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path: root/drivers/block/xen-blkfront.c
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Diffstat (limited to 'drivers/block/xen-blkfront.c')
-rw-r--r--drivers/block/xen-blkfront.c129
1 files changed, 64 insertions, 65 deletions
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 343ef7abe5fd..da05d3f9bad2 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -208,6 +208,9 @@ struct blkfront_info
struct blk_mq_tag_set tag_set;
struct blkfront_ring_info *rinfo;
unsigned int nr_rings;
+ /* Save uncomplete reqs and bios for migration. */
+ struct list_head requests;
+ struct bio_list bio_list;
};
static unsigned int nr_minors;
@@ -871,8 +874,12 @@ static int blkif_queue_rq(struct blk_mq_hw_ctx *hctx,
const struct blk_mq_queue_data *qd)
{
unsigned long flags;
- struct blkfront_ring_info *rinfo = (struct blkfront_ring_info *)hctx->driver_data;
+ int qid = hctx->queue_num;
+ struct blkfront_info *info = hctx->queue->queuedata;
+ struct blkfront_ring_info *rinfo = NULL;
+ BUG_ON(info->nr_rings <= qid);
+ rinfo = &info->rinfo[qid];
blk_mq_start_request(qd->rq);
spin_lock_irqsave(&rinfo->ring_lock, flags);
if (RING_FULL(&rinfo->ring))
@@ -898,20 +905,9 @@ out_busy:
return BLK_MQ_RQ_QUEUE_BUSY;
}
-static int blk_mq_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
- unsigned int index)
-{
- struct blkfront_info *info = (struct blkfront_info *)data;
-
- BUG_ON(info->nr_rings <= index);
- hctx->driver_data = &info->rinfo[index];
- return 0;
-}
-
static struct blk_mq_ops blkfront_mq_ops = {
.queue_rq = blkif_queue_rq,
.map_queue = blk_mq_map_queue,
- .init_hctx = blk_mq_init_hctx,
};
static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size,
@@ -947,6 +943,7 @@ static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size,
return PTR_ERR(rq);
}
+ rq->queuedata = info;
queue_flag_set_unlocked(QUEUE_FLAG_VIRT, rq);
if (info->feature_discard) {
@@ -2004,70 +2001,22 @@ static int blkif_recover(struct blkfront_info *info)
{
unsigned int i, r_index;
struct request *req, *n;
- struct blk_shadow *copy;
int rc;
struct bio *bio, *cloned_bio;
- struct bio_list bio_list, merge_bio;
unsigned int segs, offset;
int pending, size;
struct split_bio *split_bio;
- struct list_head requests;
blkfront_gather_backend_features(info);
segs = info->max_indirect_segments ? : BLKIF_MAX_SEGMENTS_PER_REQUEST;
blk_queue_max_segments(info->rq, segs);
- bio_list_init(&bio_list);
- INIT_LIST_HEAD(&requests);
for (r_index = 0; r_index < info->nr_rings; r_index++) {
- struct blkfront_ring_info *rinfo;
-
- rinfo = &info->rinfo[r_index];
- /* Stage 1: Make a safe copy of the shadow state. */
- copy = kmemdup(rinfo->shadow, sizeof(rinfo->shadow),
- GFP_NOIO | __GFP_REPEAT | __GFP_HIGH);
- if (!copy)
- return -ENOMEM;
-
- /* Stage 2: Set up free list. */
- memset(&rinfo->shadow, 0, sizeof(rinfo->shadow));
- for (i = 0; i < BLK_RING_SIZE(info); i++)
- rinfo->shadow[i].req.u.rw.id = i+1;
- rinfo->shadow_free = rinfo->ring.req_prod_pvt;
- rinfo->shadow[BLK_RING_SIZE(info)-1].req.u.rw.id = 0x0fffffff;
+ struct blkfront_ring_info *rinfo = &info->rinfo[r_index];
rc = blkfront_setup_indirect(rinfo);
- if (rc) {
- kfree(copy);
+ if (rc)
return rc;
- }
-
- for (i = 0; i < BLK_RING_SIZE(info); i++) {
- /* Not in use? */
- if (!copy[i].request)
- continue;
-
- /*
- * Get the bios in the request so we can re-queue them.
