]> git.karo-electronics.de Git - linux-beck.git/commitdiff
xen/blkfront: separate per ring information out of device info
authorBob Liu <bob.liu@oracle.com>
Sat, 14 Nov 2015 03:12:11 +0000 (11:12 +0800)
committerKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Mon, 4 Jan 2016 14:56:02 +0000 (09:56 -0500)
Split per ring information to a new structure "blkfront_ring_info".

A ring is the representation of a hardware queue, every vbd device can associate
with one or more rings depending on how many hardware queues/rings to be used.

This patch is a preparation for supporting real multi hardware queues/rings.

We also add a backpointer to 'struct blkfront_info' (dev_info) which
is not needed (we could use containers_of) but further patch
("xen/blkfront: pseudo support for multi hardware queues/rings")
will make allocation of 'blkfront_ring_info' dynamic.

Signed-off-by: Arianna Avanzini <avanzini.arianna@gmail.com>
Signed-off-by: Bob Liu <bob.liu@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
drivers/block/xen-blkfront.c

index 2fee2eef988d2992480363ea2578ddb9edf17240..0c3ad214a79295336e9cb0ec959e0948514da0aa 100644 (file)
@@ -119,6 +119,23 @@ MODULE_PARM_DESC(max_ring_page_order, "Maximum order of pages to be used for the
  */
 #define RINGREF_NAME_LEN (20)
 
+/*
+ *  Per-ring info.
+ *  Every blkfront device can associate with one or more blkfront_ring_info,
+ *  depending on how many hardware queues/rings to be used.
+ */
+struct blkfront_ring_info {
+       struct blkif_front_ring ring;
+       unsigned int ring_ref[XENBUS_MAX_RING_GRANTS];
+       unsigned int evtchn, irq;
+       struct work_struct work;
+       struct gnttab_free_callback callback;
+       struct blk_shadow shadow[BLK_MAX_RING_SIZE];
+       struct list_head indirect_pages;
+       unsigned long shadow_free;
+       struct blkfront_info *dev_info;
+};
+
 /*
  * We have one of these per vbd, whether ide, scsi or 'other'.  They
  * hang in private_data off the gendisk structure. We may end up
@@ -133,18 +150,10 @@ struct blkfront_info
        int vdevice;
        blkif_vdev_t handle;
        enum blkif_state connected;
-       int ring_ref[XENBUS_MAX_RING_GRANTS];
        unsigned int nr_ring_pages;
-       struct blkif_front_ring ring;
-       unsigned int evtchn, irq;
        struct request_queue *rq;
-       struct work_struct work;
-       struct gnttab_free_callback callback;
-       struct blk_shadow shadow[BLK_MAX_RING_SIZE];
        struct list_head grants;
-       struct list_head indirect_pages;
        unsigned int persistent_gnts_c;
-       unsigned long shadow_free;
        unsigned int feature_flush;
        unsigned int feature_discard:1;
        unsigned int feature_secdiscard:1;
@@ -155,6 +164,7 @@ struct blkfront_info
        unsigned int max_indirect_segments;
        int is_ready;
        struct blk_mq_tag_set tag_set;
+       struct blkfront_ring_info rinfo;
 };
 
 static unsigned int nr_minors;
@@ -198,33 +208,35 @@ static DEFINE_SPINLOCK(minor_lock);
 
 #define GREFS(_psegs)  ((_psegs) * GRANTS_PER_PSEG)
 
-static int blkfront_setup_indirect(struct blkfront_info *info);
+static int blkfront_setup_indirect(struct blkfront_ring_info *rinfo);
 static int blkfront_gather_backend_features(struct blkfront_info *info);
 
-static int get_id_from_freelist(struct blkfront_info *info)
+static int get_id_from_freelist(struct blkfront_ring_info *rinfo)
 {
-       unsigned long free = info->shadow_free;
-       BUG_ON(free >= BLK_RING_SIZE(info));
-       info->shadow_free = info->shadow[free].req.u.rw.id;
-       info->shadow[free].req.u.rw.id = 0x0fffffee; /* debug */
+       unsigned long free = rinfo->shadow_free;
+
+       BUG_ON(free >= BLK_RING_SIZE(rinfo->dev_info));
+       rinfo->shadow_free = rinfo->shadow[free].req.u.rw.id;
+       rinfo->shadow[free].req.u.rw.id = 0x0fffffee; /* debug */
        return free;
 }
 
-static int add_id_to_freelist(struct blkfront_info *info,
+static int add_id_to_freelist(struct blkfront_ring_info *rinfo,
                               unsigned long id)
 {
-       if (info->shadow[id].req.u.rw.id != id)
+       if (rinfo->shadow[id].req.u.rw.id != id)
                return -EINVAL;
-       if (info->shadow[id].request == NULL)
+       if (rinfo->shadow[id].request == NULL)
                return -EINVAL;
-       info->shadow[id].req.u.rw.id  = info->shadow_free;
-       info->shadow[id].request = NULL;
-       info->shadow_free = id;
+       rinfo->shadow[id].req.u.rw.id  = rinfo->shadow_free;
+       rinfo->shadow[id].request = NULL;
+       rinfo->shadow_free = id;
        return 0;
 }
 
