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-rw-r--r--block/blk-lib.c41
-rw-r--r--block/blk-merge.c117
-rw-r--r--block/genhd.c2
3 files changed, 111 insertions, 49 deletions
diff --git a/block/blk-lib.c b/block/blk-lib.c
index 2b461b496a7..19cc761cacb 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -44,6 +44,7 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
struct request_queue *q = bdev_get_queue(bdev);
int type = REQ_WRITE | REQ_DISCARD;
unsigned int max_discard_sectors;
+ unsigned int granularity, alignment, mask;
struct bio_batch bb;
struct bio *bio;
int ret = 0;
@@ -54,18 +55,20 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
if (!blk_queue_discard(q))
return -EOPNOTSUPP;
+ /* Zero-sector (unknown) and one-sector granularities are the same. */
+ granularity = max(q->limits.discard_granularity >> 9, 1U);
+ mask = granularity - 1;
+ alignment = (bdev_discard_alignment(bdev) >> 9) & mask;
+
/*
* Ensure that max_discard_sectors is of the proper
- * granularity
+ * granularity, so that requests stay aligned after a split.
*/
max_discard_sectors = min(q->limits.max_discard_sectors, UINT_MAX >> 9);
+ max_discard_sectors = round_down(max_discard_sectors, granularity);
if (unlikely(!max_discard_sectors)) {
/* Avoid infinite loop below. Being cautious never hurts. */
return -EOPNOTSUPP;
- } else if (q->limits.discard_granularity) {
- unsigned int disc_sects = q->limits.discard_granularity >> 9;
-
- max_discard_sectors &= ~(disc_sects - 1);
}
if (flags & BLKDEV_DISCARD_SECURE) {
@@ -79,25 +82,37 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
bb.wait = &wait;
while (nr_sects) {
+ unsigned int req_sects;
+ sector_t end_sect;
+
bio = bio_alloc(gfp_mask, 1);
if (!bio) {
ret = -ENOMEM;
break;
}
+ req_sects = min_t(sector_t, nr_sects, max_discard_sectors);
+
+ /*
+ * If splitting a request, and the next starting sector would be
+ * misaligned, stop the discard at the previous aligned sector.
+ */
+ end_sect = sector + req_sects;
+ if (req_sects < nr_sects && (end_sect & mask) != alignment) {
+ end_sect =
+ round_down(end_sect - alignment, granularity)
+ + alignment;
+ req_sects = end_sect - sector;
+ }
+
bio->bi_sector = sector;
bio->bi_end_io = bio_batch_end_io;
bio->bi_bdev = bdev;
bio->bi_private = &bb;
- if (nr_sects > max_discard_sectors) {
- bio->bi_size = max_discard_sectors << 9;
- nr_sects -= max_discard_sectors;
- sector += max_discard_sectors;
- } else {
- bio->bi_size = nr_sects << 9;
- nr_sects = 0;
- }
+ bio->bi_size = req_sects << 9;
+ nr_sects -= req_sects;
+ sector = end_sect;
atomic_inc(&bb.done);
submit_bio(type, bio);
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 160035f5488..e76279e4116 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -110,6 +110,49 @@ static int blk_phys_contig_segment(struct request_queue *q, struct bio *bio,
return 0;
}
+static void
+__blk_segment_map_sg(struct request_queue *q, struct bio_vec *bvec,
+ struct scatterlist *sglist, struct bio_vec **bvprv,
+ struct scatterlist **sg, int *nsegs, int *cluster)
+{
+
+ int nbytes = bvec->bv_len;
+
+ if (*bvprv && *cluster) {
+ if ((*sg)->length + nbytes > queue_max_segment_size(q))
+ goto new_segment;
+
+ if (!BIOVEC_PHYS_MERGEABLE(*bvprv, bvec))
+ goto new_segment;
+ if (!BIOVEC_SEG_BOUNDARY(q, *bvprv, bvec))
+ goto new_segment;
+
+ (*sg)->length += nbytes;
+ } else {
+new_segment:
+ if (!*sg)
+ *sg = sglist;
+ else {
+ /*
+ * If the driver previously mapped a shorter
+ * list, we could see a termination bit
+ * prematurely unless it fully inits the sg
+ * table on each mapping. We KNOW that there
+ * must be more entries here or the driver
+ * would be buggy, so force clear the
+ * termination bit to avoid doing a full
+ * sg_init_table() in drivers for each command.
