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@@ -29,7 +29,6 @@
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#include <linux/cpu.h>
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#include <linux/blktrace_api.h>
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#include <linux/fault-inject.h>
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-#include <linux/scatterlist.h>
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#include "blk.h"
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@@ -181,376 +180,6 @@ void blk_dump_rq_flags(struct request *rq, char *msg)
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EXPORT_SYMBOL(blk_dump_rq_flags);
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-static void blk_recalc_rq_segments(struct request *rq)
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-{
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- int nr_phys_segs;
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- int nr_hw_segs;
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- unsigned int phys_size;
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- unsigned int hw_size;
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- struct bio_vec *bv, *bvprv = NULL;
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- int seg_size;
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- int hw_seg_size;
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- int cluster;
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- struct req_iterator iter;
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- int high, highprv = 1;
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- struct request_queue *q = rq->q;
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-
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- if (!rq->bio)
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- return;
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-
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- cluster = q->queue_flags & (1 << QUEUE_FLAG_CLUSTER);
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- hw_seg_size = seg_size = 0;
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- phys_size = hw_size = nr_phys_segs = nr_hw_segs = 0;
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- rq_for_each_segment(bv, rq, iter) {
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- /*
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- * the trick here is making sure that a high page is never
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- * considered part of another segment, since that might
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- * change with the bounce page.
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- */
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- high = page_to_pfn(bv->bv_page) > q->bounce_pfn;
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- if (high || highprv)
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- goto new_hw_segment;
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- if (cluster) {
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- if (seg_size + bv->bv_len > q->max_segment_size)
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- goto new_segment;
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- if (!BIOVEC_PHYS_MERGEABLE(bvprv, bv))
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- goto new_segment;
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- if (!BIOVEC_SEG_BOUNDARY(q, bvprv, bv))
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- goto new_segment;
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- if (BIOVEC_VIRT_OVERSIZE(hw_seg_size + bv->bv_len))
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- goto new_hw_segment;
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-
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- seg_size += bv->bv_len;
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- hw_seg_size += bv->bv_len;
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- bvprv = bv;
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- continue;
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- }
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-new_segment:
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- if (BIOVEC_VIRT_MERGEABLE(bvprv, bv) &&
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- !BIOVEC_VIRT_OVERSIZE(hw_seg_size + bv->bv_len))
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- hw_seg_size += bv->bv_len;
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- else {
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-new_hw_segment:
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- if (nr_hw_segs == 1 &&
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- hw_seg_size > rq->bio->bi_hw_front_size)
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- rq->bio->bi_hw_front_size = hw_seg_size;
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- hw_seg_size = BIOVEC_VIRT_START_SIZE(bv) + bv->bv_len;
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- nr_hw_segs++;
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- }
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-
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- nr_phys_segs++;
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- bvprv = bv;
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- seg_size = bv->bv_len;
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- highprv = high;
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- }
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-
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- if (nr_hw_segs == 1 &&
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- hw_seg_size > rq->bio->bi_hw_front_size)
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- rq->bio->bi_hw_front_size = hw_seg_size;
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- if (hw_seg_size > rq->biotail->bi_hw_back_size)
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- rq->biotail->bi_hw_back_size = hw_seg_size;
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- rq->nr_phys_segments = nr_phys_segs;
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- rq->nr_hw_segments = nr_hw_segs;
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-}
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-
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-void blk_recount_segments(struct request_queue *q, struct bio *bio)
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-{
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- struct request rq;
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- struct bio *nxt = bio->bi_next;
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- rq.q = q;
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- rq.bio = rq.biotail = bio;
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- bio->bi_next = NULL;
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- blk_recalc_rq_segments(&rq);
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- bio->bi_next = nxt;