-static int fill_grant_buffer(struct blkfront_info *info, int num)
+static int fill_grant_buffer(struct blkfront_ring_info *rinfo, int num)
 {
+       struct blkfront_info *info = rinfo->dev_info;
        struct page *granted_page;
        struct grant *gnt_list_entry, *n;
        int i = 0;
@@ -326,8 +338,8 @@ static struct grant *get_indirect_grant(grant_ref_t *gref_head,
                struct page *indirect_page;
 
                /* Fetch a pre-allocated page to use for indirect grefs */
-               BUG_ON(list_empty(&info->indirect_pages));
-               indirect_page = list_first_entry(&info->indirect_pages,
+               BUG_ON(list_empty(&info->rinfo.indirect_pages));
+               indirect_page = list_first_entry(&info->rinfo.indirect_pages,
                                                 struct page, lru);
                list_del(&indirect_page->lru);
                gnt_list_entry->page = indirect_page;
@@ -403,8 +415,8 @@ static void xlbd_release_minors(unsigned int minor, unsigned int nr)
 
 static void blkif_restart_queue_callback(void *arg)
 {
-       struct blkfront_info *info = (struct blkfront_info *)arg;
-       schedule_work(&info->work);
+       struct blkfront_ring_info *rinfo = (struct blkfront_ring_info *)arg;
+       schedule_work(&rinfo->work);
 }
 
 static int blkif_getgeo(struct block_device *bd, struct hd_geometry *hg)
@@ -456,16 +468,16 @@ static int blkif_ioctl(struct block_device *bdev, fmode_t mode,
        return 0;
 }
 
-static int blkif_queue_discard_req(struct request *req)
+static int blkif_queue_discard_req(struct request *req, struct blkfront_ring_info *rinfo)
 {
-       struct blkfront_info *info = req->rq_disk->private_data;
+       struct blkfront_info *info = rinfo->dev_info;
        struct blkif_request *ring_req;
        unsigned long id;
 
        /* Fill out a communications ring structure. */
-       ring_req = RING_GET_REQUEST(&info->ring, info->ring.req_prod_pvt);
-       id = get_id_from_freelist(info);
-       info->shadow[id].request = req;
+       ring_req = RING_GET_REQUEST(&rinfo->ring, rinfo->ring.req_prod_pvt);
+       id = get_id_from_freelist(rinfo);
+       rinfo->shadow[id].request = req;
 
        ring_req->operation = BLKIF_OP_DISCARD;
        ring_req->u.discard.nr_sectors = blk_rq_sectors(req);
@@ -476,10 +488,10 @@ static int blkif_queue_discard_req(struct request *req)
        else
                ring_req->u.discard.flag = 0;
 
-       info->ring.req_prod_pvt++;
+       rinfo->ring.req_prod_pvt++;
 
        /* Keep a private copy so we can reissue requests when recovering. */
-       info->shadow[id].req = *ring_req;
+       rinfo->shadow[id].req = *ring_req;
 
        return 0;
 }
@@ -487,7 +499,7 @@ static int blkif_queue_discard_req(struct request *req)
 struct setup_rw_req {
        unsigned int grant_idx;
        struct blkif_request_segment *segments;
-       struct blkfront_info *info;
+       struct blkfront_ring_info *rinfo;
        struct blkif_request *ring_req;
        grant_ref_t gref_head;
        unsigned int id;
@@ -507,8 +519,9 @@ static void blkif_setup_rw_req_grant(unsigned long gfn, unsigned int offset,
        /* Convenient aliases */
        unsigned int grant_idx = setup->grant_idx;
        struct blkif_request *ring_req = setup->ring_req;
-       struct blkfront_info *info = setup->info;
-       struct blk_shadow *shadow = &info->shadow[setup->id];
+       struct blkfront_ring_info *rinfo = setup->rinfo;
+       struct blkfront_info *info = rinfo->dev_info;
+       struct blk_shadow *shadow = &rinfo->shadow[setup->id];
 
        if ((ring_req->operation == BLKIF_OP_INDIRECT) &&
            (grant_idx % GRANTS_PER_INDIRECT_FRAME == 0)) {
@@ -566,16 +579,16 @@ static void blkif_setup_rw_req_grant(unsigned long gfn, unsigned int offset,
        (setup->grant_idx)++;
 }
 
-static int blkif_queue_rw_req(struct request *req)
+static int blkif_queue_rw_req(struct request *req, struct blkfront_ring_info *rinfo)
 {
-       struct blkfront_info *info = req->rq_disk->private_data;
+       struct blkfront_info *info = rinfo->dev_info;
        struct blkif_request *ring_req;
        unsigned long id;
        int i;
        struct setup_rw_req setup = {
                .grant_idx = 0,
                .segments = NULL,
-               .info = info,
+               .rinfo = rinfo,
                .need_copy = rq_data_dir(req) && info->feature_persistent,
        };
 
@@ -603,9 +616,9 @@ static int blkif_queue_rw_req(struct request *req)
                    max_grefs - info->persistent_gnts_c,
                    &setup.gref_head) < 0) {
                        gnttab_request_free_callback(
-                               &info->callback,
+                               &rinfo->callback,
                                blkif_restart_queue_callback,
-                               info,
+                               rinfo,
                                max_grefs);
                        return 1;
                }
@@ -613,23 +626,23 @@ static int blkif_queue_rw_req(struct request *req)
                new_persistent_gnts = 0;
 
