diff options
Diffstat (limited to 'drivers/block')
| -rw-r--r-- | drivers/block/xen-blkback/blkback.c | 391 | ||||
| -rw-r--r-- | drivers/block/xen-blkback/common.h | 86 | ||||
| -rw-r--r-- | drivers/block/xen-blkback/xenbus.c | 416 | ||||
| -rw-r--r-- | drivers/block/xen-blkfront.c | 1061 |
4 files changed, 1244 insertions, 710 deletions
diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c index f9099940c272..148930c8c121 100644 --- a/drivers/block/xen-blkback/blkback.c +++ b/drivers/block/xen-blkback/blkback.c @@ -84,6 +84,16 @@ MODULE_PARM_DESC(max_persistent_grants, "Maximum number of grants to map persistently"); /* + * Maximum number of rings/queues blkback supports, allow as many queues as there + * are CPUs if user has not specified a value. + */ +unsigned int xenblk_max_queues; +module_param_named(max_queues, xenblk_max_queues, uint, 0644); +MODULE_PARM_DESC(max_queues, + "Maximum number of hardware queues per virtual disk." \ + "By default it is the number of online CPUs."); + +/* * Maximum order of pages to be used for the shared ring between front and * backend, 4KB page granularity is used. */ @@ -113,71 +123,71 @@ module_param(log_stats, int, 0644); /* Number of free pages to remove on each call to gnttab_free_pages */ #define NUM_BATCH_FREE_PAGES 10 -static inline int get_free_page(struct xen_blkif *blkif, struct page **page) +static inline int get_free_page(struct xen_blkif_ring *ring, struct page **page) { unsigned long flags; - spin_lock_irqsave(&blkif->free_pages_lock, flags); - if (list_empty(&blkif->free_pages)) { - BUG_ON(blkif->free_pages_num != 0); - spin_unlock_irqrestore(&blkif->free_pages_lock, flags); + spin_lock_irqsave(&ring->free_pages_lock, flags); + if (list_empty(&ring->free_pages)) { + BUG_ON(ring->free_pages_num != 0); + spin_unlock_irqrestore(&ring->free_pages_lock, flags); return gnttab_alloc_pages(1, page); } - BUG_ON(blkif->free_pages_num == 0); - page[0] = list_first_entry(&blkif->free_pages, struct page, lru); + BUG_ON(ring->free_pages_num == 0); + page[0] = list_first_entry(&ring->free_pages, struct page, lru); list_del(&page[0]->lru); - blkif->free_pages_num--; - spin_unlock_irqrestore(&blkif->free_pages_lock, flags); + ring->free_pages_num--; + spin_unlock_irqrestore(&ring->free_pages_lock, flags); return 0; } -static inline void put_free_pages(struct xen_blkif *blkif, struct page **page, +static inline void put_free_pages(struct xen_blkif_ring *ring, struct page **page, int num) { unsigned long flags; int i; - spin_lock_irqsave(&blkif->free_pages_lock, flags); + spin_lock_irqsave(&ring->free_pages_lock, flags); for (i = 0; i < num; i++) - list_add(&page[i]->lru, &blkif->free_pages); - blkif->free_pages_num += num; - spin_unlock_irqrestore(&blkif->free_pages_lock, flags); + list_add(&page[i]->lru, &ring->free_pages); + ring->free_pages_num += num; + spin_unlock_irqrestore(&ring->free_pages_lock, flags); } -static inline void shrink_free_pagepool(struct xen_blkif *blkif, int num) +static inline void shrink_free_pagepool(struct xen_blkif_ring *ring, int num) { /* Remove requested pages in batches of NUM_BATCH_FREE_PAGES */ struct page *page[NUM_BATCH_FREE_PAGES]; unsigned int num_pages = 0; unsigned long flags; - spin_lock_irqsave(&blkif->free_pages_lock, flags); - while (blkif->free_pages_num > num) { - BUG_ON(list_empty(&blkif->free_pages)); - page[num_pages] = list_first_entry(&blkif->free_pages, + spin_lock_irqsave(&ring->free_pages_lock, flags); + while (ring->free_pages_num > num) { + BUG_ON(list_empty(&ring->free_pages)); + page[num_pages] = list_first_entry(&ring->free_pages, struct page, lru); list_del(&page[num_pages]->lru); - blkif->free_pages_num--; + ring->free_pages_num--; if (++num_pages == NUM_BATCH_FREE_PAGES) { - spin_unlock_irqrestore(&blkif->free_pages_lock, flags); + spin_unlock_irqrestore(&ring->free_pages_lock, flags); gnttab_free_pages(num_pages, page); - spin_lock_irqsave(&blkif->free_pages_lock, flags); + spin_lock_irqsave(&ring->free_pages_lock, flags); num_pages = 0; } } - spin_unlock_irqrestore(&blkif->free_pages_lock, flags); + spin_unlock_irqrestore(&ring->free_pages_lock, flags); if (num_pages != 0) gnttab_free_pages(num_pages, page); } #define vaddr(page) ((unsigned long)pfn_to_kaddr(page_to_pfn(page))) -static int do_block_io_op(struct xen_blkif *blkif); -static int dispatch_rw_block_io(struct xen_blkif *blkif, +static int do_block_io_op(struct xen_blkif_ring *ring); +static int dispatch_rw_block_io(struct xen_blkif_ring *ring, struct blkif_request *req, struct pending_req *pending_req); -static void make_response(struct xen_blkif *blkif, u64 id, +static void make_response(struct xen_blkif_ring *ring, u64 id, unsigned short op, int st); #define foreach_grant_safe(pos, n, rbtree, node) \ @@ -190,7 +200,7 @@ static void make_response(struct xen_blkif *blkif, u64 id, /* * We don't need locking around the persistent grant helpers - * because blkback uses a single-thread for each backed, so we + * because blkback uses a single-thread for each backend, so we * can be sure that this functions will never be called recursively. * * The only exception to that is put_persistent_grant, that can be called @@ -198,19 +208,20 @@ static void make_response(struct xen_blkif *blkif, u64 id, * bit operations to modify the flags of a persistent grant and to count * the number of used grants. */ -static int add_persistent_gnt(struct xen_blkif *blkif, +static int add_persistent_gnt(struct xen_blkif_ring *ring, struct persistent_gnt *persistent_gnt) { struct rb_node **new = NULL, *parent = NULL; struct persistent_gnt *this; + struct xen_blkif *blkif = ring->blkif; - if (blkif->persistent_gnt_c >= xen_blkif_max_pgrants) { + if (ring->persistent_gnt_c >= xen_blkif_max_pgrants) { if (!blkif->vbd.overflow_max_grants) blkif->vbd.overflow_max_grants = 1; return -EBUSY; } /* Figure out where to put new node */ - new = &blkif->persistent_gnts.rb_node; + new = &ring->persistent_gnts.rb_node; while (*new) { this = container_of(*new, struct persistent_gnt, node); @@ -229,19 +240,19 @@ static int add_persistent_gnt(struct xen_blkif *blkif, set_bit(PERSISTENT_GNT_ACTIVE, persistent_gnt->flags); /* Add new node and rebalance tree. */ rb_link_node(&(persistent_gnt->node), parent, new); - rb_insert_color(&(persistent_gnt->node), &blkif->persistent_gnts); - blkif->persistent_gnt_c++; - atomic_inc(&blkif->persistent_gnt_in_use); + rb_insert_color(&(persistent_gnt->node), &ring->persistent_gnts); + ring->persistent_gnt_c++; + atomic_inc(&ring->persistent_gnt_in_use); return 0; } -static struct persistent_gnt *get_persistent_gnt(struct xen_blkif *blkif, +static struct persistent_gnt *get_persistent_gnt(struct xen_blkif_ring *ring, grant_ref_t gref) { struct persistent_gnt *data; struct rb_node *node = NULL; - node = blkif->persistent_gnts.rb_node; + node = ring->persistent_gnts.rb_node; while (node) { data = container_of(node, struct persistent_gnt, node); @@ -255,24 +266,24 @@ static struct persistent_gnt *get_persistent_gnt(struct xen_blkif *blkif, return NULL; } set_bit(PERSISTENT_GNT_ACTIVE, data->flags); - atomic_inc(&blkif->persistent_gnt_in_use); + atomic_inc(&ring->persistent_gnt_in_use); return data; } } return NULL; } -static void put_persistent_gnt(struct xen_blkif *blkif, +static void put_persistent_gnt(struct xen_blkif_ring *ring, struct persistent_gnt *persistent_gnt) { if(!test_bit(PERSISTENT_GNT_ACTIVE, persistent_gnt->flags)) pr_alert_ratelimited("freeing a grant already unused\n"); set_bit(PERSISTENT_GNT_WAS_ACTIVE, persistent_gnt->flags); clear_bit(PERSISTENT_GNT_ACTIVE, persistent_gnt->flags); - atomic_dec(&blkif->persistent_gnt_in_use); + atomic_dec(&ring->persistent_gnt_in_use); } -static void free_persistent_gnts(struct xen_blkif *blkif, struct rb_root *root, +static void free_persistent_gnts(struct xen_blkif_ring *ring, struct rb_root *root, unsigned int num) { struct gnttab_unmap_grant_ref unmap[BLKIF_MAX_SEGMENTS_PER_REQUEST]; @@ -303,7 +314,7 @@ static void free_persistent_gnts(struct xen_blkif *blkif, struct rb_root *root, unmap_data.count = segs_to_unmap; BUG_ON(gnttab_unmap_refs_sync(&unmap_data)); - put_free_pages(blkif, pages, segs_to_unmap); + put_free_pages(ring, pages, segs_to_unmap); segs_to_unmap = 0; } @@ -320,15 +331,15 @@ void xen_blkbk_unmap_purged_grants(struct work_struct *work) struct page *pages[BLKIF_MAX_SEGMENTS_PER_REQUEST]; struct persistent_gnt *persistent_gnt; int segs_to_unmap = 0; - struct xen_blkif *blkif = container_of(work, typeof(*blkif), persistent_purge_work); + struct xen_blkif_ring *ring = container_of(work, typeof(*ring), persistent_purge_work); struct gntab_unmap_queue_data unmap_data; unmap_data.pages = pages; unmap_data.unmap_ops = unmap; unmap_data.kunmap_ops = NULL; - while(!list_empty(&blkif->persistent_purge_list)) { - persistent_gnt = list_first_entry(&blkif->persistent_purge_list, + while(!list_empty(&ring->persistent_purge_list)) { + persistent_gnt = list_first_entry(&ring->persistent_purge_list, struct persistent_gnt, remove_node); list_del(&persistent_gnt->remove_node); @@ -343,7 +354,7 @@ void xen_blkbk_unmap_purged_grants(struct work_struct *work) if (++segs_to_unmap == BLKIF_MAX_SEGMENTS_PER_REQUEST) { unmap_data.count = segs_to_unmap; BUG_ON(gnttab_unmap_refs_sync(&unmap_data)); - put_free_pages(blkif, pages, segs_to_unmap); + put_free_pages(ring, pages, segs_to_unmap); segs_to_unmap = 0; } kfree(persistent_gnt); @@ -351,11 +362,11 @@ void xen_blkbk_unmap_purged_grants(struct work_struct *work) if (segs_to_unmap > 0) { unmap_data.count = segs_to_unmap; BUG_ON(gnttab_unmap_refs_sync(&unmap_data)); - put_free_pages(blkif, pages, segs_to_unmap); + put_free_pages(ring, pages, segs_to_unmap); } } -static void purge_persistent_gnt(struct xen_blkif *blkif) +static void purge_persistent_gnt(struct xen_blkif_ring *ring) { struct persistent_gnt *persistent_gnt; struct rb_node *n; @@ -363,23 +374,23 @@ static void purge_persistent_gnt(struct xen_blkif *blkif) bool scan_used = false, clean_used = false; struct rb_root *root; - if (blkif->persistent_gnt_c < xen_blkif_max_pgrants || - (blkif->persistent_gnt_c == xen_blkif_max_pgrants && - !blkif->vbd.overflow_max_grants)) { - return; + if (ring->persistent_gnt_c < xen_blkif_max_pgrants || + (ring->persistent_gnt_c == xen_blkif_max_pgrants && + !ring->blkif->vbd.overflow_max_grants)) { + goto out; } - if (work_busy(&blkif->persistent_purge_work)) { + if (work_busy(&ring->persistent_purge_work)) { pr_alert_ratelimited("Scheduled work from previous purge is still busy, cannot purge list\n"); - return; + goto out; } num_clean = (xen_blkif_max_pgrants / 100) * LRU_PERCENT_CLEAN; - num_clean = blkif->persistent_gnt_c - xen_blkif_max_pgrants + num_clean; - num_clean = min(blkif->persistent_gnt_c, num_clean); + num_clean = ring->persistent_gnt_c - xen_blkif_max_pgrants + num_clean; + num_clean = min(ring->persistent_gnt_c, num_clean); if ((num_clean == 0) || - (num_clean > (blkif->persistent_gnt_c - atomic_read(&blkif->persistent_gnt_in_use)))) - return; + (num_clean > (ring->persistent_gnt_c - atomic_read(&ring->persistent_gnt_in_use)))) + goto out; /* * At this point, we can assure that there will be no calls @@ -394,8 +405,8 @@ static void purge_persistent_gnt(struct xen_blkif *blkif) pr_debug("Going to purge %u persistent grants\n", num_clean); - BUG_ON(!list_empty(&blkif->persistent_purge_list)); - root = &blkif->persistent_gnts; + BUG_ON(!list_empty(&ring->persistent_purge_list)); + root = &ring->persistent_gnts; purge_list: foreach_grant_safe(persistent_gnt, n, root, node) { BUG_ON(persistent_gnt->handle == @@ -414,7 +425,7 @@ purge_list: rb_erase(&persistent_gnt->node, root); list_add(&persistent_gnt->remove_node, - &blkif->persistent_purge_list); + &ring->persistent_purge_list); if (--num_clean == 0) goto finished; } @@ -435,30 +446,32 @@ finished: goto purge_list; } - blkif->persistent_gnt_c -= (total - num_clean); - blkif->vbd.overflow_max_grants = 0; + ring->persistent_gnt_c -= (total - num_clean); + ring->blkif->vbd.overflow_max_grants = 0; /* We can defer this work */ - schedule_work(&blkif->persistent_purge_work); + schedule_work(&ring->persistent_purge_work); pr_debug("Purged %u/%u\n", (total - num_clean), total); + +out: return; } /* * Retrieve from the 'pending_reqs' a free pending_req structure to be used. */ -static struct pending_req *alloc_req(struct xen_blkif *blkif) +static struct pending_req *alloc_req(struct xen_blkif_ring *ring) { struct pending_req *req = NULL; unsigned long flags; - spin_lock_irqsave(&blkif->pending_free_lock, flags); - if (!list_empty(&blkif->pending_free)) { - req = list_entry(blkif->pending_free.next, struct pending_req, + spin_lock_irqsave(&ring->pending_free_lock, flags); + if (!list_empty(&ring->pending_free)) { + req = list_entry(ring->pending_free.next, struct pending_req, free_list); list_del(&req->free_list); } - spin_unlock_irqrestore(&blkif->pending_free_lock, flags); + spin_unlock_irqrestore(&ring->pending_free_lock, flags); return req; } @@ -466,17 +479,17 @@ static struct pending_req *alloc_req(struct xen_blkif *blkif) * Return the 'pending_req' structure back to the freepool. We also * wake up the thread if it was waiting for a free page. */ -static void free_req(struct xen_blkif *blkif, struct pending_req *req) +static void free_req(struct xen_blkif_ring *ring, struct pending_req *req) { unsigned long flags; int was_empty; - spin_lock_irqsave(&blkif->pending_free_lock, flags); - was_empty = list_empty(&blkif->pending_free); - list_add(&req->free_list, &blkif->pending_free); - spin_unlock_irqrestore(&blkif->pending_free_lock, flags); + spin_lock_irqsave(&ring->pending_free_lock, flags); + was_empty = list_empty(&ring->pending_free); + list_add(&req->free_list, &ring->pending_free); + spin_unlock_irqrestore(&ring->pending_free_lock, flags); if (was_empty) - wake_up(&blkif->pending_free_wq); + wake_up(&ring->pending_free_wq); } /* @@ -556,10 +569,10 @@ abort: /* * Notification from the guest OS. */ -static void blkif_notify_work(struct xen_blkif *blkif) +static void blkif_notify_work(struct xen_blkif_ring *ring) { - blkif->waiting_reqs = 1; - wake_up(&blkif->wq); + ring->waiting_reqs = 1; + wake_up(&ring->wq); } irqreturn_t xen_blkif_be_int(int irq, void *dev_id) @@ -572,31 +585,33 @@ irqreturn_t xen_blkif_be_int(int irq, void *dev_id) * SCHEDULER FUNCTIONS */ -static void print_stats(struct xen_blkif *blkif) +static void print_stats(struct xen_blkif_ring *ring) { pr_info("(%s): oo %3llu | rd %4llu | wr %4llu | f %4llu" " | ds %4llu | pg: %4u/%4d\n", - current->comm, blkif->st_oo_req, - blkif->st_rd_req, blkif->st_wr_req, - blkif->st_f_req, blkif->st_ds_req, - blkif->persistent_gnt_c, + current->comm, ring->st_oo_req, + ring->st_rd_req, ring->st_wr_req, + ring->st_f_req, ring->st_ds_req, + ring->persistent_gnt_c, xen_blkif_max_pgrants); - blkif->st_print = jiffies + msecs_to_jiffies(10 * 1000); - blkif->st_rd_req = 0; - blkif->st_wr_req = 0; - blkif->st_oo_req = 0; - blkif->st_ds_req = 0; + ring->st_print = jiffies + msecs_to_jiffies(10 * 1000); + ring->st_rd_req = 0; + ring->st_wr_req = 0; + ring->st_oo_req = 0; + ring->st_ds_req = 0; } int xen_blkif_schedule(void *arg) { - struct xen_blkif *blkif = arg; + struct xen_blkif_ring *ring = arg; + struct xen_blkif *blkif = ring->blkif; struct xen_vbd *vbd = &blkif->vbd; unsigned long timeout; int ret; xen_blkif_get(blkif); + set_freezable(); while (!kthread_should_stop()) { if (try_to_freeze()) continue; @@ -606,50 +621,50 @@ int xen_blkif_schedule(void *arg) timeout = msecs_to_jiffies(LRU_INTERVAL); timeout = wait_event_interruptible_timeout( - blkif->wq, - blkif->waiting_reqs || kthread_should_stop(), + ring->wq, + ring->waiting_reqs || kthread_should_stop(), timeout); if (timeout == 0) goto purge_gnt_list; timeout = wait_event_interruptible_timeout( - blkif->pending_free_wq, - !list_empty(&blkif->pending_free) || + ring->pending_free_wq, + !list_empty(&ring->pending_free) || kthread_should_stop(), timeout); if (timeout == 0) goto purge_gnt_list; - blkif->waiting_reqs = 0; + ring->waiting_reqs = 0; smp_mb(); /* clear flag *before* checking for work */ - ret = do_block_io_op(blkif); + ret = do_block_io_op(ring); if (ret > 0) - blkif->waiting_reqs = 1; + ring->waiting_reqs = 1; if (ret == -EACCES) - wait_event_interruptible(blkif->shutdown_wq, + wait_event_interruptible(ring->shutdown_wq, kthread_should_stop()); purge_gnt_list: if (blkif->vbd.feature_gnt_persistent && - time_after(jiffies, blkif->next_lru)) { - purge_persistent_gnt(blkif); - blkif->next_lru = jiffies + msecs_to_jiffies(LRU_INTERVAL); + time_after(jiffies, ring->next_lru)) { + purge_persistent_gnt(ring); + ring->next_lru = jiffies + msecs_to_jiffies(LRU_INTERVAL); } /* Shrink if we have more than xen_blkif_max_buffer_pages */ - shrink_free_pagepool(blkif, xen_blkif_max_buffer_pages); + shrink_free_pagepool(ring, xen_blkif_max_buffer_pages); - if (log_stats && time_after(jiffies, blkif->st_print)) - print_stats(blkif); + if (log_stats && time_after(jiffies, ring->st_print)) + print_stats(ring); } /* Drain pending purge work */ - flush_work(&blkif->persistent_purge_work); + flush_work(&ring->persistent_purge_work); if (log_stats) - print_stats(blkif); + print_stats(ring); - blkif->xenblkd = NULL; + ring->xenblkd = NULL; xen_blkif_put(blkif); return 0; @@ -658,22 +673,22 @@ purge_gnt_list: /* * Remove persistent grants and empty the pool of free pages */ -void xen_blkbk_free_caches(struct xen_blkif *blkif) +void xen_blkbk_free_caches(struct xen_blkif_ring *ring) { /* Free all persistent grant pages */ - if (!RB_EMPTY_ROOT(&blkif->persistent_gnts)) - free_persistent_gnts(blkif, &blkif->persistent_gnts, - blkif->persistent_gnt_c); + if (!RB_EMPTY_ROOT(&ring->persistent_gnts)) + free_persistent_gnts(ring, &ring->persistent_gnts, + ring->persistent_gnt_c); - BUG_ON(!RB_EMPTY_ROOT(&blkif->persistent_gnts)); - blkif->persistent_gnt_c = 0; + BUG_ON(!RB_EMPTY_ROOT(&ring->persistent_gnts)); + ring->persistent_gnt_c = 0; /* Since we are shutting down remove all pages from the buffer */ - shrink_free_pagepool(blkif, 0 /* All */); + shrink_free_pagepool(ring, 0 /* All */); } static unsigned int xen_blkbk_unmap_prepare( - struct xen_blkif *blkif, + struct xen_blkif_ring *ring, struct grant_page **pages, unsigned int num, struct gnttab_unmap_grant_ref *unmap_ops, @@ -683,7 +698,7 @@ static unsigned int xen_blkbk_unmap_prepare( for (i = 0; i < num; i++) { if (pages[i]->persistent_gnt != NULL) { - put_persistent_gnt(blkif, pages[i]->persistent_gnt); + put_persistent_gnt(ring, pages[i]->persistent_gnt); continue; } if (pages[i]->handle == BLKBACK_INVALID_HANDLE) @@ -700,17 +715,18 @@ static unsigned int xen_blkbk_unmap_prepare( static void xen_blkbk_unmap_and_respond_callback(int result, struct gntab_unmap_queue_data *data) { - struct pending_req* pending_req = (struct pending_req*) (data->data); - struct xen_blkif *blkif = pending_req->blkif; + struct pending_req *pending_req = (struct pending_req *)(data->data); + struct xen_blkif_ring *ring = pending_req->ring; + struct xen_blkif *blkif = ring->blkif; /* BUG_ON used to reproduce existing behaviour, but is this the best way to deal with this? */ BUG_ON(result); - put_free_pages(blkif, data->pages, data->count); - make_response(blkif, pending_req->id, + put_free_pages(ring, data->pages, data->count); + make_response(ring, pending_req->id, pending_req->operation, pending_req->status); - free_req(blkif, pending_req); + free_req(ring, pending_req); /* * Make sure the request is freed before releasing blkif, * or there could be a race between free_req and the @@ -723,7 +739,7 @@ static void xen_blkbk_unmap_and_respond_callback(int result, struct gntab_unmap_ * pending_free_wq if there's a drain going on, but it has * to be taken into account if the current model is changed. */ - if (atomic_dec_and_test(&blkif->inflight) && atomic_read(&blkif->drain)) { + if (atomic_dec_and_test(&ring->inflight) && atomic_read(&blkif->drain)) { complete(&blkif->drain_complete); } xen_blkif_put(blkif); @@ -732,11 +748,11 @@ static void xen_blkbk_unmap_and_respond_callback(int result, struct gntab_unmap_ static void xen_blkbk_unmap_and_respond(struct pending_req *req) { struct gntab_unmap_queue_data* work = &req->gnttab_unmap_data; - struct xen_blkif *blkif = req->blkif; + struct xen_blkif_ring *ring = req->ring; struct grant_page **pages = req->segments; unsigned int invcount; - invcount = xen_blkbk_unmap_prepare(blkif, pages, req->nr_segs, + invcount = xen_blkbk_unmap_prepare(ring, pages, req->nr_segs, req->unmap, req->unmap_pages); work->data = req; @@ -757,7 +773,7 @@ static void xen_blkbk_unmap_and_respond(struct pending_req *req) * of hypercalls, but since this is only used in error paths there's * no real need. */ -static void xen_blkbk_unmap(struct xen_blkif *blkif, +static void xen_blkbk_unmap(struct xen_blkif_ring *ring, struct grant_page *pages[], int num) { @@ -768,20 +784,20 @@ static void xen_blkbk_unmap(struct xen_blkif *blkif, while (num) { unsigned int batch = min(num, BLKIF_MAX_SEGMENTS_PER_REQUEST); - - invcount = xen_blkbk_unmap_prepare(blkif, pages, batch, + + invcount = xen_blkbk_unmap_prepare(ring, pages, batch, unmap, unmap_pages); if (invcount) { ret = gnttab_unmap_refs(unmap, NULL, unmap_pages, invcount); BUG_ON(ret); - put_free_pages(blkif, unmap_pages, invcount); + put_free_pages(ring, unmap_pages, invcount); } pages += batch; num -= batch; } } -static int xen_blkbk_map(struct xen_blkif *blkif, +static int xen_blkbk_map(struct xen_blkif_ring *ring, struct grant_page *pages[], int num, bool ro) { @@ -794,6 +810,7 @@ static int xen_blkbk_map(struct xen_blkif *blkif, int ret = 0; int last_map = 0, map_until = 0; int use_persistent_gnts; + struct xen_blkif *blkif = ring->blkif; use_persistent_gnts = (blkif->vbd.feature_gnt_persistent); @@ -806,10 +823,11 @@ again: for (i = map_until; i < num; i++) { uint32_t flags; - if (use_persistent_gnts) + if (use_persistent_gnts) { persistent_gnt = get_persistent_gnt( - blkif, + ring, pages[i]->gref); + } if (persistent_gnt) { /* @@ -819,7 +837,7 @@ again: pages[i]->page = persistent_gnt->page; pages[i]->persistent_gnt = persistent_gnt; } else { - if (get_free_page(blkif, &pages[i]->page)) + if (get_free_page(ring, &pages[i]->page)) goto out_of_memory; addr = vaddr(pages[i]->page); pages_to_gnt[segs_to_map] = pages[i]->page; @@ -852,7 +870,7 @@ again: BUG_ON(new_map_idx >= segs_to_map); if (unlikely(map[new_map_idx].status != 0)) { pr_debug("invalid buffer -- could not remap it\n"); - put_free_pages(blkif, &pages[seg_idx]->page, 1); + put_free_pages(ring, &pages[seg_idx]->page, 1); pages[seg_idx]->handle = BLKBACK_INVALID_HANDLE; ret |= 1; goto next; @@ -862,7 +880,7 @@ again: continue; } if (use_persistent_gnts && - blkif->persistent_gnt_c < xen_blkif_max_pgrants) { + ring->persistent_gnt_c < xen_blkif_max_pgrants) { /* * We are using persistent grants, the grant is * not mapped but we might have room for it. @@ -880,7 +898,7 @@ again: persistent_gnt->gnt = map[new_map_idx].ref; persistent_gnt->handle = map[new_map_idx].handle; persistent_gnt->page = pages[seg_idx]->page; - if (add_persistent_gnt(blkif, + if (add_persistent_gnt(ring, persistent_gnt)) { kfree(persistent_gnt); persistent_gnt = NULL; @@ -888,7 +906,7 @@ again: } pages[seg_idx]->persistent_gnt = persistent_gnt; pr_debug("grant %u added to the tree of persistent grants, using %u/%u\n", - persistent_gnt->gnt, blkif->persistent_gnt_c, + persistent_gnt->gnt, ring->persistent_gnt_c, xen_blkif_max_pgrants); goto next; } @@ -913,7 +931,7 @@ next: out_of_memory: pr_alert("%s: out of memory\n", __func__); - put_free_pages(blkif, pages_to_gnt, segs_to_map); + put_free_pages(ring, pages_to_gnt, segs_to_map); return -ENOMEM; } @@ -921,7 +939,7 @@ static int xen_blkbk_map_seg(struct