diff options
| -rw-r--r-- | drivers/block/xen-blkfront.c | 111 |
1 files changed, 88 insertions, 23 deletions
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index b536a9cef91..52076b0d032 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_discard; + 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_DISCARD; + ring_req->nr_segments = 0; + ring_req->u.discard.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_discard) { + 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_DISCARD: + if (unlikely(bret->status == BLKIF_RSP_EOPNOTSUPP)) { + struct request_queue *rq = info->rq; + printk(KERN_WARNING "blkfront: %s: discard op failed\n", + info->gd->disk_name); + error = -EOPNOTSUPP; + info->feature_discard = 0; + spin_lock(rq->queue_lock); + queue_flag_clear(QUEUE_FLAG_DISCARD, rq); + spin_unlock(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)) { @@ -1098,6 +1129,33 @@ blkfront_closing(struct blkfront_info *info) bdput(bdev); } +static void blkfront_setup_discard(struct blkfront_info *info) +{ + int err; + char *type; + unsigned int discard_granularity; + unsigned int discard_alignment; + + type = xenbus_read(XBT_NIL, info->xbdev->otherend, "type", NULL); + if (IS_ERR(type)) + return; + + if (strncmp(type, "phy", 3) == 0) { + err = xenbus_gather(XBT_NIL, info->xbdev->otherend, + "discard-granularity", "%u", &discard_granularity, + "discard-alignment", "%u", &discard_alignment, + NULL); + if (!err) { + info->feature_discard = 1; + info->discard_granularity = discard_granularity; + info->discard_alignment = discard_alignment; + } + } else if (strncmp(type, "file", 4) == 0) + info->feature_discard = 1; + + kfree(type); +} + /* * Invoked when the backend is finally 'ready' (and has told produced * the details about the physical device - #sectors, size, etc). @@ -1108,7 +1166,7 @@ static void blkfront_connect(struct blkfront_info *info) unsigned long sector_size; unsigned int binfo; int err; - int barrier, flush; + int barrier, flush, discard; switch (info->connected) { case BLKIF_STATE_CONNECTED: @@ -1178,7 +1236,14 @@ 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-discard", "%d", &discard, + NULL); + + if (!err && discard) + blkfront_setup_discard(info); + err = xlvbd_alloc_gendisk(sectors, info, binfo, sector_size); if (err) { xenbus_dev_fatal(info->xbdev, err, "xlvbd_add at %s", |