        /* Fill out a communications ring structure. */
-       ring_req = RING_GET_REQUEST(&info->ring, info->ring.req_prod_pvt);
-       id = get_id_from_freelist(info);
-       info->shadow[id].request = req;
+       ring_req = RING_GET_REQUEST(&rinfo->ring, rinfo->ring.req_prod_pvt);
+       id = get_id_from_freelist(rinfo);
+       rinfo->shadow[id].request = req;
 
        BUG_ON(info->max_indirect_segments == 0 &&
               GREFS(req->nr_phys_segments) > BLKIF_MAX_SEGMENTS_PER_REQUEST);
        BUG_ON(info->max_indirect_segments &&
               GREFS(req->nr_phys_segments) > info->max_indirect_segments);
 
-       num_sg = blk_rq_map_sg(req->q, req, info->shadow[id].sg);
+       num_sg = blk_rq_map_sg(req->q, req, rinfo->shadow[id].sg);
        num_grant = 0;
        /* Calculate the number of grant used */
-       for_each_sg(info->shadow[id].sg, sg, num_sg, i)
+       for_each_sg(rinfo->shadow[id].sg, sg, num_sg, i)
               num_grant += gnttab_count_grant(sg->offset, sg->length);
 
        ring_req->u.rw.id = id;
-       info->shadow[id].num_sg = num_sg;
+       rinfo->shadow[id].num_sg = num_sg;
        if (num_grant > BLKIF_MAX_SEGMENTS_PER_REQUEST) {
                /*
                 * The indirect operation can only be a BLKIF_OP_READ or
@@ -674,7 +687,7 @@ static int blkif_queue_rw_req(struct request *req)
 
        setup.ring_req = ring_req;
        setup.id = id;
-       for_each_sg(info->shadow[id].sg, sg, num_sg, i) {
+       for_each_sg(rinfo->shadow[id].sg, sg, num_sg, i) {
                BUG_ON(sg->offset + sg->length > PAGE_SIZE);
 
                if (setup.need_copy) {
@@ -694,10 +707,10 @@ static int blkif_queue_rw_req(struct request *req)
        if (setup.segments)
                kunmap_atomic(setup.segments);
 
-       info->ring.req_prod_pvt++;
+       rinfo->ring.req_prod_pvt++;
 
        /* Keep a private copy so we can reissue requests when recovering. */
-       info->shadow[id].req = *ring_req;
+       rinfo->shadow[id].req = *ring_req;
 
        if (new_persistent_gnts)
                gnttab_free_grant_references(setup.gref_head);
@@ -711,27 +724,25 @@ static int blkif_queue_rw_req(struct request *req)
  *
  * @req: a request struct
  */
-static int blkif_queue_request(struct request *req)
+static int blkif_queue_request(struct request *req, struct blkfront_ring_info *rinfo)
 {
-       struct blkfront_info *info = req->rq_disk->private_data;
-
-       if (unlikely(info->connected != BLKIF_STATE_CONNECTED))
+       if (unlikely(rinfo->dev_info->connected != BLKIF_STATE_CONNECTED))
                return 1;
 
        if (unlikely(req->cmd_flags & (REQ_DISCARD | REQ_SECURE)))
-               return blkif_queue_discard_req(req);
+               return blkif_queue_discard_req(req, rinfo);
        else
-               return blkif_queue_rw_req(req);
+               return blkif_queue_rw_req(req, rinfo);
 }
 
-static inline void flush_requests(struct blkfront_info *info)
+static inline void flush_requests(struct blkfront_ring_info *rinfo)
 {
        int notify;
 
-       RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&info->ring, notify);
+       RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&rinfo->ring, notify);
 
        if (notify)
-               notify_remote_via_irq(info->irq);
+               notify_remote_via_irq(rinfo->irq);
 }
 
 static inline bool blkif_request_flush_invalid(struct request *req,
@@ -747,20 +758,21 @@ static inline bool blkif_request_flush_invalid(struct request *req,
 static int blkif_queue_rq(struct blk_mq_hw_ctx *hctx,
                           const struct blk_mq_queue_data *qd)
 {
-       struct blkfront_info *info = qd->rq->rq_disk->private_data;
+       struct blkfront_ring_info *rinfo = (struct blkfront_ring_info *)hctx->driver_data;
+       struct blkfront_info *info = rinfo->dev_info;
 
        blk_mq_start_request(qd->rq);
        spin_lock_irq(&info->io_lock);
-       if (RING_FULL(&info->ring))
+       if (RING_FULL(&rinfo->ring))
                goto out_busy;
 
-       if (blkif_request_flush_invalid(qd->rq, info))
+       if (blkif_request_flush_invalid(qd->rq, rinfo->dev_info))
                goto out_err;
 
-       if (blkif_queue_request(qd->rq))
+       if (blkif_queue_request(qd->rq, rinfo))
                goto out_busy;
 
-       flush_requests(info);
+       flush_requests(rinfo);
        spin_unlock_irq(&info->io_lock);
        return BLK_MQ_RQ_QUEUE_OK;
 