pending_req *pending_req) { int rc; - rc = xen_blkbk_map(pending_req->blkif, pending_req->segments, + rc = xen_blkbk_map(pending_req->ring, pending_req->segments, pending_req->nr_segs, (pending_req->operation != BLKIF_OP_READ)); @@ -934,7 +952,7 @@ static int xen_blkbk_parse_indirect(struct blkif_request *req, struct phys_req *preq) { struct grant_page **pages = pending_req->indirect_pages; - struct xen_blkif *blkif = pending_req->blkif; + struct xen_blkif_ring *ring = pending_req->ring; int indirect_grefs, rc, n, nseg, i; struct blkif_request_segment *segments = NULL; @@ -945,7 +963,7 @@ static int xen_blkbk_parse_indirect(struct blkif_request *req, for (i = 0; i < indirect_grefs; i++) pages[i]->gref = req->u.indirect.indirect_grefs[i]; - rc = xen_blkbk_map(blkif, pages, indirect_grefs, true); + rc = xen_blkbk_map(ring, pages, indirect_grefs, true); if (rc) goto unmap; @@ -972,15 +990,16 @@ static int xen_blkbk_parse_indirect(struct blkif_request *req, unmap: if (segments) kunmap_atomic(segments); - xen_blkbk_unmap(blkif, pages, indirect_grefs); + xen_blkbk_unmap(ring, pages, indirect_grefs); return rc; } -static int dispatch_discard_io(struct xen_blkif *blkif, +static int dispatch_discard_io(struct xen_blkif_ring *ring, struct blkif_request *req) { int err = 0; int status = BLKIF_RSP_OKAY; + struct xen_blkif *blkif = ring->blkif; struct block_device *bdev = blkif->vbd.bdev; unsigned long secure; struct phys_req preq; @@ -997,7 +1016,7 @@ static int dispatch_discard_io(struct xen_blkif *blkif, preq.sector_number + preq.nr_sects, blkif->vbd.pdevice); goto fail_response; } - blkif->st_ds_req++; + ring->st_ds_req++; secure = (blkif->vbd.discard_secure && (req->u.discard.flag & BLKIF_DISCARD_SECURE)) ? @@ -1013,26 +1032,28 @@ fail_response: } else if (err) status = BLKIF_RSP_ERROR; - make_response(blkif, req->u.discard.id, req->operation, status); + make_response(ring, req->u.discard.id, req->operation, status); xen_blkif_put(blkif); return err; } -static int dispatch_other_io(struct xen_blkif *blkif, +static int dispatch_other_io(struct xen_blkif_ring *ring, struct blkif_request *req, struct pending_req *pending_req) { - free_req(blkif, pending_req); - make_response(blkif, req->u.other.id, req->operation, + free_req(ring, pending_req); + make_response(ring, req->u.other.id, req->operation, BLKIF_RSP_EOPNOTSUPP); return -EIO; } -static void xen_blk_drain_io(struct xen_blkif *blkif) +static void xen_blk_drain_io(struct xen_blkif_ring *ring) { + struct xen_blkif *blkif = ring->blkif; + atomic_set(&blkif->drain, 1); do { - if (atomic_read(&blkif->inflight) == 0) + if (atomic_read(&ring->inflight) == 0) break; wait_for_completion_interruptible_timeout( &blkif->drain_complete, HZ); @@ -1053,12 +1074,12 @@ static void __end_block_io_op(struct pending_req *pending_req, int error) if ((pending_req->operation == BLKIF_OP_FLUSH_DISKCACHE) && (error == -EOPNOTSUPP)) { pr_debug("flush diskcache op failed, not supported\n"); - xen_blkbk_flush_diskcache(XBT_NIL, pending_req->blkif->be, 0); + xen_blkbk_flush_diskcache(XBT_NIL, pending_req->ring->blkif->be, 0); pending_req->status = BLKIF_RSP_EOPNOTSUPP; } else if ((pending_req->operation == BLKIF_OP_WRITE_BARRIER) && (error == -EOPNOTSUPP)) { pr_debug("write barrier op failed, not supported\n"); - xen_blkbk_barrier(XBT_NIL, pending_req->blkif->be, 0); + xen_blkbk_barrier(XBT_NIL, pending_req->ring->blkif->be, 0); pending_req->status = BLKIF_RSP_EOPNOTSUPP; } else if (error) { pr_debug("Buffer not up-to-date at end of operation," @@ -1092,9 +1113,9 @@ static void end_block_io_op(struct bio *bio) * and transmute it to the block API to hand it over to the proper block disk. */ static int -__do_block_io_op(struct xen_blkif *blkif) +__do_block_io_op(struct xen_blkif_ring *ring) { - union blkif_back_rings *blk_rings = &blkif->blk_rings; + union blkif_back_rings *blk_rings = &ring->blk_rings; struct blkif_request req; struct pending_req *pending_req; RING_IDX rc, rp; @@ -1107,7 +1128,7 @@ __do_block_io_op(struct xen_blkif *blkif) if (RING_REQUEST_PROD_OVERFLOW(&blk_rings->common, rp)) { rc = blk_rings->common.rsp_prod_pvt; pr_warn("Frontend provided bogus ring requests (%d - %d = %d). Halting ring processing on dev=%04x\n", - rp, rc, rp - rc, blkif->vbd.pdevice); + rp, rc, rp - rc, ring->blkif->vbd.pdevice); return -EACCES; } while (rc != rp) { @@ -1120,14 +1141,14 @@ __do_block_io_op(struct xen_blkif *blkif) break; } - pending_req = alloc_req(blkif); + pending_req = alloc_req(ring); if (NULL == pending_req) { - blkif->st_oo_req++; + ring->st_oo_req++; more_to_do = 1; break; } - switch (blkif->blk_protocol) { + switch (ring->blkif->blk_protocol) { case BLKIF_PROTOCOL_NATIVE: memcpy(&req, RING_GET_REQUEST(&blk_rings->native, rc), sizeof(req)); break; @@ -1151,16 +1172,16 @@ __do_block_io_op(struct xen_blkif *blkif) case BLKIF_OP_WRITE_BARRIER: case BLKIF_OP_FLUSH_DISKCACHE: case BLKIF_OP_INDIRECT: - if (dispatch_rw_block_io(blkif, &req, pending_req)) + if (dispatch_rw_block_io(ring, &req, pending_req)) goto done; break; case BLKIF_OP_DISCARD: - free_req(blkif, pending_req); - if (dispatch_discard_io(blkif, &req)) + free_req(ring, pending_req); + if (dispatch_discard_io(ring, &req)) goto done; break; default: - if (dispatch_other_io(blkif, &req, pending_req)) + if (dispatch_other_io(ring, &req, pending_req)) goto done; break; } @@ -1173,13 +1194,13 @@ done: } static int -do_block_io_op(struct xen_blkif *blkif) +do_block_io_op(struct xen_blkif_ring *ring) { - union blkif_back_rings *blk_rings = &blkif->blk_rings; + union blkif_back_rings *blk_rings = &ring->blk_rings; int more_to_do; do { - more_to_do = __do_block_io_op(blkif); + more_to_do = __do_block_io_op(ring); if (more_to_do) break; @@ -1192,7 +1213,7 @@ do_block_io_op(struct xen_blkif *blkif) * Transmutation of the 'struct blkif_request' to a proper 'struct bio' * and call the 'submit_bio' to pass it to the underlying storage. */ -static int dispatch_rw_block_io(struct xen_blkif *blkif, +static int dispatch_rw_block_io(struct xen_blkif_ring *ring, struct blkif_request *req, struct pending_req *pending_req) { @@ -1220,17 +1241,17 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif, switch (req_operation) { case BLKIF_OP_READ: - blkif->st_rd_req++; + ring->st_rd_req++; operation = READ; break; case BLKIF_OP_WRITE: - blkif->st_wr_req++; + ring->st_wr_req++; operation = WRITE_ODIRECT; break; case BLKIF_OP_WRITE_BARRIER: drain = true; case BLKIF_OP_FLUSH_DISKCACHE: - blkif->st_f_req++; + ring->st_f_req++; operation = WRITE_FLUSH; break; default: @@ -1255,7 +1276,7 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif, preq.nr_sects = 0; - pending_req->blkif = blkif; + pending_req->ring = ring; pending_req->id = req->u.rw.id; pending_req->operation = req_operation; pending_req->status = BLKIF_RSP_OKAY; @@ -1282,12 +1303,12 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif, goto fail_response; } - if (xen_vbd_translate(&preq, blkif, operation) != 0) { + if (xen_vbd_translate(&preq, ring->blkif, operation) != 0) { pr_debug("access denied: %s of [%llu,%llu] on dev=%04x\n", operation == READ ? "read" : "write", preq.sector_number, preq.sector_number + preq.nr_sects, - blkif->vbd.pdevice); + ring->blkif->vbd.pdevice); goto fail_response; } @@ -1299,7 +1320,7 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif, if (((int)preq.sector_number|(int)seg[i].nsec) & ((bdev_logical_block_size(preq.bdev) >> 9) - 1)) { pr_debug("Misaligned I/O request from domain %d\n", - blkif->domid); + ring->blkif->domid); goto fail_response; } } @@ -1308,7 +1329,7 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif, * issue the WRITE_FLUSH. */ if (drain) - xen_blk_drain_io(pending_req->blkif); + xen_blk_drain_io(pending_req->ring); /* * If we have failed at this point, we need to undo the M2P override, @@ -1323,8 +1344,8 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif, * This corresponding xen_blkif_put is done in __end_block_io_op, or * below (in "!bio") if we are handling a BLKIF_OP_DISCARD. */ - xen_blkif_get(blkif); - atomic_inc(&blkif->inflight); + xen_blkif_get(ring->blkif); + atomic_inc(&ring->inflight); for (i = 0; i < nseg; i++) { while ((bio == NULL) || @@ -1372,19 +1393,19 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif, blk_finish_plug(&plug); if (operation == READ) - blkif->st_rd_sect += preq.nr_sects; + ring->st_rd_sect += preq.nr_sects; else if (operation & WRITE) - blkif->st_wr_sect += preq.nr_sects; + ring->st_wr_sect += preq.nr_sects; return 0; fail_flush: - xen_blkbk_unmap(blkif, pending_req->segments, + xen_blkbk_unmap(ring, pending_req->segments, pending_req->nr_segs); fail_response: /* Haven't submitted any bio's yet. */ - make_response(blkif, req->u.rw.id, req_operation, BLKIF_RSP_ERROR); - free_req(blkif, pending_req); + make_response(ring, req->u.rw.id, req_operation, BLKIF_RSP_ERROR); + free_req(ring, pending_req); msleep(1); /* back off a bit */ return -EIO; @@ -1402,21 +1423,22 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif, /* * Put a response on the ring on how the operation fared. */ -static void make_response(struct xen_blkif *blkif, u64 id, +static void make_response(struct xen_blkif_ring *ring, u64 id, unsigned short op, int st) { struct blkif_response resp; unsigned long flags; - union blkif_back_rings *blk_rings = &blkif->blk_rings; + union blkif_back_rings *blk_rings; int notify; resp.id = id; resp.operation = op; resp.status = st; - spin_lock_irqsave(&blkif->blk_ring_lock, flags); + spin_lock_irqsave(&ring->blk_ring_lock, flags); + blk_rings = &ring->blk_rings; /* Place on the response ring for the relevant domain. */ - switch (blkif->blk_protocol) { + switch (ring->blkif->blk_protocol) { case BLKIF_PROTOCOL_NATIVE: memcpy(RING_GET_RESPONSE(&blk_rings->native, blk_rings->native.rsp_prod_pvt), &resp, sizeof(resp)); @@ -1434,9 +1456,9 @@ static void make_response(struct xen_blkif *blkif, u64 id, } blk_rings->common.rsp_prod_pvt++; RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&blk_rings->common, notify); - spin_unlock_irqrestore(&blkif->blk_ring_lock, flags); + spin_unlock_irqrestore(&ring->blk_ring_lock, flags); if (notify) - notify_remote_via_irq(blkif->irq); + notify_remote_via_irq(ring->irq); } static int __init xen_blkif_init(void) @@ -1452,6 +1474,9 @@ static int __init xen_blkif_init(void) xen_blkif_max_ring_order = XENBUS_MAX_RING_GRANT_ORDER; } + if (xenblk_max_queues == 0) + xenblk_max_queues = num_online_cpus(); + rc = xen_blkif_interface_init(); if (rc) goto failed_init; diff --git a/drivers/block/xen-blkback/common.h b/drivers/block/xen-blkback/common.h index 68e87a037b99..b27c5ba15600 100644 --- a/drivers/block/xen-blkback/common.h +++ b/drivers/block/xen-blkback/common.h @@ -46,6 +46,7 @@ #include <xen/interface/io/protocols.h> extern unsigned int xen_blkif_max_ring_order; +extern unsigned int xenblk_max_queues; /* * This is the maximum number of segments that would be allowed in indirect * requests. This value will also be passed to the frontend. @@ -269,68 +270,79 @@ struct persistent_gnt { struct list_head remove_node; }; -struct xen_blkif { - /* Unique identifier for this interface. */ - domid_t domid; - unsigned int handle; +/* Per-ring information. */ +struct xen_blkif_ring { /* Physical parameters of the comms window. */ unsigned int irq; - /* Comms information. */ - enum blkif_protocol blk_protocol; union blkif_back_rings blk_rings; void *blk_ring; - /* The VBD attached to this interface. */ - struct xen_vbd vbd; - /* Back pointer to the backend_info. */ - struct backend_info *be; /* Private fields. */ spinlock_t blk_ring_lock; - atomic_t refcnt; wait_queue_head_t wq; - /* for barrier (drain) requests */ - struct completion drain_complete; - atomic_t drain; atomic_t inflight; - /* One thread per one blkif. */ + /* One thread per blkif ring. */ struct task_struct *xenblkd; unsigned int waiting_reqs; - /* tree