]> git.kernelconcepts.de Git - karo-tx-linux.git/blobdiff - drivers/block/xen-blkfront.c
Merge branch 'for-4.8/core' of git://git.kernel.dk/linux-block
[karo-tx-linux.git] / drivers / block / xen-blkfront.c
index 343ef7abe5fd302e41cb26aff41e83d7392d98a1..da05d3f9bad206b193135e44b7c979894b50e42a 100644 (file)
@@ -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;