@@ -774,9 +786,19 @@ 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;
+
+       hctx->driver_data = &info->rinfo;
+       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,
@@ -1029,6 +1051,7 @@ static int xlvbd_alloc_gendisk(blkif_sector_t capacity,
 static void xlvbd_release_gendisk(struct blkfront_info *info)
 {
        unsigned int minor, nr_minors;
+       struct blkfront_ring_info *rinfo = &info->rinfo;
 
        if (info->rq == NULL)
                return;
@@ -1037,10 +1060,10 @@ static void xlvbd_release_gendisk(struct blkfront_info *info)
        blk_mq_stop_hw_queues(info->rq);
 
        /* No more gnttab callback work. */
-       gnttab_cancel_free_callback(&info->callback);
+       gnttab_cancel_free_callback(&rinfo->callback);
 
        /* Flush gnttab callback work. Must be done with no locks held. */
-       flush_work(&info->work);
+       flush_work(&rinfo->work);
 
        del_gendisk(info->gd);
 
@@ -1057,20 +1080,20 @@ static void xlvbd_release_gendisk(struct blkfront_info *info)
 }
 
 /* Must be called with io_lock holded */
-static void kick_pending_request_queues(struct blkfront_info *info)
+static void kick_pending_request_queues(struct blkfront_ring_info *rinfo)
 {
-       if (!RING_FULL(&info->ring))
-               blk_mq_start_stopped_hw_queues(info->rq, true);
+       if (!RING_FULL(&rinfo->ring))
+               blk_mq_start_stopped_hw_queues(rinfo->dev_info->rq, true);
 }
 
 static void blkif_restart_queue(struct work_struct *work)
 {
-       struct blkfront_info *info = container_of(work, struct blkfront_info, work);
+       struct blkfront_ring_info *rinfo = container_of(work, struct blkfront_ring_info, work);
 
-       spin_lock_irq(&info->io_lock);
-       if (info->connected == BLKIF_STATE_CONNECTED)
-               kick_pending_request_queues(info);
-       spin_unlock_irq(&info->io_lock);
+       spin_lock_irq(&rinfo->dev_info->io_lock);
+       if (rinfo->dev_info->connected == BLKIF_STATE_CONNECTED)
+               kick_pending_request_queues(rinfo);
+       spin_unlock_irq(&rinfo->dev_info->io_lock);
 }
 
 static void blkif_free(struct blkfront_info *info, int suspend)
@@ -1078,6 +1101,7 @@ static void blkif_free(struct blkfront_info *info, int suspend)
        struct grant *persistent_gnt;
        struct grant *n;
        int i, j, segs;
+       struct blkfront_ring_info *rinfo = &info->rinfo;
 
        /* Prevent new requests being issued until we fix things up. */
        spin_lock_irq(&info->io_lock);
@@ -1090,7 +1114,7 @@ static void blkif_free(struct blkfront_info *info, int suspend)
        /* Remove all persistent grants */
        if (!list_empty(&info->grants)) {
                list_for_each_entry_safe(persistent_gnt, n,
-                                        &info->grants, node) {
+                                        &info->grants, node) {
                        list_del(&persistent_gnt->node);
                        if (persistent_gnt->gref != GRANT_INVALID_REF) {
                                gnttab_end_foreign_access(persistent_gnt->gref,
@@ -1108,11 +1132,11 @@ static void blkif_free(struct blkfront_info *info, int suspend)
         * Remove indirect pages, this only happens when using indirect
         * descriptors but not persistent grants
         */
-       if (!list_empty(&info->indirect_pages)) {
+       if (!list_empty(&rinfo->indirect_pages)) {
                struct page *indirect_page, *n;
 
                BUG_ON(info->feature_persistent);
-               list_for_each_entry_safe(indirect_page, n, &info->indirect_pages, lru) {
+               list_for_each_entry_safe(indirect_page, n, &rinfo->indirect_pages, lru) {
                        list_del(&indirect_page->lru);
                        __free_page(indirect_page);
                }
@@ -1123,21 +1147,21 @@ static void blkif_free(struct blkfront_info *info, int suspend)
                 * Clear persistent grants present in requests already
                 * on the shared ring
                 */
-               if (!info->shadow[i].request)
+               if (!rinfo->shadow[i].request)
                        goto free_shadow;
 
-               segs = info->shadow[i].req.operation == BLKIF_OP_INDIRECT ?
-                      info->shadow[i].req.u.indirect.nr_segments :
-                      info->shadow[i].req.u.rw.nr_segments;
+               segs = rinfo->shadow[i].req.operation == BLKIF_OP_INDIRECT ?
+                      rinfo->shadow[i].req.u.indirect.nr_segments :
+                      rinfo->shadow[i].req.u.rw.nr_segments;
                for (j = 0; j < segs; j++) {
-                       persistent_gnt = info->shadow[i].grants_used[j];
+                       persistent_gnt = rinfo->shadow[i].grants_used[j];
                        gnttab_end_foreign_access(persistent_gnt->gref, 0, 0UL);
                        if (info->feature_persistent)
                                __free_page(persistent_gnt->page);
                        kfree(persistent_gnt);
                }
 
