diff options
Diffstat (limited to 'drivers/block/xen-blkback')
| -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 |
3 files changed, 529 insertions, 364 deletions
diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c index 41fb1a917..4809c1501 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; @@ -977,15 +995,16 @@ 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; @@ -1002,7 +1021,7 @@ 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)) ? @@ -1018,26 +1037,28 @@ 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); @@ -1058,12 +1079,12 @@ 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," @@ -1097,9 +1118,9 @@ 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; @@ -1112,7 +1133,7 @@ __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) { @@ -1125,14 +1146,14 @@ __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; @@ -1156,16 +1177,16 @@ __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; } @@ -1178,13 +1199,13 @@ 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; @@ -1197,7 +1218,7 @@ 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) { @@ -1225,17 +1246,17 @@ 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: @@ -1260,7 +1281,7 @@ 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; @@ -1287,12 +1308,12 @@ 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; } @@ -1304,7 +1325,7 @@ 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; } } @@ -1313,7 +1334,7 @@ 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, @@ -1328,8 +1349,8 @@ 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) || @@ -1377,19 +1398,19 @@ 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; @@ -1407,21 +1428,22 @@ 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)); @@ -1439,9 +1461,9 @@ 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) @@ -1457,6 +1479,9 @@ 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 c929ae227..dea61f6ab 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 f53cff42f..876763f7f 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[] = { |