The blkfront driver now will read feature-discard from xenstore,
and set up the request queue, also forward the discard request to
backend driver.
Signed-off-by: Li Dongyang <lidongyang@xxxxxxxxxx>
---
drivers/xen/blkfront/blkfront.c | 48 +++++++++++++++++++++++++++++++++++---
drivers/xen/blkfront/block.h | 3 ++
drivers/xen/blkfront/vbd.c | 8 ++++++
3 files changed, 55 insertions(+), 4 deletions(-)
diff --git a/drivers/xen/blkfront/blkfront.c b/drivers/xen/blkfront/blkfront.c
index 9410fae..8a32e27 100644
--- a/drivers/xen/blkfront/blkfront.c
+++ b/drivers/xen/blkfront/blkfront.c
@@ -328,7 +328,9 @@ static void connect(struct blkfront_info *info)
unsigned long long sectors;
unsigned long sector_size;
unsigned int binfo;
- int err, barrier;
+ unsigned int discard_granularity;
+ unsigned int discard_alignment;
+ int err, barrier, discard;
switch (info->connected) {
case BLKIF_STATE_CONNECTED:
@@ -377,6 +379,21 @@ static void connect(struct blkfront_info *info)
else
info->feature_flush = 0;
+ err = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
+ "feature-discard", "%d", &discard);
+ if (err > 0 && discard) {
+ info->feature_discard = 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_discard = 0;
+
err = xlvbd_add(sectors, info->vdevice, binfo, sector_size, info);
if (err) {
xenbus_dev_fatal(info->xbdev, err, "xlvbd_add at %s",
@@ -704,9 +721,18 @@ static int blkif_queue_request(struct request *req)
if (req->cmd_type == REQ_TYPE_BLOCK_PC)
ring_req->operation = BLKIF_OP_PACKET;
- 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) {
+ if (req->cmd_flags & REQ_DISCARD) {
+ /* id sector_number and handle are initialized above. */
+ blkif_request_trim_t *trim_req =
+ (blkif_request_trim_t *)ring_req;
+ trim_req->operation = BLKIF_OP_TRIM;
+ trim_req->reserved = 0;
+ trim_req->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 = page_to_phys(sg_page(sg)) >> PAGE_SHIFT;
fsect = sg->offset >> 9;
lsect = fsect + (sg->length >> 9) - 1;
@@ -726,6 +752,7 @@ static int blkif_queue_request(struct request *req)
.gref = ref,
.first_sect = fsect,
.last_sect = lsect };
+ }
}
info->ring.req_prod_pvt++;
@@ -821,6 +848,19 @@ static irqreturn_t blkif_int(int irq, void *dev_id)
ret = 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;
+ pr_warning("blkfront: %s: trim op failed\n",
+ info->gd->disk_name);
+ ret = -EOPNOTSUPP;
+ info->feature_discard = 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, ret);
+ break;
case BLKIF_OP_WRITE_BARRIER:
if (unlikely(bret->status == BLKIF_RSP_EOPNOTSUPP)) {
pr_warning("blkfront: %s:"
diff --git a/drivers/xen/blkfront/block.h b/drivers/xen/blkfront/block.h
index 8db27a3..25926f3 100644
--- a/drivers/xen/blkfront/block.h
+++ b/drivers/xen/blkfront/block.h
@@ -112,6 +112,9 @@ struct blkfront_info
struct blk_shadow shadow[BLK_RING_SIZE];
unsigned long shadow_free;
int feature_flush;
+ int feature_discard;
+ unsigned int discard_granularity;
+ unsigned int discard_alignment;
int is_ready;
/**
diff --git a/drivers/xen/blkfront/vbd.c b/drivers/xen/blkfront/vbd.c
index 2a98439..c0170cf 100644
--- a/drivers/xen/blkfront/vbd.c
+++ b/drivers/xen/blkfront/vbd.c
@@ -300,6 +300,7 @@ 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)
@@ -307,6 +308,13 @@ xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size)
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,29)
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;
+ }
#endif
/* Hard sector size and max sectors impersonate the equiv. hardware. */
--
1.7.6
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