to store persistent grants */ + /* List of all 'pending_req' available */ + struct list_head pending_free; + /* And its spinlock. */ + spinlock_t pending_free_lock; + wait_queue_head_t pending_free_wq; + + /* Tree to store persistent grants. */ + spinlock_t pers_gnts_lock; struct rb_root persistent_gnts; unsigned int persistent_gnt_c; atomic_t persistent_gnt_in_use; unsigned long next_lru; - /* used by the kworker that offload work from the persistent purge */ + /* Statistics. */ + unsigned long st_print; + unsigned long long st_rd_req; + unsigned long long st_wr_req; + unsigned long long st_oo_req; + unsigned long long st_f_req; + unsigned long long st_ds_req; + unsigned long long st_rd_sect; + unsigned long long st_wr_sect; + + /* Used by the kworker that offload work from the persistent purge. */ struct list_head persistent_purge_list; struct work_struct persistent_purge_work; - /* buffer of free pages to map grant refs */ + /* Buffer of free pages to map grant refs. */ spinlock_t free_pages_lock; int free_pages_num; struct list_head free_pages; - /* List of all 'pending_req' available */ - struct list_head pending_free; - /* And its spinlock. */ - spinlock_t pending_free_lock; - wait_queue_head_t pending_free_wq; - - /* statistics */ - unsigned long st_print; - unsigned long long st_rd_req; - unsigned long long st_wr_req; - unsigned long long st_oo_req; - unsigned long long st_f_req; - unsigned long long st_ds_req; - unsigned long long st_rd_sect; - unsigned long long st_wr_sect; - struct work_struct free_work; /* Thread shutdown wait queue. */ wait_queue_head_t shutdown_wq; - unsigned int nr_ring_pages; + struct xen_blkif *blkif; +}; + +struct xen_blkif { + /* Unique identifier for this interface. */ + domid_t domid; + unsigned int handle; + /* Comms information. */ + enum blkif_protocol blk_protocol; + /* The VBD attached to this interface. */ + struct xen_vbd vbd; + /* Back pointer to the backend_info. */ + struct backend_info *be; + atomic_t refcnt; + /* for barrier (drain) requests */ + struct completion drain_complete; + atomic_t drain; + + struct work_struct free_work; + unsigned int nr_ring_pages; + /* All rings for this device. */ + struct xen_blkif_ring *rings; + unsigned int nr_rings; }; struct seg_buf { @@ -352,7 +364,7 @@ struct grant_page { * response queued for it, with the saved 'id' passed back. */ struct pending_req { - struct xen_blkif *blkif; + struct xen_blkif_ring *ring; u64 id; int nr_segs; atomic_t pendcnt; @@ -394,7 +406,7 @@ int xen_blkif_xenbus_init(void); irqreturn_t xen_blkif_be_int(int irq, void *dev_id); int xen_blkif_schedule(void *arg); int xen_blkif_purge_persistent(void *arg); -void xen_blkbk_free_caches(struct xen_blkif *blkif); +void xen_blkbk_free_caches(struct xen_blkif_ring *ring); int xen_blkbk_flush_diskcache(struct xenbus_transaction xbt, struct backend_info *be, int state); diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c index f53cff42f8da..876763f7f13e 100644 --- a/drivers/block/xen-blkback/xenbus.c +++ b/drivers/block/xen-blkback/xenbus.c @@ -86,9 +86,11 @@ static void xen_update_blkif_status(struct xen_blkif *blkif) { int err; char name[BLKBACK_NAME_LEN]; + struct xen_blkif_ring *ring; + int i; /* Not ready to connect? */ - if (!blkif->irq || !blkif->vbd.bdev) + if (!blkif->rings || !blkif->rings[0].irq || !blkif->vbd.bdev) return; /* Already connected? */ @@ -113,13 +115,55 @@ static void xen_update_blkif_status(struct xen_blkif *blkif) } invalidate_inode_pages2(blkif->vbd.bdev->bd_inode->i_mapping); - blkif->xenblkd = kthread_run(xen_blkif_schedule, blkif, "%s", name); - if (IS_ERR(blkif->xenblkd)) { - err = PTR_ERR(blkif->xenblkd); - blkif->xenblkd = NULL; - xenbus_dev_error(blkif->be->dev, err, "start xenblkd"); - return; + for (i = 0; i < blkif->nr_rings; i++) { + ring = &blkif->rings[i]; + ring->xenblkd = kthread_run(xen_blkif_schedule, ring, "%s-%d", name, i); + if (IS_ERR(ring->xenblkd)) { + err = PTR_ERR(ring->xenblkd); + ring->xenblkd = NULL; + xenbus_dev_fatal(blkif->be->dev, err, + "start %s-%d xenblkd", name, i); + goto out; + } + } + return; + +out: + while (--i >= 0) { + ring = &blkif->rings[i]; + kthread_stop(ring->xenblkd); + } + return; +} + +static int xen_blkif_alloc_rings(struct xen_blkif *blkif) +{ + unsigned int r; + + blkif->rings = kzalloc(blkif->nr_rings * sizeof(struct xen_blkif_ring), GFP_KERNEL); + if (!blkif->rings) + return -ENOMEM; + + for (r = 0; r < blkif->nr_rings; r++) { + struct xen_blkif_ring *ring = &blkif->rings[r]; + + spin_lock_init(&ring->blk_ring_lock); + init_waitqueue_head(&ring->wq); + INIT_LIST_HEAD(&ring->pending_free); + INIT_LIST_HEAD(&ring->persistent_purge_list); + INIT_WORK(&ring->persistent_purge_work, xen_blkbk_unmap_purged_grants); + spin_lock_init(&ring->free_pages_lock); + INIT_LIST_HEAD(&ring->free_pages); + + spin_lock_init(&ring->pending_free_lock); + init_waitqueue_head(&ring->pending_free_wq); + init_waitqueue_head(&ring->shutdown_wq); + ring->blkif = blkif; + ring->st_print = jiffies; + xen_blkif_get(blkif); } + + return 0; } static struct xen_blkif *xen_blkif_alloc(domid_t domid) @@ -133,41 +177,25 @@ static struct xen_blkif *xen_blkif_alloc(domid_t domid) return ERR_PTR(-ENOMEM); blkif->domid = domid; - spin_lock_init(&blkif->blk_ring_lock); atomic_set(&blkif->refcnt, 1); - init_waitqueue_head(&blkif->wq); init_completion(&blkif->drain_complete); - atomic_set(&blkif->drain, 0); - blkif->st_print = jiffies; - blkif->persistent_gnts.rb_node = NULL; - spin_lock_init(&blkif->free_pages_lock); - INIT_LIST_HEAD(&blkif->free_pages); - INIT_LIST_HEAD(&blkif->persistent_purge_list); - blkif->free_pages_num = 0; - atomic_set(&blkif->persistent_gnt_in_use, 0); - atomic_set(&blkif->inflight, 0); - INIT_WORK(&blkif->persistent_purge_work, xen_blkbk_unmap_purged_grants); - - INIT_LIST_HEAD(&blkif->pending_free); INIT_WORK(&blkif->free_work, xen_blkif_deferred_free); - spin_lock_init(&blkif->pending_free_lock); - init_waitqueue_head(&blkif->pending_free_wq); - init_waitqueue_head(&blkif->shutdown_wq); return blkif; } -static int xen_blkif_map(struct xen_blkif *blkif, grant_ref_t *gref, +static int xen_blkif_map(struct xen_blkif_ring *ring, grant_ref_t *gref, unsigned int nr_grefs, unsigned int evtchn) { int err; + struct xen_blkif *blkif = ring->blkif; /* Already connected through? */ - if (blkif->irq) + if (ring->irq) return 0; err = xenbus_map_ring_valloc(blkif->be->dev, gref, nr_grefs, - &blkif->blk_ring); + &ring->blk_ring); if (err < 0) return err; @@ -175,24 +203,24 @@ static int xen_blkif_map(struct xen_blkif *blkif, grant_ref_t *gref, case BLKIF_PROTOCOL_NATIVE: { struct blkif_sring *sring; - sring = (struct blkif_sring *)blkif->blk_ring; - BACK_RING_INIT(&blkif->blk_rings.native, sring, + sring = (struct blkif_sring *)ring->blk_ring; + BACK_RING_INIT(&ring->blk_rings.native, sring, XEN_PAGE_SIZE * nr_grefs); break; } case BLKIF_PROTOCOL_X86_32: { struct blkif_x86_32_sring *sring_x86_32; - sring_x86_32 = (struct blkif_x86_32_sring *)blkif->blk_ring; - BACK_RING_INIT(&blkif->blk_rings.x86_32, sring_x86_32, + sring_x86_32 = (struct blkif_x86_32_sring *)ring->blk_ring; + BACK_RING_INIT(&ring->blk_rings.x86_32, sring_x86_32, XEN_PAGE_SIZE * nr_grefs); break; } case BLKIF_PROTOCOL_X86_64: { struct blkif_x86_64_sring *sring_x86_64; - sring_x86_64 = (struct blkif_x86_64_sring *)blkif->blk_ring; - BACK_RING_INIT(&blkif->blk_rings.x86_64, sring_x86_64, + sring_x86_64 = (struct blkif_x86_64_sring *)ring->blk_ring; + BACK_RING_INIT(&ring->blk_rings.x86_64, sring_x86_64, XEN_PAGE_SIZE * nr_grefs); break; } @@ -202,13 +230,13 @@ static int xen_blkif_map(struct xen_blkif *blkif, grant_ref_t *gref, err = bind_interdomain_evtchn_to_irqhandler(blkif->domid, evtchn, xen_blkif_be_int, 0, - "blkif-backend", blkif); + "blkif-backend", ring); if (err < 0) { - xenbus_unmap_ring_vfree(blkif->be->dev, blkif->blk_ring); - blkif->blk_rings.common.sring = NULL; + xenbus_unmap_ring_vfree(blkif->be->dev, ring->blk_ring); + ring->blk_rings.common.sring = NULL; return err; } - blkif->irq = err; + ring->irq = err; return 0; } @@ -216,50 +244,69 @@ static int xen_blkif_map(struct xen_blkif *blkif, grant_ref_t *gref, static int xen_blkif_disconnect(struct xen_blkif *blkif) { struct pending_req *req, *n; - int i = 0, j; + unsigned int j, r; - if (blkif->xenblkd) { - kthread_stop(blkif->xenblkd); - wake_up(&blkif->shutdown_wq); - blkif->xenblkd = NULL; - } + for (r = 0; r < blkif->nr_rings; r++) { + struct xen_blkif_ring *ring = &blkif->rings[r]; + unsigned int i = 0; - /* The above kthread_stop() guarantees that at this point we - * don't have any discard_io or other_io requests. So, checking - * for inflight IO is enough. - */ - if (atomic_read(&blkif->inflight) > 0) - return -EBUSY; + if (ring->xenblkd) { + kthread_stop(ring->xenblkd); + wake_up(&ring->shutdown_wq); + ring->xenblkd = NULL; + } - if (blkif->irq) { - unbind_from_irqhandler(blkif->irq, blkif); - blkif->irq = 0; - } + /* The above kthread_stop() guarantees that at this point we + * don't have any discard_io or other_io requests. So, checking + * for inflight IO is enough. + */ + if (atomic_read(&ring->inflight) > 0) + return -EBUSY; - if (blkif->blk_rings.common.sring) { - xenbus_unmap_ring_vfree(blkif->be->dev, blkif->blk_ring); - blkif->blk_rings.common.sring = NULL; - } + if (ring->irq) { + unbind_from_irqhandler(ring->irq, ring); + ring->irq = 0; + } - /* Remove all persistent grants and the cache of ballooned pages. */ - xen_blkbk_free_caches(blkif); + if (ring->blk_rings.common.sring) { + xenbus_unmap_ring_vfree(blkif->be->dev, ring->blk_ring); + ring->blk_rings.common.sring = NULL; + } - /* Check that there is no request in use */ - list_for_each_entry_safe(req, n, &blkif->pending_free, free_list) { - list_del(&req->free_list); + /* Remove all persistent grants and the cache of ballooned pages. */ + xen_blkbk_free_caches(ring); - for (j = 0; j < MAX_INDIRECT_SEGMENTS; j++) - kfree(req->segments[j]); + /* Check that there is no request in use */ + list_for_each_entry_safe(req, n, &ring->pending_free, free_list) { + list_del(&req->free_list); - for (j = 0; j < MAX_INDIRECT_PAGES; j++) - kfree(req->indirect_pages[j]); + for (j = 0; j < MAX_INDIRECT_SEGMENTS; j++) + kfree(req->segments[j]); - kfree(req); - i++; - } + for (j = 0; j < MAX_INDIRECT_PAGES; j++) + kfree(req->indirect_pages[j]); + + kfree(req); + i++; + } - WARN_ON(i != (XEN_BLKIF_REQS_PER_PAGE * blkif->nr_ring_pages)); + BUG_ON(atomic_read(&ring->persistent_gnt_in_use) != 0); + BUG_ON(!list_empty(&ring->persistent_purge_list)); + BUG_ON(!RB_EMPTY_ROOT(&ring->persistent_gnts)); + BUG_ON(!list_empty(&ring->free_pages)); + BUG_ON(ring->free_pages_num != 0); + BUG_ON(ring->persistent_gnt_c != 0); + WARN_ON(i != (XEN_BLKIF_REQS_PER_PAGE * blkif->nr_ring_pages)); + xen_blkif_put(blkif); + } blkif->nr_ring_pages = 0; + /* + * blkif->rings was allocated in connect_ring, so we should free it in + * here. + */ + kfree(blkif->rings); + blkif->rings = NULL; + blkif->nr_rings = 0; return 0; } @@ -271,13 +318,6 @@ static void xen_blkif_free(struct xen_blkif *blkif) xen_vbd_free(&blkif->vbd); /* Make sure everything is drained before shutting down */ - BUG_ON(blkif->persistent_gnt_c != 0); - BUG_ON(atomic_read(&blkif->persistent_gnt_in_use) != 0); - BUG_ON(blkif->free_pages_num != 0); - BUG_ON(!list_empty(&blkif->persistent_purge_list)); - BUG_ON(!list_empty(&blkif->free_pages)); - BUG_ON(!RB_EMPTY_ROOT(&blkif->persistent_gnts)); - kmem_cache_free(xen_blkif_cachep, blkif); } @@ -296,25 +336,38 @@ int __init xen_blkif_interface_init(void) * sysfs interface for VBD I/O requests */ -#define VBD_SHOW(name, format, args...) \ +#define VBD_SHOW_ALLRING(name, format) \ static ssize_t show_##name(struct device *_dev, \ struct device_attribute *attr, \ char *buf) \ { \ struct xenbus_device *dev = to_xenbus_device(_dev); \ struct backend_info *be = dev_get_drvdata(&dev->dev); \ + struct xen_blkif *blkif = be->blkif; \ + unsigned int i; \ + unsigned long long result = 0; \ \ - return sprintf(buf, format, ##args); \ + if (!blkif->rings) \ + goto out; \ + \ + for (i = 0; i < blkif->nr_rings; i++) { \ + struct xen_blkif_ring *ring = &blkif->rings[i]; \ + \ + result += ring->st_##name; \ + } \ + \ +out: \ + return sprintf(buf, format, result); \ } \ static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL) -VBD_SHOW(oo_req, "%llu\n", be->blkif->st_oo_req); -VBD_SHOW(rd_req, "%llu\n", be->blkif->st_rd_req); -VBD_SHOW(wr_req, "%llu\n", be->blkif->st_wr_req); -VBD_SHOW(f_req, "%llu\n", be->blkif->st_f_req); -VBD_SHOW(ds_req, "%llu\n", be->blkif->st_ds_req); -VBD_SHOW(rd_sect, "%llu\n", be->blkif->st_rd_sect); -VBD_SHOW(wr_sect, "%llu\n", be->blkif->st_wr_sect); +VBD_SHOW_ALLRING(oo_req, "%llu\n"); +VBD_SHOW_ALLRING(rd_req, "%llu\n"); +VBD_SHOW_ALLRING(wr_req, "%llu\n"); +VBD_SHOW_ALLRING(f_req, "%llu\n"); +VBD_SHOW_ALLRING(ds_req, "%llu\n"); +VBD_SHOW_ALLRING(rd_sect, "%llu\n"); +VBD_SHOW_ALLRING(wr_sect, "%llu\n"); static struct attribute *xen_vbdstat_attrs[] = { &dev_attr_oo_req.attr, @@ -332,6 +385,18 @@ static struct attribute_group xen_vbdstat_group = { .attrs = xen_vbdstat_attrs, }; +#define VBD_SHOW(name, format, args...) \ + static ssize_t show_##name(struct device *_dev, \ + struct device_attribute *attr, \ + char *buf) \ + { \ + struct xenbus_device *dev = to_xenbus_device(_dev); \ + struct backend_info *be = dev_get_drvdata(&dev->dev); \ + \ + return sprintf(buf, format, ##args); \ + } \ + static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL) + VBD_SHOW(physical_device, "%x:%x\n", be->major, be->minor); VBD_SHOW(mode, "%s\n", be->mode); @@ -440,11 +505,11 @@ static int xen_blkbk_remove(struct xenbus_device *dev) dev_set_drvdata(&dev->dev, NULL); - if (be->blkif) { + if (be->blkif) xen_blkif_disconnect(be->blkif); - xen_blkif_put(be->blkif); - } + /* Put the reference we set in xen_blkif_alloc(). */ + xen_blkif_put(be->blkif); kfree(be->mode); kfree(be); return 0; @@ -553,6 +618,12 @@ static int xen_blkbk_probe(struct xenbus_device *dev, goto fail; } + /* Multi-queue: advertise how many queues are supported by us.*/ + err = xenbus_printf(XBT_NIL, dev->nodename, + "multi-queue-max-queues", "%u", xenblk_max_queues); + if (err) + pr_warn("Error writing multi-queue-max-queues\n"); + /* setup back pointer */ be->blkif->be = be; @@ -708,8 +779,14 @@ static void frontend_changed(struct xenbus_device *dev, } err = connect_ring(be); - if (err) + if (err) { + /* + * Clean up so that memory resources can be used by + * other devices. connect_ring reported already error. + */ + xen_blkif_disconnect(be->blkif); break; + } xen_update_blkif_status(be->blkif); break; @@ -825,50 +902,43 @@ again: xenbus_transaction_end(xbt, 1); } - -static int connect_ring(struct backend_info *be) +/* + * Each ring may have multi pages, depends on "ring-page-order". + */ +static int read_per_ring_refs(struct xen_blkif_ring *ring, const char *dir) { - struct xenbus_device *dev = be->dev; unsigned int ring_ref[XENBUS_MAX_RING_GRANTS]; - unsigned int evtchn, nr_grefs, ring_page_order; - unsigned int pers_grants; - char protocol[64] = ""; struct pending_req *req, *n; int err, i, j; + struct xen_blkif *blkif = ring->blkif; + struct xenbus_device *dev = blkif->be->dev; + unsigned int ring_page_order, nr_grefs, evtchn; - pr_debug("%s %s\n", __func__, dev->otherend); - - err = xenbus_scanf(XBT_NIL, dev->otherend, "event-channel", "%u", + err = xenbus_scanf(XBT_NIL, dir, "event-channel", "%u", &evtchn); if (err != 1) { err = -EINVAL; - xenbus_dev_fatal(dev, err, "reading %s/event-channel", - dev->otherend); + xenbus_dev_fatal(dev, err, "reading %s/event-channel", dir); return err; } - pr_info("event-channel %u\n", evtchn); err = xenbus_scanf(XBT_NIL, dev->otherend, "ring-page-order", "%u", &ring_page_order); if (err != 1) { - err = xenbus_scanf(XBT_NIL, dev->otherend, "ring-ref", - "%u", &ring_ref[0]); + err = xenbus_scanf(XBT_NIL, dir, "ring-ref", "%u", &ring_ref[0]); if (err != 1) { err = -EINVAL; - xenbus_dev_fatal(dev, err, "reading %s/ring-ref", - dev->otherend); + xenbus_dev_fatal(dev, err, "reading %s/ring-ref", dir); return err; } nr_grefs = 1; - pr_info("%s:using single page: ring-ref %d\n", dev->otherend, - ring_ref[0]); } else { unsigned int i; if (ring_page_order > xen_blkif_max_ring_order) { err = -EINVAL; xenbus_dev_fatal(dev, err, "%s/request %d ring page order exceed max:%d", - dev->otherend, ring_page_order, + dir, ring_page_order, xen_blkif_max_ring_order); return err; } @@ -878,52 +948,23 @@ static int connect_ring(struct backend_info *be) char ring_ref_name[RINGREF_NAME_LEN]; snprintf(ring_ref_name, RINGREF_NAME_LEN, "ring-ref%u", i); - err = xenbus_scanf(XBT_NIL, dev->otherend, ring_ref_name, + err = xenbus_scanf(XBT_NIL, dir, ring_ref_name, "%u", &ring_ref[i]); if (err != 1) { err = -EINVAL; xenbus_dev_fatal(dev, err, "reading %s/%s", - dev->otherend, ring_ref_name); + dir, ring_ref_name); return err; } - pr_info("ring-ref%u: %u\n", i, ring_ref[i]); } } - - be->blkif->blk_protocol = BLKIF_PROTOCOL_DEFAULT; - err = xenbus_gather(XBT_NIL, dev->otherend, "protocol", - "%63s", protocol, NULL); - if (err) - strcpy(protocol, "unspecified, assuming default"); - else if (0 == strcmp(protocol, XEN_IO_PROTO_ABI_NATIVE)) - be->blkif->blk_protocol = BLKIF_PROTOCOL_NATIVE; - else if (0 == strcmp(protocol, XEN_IO_PROTO_ABI_X86_32)) - be->blkif->blk_protocol = BLKIF_PROTOCOL_X86_32; - else if (0 == strcmp(protocol, XEN_IO_PROTO_ABI_X86_64)) - be->blkif->blk_protocol = BLKIF_PROTOCOL_X86_64; - else { - xenbus_dev_fatal(dev, err, "unknown fe protocol %s", protocol); - return -1; - } - err = xenbus_gather(XBT_NIL, dev->otherend, - "feature-persistent", "%u", - &pers_grants, NULL); - if (err) - pers_grants = 0; - - be->blkif->vbd.feature_gnt_persistent = pers_grants; - be->blkif->vbd.overflow_max_grants = 0; - be->blkif->nr_ring_pages = nr_grefs; - - pr_info("ring-pages:%d, event-channel %d, protocol %d (%s) %s\n", - nr_grefs, evtchn, be->blkif->blk_protocol, protocol, - pers_grants ? "persistent grants" : ""); + blkif->nr_ring_pages = nr_grefs; for (i = 0; i < nr_grefs * XEN_BLKIF_REQS_PER_PAGE; i++) { req = kzalloc(sizeof(*req), GFP_KERNEL); if (!req) goto fail; - list_add_tail(&req->free_list, &be->blkif->pending_free); + list_add_tail(&req->free_list, &ring->pending_free); for (j = 0; j < MAX_INDIRECT_SEGMENTS; j++) { req->segments[j] = kzalloc(sizeof(*req->segments[0]), GFP_KERNEL); if (!req->segments[j]) @@ -938,7 +979,7 @@ static int connect_ring(struct backend_info *be) } /* Map the shared frame, irq etc. */ - err = xen_blkif_map(be->blkif, ring_ref, nr_grefs, evtchn); + err = xen_blkif_map(ring, ring_ref, nr_grefs, evtchn); if (err) { xenbus_dev_fatal(dev, err, "mapping ring-ref port %u", evtchn); return err; @@ -947,7 +988,7 @@ static int connect_ring(struct backend_info *be) return 0; fail: - list_for_each_entry_safe(req, n, &be->blkif->pending_free, free_list) { + list_for_each_entry_safe(req, n, &ring->pending_free, free_list) { list_del(&req->free_list); for (j = 0; j < MAX_INDIRECT_SEGMENTS; j++) { if (!req->segments[j]) @@ -962,6 +1003,93 @@ fail: kfree(req); } return -ENOMEM; + +} + +static int connect_ring(struct backend_info *be) +{ + struct xenbus_device *dev = be->dev; + unsigned int pers_grants; + char protocol[64] = ""; + int err, i; + char *xspath; + size_t xspathsize; + const size_t xenstore_path_ext_size = 11; /* sufficient for "/queue-NNN" */ + unsigned int requested_num_queues = 0; + + pr_debug("%s %s\n", __func__, dev->otherend); + + be->blkif->blk_protocol = BLKIF_PROTOCOL_DEFAULT; + err = xenbus_gather(XBT_NIL, dev->otherend, "protocol", + "%63s", protocol, NULL); + if (err) + strcpy(protocol, "unspecified, assuming default"); + else if (0 == strcmp(protocol, XEN_IO_PROTO_ABI_NATIVE)) + be->blkif->blk_protocol = BLKIF_PROTOCOL_NATIVE; + else if (0 == strcmp(protocol, XEN_IO_PROTO_ABI_X86_32)) + be->blkif->blk_protocol = BLKIF_PROTOCOL_X86_32; + else if (0 == strcmp(protocol, XEN_IO_PROTO_ABI_X86_64)) + be->blkif->blk_protocol = BLKIF_PROTOCOL_X86_64; + else { + xenbus_dev_fatal(dev, err, "unknown fe protocol %s", protocol); + return -ENOSYS; + } + err = xenbus_gather(XBT_NIL, dev->otherend, + "feature-persistent", "%u", + &pers_grants, NULL); + if (err) + pers_grants = 0; + + be->blkif->vbd.feature_gnt_persistent = pers_grants; + be->blkif->vbd.overflow_max_grants = 0; + + /* + * Read the number of hardware queues from frontend. + */ + err = xenbus_scanf(XBT_NIL, dev->otherend, "multi-queue-num-queues", + "%u", &requested_num_queues); + if (err < 0) { + requested_num_queues = 1; + } else { + if (requested_num_queues > xenblk_max_queues + || requested_num_queues == 0) { + /* Buggy or malicious guest. */ + xenbus_dev_fatal(dev, err, + "guest requested %u queues, exceeding the maximum of %u.", + requested_num_queues, xenblk_max_queues); + return -ENOSYS; + } + } + be->blkif->nr_rings = requested_num_queues; + if (xen_blkif_alloc_rings(be->blkif)) + return -ENOMEM; + + pr_info("%s: using %d queues, protocol %d (%s) %s\n", dev->nodename, + be->blkif->nr_rings, be->blkif->blk_protocol, protocol, + pers_grants ? "persistent grants" : ""); + + if (be->blkif->nr_rings == 1) + return read_per_ring_refs(&be->blkif->rings[0], dev->otherend); + else { + xspathsize = strlen(dev->otherend) + xenstore_path_ext_size; + xspath = kmalloc(xspathsize, GFP_KERNEL); + if (!xspath) { + xenbus_dev_fatal(dev, -ENOMEM, "reading ring references"); + return -ENOMEM; + } + + for (i = 0; i < be->blkif->nr_rings; i++) { + memset(xspath, 0, xspathsize); + snprintf(xspath, xspathsize, "%s/queue-%u", dev->otherend, i); + err = read_per_ring_refs(&be->blkif->rings[i], xspath); + if (err) { + kfree(xspath); + return err; + } + } + kfree(xspath); + } + return 0; } static const struct xenbus_device_id xen_blkbk_ids[] = { diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index 2fee2eef988d..8a8dc91c39f7 100644 --- a/drivers/block/xen-blkfront.c +++ b/drivers/block/xen-blkfront.c @@ -60,6 +60,20 @@ #include <asm/xen/hypervisor.h> +/* + * The minimal size of segment supported by the block framework is PAGE_SIZE. + * When Linux is using a different page size than Xen, it may not be possible + * to put all the data in a single segment. + * This can happen when the backend doesn't support indirect descriptor and + * therefore the maximum amount of data that a request can carry is + * BLKIF_MAX_SEGMENTS_PER_REQUEST * XEN_PAGE_SIZE = 44KB + * + * Note that we only support one extra request. So the Linux page size + * should be <= ( 2 * BLKIF_MAX_SEGMENTS_PER_REQUEST * XEN_PAGE_SIZE) = + * 88KB. + */ +#define HAS_EXTRA_REQ (BLKIF_MAX_SEGMENTS_PER_REQUEST < XEN_PFN_PER_PAGE) + enum blkif_state { BLKIF_STATE_DISCONNECTED, BLKIF_STATE_CONNECTED, @@ -72,6 +86,13 @@ struct grant { struct list_head node; }; +enum blk_req_status { + REQ_WAITING, + REQ_DONE, + REQ_ERROR, + REQ_EOPNOTSUPP, +}; + struct blk_shadow { struct blkif_request req; struct request *request; @@ -79,6 +100,14 @@ struct blk_shadow { struct grant **indirect_grants; struct scatterlist *sg; unsigned int num_sg; + enum blk_req_status status; + + #define NO_ASSOCIATED_ID ~0UL + /* + * Id of the sibling if we ever need 2 requests when handling a + * block I/O request + */ + unsigned long associated_id; }; struct split_bio { @@ -99,6 +128,10 @@ static unsigned int xen_blkif_max_segments = 32; module_param_named(max, xen_blkif_max_segments, int, S_IRUGO); MODULE_PARM_DESC(max, "Maximum amount of segments in indirect requests (default is 32)"); +static unsigned int xen_blkif_max_queues = 4; +module_param_named(max_queues, xen_blkif_max_queues, uint, S_IRUGO); +MODULE_PARM_DESC(max_queues, "Maximum number of hardware queues/rings used per virtual disk"); + /* * Maximum order of pages to be used for the shared ring