-               if (info->shadow[i].req.operation != BLKIF_OP_INDIRECT)
+               if (rinfo->shadow[i].req.operation != BLKIF_OP_INDIRECT)
                        /*
                         * If this is not an indirect operation don't try to
                         * free indirect segments
@@ -1145,41 +1169,41 @@ static void blkif_free(struct blkfront_info *info, int suspend)
                        goto free_shadow;
 
                for (j = 0; j < INDIRECT_GREFS(segs); j++) {
-                       persistent_gnt = info->shadow[i].indirect_grants[j];
+                       persistent_gnt = rinfo->shadow[i].indirect_grants[j];
                        gnttab_end_foreign_access(persistent_gnt->gref, 0, 0UL);
                        __free_page(persistent_gnt->page);
                        kfree(persistent_gnt);
                }
 
 free_shadow:
-               kfree(info->shadow[i].grants_used);
-               info->shadow[i].grants_used = NULL;
-               kfree(info->shadow[i].indirect_grants);
-               info->shadow[i].indirect_grants = NULL;
-               kfree(info->shadow[i].sg);
-               info->shadow[i].sg = NULL;
+               kfree(rinfo->shadow[i].grants_used);
+               rinfo->shadow[i].grants_used = NULL;
+               kfree(rinfo->shadow[i].indirect_grants);
+               rinfo->shadow[i].indirect_grants = NULL;
+               kfree(rinfo->shadow[i].sg);
+               rinfo->shadow[i].sg = NULL;
        }
 
        /* No more gnttab callback work. */
-       gnttab_cancel_free_callback(&info->callback);
+       gnttab_cancel_free_callback(&rinfo->callback);
        spin_unlock_irq(&info->io_lock);
 
        /* Flush gnttab callback work. Must be done with no locks held. */
-       flush_work(&info->work);
+       flush_work(&rinfo->work);
 
        /* Free resources associated with old device channel. */
        for (i = 0; i < info->nr_ring_pages; i++) {
-               if (info->ring_ref[i] != GRANT_INVALID_REF) {
-                       gnttab_end_foreign_access(info->ring_ref[i], 0, 0);
-                       info->ring_ref[i] = GRANT_INVALID_REF;
+               if (rinfo->ring_ref[i] != GRANT_INVALID_REF) {
+                       gnttab_end_foreign_access(rinfo->ring_ref[i], 0, 0);
+                       rinfo->ring_ref[i] = GRANT_INVALID_REF;
                }
        }
-       free_pages((unsigned long)info->ring.sring, get_order(info->nr_ring_pages * PAGE_SIZE));
-       info->ring.sring = NULL;
+       free_pages((unsigned long)rinfo->ring.sring, get_order(info->nr_ring_pages * PAGE_SIZE));
+       rinfo->ring.sring = NULL;
 
-       if (info->irq)
-               unbind_from_irqhandler(info->irq, info);
-       info->evtchn = info->irq = 0;
+       if (rinfo->irq)
+               unbind_from_irqhandler(rinfo->irq, rinfo);
+       rinfo->evtchn = rinfo->irq = 0;
 
 }
 
@@ -1209,12 +1233,13 @@ static void blkif_copy_from_grant(unsigned long gfn, unsigned int offset,
        kunmap_atomic(shared_data);
 }
 
-static void blkif_completion(struct blk_shadow *s, struct blkfront_info *info,
+static void blkif_completion(struct blk_shadow *s, struct blkfront_ring_info *rinfo,
                             struct blkif_response *bret)
 {
        int i = 0;
        struct scatterlist *sg;
        int num_sg, num_grant;
+       struct blkfront_info *info = rinfo->dev_info;
        struct copy_from_grant data = {
                .s = s,
                .grant_idx = 0,
@@ -1284,7 +1309,7 @@ static void blkif_completion(struct blk_shadow *s, struct blkfront_info *info,
                                 */
                                if (!info->feature_persistent) {
                                        indirect_page = s->indirect_grants[i]->page;
-                                       list_add(&indirect_page->lru, &info->indirect_pages);
+                                       list_add(&indirect_page->lru, &rinfo->indirect_pages);
                                }
                                s->indirect_grants[i]->gref = GRANT_INVALID_REF;
                                list_add_tail(&s->indirect_grants[i]->node, &info->grants);
@@ -1299,7 +1324,8 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
        struct blkif_response *bret;
        RING_IDX i, rp;
        unsigned long flags;
-       struct blkfront_info *info = (struct blkfront_info *)dev_id;
+       struct blkfront_ring_info *rinfo = (struct blkfront_ring_info *)dev_id;
+       struct blkfront_info *info = rinfo->dev_info;
        int error;
 
        spin_lock_irqsave(&info->io_lock, flags);
@@ -1310,13 +1336,13 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
        }
 
  again:
-       rp = info->ring.sring->rsp_prod;
+       rp = rinfo->ring.sring->rsp_prod;
        rmb(); /* Ensure we see queued responses up to 'rp'. */
 
-       for (i = info->ring.rsp_cons; i != rp; i++) {
+       for (i = rinfo->ring.rsp_cons; i != rp; i++) {
                unsigned long id;
 