+ */
+ (*sg)->page_link &= ~0x02;
+ *sg = sg_next(*sg);
+ }
+
+ sg_set_page(*sg, bvec->bv_page, nbytes, bvec->bv_offset);
+ (*nsegs)++;
+ }
+ *bvprv = bvec;
+}
+
/*
* map a request to scatterlist, return number of sg entries setup. Caller
* must make sure sg can hold rq->nr_phys_segments entries
@@ -131,41 +174,8 @@ int blk_rq_map_sg(struct request_queue *q, struct request *rq,
bvprv = NULL;
sg = NULL;
rq_for_each_segment(bvec, rq, iter) {
- int nbytes = bvec->bv_len;
-
- if (bvprv && cluster) {
- if (sg->length + nbytes > queue_max_segment_size(q))
- goto new_segment;
-
- if (!BIOVEC_PHYS_MERGEABLE(bvprv, bvec))
- goto new_segment;
- if (!BIOVEC_SEG_BOUNDARY(q, bvprv, bvec))
- goto new_segment;
-
- sg->length += nbytes;
- } else {
-new_segment:
- if (!sg)
- sg = sglist;
- else {
- /*
- * If the driver previously mapped a shorter
- * list, we could see a termination bit
- * prematurely unless it fully inits the sg
- * table on each mapping. We KNOW that there
- * must be more entries here or the driver
- * would be buggy, so force clear the
- * termination bit to avoid doing a full
- * sg_init_table() in drivers for each command.
- */
- sg->page_link &= ~0x02;
- sg = sg_next(sg);
- }
-
- sg_set_page(sg, bvec->bv_page, nbytes, bvec->bv_offset);
- nsegs++;
- }
- bvprv = bvec;
+ __blk_segment_map_sg(q, bvec, sglist, &bvprv, &sg,
+ &nsegs, &cluster);
} /* segments in rq */
@@ -199,6 +209,43 @@ new_segment:
}
EXPORT_SYMBOL(blk_rq_map_sg);
+/**
+ * blk_bio_map_sg - map a bio to a scatterlist
+ * @q: request_queue in question
+ * @bio: bio being mapped
+ * @sglist: scatterlist being mapped
+ *
+ * Note:
+ * Caller must make sure sg can hold bio->bi_phys_segments entries
+ *
+ * Will return the number of sg entries setup
+ */
+int blk_bio_map_sg(struct request_queue *q, struct bio *bio,
+ struct scatterlist *sglist)
+{
+ struct bio_vec *bvec, *bvprv;
+ struct scatterlist *sg;
+ int nsegs, cluster;
+ unsigned long i;
+
+ nsegs = 0;
+ cluster = blk_queue_cluster(q);
+
+ bvprv = NULL;
+ sg = NULL;
+ bio_for_each_segment(bvec, bio, i) {
+ __blk_segment_map_sg(q, bvec, sglist, &bvprv, &sg,
+ &nsegs, &cluster);
+ } /* segments in bio */
+
+ if (sg)
+ sg_mark_end(sg);
+
+ BUG_ON(bio->bi_phys_segments && nsegs > bio->bi_phys_segments);
+ return nsegs;
+}
+EXPORT_SYMBOL(blk_bio_map_sg);
+
static inline int ll_new_hw_segment(struct request_queue *q,
struct request *req,
struct bio *bio)
diff --git a/block/genhd.c b/block/genhd.c
index cac7366957c..d839723303c 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -835,7 +835,7 @@ static void disk_seqf_stop(struct seq_file *seqf, void *v)
static void *show_partition_start(struct seq_file *seqf, loff_t *pos)
{
- static void *p;
+ void *p;
p = disk_seqf_start(seqf, pos);
if (!IS_ERR_OR_NULL(p) && !*pos)
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-29 06:05:37 +0000