between front and * backend, 4KB page granularity is used. @@ -114,10 +147,35 @@ MODULE_PARM_DESC(max_ring_page_order, "Maximum order of pages to be used for the __CONST_RING_SIZE(blkif, XEN_PAGE_SIZE * XENBUS_MAX_RING_GRANTS) /* - * ring-ref%i i=(-1UL) would take 11 characters + 'ring-ref' is 8, so 19 - * characters are enough. Define to 20 to keep consist with backend. + * ring-ref%u i=(-1UL) would take 11 characters + 'ring-ref' is 8, so 19 + * characters are enough. Define to 20 to keep consistent with backend. */ #define RINGREF_NAME_LEN (20) +/* + * queue-%u would take 7 + 10(UINT_MAX) = 17 characters. + */ +#define QUEUE_NAME_LEN (17) + +/* + * 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 { + /* Lock to protect data in every ring buffer. */ + spinlock_t ring_lock; + 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; + struct list_head grants; + unsigned int persistent_gnts_c; + unsigned long shadow_free; + struct blkfront_info *dev_info; +}; /* * We have one of these per vbd, whether ide, scsi or 'other'. They @@ -126,25 +184,15 @@ MODULE_PARM_DESC(max_ring_page_order, "Maximum order of pages to be used for the */ struct blkfront_info { - spinlock_t io_lock; struct mutex mutex; struct xenbus_device *xbdev; struct gendisk *gd; int vdevice; blkif_vdev_t handle; enum blkif_state connected; - int ring_ref[XENBUS_MAX_RING_GRANTS]; + /* Number of pages per ring buffer. */ 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 +203,8 @@ struct blkfront_info unsigned int max_indirect_segments; int is_ready; struct blk_mq_tag_set tag_set; + struct blkfront_ring_info *rinfo; + unsigned int nr_rings; }; static unsigned int nr_minors; @@ -198,38 +248,40 @@ static DEFINE_SPINLOCK(minor_lock); #define GREFS(_psegs) ((_psegs) * GRANTS_PER_PSEG) -static int blkfront_setup_indirect(struct blkfront_info *info); -static int blkfront_gather_backend_features(struct blkfront_info *info); +static int blkfront_setup_indirect(struct blkfront_ring_info *rinfo); +static void 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, - unsigned long id) +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; - while(i < num) { + while (i < num) { gnt_list_entry = kzalloc(sizeof(struct grant), GFP_NOIO); if (!gnt_list_entry) goto out_of_memory; @@ -244,7 +296,7 @@ static int fill_grant_buffer(struct blkfront_info *info, int num) } gnt_list_entry->gref = GRANT_INVALID_REF; - list_add(&gnt_list_entry->node, &info->grants); + list_add(&gnt_list_entry->node, &rinfo->grants); i++; } @@ -252,7 +304,7 @@ static int fill_grant_buffer(struct blkfront_info *info, int num) out_of_memory: list_for_each_entry_safe(gnt_list_entry, n, - &info->grants, node) { + &rinfo->grants, node) { list_del(&gnt_list_entry->node); if (info->feature_persistent) __free_page(gnt_list_entry->page); @@ -263,17 +315,17 @@ out_of_memory: return -ENOMEM; } -static struct grant *get_free_grant(struct blkfront_info *info) +static struct grant *get_free_grant(struct blkfront_ring_info *rinfo) { struct grant *gnt_list_entry; - BUG_ON(list_empty(&info->grants)); - gnt_list_entry = list_first_entry(&info->grants, struct grant, + BUG_ON(list_empty(&rinfo->grants)); + gnt_list_entry = list_first_entry(&rinfo->grants, struct grant, node); list_del(&gnt_list_entry->node); if (gnt_list_entry->gref != GRANT_INVALID_REF) - info->persistent_gnts_c--; + rinfo->persistent_gnts_c--; return gnt_list_entry; } @@ -289,9 +341,10 @@ static inline void grant_foreign_access(const struct grant *gnt_list_entry, static struct grant *get_grant(grant_ref_t *gref_head, unsigned long gfn, - struct blkfront_info *info) + struct blkfront_ring_info *rinfo) { - struct grant *gnt_list_entry = get_free_grant(info); + struct grant *gnt_list_entry = get_free_grant(rinfo); + struct blkfront_info *info = rinfo->dev_info; if (gnt_list_entry->gref != GRANT_INVALID_REF) return gnt_list_entry; @@ -312,9 +365,10 @@ static struct grant *get_grant(grant_ref_t *gref_head, } static struct grant *get_indirect_grant(grant_ref_t *gref_head, - struct blkfront_info *info) + struct blkfront_ring_info *rinfo) { - struct grant *gnt_list_entry = get_free_grant(info); + struct grant *gnt_list_entry = get_free_grant(rinfo); + struct blkfront_info *info = rinfo->dev_info; if (gnt_list_entry->gref != GRANT_INVALID_REF) return gnt_list_entry; @@ -326,8 +380,8 @@ 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(&rinfo->indirect_pages)); + indirect_page = list_first_entry(&rinfo->indirect_pages, struct page, lru); list_del(&indirect_page->lru); gnt_list_entry->page = indirect_page; @@ -403,8 +457,8 @@ 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 +510,33 @@ static int blkif_ioctl(struct block_device *bdev, fmode_t mode, return 0; } -static int blkif_queue_discard_req(struct request *req) +static unsigned long blkif_ring_get_request(struct blkfront_ring_info *rinfo, + struct request *req, + struct blkif_request **ring_req) { - struct blkfront_info *info = req->rq_disk->private_data; + unsigned long id; + + *ring_req = RING_GET_REQUEST(&rinfo->ring, rinfo->ring.req_prod_pvt); + rinfo->ring.req_prod_pvt++; + + id = get_id_from_freelist(rinfo); + rinfo->shadow[id].request = req; + rinfo->shadow[id].status = REQ_WAITING; + rinfo->shadow[id].associated_id = NO_ASSOCIATED_ID; + + (*ring_req)->u.rw.id = id; + + return id; +} + +static int blkif_queue_discard_req(struct request *req, struct blkfront_ring_info *rinfo) +{ + 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; + id = blkif_ring_get_request(rinfo, req, &ring_req); ring_req->operation = BLKIF_OP_DISCARD; ring_req->u.discard.nr_sectors = blk_rq_sectors(req); @@ -476,10 +547,8 @@ static int blkif_queue_discard_req(struct request *req) else ring_req->u.discard.flag = 0; - info->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 +556,7 @@ 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; @@ -495,6 +564,9 @@ struct setup_rw_req { bool need_copy; unsigned int bvec_off; char *bvec_data; + + bool require_extra_req; + struct blkif_request *extra_ring_req; }; static void blkif_setup_rw_req_grant(unsigned long gfn, unsigned int offset, @@ -507,8 +579,24 @@ 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; + /* + * We always use the shadow of the first request to store the list + * of grant associated to the block I/O request. This made the + * completion more easy to handle even if the block I/O request is + * split. + */ + struct blk_shadow *shadow = &rinfo->shadow[setup->id]; + + if (unlikely(setup->require_extra_req && + grant_idx >= BLKIF_MAX_SEGMENTS_PER_REQUEST)) { + /* + * We are using the second request, setup grant_idx + * to be the index of the segment array. + */ + grant_idx -= BLKIF_MAX_SEGMENTS_PER_REQUEST; + ring_req = setup->extra_ring_req; + } if ((ring_req->operation == BLKIF_OP_INDIRECT) && (grant_idx % GRANTS_PER_INDIRECT_FRAME == 0)) { @@ -516,15 +604,19 @@ static void blkif_setup_rw_req_grant(unsigned long gfn, unsigned int offset, kunmap_atomic(setup->segments); n = grant_idx / GRANTS_PER_INDIRECT_FRAME; - gnt_list_entry = get_indirect_grant(&setup->gref_head, info); + gnt_list_entry = get_indirect_grant(&setup->gref_head, rinfo); shadow->indirect_grants[n] = gnt_list_entry; setup->segments = kmap_atomic(gnt_list_entry->page); ring_req->u.indirect.indirect_grefs[n] = gnt_list_entry->gref; } - gnt_list_entry = get_grant(&setup->gref_head, gfn, info); + gnt_list_entry = get_grant(&setup->gref_head, gfn, rinfo); ref = gnt_list_entry->gref; - shadow->grants_used[grant_idx] = gnt_list_entry; + /* + * All the grants are stored in the shadow of the first + * request. Therefore we have to use the global index. + */ + shadow->grants_used[setup->grant_idx] = gnt_list_entry; if (setup->need_copy) { void *shared_data; @@ -566,16 +658,36 @@ 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 void blkif_setup_extra_req(struct blkif_request *first, + struct blkif_request *second) { - struct blkfront_info *info = req->rq_disk->private_data; - struct blkif_request *ring_req; - unsigned long id; + uint16_t nr_segments = first->u.rw.nr_segments; + + /* + * The second request is only present when the first request uses + * all its segments. It's always the continuity of the first one. + */ + first->u.rw.nr_segments = BLKIF_MAX_SEGMENTS_PER_REQUEST; + + second->u.rw.nr_segments = nr_segments - BLKIF_MAX_SEGMENTS_PER_REQUEST; + second->u.rw.sector_number = first->u.rw.sector_number + + (BLKIF_MAX_SEGMENTS_PER_REQUEST * XEN_PAGE_SIZE) / 512; + + second->u.rw.handle = first->u.rw.handle; + second->operation = first->operation; +} + +static int blkif_queue_rw_req(struct request *req, struct blkfront_ring_info *rinfo) +{ + struct blkfront_info *info = rinfo->dev_info; + struct blkif_request *ring_req, *extra_ring_req = NULL; + unsigned long id, extra_id = NO_ASSOCIATED_ID; + bool require_extra_req = false; 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, }; @@ -584,7 +696,6 @@ static int blkif_queue_rw_req(struct request *req) * existing persistent grants, or if we have to get new grants, * as there are not sufficiently many free. */ - bool new_persistent_gnts; struct scatterlist *sg; int num_sg, max_grefs, num_grant; @@ -596,41 +707,36 @@ static int blkif_queue_rw_req(struct request *req) */ max_grefs += INDIRECT_GREFS(max_grefs); - /* Check if we have enough grants to allocate a requests */ - if (info->persistent_gnts_c < max_grefs) { - new_persistent_gnts = 1; - if (gnttab_alloc_grant_references( - max_grefs - info->persistent_gnts_c, - &setup.gref_head) < 0) { + /* + * We have to reserve 'max_grefs' grants because persistent + * grants are shared by all rings. + */ + if (max_grefs > 0) + if (gnttab_alloc_grant_references(max_grefs, &setup.gref_head) < 0) { gnttab_request_free_callback( - &info->callback, + &rinfo->callback, blkif_restart_queue_callback, - info, + rinfo, max_grefs); return 1; } - } else - 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; - - 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); + id = blkif_ring_get_request(rinfo, req, &ring_req); - 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; - if (num_grant > BLKIF_MAX_SEGMENTS_PER_REQUEST) { + require_extra_req = info->max_indirect_segments == 0 && + num_grant > BLKIF_MAX_SEGMENTS_PER_REQUEST; + BUG_ON(!HAS_EXTRA_REQ && require_extra_req); + + rinfo->shadow[id].num_sg = num_sg; + if (num_grant > BLKIF_MAX_SEGMENTS_PER_REQUEST && + likely(!require_extra_req)) { /* * The indirect operation can only be a BLKIF_OP_READ or * BLKIF_OP_WRITE @@ -670,11 +776,31 @@ static int blkif_queue_rw_req(struct request *req) } } ring_req->u.rw.nr_segments = num_grant; + if (unlikely(require_extra_req)) { + extra_id = blkif_ring_get_request(rinfo, req, + &extra_ring_req); + /* + * Only the first request contains the scatter-gather + * list. + */ + rinfo->shadow[extra_id].num_sg = 0; + + blkif_setup_extra_req(ring_req, extra_ring_req); + + /* Link the 2 requests together */ + rinfo->shadow[extra_id].associated_id = id; + rinfo->shadow[id].associated_id = extra_id; + } } setup.ring_req = ring_req; setup.id = id; - for_each_sg(info->shadow[id].sg, sg, num_sg, i) { + + setup.require_extra_req = require_extra_req; + if (unlikely(require_extra_req)) + setup.extra_ring_req = extra_ring_req; + + for_each_sg(rinfo->shadow[id].sg, sg, num_sg, i) { BUG_ON(sg->offset + sg->length > PAGE_SIZE); if (setup.need_copy) { @@ -694,12 +820,12 @@ static int blkif_queue_rw_req(struct request *req) if (setup.segments) kunmap_atomic(setup.segments); - info->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 (unlikely(require_extra_req)) + rinfo->shadow[extra_id].req = *extra_ring_req; - if (new_persistent_gnts) + if (max_grefs > 0) gnttab_free_grant_references(setup.gref_head); return 0; @@ -711,27 +837,25 @@ 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, @@ -745,38 +869,50 @@ 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) + const struct