put_bio; @@ -573,7 +563,7 @@ static void dispatch_rw_block_io(struct blkif_st *blkif, /* This will be hit if the operation was a barrier. */ if (!bio) { BUG_ON(operation != WRITE_BARRIER); - bio = bio_alloc(GFP_KERNEL, 0); + bio = biolist[nbio++] = bio_alloc(GFP_KERNEL, 0); if (unlikely(bio == NULL)) goto fail_put_bio; @@ -583,15 +573,28 @@ static void dispatch_rw_block_io(struct blkif_st *blkif, bio->bi_sector = -1; } - submit_bio(operation, bio); + + /* We set it one so that the last submit_bio does not have to call + * atomic_inc. + */ + atomic_set(&pending_req->pendcnt, nbio); + + /* Get a reference count for the disk queue and start sending I/O */ + blk_get_queue(q); + blk_start_plug(&plug); + + for (i = 0; i < nbio; i++) + submit_bio(operation, biolist[i]); + + blk_finish_plug(&plug); + /* Let the I/Os go.. */ + blk_put_queue(q); if (operation == READ) blkif->st_rd_sect += preq.nr_sects; else if (operation == WRITE || operation == WRITE_BARRIER) blkif->st_wr_sect += preq.nr_sects; - blk_finish_plug(&plug); - blk_put_queue(q); return; fail_flush: @@ -604,11 +607,9 @@ static void dispatch_rw_block_io(struct blkif_st *blkif, return; fail_put_bio: + for (i = 0; i < (nbio-1); i++) + bio_put(biolist[i]); __end_block_io_op(pending_req, -EINVAL); - if (bio) - bio_put(bio); - blk_finish_plug(&plug); - blk_put_queue(q); msleep(1); /* back off a bit */ return; } |