-               bret = RING_GET_RESPONSE(&info->ring, i);
+               bret = RING_GET_RESPONSE(&rinfo->ring, i);
                id   = bret->id;
                /*
                 * The backend has messed up and given us an id that we would
@@ -1330,12 +1356,12 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
                         * the id is busted. */
                        continue;
                }
-               req  = info->shadow[id].request;
+               req  = rinfo->shadow[id].request;
 
                if (bret->operation != BLKIF_OP_DISCARD)
-                       blkif_completion(&info->shadow[id], info, bret);
+                       blkif_completion(&rinfo->shadow[id], rinfo, bret);
 
-               if (add_id_to_freelist(info, id)) {
+               if (add_id_to_freelist(rinfo, id)) {
                        WARN(1, "%s: response to %s (id %ld) couldn't be recycled!\n",
                             info->gd->disk_name, op_name(bret->operation), id);
                        continue;
@@ -1364,7 +1390,7 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
                                error = -EOPNOTSUPP;
                        }
                        if (unlikely(bret->status == BLKIF_RSP_ERROR &&
-                                    info->shadow[id].req.u.rw.nr_segments == 0)) {
+                                    rinfo->shadow[id].req.u.rw.nr_segments == 0)) {
                                printk(KERN_WARNING "blkfront: %s: empty %s op failed\n",
                                       info->gd->disk_name, op_name(bret->operation));
                                error = -EOPNOTSUPP;
@@ -1389,17 +1415,17 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
                }
        }
 
-       info->ring.rsp_cons = i;
+       rinfo->ring.rsp_cons = i;
 
-       if (i != info->ring.req_prod_pvt) {
+       if (i != rinfo->ring.req_prod_pvt) {
                int more_to_do;
-               RING_FINAL_CHECK_FOR_RESPONSES(&info->ring, more_to_do);
+               RING_FINAL_CHECK_FOR_RESPONSES(&rinfo->ring, more_to_do);
                if (more_to_do)
                        goto again;
        } else
-               info->ring.sring->rsp_event = i + 1;
+               rinfo->ring.sring->rsp_event = i + 1;
 
-       kick_pending_request_queues(info);
+       kick_pending_request_queues(rinfo);
 
        spin_unlock_irqrestore(&info->io_lock, flags);
 
@@ -1408,15 +1434,16 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
 
 
 static int setup_blkring(struct xenbus_device *dev,
-                        struct blkfront_info *info)
+                        struct blkfront_ring_info *rinfo)
 {
        struct blkif_sring *sring;
        int err, i;
+       struct blkfront_info *info = rinfo->dev_info;
        unsigned long ring_size = info->nr_ring_pages * XEN_PAGE_SIZE;
        grant_ref_t gref[XENBUS_MAX_RING_GRANTS];
 
        for (i = 0; i < info->nr_ring_pages; i++)
-               info->ring_ref[i] = GRANT_INVALID_REF;
+               rinfo->ring_ref[i] = GRANT_INVALID_REF;
 
        sring = (struct blkif_sring *)__get_free_pages(GFP_NOIO | __GFP_HIGH,
                                                       get_order(ring_size));
@@ -1425,29 +1452,29 @@ static int setup_blkring(struct xenbus_device *dev,
                return -ENOMEM;
        }
        SHARED_RING_INIT(sring);
-       FRONT_RING_INIT(&info->ring, sring, ring_size);
+       FRONT_RING_INIT(&rinfo->ring, sring, ring_size);
 
-       err = xenbus_grant_ring(dev, info->ring.sring, info->nr_ring_pages, gref);
+       err = xenbus_grant_ring(dev, rinfo->ring.sring, info->nr_ring_pages, gref);
        if (err < 0) {
                free_pages((unsigned long)sring, get_order(ring_size));
-               info->ring.sring = NULL;
+               rinfo->ring.sring = NULL;
                goto fail;
        }
        for (i = 0; i < info->nr_ring_pages; i++)
-               info->ring_ref[i] = gref[i];
+               rinfo->ring_ref[i] = gref[i];
 
-       err = xenbus_alloc_evtchn(dev, &info->evtchn);
+       err = xenbus_alloc_evtchn(dev, &rinfo->evtchn);
        if (err)
                goto fail;
 
-       err = bind_evtchn_to_irqhandler(info->evtchn, blkif_interrupt, 0,
-                                       "blkif", info);
+       err = bind_evtchn_to_irqhandler(rinfo->evtchn, blkif_interrupt, 0,
+                                       "blkif", rinfo);
        if (err <= 0) {
                xenbus_dev_fatal(dev, err,
                                 "bind_evtchn_to_irqhandler failed");
                goto fail;
        }
-       info->irq = err;
+       rinfo->irq = err;
 
        return 0;
 fail:
@@ -1465,6 +1492,7 @@ static int talk_to_blkback(struct xenbus_device *dev,
        int err, i;
        unsigned int max_page_order = 0;
        unsigned int ring_page_order = 0;
+       struct blkfront_ring_info *rinfo = &info->rinfo;
 
        err = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
                           "max-ring-page-order", "%u", &max_page_order);
@@ -1476,7 +1504,7 @@ static int talk_to_blkback(struct xenbus_device *dev,
        }
 
        /* Create shared ring, alloc event channel. */
-       err = setup_blkring(dev, info);
+       err = setup_blkring(dev, rinfo);
        if (err)
                goto out;
 