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- bio->bi_phys_segments = rq.nr_phys_segments;
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- bio->bi_hw_segments = rq.nr_hw_segments;
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- bio->bi_flags |= (1 << BIO_SEG_VALID);
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-}
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-EXPORT_SYMBOL(blk_recount_segments);
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-
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-static int blk_phys_contig_segment(struct request_queue *q, struct bio *bio,
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- struct bio *nxt)
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-{
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- if (!(q->queue_flags & (1 << QUEUE_FLAG_CLUSTER)))
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- return 0;
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-
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- if (!BIOVEC_PHYS_MERGEABLE(__BVEC_END(bio), __BVEC_START(nxt)))
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- return 0;
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- if (bio->bi_size + nxt->bi_size > q->max_segment_size)
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- return 0;
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-
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- /*
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- * bio and nxt are contigous in memory, check if the queue allows
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- * these two to be merged into one
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- */
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- if (BIO_SEG_BOUNDARY(q, bio, nxt))
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- return 1;
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-
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- return 0;
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-}
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-
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-static int blk_hw_contig_segment(struct request_queue *q, struct bio *bio,
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- struct bio *nxt)
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-{
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- if (unlikely(!bio_flagged(bio, BIO_SEG_VALID)))
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- blk_recount_segments(q, bio);
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- if (unlikely(!bio_flagged(nxt, BIO_SEG_VALID)))
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- blk_recount_segments(q, nxt);
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- if (!BIOVEC_VIRT_MERGEABLE(__BVEC_END(bio), __BVEC_START(nxt)) ||
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- BIOVEC_VIRT_OVERSIZE(bio->bi_hw_back_size + nxt->bi_hw_front_size))
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- return 0;
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- if (bio->bi_hw_back_size + nxt->bi_hw_front_size > q->max_segment_size)
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- return 0;
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-
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- return 1;
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-}
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-
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-/*
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- * map a request to scatterlist, return number of sg entries setup. Caller
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- * must make sure sg can hold rq->nr_phys_segments entries
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- */
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-int blk_rq_map_sg(struct request_queue *q, struct request *rq,
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- struct scatterlist *sglist)
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-{
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- struct bio_vec *bvec, *bvprv;
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- struct req_iterator iter;
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- struct scatterlist *sg;
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- int nsegs, cluster;
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-
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- nsegs = 0;
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- cluster = q->queue_flags & (1 << QUEUE_FLAG_CLUSTER);
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-
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- /*
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- * for each bio in rq
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- */
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- bvprv = NULL;
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- sg = NULL;
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- rq_for_each_segment(bvec, rq, iter) {
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- int nbytes = bvec->bv_len;
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-
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- if (bvprv && cluster) {
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- if (sg->length + nbytes > q->max_segment_size)
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- goto new_segment;
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-
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- if (!BIOVEC_PHYS_MERGEABLE(bvprv, bvec))
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- goto new_segment;
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- if (!BIOVEC_SEG_BOUNDARY(q, bvprv, bvec))
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- goto new_segment;
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-
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- sg->length += nbytes;
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- } else {
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-new_segment:
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- if (!sg)
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- sg = sglist;
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- else {
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- /*
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- * If the driver previously mapped a shorter
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- * list, we could see a termination bit
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- * prematurely unless it fully inits the sg
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- * table on each mapping. We KNOW that there
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- * must be more entries here or the driver
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- * would be buggy, so force clear the
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- * termination bit to avoid doing a full
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- * sg_init_table() in drivers for each command.