- */
- if (req_op(copy[i].request) == REQ_OP_FLUSH ||
- req_op(copy[i].request) == REQ_OP_DISCARD ||
- copy[i].request->cmd_flags & (REQ_FUA | REQ_SECURE)) {
- /*
- * Flush operations don't contain bios, so
- * we need to requeue the whole request
- */
- list_add(&copy[i].request->queuelist, &requests);
- continue;
- }
- merge_bio.head = copy[i].request->bio;
- merge_bio.tail = copy[i].request->biotail;
- bio_list_merge(&bio_list, &merge_bio);
- copy[i].request->bio = NULL;
- blk_end_request_all(copy[i].request, 0);
- }
-
- kfree(copy);
}
xenbus_switch_state(info->xbdev, XenbusStateConnected);
@@ -2082,7 +2031,7 @@ static int blkif_recover(struct blkfront_info *info)
kick_pending_request_queues(rinfo);
}
- list_for_each_entry_safe(req, n, &requests, queuelist) {
+ list_for_each_entry_safe(req, n, &info->requests, queuelist) {
/* Requeue pending requests (flush or discard) */
list_del_init(&req->queuelist);
BUG_ON(req->nr_phys_segments > segs);
@@ -2090,7 +2039,7 @@ static int blkif_recover(struct blkfront_info *info)
}
blk_mq_kick_requeue_list(info->rq);
- while ((bio = bio_list_pop(&bio_list)) != NULL) {
+ while ((bio = bio_list_pop(&info->bio_list)) != NULL) {
/* Traverse the list of pending bios and re-queue them */
if (bio_segments(bio) > segs) {
/*
@@ -2136,9 +2085,44 @@ static int blkfront_resume(struct xenbus_device *dev)
{
struct blkfront_info *info = dev_get_drvdata(&dev->dev);
int err = 0;
+ unsigned int i, j;
dev_dbg(&dev->dev, "blkfront_resume: %s\n", dev->nodename);
+ bio_list_init(&info->bio_list);
+ INIT_LIST_HEAD(&info->requests);
+ for (i = 0; i < info->nr_rings; i++) {
+ struct blkfront_ring_info *rinfo = &info->rinfo[i];
+ struct bio_list merge_bio;
+ struct blk_shadow *shadow = rinfo->shadow;
+
+ for (j = 0; j < BLK_RING_SIZE(info); j++) {
+ /* Not in use? */
+ if (!shadow[j].request)
+ continue;
+
+ /*
+ * Get the bios in the request so we can re-queue them.
+ */
+ if (req_op(shadow[i].request) == REQ_OP_FLUSH ||
+ req_op(shadow[i].request) == REQ_OP_DISCARD ||
+ shadow[j].request->cmd_flags & (REQ_FUA | REQ_SECURE)) {
+
+ /*
+ * Flush operations don't contain bios, so
+ * we need to requeue the whole request
+ */
+ list_add(&shadow[j].request->queuelist, &info->requests);
+ continue;
+ }
+ merge_bio.head = shadow[j].request->bio;
+ merge_bio.tail = shadow[j].request->biotail;
+ bio_list_merge(&info->bio_list, &merge_bio);
+ shadow[j].request->bio = NULL;
+ blk_mq_end_request(shadow[j].request, 0);
+ }
+ }
+
blkif_free(info, info->connected == BLKIF_STATE_CONNECTED);
err = negotiate_mq(info);
@@ -2146,6 +2130,8 @@ static int blkfront_resume(struct xenbus_device *dev)
return err;
err = talk_to_blkback(dev, info);
+ if (!err)
+ blk_mq_update_nr_hw_queues(&info->tag_set, info->nr_rings);
/*
* We have to wait for the backend to switch to
@@ -2488,10 +2474,23 @@ static void blkback_changed(struct xenbus_device *dev,
break;
case XenbusStateConnected:
- if (dev->state != XenbusStateInitialised) {
+ /*
+ * talk_to_blkback sets state to XenbusStateInitialised
+ * and blkfront_connect sets it to XenbusStateConnected
+ * (if connection went OK).
+ *
+ * If the backend (or toolstack) decides to poke at backend
+ * state (and re-trigger the watch by setting the state repeatedly
+ * to XenbusStateConnected (4)) we need to deal with this.
+ * This is allowed as this is used to communicate to the guest
+ * that the size of disk has changed!
+ */
+ if ((dev->state != XenbusStateInitialised) &&
+ (dev->state != XenbusStateConnected)) {
if (talk_to_blkback(dev, info))
break;
}
+
blkfront_connect(info);
break;
generated by cgit (git 2.34.1) at 2024-05-19 18:32:27 +0000