@@ -1489,7 +1517,7 @@ again:
 
        if (info->nr_ring_pages == 1) {
                err = xenbus_printf(xbt, dev->nodename,
-                                   "ring-ref", "%u", info->ring_ref[0]);
+                                   "ring-ref", "%u", rinfo->ring_ref[0]);
                if (err) {
                        message = "writing ring-ref";
                        goto abort_transaction;
@@ -1507,7 +1535,7 @@ again:
 
                        snprintf(ring_ref_name, RINGREF_NAME_LEN, "ring-ref%u", i);
                        err = xenbus_printf(xbt, dev->nodename, ring_ref_name,
-                                           "%u", info->ring_ref[i]);
+                                           "%u", rinfo->ring_ref[i]);
                        if (err) {
                                message = "writing ring-ref";
                                goto abort_transaction;
@@ -1515,7 +1543,7 @@ again:
                }
        }
        err = xenbus_printf(xbt, dev->nodename,
-                           "event-channel", "%u", info->evtchn);
+                           "event-channel", "%u", rinfo->evtchn);
        if (err) {
                message = "writing event-channel";
                goto abort_transaction;
@@ -1541,8 +1569,8 @@ again:
        }
 
        for (i = 0; i < BLK_RING_SIZE(info); i++)
-               info->shadow[i].req.u.rw.id = i+1;
-       info->shadow[BLK_RING_SIZE(info)-1].req.u.rw.id = 0x0fffffff;
+               rinfo->shadow[i].req.u.rw.id = i+1;
+       rinfo->shadow[BLK_RING_SIZE(info)-1].req.u.rw.id = 0x0fffffff;
        xenbus_switch_state(dev, XenbusStateInitialised);
 
        return 0;
@@ -1568,6 +1596,7 @@ static int blkfront_probe(struct xenbus_device *dev,
 {
        int err, vdevice;
        struct blkfront_info *info;
+       struct blkfront_ring_info *rinfo;
 
        /* FIXME: Use dynamic device id if this is not set. */
        err = xenbus_scanf(XBT_NIL, dev->nodename,
@@ -1617,15 +1646,18 @@ static int blkfront_probe(struct xenbus_device *dev,
                return -ENOMEM;
        }
 
+       rinfo = &info->rinfo;
+       INIT_LIST_HEAD(&rinfo->indirect_pages);
+       rinfo->dev_info = info;
+       INIT_WORK(&rinfo->work, blkif_restart_queue);
+
        mutex_init(&info->mutex);
        spin_lock_init(&info->io_lock);
        info->xbdev = dev;
        info->vdevice = vdevice;
        INIT_LIST_HEAD(&info->grants);
-       INIT_LIST_HEAD(&info->indirect_pages);
        info->persistent_gnts_c = 0;
        info->connected = BLKIF_STATE_DISCONNECTED;
-       INIT_WORK(&info->work, blkif_restart_queue);
 
        /* Front end dir is a number, which is used as the id. */
        info->handle = simple_strtoul(strrchr(dev->nodename, '/')+1, NULL, 0);
@@ -1659,19 +1691,20 @@ static int blkif_recover(struct blkfront_info *info)
        int pending, size;
        struct split_bio *split_bio;
        struct list_head requests;
+       struct blkfront_ring_info *rinfo = &info->rinfo;
 
        /* Stage 1: Make a safe copy of the shadow state. */
-       copy = kmemdup(info->shadow, sizeof(info->shadow),
+       copy = kmemdup(rinfo->shadow, sizeof(rinfo->shadow),
                       GFP_NOIO | __GFP_REPEAT | __GFP_HIGH);
        if (!copy)
                return -ENOMEM;
 
        /* Stage 2: Set up free list. */
-       memset(&info->shadow, 0, sizeof(info->shadow));
+       memset(&rinfo->shadow, 0, sizeof(rinfo->shadow));
        for (i = 0; i < BLK_RING_SIZE(info); i++)
-               info->shadow[i].req.u.rw.id = i+1;
-       info->shadow_free = info->ring.req_prod_pvt;
-       info->shadow[BLK_RING_SIZE(info)-1].req.u.rw.id = 0x0fffffff;
+               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;
 
        rc = blkfront_gather_backend_features(info);
        if (rc) {
@@ -1717,7 +1750,7 @@ static int blkif_recover(struct blkfront_info *info)
        info->connected = BLKIF_STATE_CONNECTED;
 
        /* Kick any other new requests queued since we resumed */
-       kick_pending_request_queues(info);
+       kick_pending_request_queues(rinfo);
 
        list_for_each_entry_safe(req, n, &requests, queuelist) {
                /* Requeue pending requests (flush or discard) */
@@ -1851,10 +1884,11 @@ static void blkfront_setup_discard(struct blkfront_info *info)
                info->feature_secdiscard = !!discard_secure;
 }
 
-static int blkfront_setup_indirect(struct blkfront_info *info)
+static int blkfront_setup_indirect(struct blkfront_ring_info *rinfo)
 {
        unsigned int psegs, grants;
        int err, i;
+       struct blkfront_info *info = rinfo->dev_info;
 
        if (info->max_indirect_segments == 0)
                grants = BLKIF_MAX_SEGMENTS_PER_REQUEST;
@@ -1862,7 +1896,7 @@ static int blkfront_setup_indirect(struct blkfront_info *info)
                grants = info->max_indirect_segments;
        psegs = grants / GRANTS_PER_PSEG;
 