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- */
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- sg->page_link &= ~0x02;
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- sg = sg_next(sg);
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- }
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-
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- sg_set_page(sg, bvec->bv_page, nbytes, bvec->bv_offset);
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- nsegs++;
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- }
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- bvprv = bvec;
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- } /* segments in rq */
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-
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- if (q->dma_drain_size) {
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- sg->page_link &= ~0x02;
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- sg = sg_next(sg);
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- sg_set_page(sg, virt_to_page(q->dma_drain_buffer),
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- q->dma_drain_size,
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- ((unsigned long)q->dma_drain_buffer) &
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- (PAGE_SIZE - 1));
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- nsegs++;
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- }
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-
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- if (sg)
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- sg_mark_end(sg);
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-
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- return nsegs;
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-}
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-
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-EXPORT_SYMBOL(blk_rq_map_sg);
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-
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-static inline int ll_new_mergeable(struct request_queue *q,
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- struct request *req,
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- struct bio *bio)
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-{
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- int nr_phys_segs = bio_phys_segments(q, bio);
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-
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- if (req->nr_phys_segments + nr_phys_segs > q->max_phys_segments) {
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- req->cmd_flags |= REQ_NOMERGE;
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- if (req == q->last_merge)
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- q->last_merge = NULL;
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- return 0;
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- }
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-
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- /*
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- * A hw segment is just getting larger, bump just the phys
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- * counter.
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- */
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- req->nr_phys_segments += nr_phys_segs;
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- return 1;
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-}
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-
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-static inline int ll_new_hw_segment(struct request_queue *q,
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- struct request *req,
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- struct bio *bio)
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-{
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- int nr_hw_segs = bio_hw_segments(q, bio);
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- int nr_phys_segs = bio_phys_segments(q, bio);
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-
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- if (req->nr_hw_segments + nr_hw_segs > q->max_hw_segments
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- || req->nr_phys_segments + nr_phys_segs > q->max_phys_segments) {
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- req->cmd_flags |= REQ_NOMERGE;
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- if (req == q->last_merge)
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- q->last_merge = NULL;
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- return 0;
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- }
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-
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- /*
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- * This will form the start of a new hw segment. Bump both
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- * counters.
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- */
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- req->nr_hw_segments += nr_hw_segs;
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- req->nr_phys_segments += nr_phys_segs;
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- return 1;
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-}
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-
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-int ll_back_merge_fn(struct request_queue *q, struct request *req,
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- struct bio *bio)
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-{
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- unsigned short max_sectors;
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- int len;
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-
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- if (unlikely(blk_pc_request(req)))
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- max_sectors = q->max_hw_sectors;
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- else
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- max_sectors = q->max_sectors;
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-
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- if (req->nr_sectors + bio_sectors(bio) > max_sectors) {
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- req->cmd_flags |= REQ_NOMERGE;
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- if (req == q->last_merge)
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- q->last_merge = NULL;
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- return 0;
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- }
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- if (unlikely(!bio_flagged(req->biotail, BIO_SEG_VALID)))
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- blk_recount_segments(q, req->biotail);
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- if (unlikely(!bio_flagged(bio, BIO_SEG_VALID)))
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- blk_recount_segments(q, bio);
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- len = req->biotail->bi_hw_back_size + bio->bi_hw_front_size;
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- if (BIOVEC_VIRT_MERGEABLE(__BVEC_END(req->biotail), __BVEC_START(bio)) &&
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- !BIOVEC_VIRT_OVERSIZE(len)) {
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- int mergeable = ll_new_mergeable(q, req, bio);
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-
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- if (mergeable) {
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- if (req->nr_hw_segments == 1)
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- req->bio->bi_hw_front_size = len;
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- if (bio->bi_hw_segments == 1)
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- bio->bi_hw_back_size = len;
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- }
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- return mergeable;
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- }
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-
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- return ll_new_hw_segment(q, req, bio);
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-}
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-
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-static int ll_front_merge_fn(struct request_queue *q, struct request *req,
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- struct bio *bio)
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-{
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- unsigned short max_sectors;
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- int len;
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-
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- if (unlikely(blk_pc_request(req)))
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- max_sectors = q->max_hw_sectors;
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- else
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- max_sectors = q->max_sectors;
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-
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-
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- if (req->nr_sectors + bio_sectors(bio) > max_sectors) {
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- req->cmd_flags |= REQ_NOMERGE;
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- if (req == q->last_merge)
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- q->last_merge = NULL;
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- return 0;
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- }
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- len = bio->bi_hw_back_size + req->bio->bi_hw_front_size;
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- if (unlikely(!bio_flagged(bio, BIO_SEG_VALID)))
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- blk_recount_segments(q, bio);
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- if (unlikely(!bio_flagged(req->bio, BIO_SEG_VALID)))
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- blk_recount_segments(q, req->bio);
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- if (BIOVEC_VIRT_MERGEABLE(__BVEC_END(bio), __BVEC_START(req->bio)) &&
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- !BIOVEC_VIRT_OVERSIZE(len)) {
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- int mergeable = ll_new_mergeable(q, req, bio);
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-
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- if (mergeable) {
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- if (bio->bi_hw_segments == 1)
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- bio->bi_hw_front_size = len;
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- if (req->nr_hw_segments == 1)
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- req->biotail->bi_hw_back_size = len;
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- }
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- return mergeable;
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- }
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-
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- return ll_new_hw_segment(q, req, bio);
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-}
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-
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-static int ll_merge_requests_fn(struct request_queue *q, struct request *req,
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- struct request *next)
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-{
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- int total_phys_segments;
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- int total_hw_segments;
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-
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- /*
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- * First check if the either of the requests are re-queued
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- * requests. Can't merge them if they are.
