The blkfront driver now will read feature-trim from xenstore,
and set up the request queue with trim params, then we can forward the
discard requests to backend driver.
Signed-off-by: Li Dongyang <lidongyang@xxxxxxxxxx>
---
drivers/block/xen-blkfront.c | 96 ++++++++++++++++++++++++++++++++----------
1 files changed, 73 insertions(+), 23 deletions(-)
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index b536a9c..c22fb07 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -98,6 +98,9 @@ struct blkfront_info
unsigned long shadow_free;
unsigned int feature_flush;
unsigned int flush_op;
+ unsigned int feature_trim;
+ unsigned int discard_granularity;
+ unsigned int discard_alignment;
int is_ready;
};
@@ -302,29 +305,36 @@ static int blkif_queue_request(struct request *req)
ring_req->operation = info->flush_op;
}
- ring_req->nr_segments = blk_rq_map_sg(req->q, req, info->sg);
- BUG_ON(ring_req->nr_segments > BLKIF_MAX_SEGMENTS_PER_REQUEST);
+ if (unlikely(req->cmd_flags & REQ_DISCARD)) {
+ /* id, sector_number and handle are set above. */
+ ring_req->operation = BLKIF_OP_TRIM;
+ ring_req->nr_segments = 0;
+ ring_req->u.trim.nr_sectors = blk_rq_sectors(req);
+ } else {
+ ring_req->nr_segments = blk_rq_map_sg(req->q, req, info->sg);
+ BUG_ON(ring_req->nr_segments > BLKIF_MAX_SEGMENTS_PER_REQUEST);
- for_each_sg(info->sg, sg, ring_req->nr_segments, i) {
- buffer_mfn = pfn_to_mfn(page_to_pfn(sg_page(sg)));
- fsect = sg->offset >> 9;
- lsect = fsect + (sg->length >> 9) - 1;
- /* install a grant reference. */
- ref = gnttab_claim_grant_reference(&gref_head);
- BUG_ON(ref == -ENOSPC);
+ for_each_sg(info->sg, sg, ring_req->nr_segments, i) {
+ buffer_mfn = pfn_to_mfn(page_to_pfn(sg_page(sg)));
+ fsect = sg->offset >> 9;
+ lsect = fsect + (sg->length >> 9) - 1;
+ /* install a grant reference. */
+ ref = gnttab_claim_grant_reference(&gref_head);
+ BUG_ON(ref == -ENOSPC);
- gnttab_grant_foreign_access_ref(
- ref,
- info->xbdev->otherend_id,
- buffer_mfn,
- rq_data_dir(req) );
-
- info->shadow[id].frame[i] = mfn_to_pfn(buffer_mfn);
- ring_req->u.rw.seg[i] =
- (struct blkif_request_segment) {
- .gref = ref,
- .first_sect = fsect,
- .last_sect = lsect };
+ gnttab_grant_foreign_access_ref(
+ ref,
+ info->xbdev->otherend_id,
+ buffer_mfn,
+ rq_data_dir(req));
+
+ info->shadow[id].frame[i] = mfn_to_pfn(buffer_mfn);
+ ring_req->u.rw.seg[i] =
+ (struct blkif_request_segment) {
+ .gref = ref,
+ .first_sect = fsect,
+ .last_sect = lsect };
+ }
}
info->ring.req_prod_pvt++;
@@ -399,6 +409,7 @@ wait:
static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size)
{
struct request_queue *rq;
+ struct blkfront_info *info = gd->private_data;
rq = blk_init_queue(do_blkif_request, &blkif_io_lock);
if (rq == NULL)
@@ -406,6 +417,13 @@ static int xlvbd_init_blk_queue(struct gendisk *gd, u16
sector_size)
queue_flag_set_unlocked(QUEUE_FLAG_VIRT, rq);
+ if (info->feature_trim) {
+ queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, rq);
+ blk_queue_max_discard_sectors(rq, get_capacity(gd));
+ rq->limits.discard_granularity = info->discard_granularity;
+ rq->limits.discard_alignment = info->discard_alignment;
+ }
+
/* Hard sector size and max sectors impersonate the equiv. hardware. */
blk_queue_logical_block_size(rq, sector_size);
blk_queue_max_hw_sectors(rq, 512);
@@ -722,6 +740,19 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
error = (bret->status == BLKIF_RSP_OKAY) ? 0 : -EIO;
switch (bret->operation) {
+ case BLKIF_OP_TRIM:
+ if (unlikely(bret->status == BLKIF_RSP_EOPNOTSUPP)) {
+ struct request_queue *rq = info->rq;
+ printk(KERN_WARNING "blkfront: %s: trim op
failed\n",
+ info->gd->disk_name);
+ error = -EOPNOTSUPP;
+ info->feature_trim = 0;
+ spin_lock_irq(rq->queue_lock);
+ queue_flag_clear(QUEUE_FLAG_DISCARD, rq);
+ spin_unlock_irq(rq->queue_lock);
+ }
+ __blk_end_request_all(req, error);
+ break;
case BLKIF_OP_FLUSH_DISKCACHE:
case BLKIF_OP_WRITE_BARRIER:
if (unlikely(bret->status == BLKIF_RSP_EOPNOTSUPP)) {
@@ -1108,7 +1139,9 @@ static void blkfront_connect(struct blkfront_info *info)
unsigned long sector_size;
unsigned int binfo;
int err;
- int barrier, flush;
+ unsigned int discard_granularity;
+ unsigned int discard_alignment;
+ int barrier, flush, trim;
switch (info->connected) {
case BLKIF_STATE_CONNECTED:
@@ -1178,7 +1211,24 @@ static void blkfront_connect(struct blkfront_info *info)
info->feature_flush = REQ_FLUSH;
info->flush_op = BLKIF_OP_FLUSH_DISKCACHE;
}
-
+
+ err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
+ "feature-trim", "%d", &trim,
+ NULL);
+
+ if (!err && trim) {
+ info->feature_trim = 1;
+ err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
+ "discard_granularity", "%u", &discard_granularity,
+ "discard_alignment", "%u", &discard_alignment,
+ NULL);
+ if (!err) {
+ info->discard_granularity = discard_granularity;
+ info->discard_alignment = discard_alignment;
+ }
+ } else
+ info->feature_trim = 0;
+
err = xlvbd_alloc_gendisk(sectors, info, binfo, sector_size);
if (err) {
xenbus_dev_fatal(info->xbdev, err, "xlvbd_add at %s",
--
1.7.6
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