blk_mq_queue_data *qd) { - struct blkfront_info *info = qd->rq->rq_disk->private_data; + unsigned long flags; + struct blkfront_ring_info *rinfo = (struct blkfront_ring_info *)hctx->driver_data; blk_mq_start_request(qd->rq); - spin_lock_irq(&info->io_lock); - if (RING_FULL(&info->ring)) + spin_lock_irqsave(&rinfo->ring_lock, flags); + 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); - spin_unlock_irq(&info->io_lock); + flush_requests(rinfo); + spin_unlock_irqrestore(&rinfo->ring_lock, flags); return BLK_MQ_RQ_QUEUE_OK; out_err: - spin_unlock_irq(&info->io_lock); + spin_unlock_irqrestore(&rinfo->ring_lock, flags); return BLK_MQ_RQ_QUEUE_ERROR; out_busy: - spin_unlock_irq(&info->io_lock); + spin_unlock_irqrestore(&rinfo->ring_lock, flags); blk_mq_stop_hw_queue(hctx); 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, @@ -788,19 +924,28 @@ static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size, memset(&info->tag_set, 0, sizeof(info->tag_set)); info->tag_set.ops = &blkfront_mq_ops; - info->tag_set.nr_hw_queues = 1; - info->tag_set.queue_depth = BLK_RING_SIZE(info); + info->tag_set.nr_hw_queues = info->nr_rings; + if (HAS_EXTRA_REQ && info->max_indirect_segments == 0) { + /* + * When indirect descriptior is not supported, the I/O request + * will be split between multiple request in the ring. + * To avoid problems when sending the request, divide by + * 2 the depth of the queue. + */ + info->tag_set.queue_depth = BLK_RING_SIZE(info) / 2; + } else + info->tag_set.queue_depth = BLK_RING_SIZE(info); info->tag_set.numa_node = NUMA_NO_NODE; info->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE; info->tag_set.cmd_size = 0; info->tag_set.driver_data = info; if (blk_mq_alloc_tag_set(&info->tag_set)) - return -1; + return -EINVAL; rq = blk_mq_init_queue(&info->tag_set); if (IS_ERR(rq)) { blk_mq_free_tag_set(&info->tag_set); - return -1; + return PTR_ERR(rq); } queue_flag_set_unlocked(QUEUE_FLAG_VIRT, rq); @@ -1028,7 +1173,7 @@ static int xlvbd_alloc_gendisk(blkif_sector_t capacity, static void xlvbd_release_gendisk(struct blkfront_info *info) { - unsigned int minor, nr_minors; + unsigned int minor, nr_minors, i; if (info->rq == NULL) return; @@ -1036,11 +1181,15 @@ static void xlvbd_release_gendisk(struct blkfront_info *info) /* No more blkif_request(). */ blk_mq_stop_hw_queues(info->rq); - /* No more gnttab callback work. */ - gnttab_cancel_free_callback(&info->callback); + for (i = 0; i < info->nr_rings; i++) { + struct blkfront_ring_info *rinfo = &info->rinfo[i]; - /* Flush gnttab callback work. Must be done with no locks held. */ - flush_work(&info->work); + /* No more gnttab callback work. */ + gnttab_cancel_free_callback(&rinfo->callback); + + /* Flush gnttab callback work. Must be done with no locks held. */ + flush_work(&rinfo->work); + } del_gendisk(info->gd); @@ -1056,88 +1205,87 @@ static void xlvbd_release_gendisk(struct blkfront_info *info) info->gd = NULL; } -/* Must be called with io_lock holded */ -static void kick_pending_request_queues(struct blkfront_info *info) +/* Already hold rinfo->ring_lock. */ +static inline void kick_pending_request_queues_locked(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) +static void kick_pending_request_queues(struct blkfront_ring_info *rinfo) { - struct blkfront_info *info = container_of(work, struct blkfront_info, work); + unsigned long flags; - 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_irqsave(&rinfo->ring_lock, flags); + kick_pending_request_queues_locked(rinfo); + spin_unlock_irqrestore(&rinfo->ring_lock, flags); } -static void blkif_free(struct blkfront_info *info, int suspend) +static void blkif_restart_queue(struct work_struct *work) { - struct grant *persistent_gnt; - struct grant *n; - int i, j, segs; + struct blkfront_ring_info *rinfo = container_of(work, struct blkfront_ring_info, work); - /* Prevent new requests being issued until we fix things up. */ - spin_lock_irq(&info->io_lock); - info->connected = suspend ? - BLKIF_STATE_SUSPENDED : BLKIF_STATE_DISCONNECTED; - /* No more blkif_request(). */ - if (info->rq) - blk_mq_stop_hw_queues(info->rq); + if (rinfo->dev_info->connected == BLKIF_STATE_CONNECTED) + kick_pending_request_queues(rinfo); +} - /* Remove all persistent grants */ - if (!list_empty(&info->grants)) { - list_for_each_entry_safe(persistent_gnt, n, - &info->grants, node) { - list_del(&persistent_gnt->node); - if (persistent_gnt->gref != GRANT_INVALID_REF) { - gnttab_end_foreign_access(persistent_gnt->gref, - 0, 0UL); - info->persistent_gnts_c--; - } - if (info->feature_persistent) - __free_page(persistent_gnt->page); - kfree(persistent_gnt); - } - } - BUG_ON(info->persistent_gnts_c != 0); +static void blkif_free_ring(struct blkfront_ring_info *rinfo) +{ + struct grant *persistent_gnt, *n; + struct blkfront_info *info = rinfo->dev_info; + int i, j, segs; /* * 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); } } + /* Remove all persistent grants. */ + if (!list_empty(&rinfo->grants)) { + list_for_each_entry_safe(persistent_gnt, n, + &rinfo->grants, node) { + list_del(&persistent_gnt->node); + if (persistent_gnt->gref != GRANT_INVALID_REF) { + gnttab_end_foreign_access(persistent_gnt->gref, + 0, 0UL); + rinfo->persistent_gnts_c--; + } + if (info->feature_persistent) + __free_page(persistent_gnt->page); + kfree(persistent_gnt); + } + } + BUG_ON(rinfo->persistent_gnts_c != 0); + for (i = 0; i < BLK_RING_SIZE(info); i++) { /* * 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 @@ -1145,42 +1293,59 @@ 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); - spin_unlock_irq(&info->io_lock); + 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); /* 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; +} +static void blkif_free(struct blkfront_info *info, int suspend) +{ + unsigned int i; + + /* Prevent new requests being issued until we fix things up. */ + info->connected = suspend ? + BLKIF_STATE_SUSPENDED : BLKIF_STATE_DISCONNECTED; + /* No more blkif_request(). */ + if (info->rq) + blk_mq_stop_hw_queues(info->rq); + + for (i = 0; i < info->nr_rings; i++) + blkif_free_ring(&info->rinfo[i]); + + kfree(info->rinfo); + info->rinfo = NULL; + info->nr_rings = 0; } struct copy_from_grant { @@ -1209,19 +1374,93 @@ 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 enum blk_req_status blkif_rsp_to_req_status(int rsp) +{ + switch (rsp) + { + case BLKIF_RSP_OKAY: + return REQ_DONE; + case BLKIF_RSP_EOPNOTSUPP: + return REQ_EOPNOTSUPP; + case BLKIF_RSP_ERROR: + /* Fallthrough. */ + default: + return REQ_ERROR; + } +} + +/* + * Get the final status of the block request based on two ring response + */ +static int blkif_get_final_status(enum blk_req_status s1, + enum blk_req_status s2) +{ + BUG_ON(s1 == REQ_WAITING); + BUG_ON(s2 == REQ_WAITING); + + if (s1 == REQ_ERROR || s2 == REQ_ERROR) + return BLKIF_RSP_ERROR; + else if (s1 == REQ_EOPNOTSUPP || s2 == REQ_EOPNOTSUPP) + return BLKIF_RSP_EOPNOTSUPP; + return BLKIF_RSP_OKAY; +} + +static bool blkif_completion(unsigned long *id, + 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 blk_shadow *s = &rinfo->shadow[*id]; struct copy_from_grant data = { - .s = s, .grant_idx = 0, }; num_grant = s->req.operation == BLKIF_OP_INDIRECT ? s->req.u.indirect.nr_segments : s->req.u.rw.nr_segments; + + /* The I/O request may be split in two. */ + if (unlikely(s->associated_id != NO_ASSOCIATED_ID)) { + struct blk_shadow *s2 = &rinfo->shadow[s->associated_id]; + + /* Keep the status of the current response in shadow. */ + s->status = blkif_rsp_to_req_status(bret->status); + + /* Wait the second response if not yet here. */ + if (s2->status == REQ_WAITING) + return 0; + + bret->status = blkif_get_final_status(s->status, + s2->status); + + /* + * All the grants is stored in the first shadow in order + * to make the completion code simpler. + */ + num_grant += s2->req.u.rw.nr_segments; + + /* + * The two responses may not come in order. Only the + * first request will store the scatter-gather list. + */ + if (s2->num_sg != 0) { + /* Update "id" with the ID of the first response. */ + *id = s->associated_id; + s = s2; + } + + /* + * We don't need anymore the second request, so recycling + * it now. + */ + if (add_id_to_freelist(rinfo, s->associated_id)) + WARN(1, "%s: can't recycle the second part (id = %ld) of the request\n", + info->gd->disk_name, s->associated_id); + } + + data.s = s; num_sg = s->num_sg; if (bret->operation == BLKIF_OP_READ && info->feature_persistent) { @@ -1252,8 +1491,8 @@ static void blkif_completion(struct blk_shadow *s, struct blkfront_info *info, if (!info->feature_persistent) pr_alert_ratelimited("backed has not unmapped grant: %u\n", s->grants_used[i]->gref); - list_add(&s->grants_used[i]->node, &info->grants); - info->persistent_gnts_c++; + list_add(&s->grants_used[i]->node, &rinfo->grants); + rinfo->persistent_gnts_c++; } else { /* * If the grant is not mapped by the backend we end the @@ -1263,7 +1502,7 @@ static void blkif_completion(struct blk_shadow *s, struct blkfront_info *info, */ gnttab_end_foreign_access(s->grants_used[i]->gref, 0, 0UL); s->grants_used[i]->gref = GRANT_INVALID_REF; - list_add_tail(&s->grants_used[i]->node, &info->grants); + list_add_tail(&s->grants_used[i]->node, &rinfo->grants); } } if (s->req.operation == BLKIF_OP_INDIRECT) { @@ -1272,8 +1511,8 @@ static void blkif_completion(struct blk_shadow *s, struct blkfront_info *info, if (!info->feature_persistent) pr_alert_ratelimited("backed has not unmapped grant: %u\n", s->indirect_grants[i]->gref); - list_add(&s->indirect_grants[i]->node, &info->grants); - info->persistent_gnts_c++; + list_add(&s->indirect_grants[i]->node, &rinfo->grants); + rinfo->persistent_gnts_c++; } else { struct page *indirect_page; @@ -1284,13 +1523,15 @@ 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); + list_add_tail(&s->indirect_grants[i]->node, &rinfo->grants); } } } + + return 1; } static irqreturn_t blkif_interrupt(int irq, void *dev_id) @@ -1299,24 +1540,22 @@ 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); - - if (unlikely(info->connected != BLKIF_STATE_CONNECTED)) { - spin_unlock_irqrestore(&info->io_lock, flags); + if (unlikely(info->connected != BLKIF_STATE_CONNECTED)) return IRQ_HANDLED; - } + spin_lock_irqsave(&rinfo->ring_lock, flags); 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 +1569,18 @@ 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); + if (bret->operation != BLKIF_OP_DISCARD) { + /* + * We may need to wait for an extra response if the + * I/O request is split in 2 + */ + if (!blkif_completion(&id, rinfo, bret)) + continue; + } - 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 +1609,7 @@ 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; @@ -1389,34 +1634,35 @@ 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_locked(rinfo); - spin_unlock_irqrestore(&info->io_lock, flags); + spin_unlock_irqrestore(&rinfo->ring_lock, flags); return IRQ_HANDLED; } 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 +1671,29 @@ 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: @@ -1455,6 +1701,53 @@ fail: return err; } +/* + * Write out per-ring/queue nodes including ring-ref and event-channel, and each + * ring buffer may have multi pages depending on ->nr_ring_pages. + */ +static int write_per_ring_nodes(struct xenbus_transaction xbt, + struct blkfront_ring_info *rinfo, const char *dir) +{ + int err; + unsigned int i; + const char *message = NULL; + struct blkfront_info *info = rinfo->dev_info; + + if (info->nr_ring_pages == 1) { + err = xenbus_printf(xbt, dir, "ring-ref", "%u", rinfo->ring_ref[0]); + if (err) { + message = "writing ring-ref"; + goto abort_transaction; + } + } else { + for (i = 0; i < info->nr_ring_pages; i++) { + char ring_ref_name[RINGREF_NAME_LEN]; + + snprintf(ring_ref_name, RINGREF_NAME_LEN, "ring-ref%u", i); + err = xenbus_printf(xbt, dir, ring_ref_name, + "%u", rinfo->ring_ref[i]); + if (err) { + message = "writing ring-ref"; + goto abort_transaction; + } + } + } + + err = xenbus_printf(xbt, dir, "event-channel", "%u", rinfo->evtchn); + if (err) { + message = "writing event-channel"; + goto abort_transaction; + } + + return 0; + +abort_transaction: + xenbus_transaction_end(xbt, 1); + if (message) + xenbus_dev_fatal(info->xbdev, err, "%s", message); + + return err; +} /* Common code used when first setting up, and when resuming. */ static int talk_to_blkback(struct xenbus_device *dev, @@ -1462,8 +1755,8 @@ static int talk_to_blkback(struct xenbus_device *dev, { const char *message = NULL; struct xenbus_transaction xbt; - int err, i; - unsigned int max_page_order = 0; + int err; + unsigned int i, max_page_order = 0; unsigned int ring_page_order = 0; err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, @@ -1475,10 +1768,14 @@ static int talk_to_blkback(struct xenbus_device *dev, info->nr_ring_pages = 1 << ring_page_order; } - /* Create shared ring, alloc event channel. */ - err = setup_blkring(dev, info); - if (err) - goto out; + for (i = 0; i < info->nr_rings; i++) { + struct blkfront_ring_info *rinfo = &info->rinfo[i]; + + /* Create shared ring, alloc event channel. */ + err = setup_blkring(dev, rinfo); + if (err) + goto destroy_blkring; + } again: err = xenbus_transaction_start(&xbt); @@ -1487,38 +1784,49 @@ again: goto destroy_blkring; } - if (info->nr_ring_pages == 1) { - err = xenbus_printf(xbt, dev->nodename, - "ring-ref", "%u", info->ring_ref[0]); + if (info->nr_ring_pages > 1) { + err = xenbus_printf(xbt, dev->nodename, "ring-page-order", "%u", + ring_page_order); if (err) { - message = "writing ring-ref"; + message = "writing ring-page-order"; goto abort_transaction; } + } + + /* We already got the number of queues/rings in _probe */ + if (info->nr_rings == 1) { + err = write_per_ring_nodes(xbt, &info->rinfo[0], dev->nodename); + if (err) + goto destroy_blkring; } else { - err = xenbus_printf(xbt, dev->nodename, - "ring-page-order", "%u", ring_page_order); + char *path; + size_t pathsize; + + err = xenbus_printf(xbt, dev->nodename, "multi-queue-num-queues", "%u", + info->nr_rings); if (err) { - message = "writing ring-page-order"; + message = "writing multi-queue-num-queues"; goto abort_transaction; } - for (i = 0; i < info->nr_ring_pages; i++) { - char ring_ref_name[RINGREF_NAME_LEN]; + pathsize = strlen(dev->nodename) + QUEUE_NAME_LEN; + path = kmalloc(pathsize, GFP_KERNEL); + if (!path) { + err = -ENOMEM; + message = "ENOMEM while writing ring references"; + goto abort_transaction; + } - 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]); + for (i = 0; i < info->nr_rings; i++) { + memset(path, 0, pathsize); + snprintf(path, pathsize, "%s/queue-%u", dev->nodename, i); + err = write_per_ring_nodes(xbt, &info->rinfo[i], path); if (err) { - message = "writing ring-ref"; - goto abort_transaction; + kfree(path); + goto destroy_blkring; } } - } - err = xenbus_printf(xbt, dev->nodename, - "event-channel", "%u", info->evtchn); - if (err) { - message = "writing event-channel"; - goto abort_transaction; + kfree(path); } err = xenbus_printf(xbt, dev->nodename, "protocol", "%s", XEN_IO_PROTO_ABI_NATIVE); @@ -1540,9 +1848,14 @@ again: goto destroy_blkring; } - 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; + for (i = 0; i < info->nr_rings; i++) { + unsigned int j; + struct blkfront_ring_info *rinfo = &info->rinfo[i]; + + for (j = 0; j < BLK_RING_SIZE(info); j++) + rinfo->shadow[j].req.u.rw.id = j + 1; + rinfo->shadow[BLK_RING_SIZE(info)-1].req.u.rw.id = 0x0fffffff; + } xenbus_switch_state(dev, XenbusStateInitialised); return 0; @@ -1553,7 +1866,10 @@ again: xenbus_dev_fatal(dev, err, "%s", message); destroy_blkring: blkif_free(info, 0); - out: + + kfree(info); + dev_set_drvdata(&dev->dev, NULL); + return err; } @@ -1567,7 +1883,9 @@ static int blkfront_probe(struct xenbus_device *dev, const struct xenbus_device_id *id) { int err, vdevice; + unsigned int r_index; struct blkfront_info *info; + unsigned int backend_max_queues = 0; /* FIXME: Use dynamic device id if this is not set. */ err = xenbus_scanf(XBT_NIL, dev->nodename, @@ -1617,15 +1935,39 @@ static int blkfront_probe(struct xenbus_device *dev, return -ENOMEM; } - mutex_init(&info->mutex); - spin_lock_init(&info->io_lock); info->xbdev = dev; + /* Check if backend supports multiple queues. */ + err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, + "multi-queue-max-queues", "%u", &backend_max_queues); + if (err < 0) + backend_max_queues = 1; + + info->nr_rings = min(backend_max_queues, xen_blkif_max_queues); + /* We need at least one ring. */ + if (!info->nr_rings) + info->nr_rings = 1; + + info->rinfo = kzalloc(sizeof(struct blkfront_ring_info) * info->nr_rings, GFP_KERNEL); + if (!info->rinfo) { + xenbus_dev_fatal(dev, -ENOMEM, "allocating ring_info structure"); + kfree(info); + return -ENOMEM; + } + + for (r_index = 0; r_index < info->nr_rings; r_index++) { + struct blkfront_ring_info *rinfo; + + rinfo = &info->rinfo[r_index]; + INIT_LIST_HEAD(&rinfo->indirect_pages); + INIT_LIST_HEAD(&rinfo->grants); + rinfo->dev_info = info; + INIT_WORK(&rinfo->work, blkif_restart_queue); + spin_lock_init(&rinfo->ring_lock); + } + + mutex_init(&info->mutex); 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); @@ -1649,7 +1991,7 @@ static void split_bio_end(struct bio *bio) static int blkif_recover(struct blkfront_info *info) { - int i; + unsigned int i, r_index; struct request *req, *n; struct blk_shadow *copy; int rc; @@ -1660,64 +2002,73 @@ static int blkif_recover(struct blkfront_info *info) struct split_bio *split_bio; struct list_head requests; - /* Stage 1: Make a safe copy of the shadow state. */ - copy = kmemdup(info->shadow, sizeof(info->shadow), - GFP_NOIO | __GFP_REPEAT | __GFP_HIGH); - if (!copy) - return -ENOMEM; - - /* Stage 2: Set up free list. */ - memset(&info->shadow, 0, sizeof(info->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; - - rc = blkfront_gather_backend_features(info); - if (rc) { - kfree(copy); - return rc; - } - + 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 (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 (copy[i].request->cmd_flags & - (REQ_FLUSH | REQ_FUA | REQ_DISCARD | REQ_SECURE)) { + 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; + + rc = blkfront_setup_indirect(rinfo); + if (rc) { + kfree(copy); + return rc; + } + + for (i = 0; i < BLK_RING_SIZE(info); i++) { + /* Not in use? */ + if (!copy[i].request) + continue; + /* - * Flush operations don't contain bios, so - * we need to requeue the whole request + * Get the bios in the request so we can re-queue them. */ - list_add(©[i].request->queuelist, &requests); - continue; + if (copy[i].request->cmd_flags & + (REQ_FLUSH | REQ_FUA | REQ_DISCARD | REQ_SECURE)) { + /* + * Flush operations don't contain bios, so + * we need to requeue the whole request + */ + list_add(©[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); } - 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); + kfree(copy); + } xenbus_switch_state(info->xbdev, XenbusStateConnected); - spin_lock_irq(&info->io_lock); - /* Now safe for us to use the shared ring */ info->connected = BLKIF_STATE_CONNECTED; - /* Kick any other new requests queued since we resumed */ - kick_pending_request_queues(info); + for (r_index = 0; r_index < info->nr_rings; r_index++) { + struct blkfront_ring_info *rinfo; + + rinfo = &info->rinfo[r_index]; + /* Kick any other new requests queued since we resumed */ + kick_pending_request_queues(rinfo); + } list_for_each_entry_safe(req, n, &requests, queuelist) { /* Requeue pending requests (flush or discard) */ @@ -1725,7 +2076,6 @@ static int blkif_recover(struct blkfront_info *info) BUG_ON(req->nr_phys_segments > segs); blk_mq_requeue_request(req); } - spin_unlock_irq(&info->io_lock); blk_mq_kick_requeue_list(info->rq); while ((bio = bio_list_pop(&bio_list)) != NULL) { @@ -1790,8 +2140,7 @@ static int blkfront_resume(struct xenbus_device *dev) return err; } -static void -blkfront_closing(struct blkfront_info *info) +static void blkfront_closing(struct blkfront_info *info) { struct xenbus_device *xbdev = info->xbdev; struct block_device *bdev = NULL; @@ -1851,18 +2200,29 @@ 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; + if (info->max_indirect_segments == 0) { + if (!HAS_EXTRA_REQ) + grants = BLKIF_MAX_SEGMENTS_PER_REQUEST; + else { + /* + * When an extra req is required, the maximum + * grants supported is related to the size of the + * Linux block segment. + */ + grants = GRANTS_PER_PSEG; + } + } else 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 +2235,31 @@ 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 +2267,16 @@ 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); } @@ -1927,7 +2287,7 @@ out_of_memory: /* * Gather all backend feature-* */ -static int blkfront_gather_backend_features(struct blkfront_info *info) +static void blkfront_gather_backend_features(struct blkfront_info *info) { int err; int barrier, flush, discard, persistent; @@ -1982,8 +2342,6 @@ static int blkfront_gather_backend_features(struct blkfront_info *info) else info->max_indirect_segments = min(indirect_segments, xen_blkif_max_segments); - - return blkfront_setup_indirect(info); } /* @@ -1996,7 +2354,7 @@ static void blkfront_connect(struct blkfront_info *info) unsigned long sector_size; unsigned int physical_sector_size; unsigned int binfo; - int err; + int err, i; switch (info->connected) { case BLKIF_STATE_CONNECTED: @@ -2053,11 +2411,15 @@ static void blkfront_connect(struct blkfront_info *info) if (err != 1) physical_sector_size = sector_size; - err = blkfront_gather_backend_features(info); - if (err) { - xenbus_dev_fatal(info->xbdev, err, "setup_indirect at %s", - info->xbdev->otherend); - return; + blkfront_gather_backend_features(info); + for (i = 0; i < info->nr_rings; i++) { + err = blkfront_setup_indirect(&info->rinfo[i]); + if (err) { + xenbus_dev_fatal(info->xbdev, err, "setup_indirect at %s", + info->xbdev->otherend); + blkif_free(info, 0); + break; + } } err = xlvbd_alloc_gendisk(sectors, info, binfo, sector_size, @@ -2071,10 +2433,9 @@ static void blkfront_connect(struct blkfront_info *info) xenbus_switch_state(info->xbdev, XenbusStateConnected); /* Kick pending requests. */ - spin_lock_irq(&info->io_lock); info->connected = BLKIF_STATE_CONNECTED; - kick_pending_request_queues(info); - spin_unlock_irq(&info->io_lock); + for (i = 0; i < info->nr_rings; i++) + kick_pending_request_queues(&info->rinfo[i]); add_disk(info->gd); @@ -2095,11 +2456,8 @@ static void blkback_changed(struct xenbus_device *dev, case XenbusStateInitWait: if (dev->state != XenbusStateInitialising) break; - if (talk_to_blkback(dev, info)) { - kfree(info); - dev_set_drvdata(&dev->dev, NULL); + if (talk_to_blkback(dev, info)) break; - } case XenbusStateInitialising: case XenbusStateInitialised: case XenbusStateReconfiguring: @@ -2108,6 +2466,10 @@ static void blkback_changed(struct xenbus_device *dev, break; case XenbusStateConnected: + if (dev->state != XenbusStateInitialised) { + if (talk_to_blkback(dev, info)) + break; + } blkfront_connect(info); break; @@ -2281,6 +2643,7 @@ static struct xenbus_driver blkfront_driver = { static int __init xlblk_init(void) { int ret; + int nr_cpus = num_online_cpus(); if (!xen_domain()) return -ENODEV; @@ -2288,7 +2651,13 @@ static int __init xlblk_init(void) if (xen_blkif_max_ring_order > XENBUS_MAX_RING_GRANT_ORDER) { pr_info("Invalid max_ring_order (%d), will use default max: %d.\n", xen_blkif_max_ring_order, XENBUS_MAX_RING_GRANT_ORDER); - xen_blkif_max_ring_order = 0; + xen_blkif_max_ring_order = XENBUS_MAX_RING_GRANT_ORDER; + } + + if (xen_blkif_max_queues > nr_cpus) { + pr_info("Invalid max_queues (%d), will use default max: %d.\n", + xen_blkif_max_queues, nr_cpus); + xen_blkif_max_queues = nr_cpus; } if (!xen_has_pv_disk_devices()) |