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- */
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- if (req->special || next->special)
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- return 0;
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-
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- /*
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- * Will it become too large?
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- */
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- if ((req->nr_sectors + next->nr_sectors) > q->max_sectors)
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- return 0;
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-
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- total_phys_segments = req->nr_phys_segments + next->nr_phys_segments;
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- if (blk_phys_contig_segment(q, req->biotail, next->bio))
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- total_phys_segments--;
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-
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- if (total_phys_segments > q->max_phys_segments)
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- return 0;
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-
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- total_hw_segments = req->nr_hw_segments + next->nr_hw_segments;
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- if (blk_hw_contig_segment(q, req->biotail, next->bio)) {
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- int len = req->biotail->bi_hw_back_size + next->bio->bi_hw_front_size;
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- /*
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- * propagate the combined length to the end of the requests
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- */
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- if (req->nr_hw_segments == 1)
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- req->bio->bi_hw_front_size = len;
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- if (next->nr_hw_segments == 1)
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- next->biotail->bi_hw_back_size = len;
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- total_hw_segments--;
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- }
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-
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- if (total_hw_segments > q->max_hw_segments)
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- return 0;
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-
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- /* Merge is OK... */
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- req->nr_phys_segments = total_phys_segments;
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- req->nr_hw_segments = total_hw_segments;
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- return 1;
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-}
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-
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/*
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* "plug" the device if there are no outstanding requests: this will
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* force the transfer to start only after we have put all the requests
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|
@@ -1409,84 +1038,6 @@ void blk_put_request(struct request *req)
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EXPORT_SYMBOL(blk_put_request);
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-/*
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- * Has to be called with the request spinlock acquired
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- */
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-static int attempt_merge(struct request_queue *q, struct request *req,
|
|
|
- struct request *next)
|
|
|
-{
|
|
|
- if (!rq_mergeable(req) || !rq_mergeable(next))
|
|
|
- return 0;
|
|
|
-
|
|
|
- /*
|
|
|
- * not contiguous
|
|
|
- */
|
|
|
- if (req->sector + req->nr_sectors != next->sector)
|
|
|
- return 0;
|
|
|
-
|
|
|
- if (rq_data_dir(req) != rq_data_dir(next)
|
|
|
- || req->rq_disk != next->rq_disk
|
|
|
- || next->special)
|
|
|
- return 0;
|
|
|
-
|
|
|
- /*
|
|
|
- * If we are allowed to merge, then append bio list
|
|
|
- * from next to rq and release next. merge_requests_fn
|
|
|
- * will have updated segment counts, update sector
|
|
|
- * counts here.