-       err = fill_grant_buffer(info,
+       err = fill_grant_buffer(rinfo,
                                (grants + INDIRECT_GREFS(grants)) * BLK_RING_SIZE(info));
        if (err)
                goto out_of_memory;
@@ -1875,31 +1909,31 @@ static int blkfront_setup_indirect(struct blkfront_info *info)
                 */
                int num = INDIRECT_GREFS(grants) * BLK_RING_SIZE(info);
 
-               BUG_ON(!list_empty(&info->indirect_pages));
+               BUG_ON(!list_empty(&rinfo->indirect_pages));
                for (i = 0; i < num; i++) {
                        struct page *indirect_page = alloc_page(GFP_NOIO);
                        if (!indirect_page)
                                goto out_of_memory;
-                       list_add(&indirect_page->lru, &info->indirect_pages);
+                       list_add(&indirect_page->lru, &rinfo->indirect_pages);
                }
        }
 
        for (i = 0; i < BLK_RING_SIZE(info); i++) {
-               info->shadow[i].grants_used = kzalloc(
-                       sizeof(info->shadow[i].grants_used[0]) * grants,
+               rinfo->shadow[i].grants_used = kzalloc(
+                       sizeof(rinfo->shadow[i].grants_used[0]) * grants,
                        GFP_NOIO);
-               info->shadow[i].sg = kzalloc(sizeof(info->shadow[i].sg[0]) * psegs, GFP_NOIO);
+               rinfo->shadow[i].sg = kzalloc(sizeof(rinfo->shadow[i].sg[0]) * psegs, GFP_NOIO);
                if (info->max_indirect_segments)
-                       info->shadow[i].indirect_grants = kzalloc(
-                               sizeof(info->shadow[i].indirect_grants[0]) *
+                       rinfo->shadow[i].indirect_grants = kzalloc(
+                               sizeof(rinfo->shadow[i].indirect_grants[0]) *
                                INDIRECT_GREFS(grants),
                                GFP_NOIO);
-               if ((info->shadow[i].grants_used == NULL) ||
-                       (info->shadow[i].sg == NULL) ||
+               if ((rinfo->shadow[i].grants_used == NULL) ||
+                       (rinfo->shadow[i].sg == NULL) ||
                     (info->max_indirect_segments &&
-                    (info->shadow[i].indirect_grants == NULL)))
+                    (rinfo->shadow[i].indirect_grants == NULL)))
                        goto out_of_memory;
-               sg_init_table(info->shadow[i].sg, psegs);
+               sg_init_table(rinfo->shadow[i].sg, psegs);
        }
 
 
@@ -1907,16 +1941,16 @@ static int blkfront_setup_indirect(struct blkfront_info *info)
 
 out_of_memory:
        for (i = 0; i < BLK_RING_SIZE(info); i++) {
-               kfree(info->shadow[i].grants_used);
-               info->shadow[i].grants_used = NULL;
-               kfree(info->shadow[i].sg);
-               info->shadow[i].sg = NULL;
-               kfree(info->shadow[i].indirect_grants);
-               info->shadow[i].indirect_grants = NULL;
-       }
-       if (!list_empty(&info->indirect_pages)) {
+               kfree(rinfo->shadow[i].grants_used);
+               rinfo->shadow[i].grants_used = NULL;
+               kfree(rinfo->shadow[i].sg);
+               rinfo->shadow[i].sg = NULL;
+               kfree(rinfo->shadow[i].indirect_grants);
+               rinfo->shadow[i].indirect_grants = NULL;
+       }
+       if (!list_empty(&rinfo->indirect_pages)) {
                struct page *indirect_page, *n;
-               list_for_each_entry_safe(indirect_page, n, &info->indirect_pages, lru) {
+               list_for_each_entry_safe(indirect_page, n, &rinfo->indirect_pages, lru) {
                        list_del(&indirect_page->lru);
                        __free_page(indirect_page);
                }
@@ -1983,7 +2017,7 @@ static int blkfront_gather_backend_features(struct blkfront_info *info)
                info->max_indirect_segments = min(indirect_segments,
                                                  xen_blkif_max_segments);
 
-       return blkfront_setup_indirect(info);
+       return blkfront_setup_indirect(&info->rinfo);
 }
 
 /*
@@ -1997,6 +2031,7 @@ static void blkfront_connect(struct blkfront_info *info)
        unsigned int physical_sector_size;
        unsigned int binfo;
        int err;
+       struct blkfront_ring_info *rinfo = &info->rinfo;
 
        switch (info->connected) {
        case BLKIF_STATE_CONNECTED:
@@ -2073,7 +2108,7 @@ static void blkfront_connect(struct blkfront_info *info)
        /* Kick pending requests. */
        spin_lock_irq(&info->io_lock);
        info->connected = BLKIF_STATE_CONNECTED;
-       kick_pending_request_queues(info);
+       kick_pending_request_queues(rinfo);
        spin_unlock_irq(&info->io_lock);
 
        add_disk(info->gd);