|
|
|
- */
|
|
|
- if (!ll_merge_requests_fn(q, req, next))
|
|
|
- return 0;
|
|
|
-
|
|
|
- /*
|
|
|
- * At this point we have either done a back merge
|
|
|
- * or front merge. We need the smaller start_time of
|
|
|
- * the merged requests to be the current request
|
|
|
- * for accounting purposes.
|
|
|
- */
|
|
|
- if (time_after(req->start_time, next->start_time))
|
|
|
- req->start_time = next->start_time;
|
|
|
-
|
|
|
- req->biotail->bi_next = next->bio;
|
|
|
- req->biotail = next->biotail;
|
|
|
-
|
|
|
- req->nr_sectors = req->hard_nr_sectors += next->hard_nr_sectors;
|
|
|
-
|
|
|
- elv_merge_requests(q, req, next);
|
|
|
-
|
|
|
- if (req->rq_disk) {
|
|
|
- disk_round_stats(req->rq_disk);
|
|
|
- req->rq_disk->in_flight--;
|
|
|
- }
|
|
|
-
|
|
|
- req->ioprio = ioprio_best(req->ioprio, next->ioprio);
|
|
|
-
|
|
|
- __blk_put_request(q, next);
|
|
|
- return 1;
|
|
|
-}
|
|
|
-
|
|
|
-static inline int attempt_back_merge(struct request_queue *q,
|
|
|
- struct request *rq)
|
|
|
-{
|
|
|
- struct request *next = elv_latter_request(q, rq);
|
|
|
-
|
|
|
- if (next)
|
|
|
- return attempt_merge(q, rq, next);
|
|
|
-
|
|
|
- return 0;
|
|
|
-}
|
|
|
-
|
|
|
-static inline int attempt_front_merge(struct request_queue *q,
|
|
|
- struct request *rq)
|
|
|
-{
|
|
|
- struct request *prev = elv_former_request(q, rq);
|
|
|
-
|
|
|
- if (prev)
|
|
|
- return attempt_merge(q, prev, rq);
|
|
|
-
|
|
|
- return 0;
|
|
|
-}
|
|
|
-
|
|
|
void init_request_from_bio(struct request *req, struct bio *bio)
|
|
|
{
|
|
|
req->cmd_type = REQ_TYPE_FS;
|
|
|
@@ -1938,35 +1489,6 @@ void submit_bio(int rw, struct bio *bio)
|
|
|
|
|
|
EXPORT_SYMBOL(submit_bio);
|
|
|
|
|
|
-static void blk_recalc_rq_sectors(struct request *rq, int nsect)
|
|
|
-{
|
|
|
- if (blk_fs_request(rq)) {
|
|
|
- rq->hard_sector += nsect;
|
|
|
- rq->hard_nr_sectors -= nsect;
|
|
|
-
|
|
|
- /*
|
|
|
- * Move the I/O submission pointers ahead if required.
|
|
|
- */
|
|
|
- if ((rq->nr_sectors >= rq->hard_nr_sectors) &&
|
|
|
- (rq->sector <= rq->hard_sector)) {
|
|
|
- rq->sector = rq->hard_sector;
|
|
|
- rq->nr_sectors = rq->hard_nr_sectors;
|
|
|
- rq->hard_cur_sectors = bio_cur_sectors(rq->bio);
|
|
|
- rq->current_nr_sectors = rq->hard_cur_sectors;
|
|
|
- rq->buffer = bio_data(rq->bio);
|
|
|
- }
|
|
|
-
|
|
|
- /*
|
|
|
- * if total number of sectors is less than the first segment
|
|
|
- * size, something has gone terribly wrong
|
|
|
- */
|
|
|
- if (rq->nr_sectors < rq->current_nr_sectors) {
|
|
|
- printk("blk: request botched\n");
|
|
|
- rq->nr_sectors = rq->current_nr_sectors;
|
|
|
- }
|
|
|
- }
|
|
|
-}
|
|
|
-
|
|
|
/**
|
|
|
* __end_that_request_first - end I/O on a request
|
|
|
* @req: the request being processed
|
Jens Axboe