diff options
Diffstat (limited to 'drivers/block/xen-blkfront.c')
| -rw-r--r-- | drivers/block/xen-blkfront.c | 157 |
1 files changed, 92 insertions, 65 deletions
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index c3dae2e0f29..d89ef86220f 100644 --- a/drivers/block/xen-blkfront.c +++ b/drivers/block/xen-blkfront.c @@ -44,7 +44,7 @@ #include <linux/mutex.h> #include <linux/scatterlist.h> #include <linux/bitmap.h> -#include <linux/llist.h> +#include <linux/list.h> #include <xen/xen.h> #include <xen/xenbus.h> @@ -68,13 +68,12 @@ enum blkif_state { struct grant { grant_ref_t gref; unsigned long pfn; - struct llist_node node; + struct list_head node; }; struct blk_shadow { struct blkif_request req; struct request *request; - unsigned long frame[BLKIF_MAX_SEGMENTS_PER_REQUEST]; struct grant *grants_used[BLKIF_MAX_SEGMENTS_PER_REQUEST]; }; @@ -105,7 +104,7 @@ struct blkfront_info struct work_struct work; struct gnttab_free_callback callback; struct blk_shadow shadow[BLK_RING_SIZE]; - struct llist_head persistent_gnts; + struct list_head persistent_gnts; unsigned int persistent_gnts_c; unsigned long shadow_free; unsigned int feature_flush; @@ -165,6 +164,69 @@ static int add_id_to_freelist(struct blkfront_info *info, return 0; } +static int fill_grant_buffer(struct blkfront_info *info, int num) +{ + struct page *granted_page; + struct grant *gnt_list_entry, *n; + int i = 0; + + while(i < num) { + gnt_list_entry = kzalloc(sizeof(struct grant), GFP_NOIO); + if (!gnt_list_entry) + goto out_of_memory; + + granted_page = alloc_page(GFP_NOIO); + if (!granted_page) { + kfree(gnt_list_entry); + goto out_of_memory; + } + + gnt_list_entry->pfn = page_to_pfn(granted_page); + gnt_list_entry->gref = GRANT_INVALID_REF; + list_add(&gnt_list_entry->node, &info->persistent_gnts); + i++; + } + + return 0; + +out_of_memory: + list_for_each_entry_safe(gnt_list_entry, n, + &info->persistent_gnts, node) { + list_del(&gnt_list_entry->node); + __free_page(pfn_to_page(gnt_list_entry->pfn)); + kfree(gnt_list_entry); + i--; + } + BUG_ON(i != 0); + return -ENOMEM; +} + +static struct grant *get_grant(grant_ref_t *gref_head, + struct blkfront_info *info) +{ + struct grant *gnt_list_entry; + unsigned long buffer_mfn; + + BUG_ON(list_empty(&info->persistent_gnts)); + gnt_list_entry = list_first_entry(&info->persistent_gnts, struct grant, + node); + list_del(&gnt_list_entry->node); + + if (gnt_list_entry->gref != GRANT_INVALID_REF) { + info->persistent_gnts_c--; + return gnt_list_entry; + } + + /* Assign a gref to this page */ + gnt_list_entry->gref = gnttab_claim_grant_reference(gref_head); + BUG_ON(gnt_list_entry->gref == -ENOSPC); + buffer_mfn = pfn_to_mfn(gnt_list_entry->pfn); + gnttab_grant_foreign_access_ref(gnt_list_entry->gref, + info->xbdev->otherend_id, + buffer_mfn, 0); + return gnt_list_entry; +} + static const char *op_name(int op) { static const char *const names[] = { @@ -293,7 +355,6 @@ static int blkif_ioctl(struct block_device *bdev, fmode_t mode, static int blkif_queue_request(struct request *req) { struct blkfront_info *info = req->rq_disk->private_data; - unsigned long buffer_mfn; struct blkif_request *ring_req; unsigned long id; unsigned int fsect, lsect; @@ -306,7 +367,6 @@ static int blkif_queue_request(struct request *req) */ bool new_persistent_gnts; grant_ref_t gref_head; - struct page *granted_page; struct grant *gnt_list_entry = NULL; struct scatterlist *sg; @@ -370,41 +430,8 @@ static int blkif_queue_request(struct request *req) fsect = sg->offset >> 9; lsect = fsect + (sg->length >> 9) - 1; - if (info->persistent_gnts_c) { - BUG_ON(llist_empty(&info->persistent_gnts)); - gnt_list_entry = llist_entry( - llist_del_first(&info->persistent_gnts), - struct grant, node); - - ref = gnt_list_entry->gref; - buffer_mfn = pfn_to_mfn(gnt_list_entry->pfn); - info->persistent_gnts_c--; - } else { - ref = gnttab_claim_grant_reference(&gref_head); - BUG_ON(ref == -ENOSPC); - - gnt_list_entry = - kmalloc(sizeof(struct grant), - GFP_ATOMIC); - if (!gnt_list_entry) - return -ENOMEM; - - granted_page = alloc_page(GFP_ATOMIC); - if (!granted_page) { - kfree(gnt_list_entry); - return -ENOMEM; - } - - gnt_list_entry->pfn = - page_to_pfn(granted_page); - gnt_list_entry->gref = ref; - - buffer_mfn = pfn_to_mfn(page_to_pfn( - granted_page)); - gnttab_grant_foreign_access_ref(ref, - info->xbdev->otherend_id, - buffer_mfn, 0); - } + gnt_list_entry = get_grant(&gref_head, info); + ref = gnt_list_entry->gref; info->shadow[id].grants_used[i] = gnt_list_entry; @@ -435,7 +462,6 @@ static int blkif_queue_request(struct request *req) kunmap_atomic(shared_data); } - info->shadow[id].frame[i] = mfn_to_pfn(buffer_mfn); ring_req->u.rw.seg[i] = (struct blkif_request_segment) { .gref = ref, @@ -790,9 +816,8 @@ static void blkif_restart_queue(struct work_struct *work) static void blkif_free(struct blkfront_info *info, int suspend) { - struct llist_node *all_gnts; - struct grant *persistent_gnt, *tmp; - struct llist_node *n; + struct grant *persistent_gnt; + struct grant *n; /* Prevent new requests being issued until we fix things up. */ spin_lock_irq(&info->io_lock); @@ -803,22 +828,20 @@ static void blkif_free(struct blkfront_info *info, int suspend) blk_stop_queue(info->rq); /* Remove all persistent grants */ - if (info->persistent_gnts_c) { - all_gnts = llist_del_all(&info->persistent_gnts); - persistent_gnt = llist_entry(all_gnts, typeof(*(persistent_gnt)), node); - while (persistent_gnt) { - gnttab_end_foreign_access(persistent_gnt->gref, 0, 0UL); + if (!list_empty(&info->persistent_gnts)) { + list_for_each_entry_safe(persistent_gnt, n, + &info->persistent_gnts, 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--; + } __free_page(pfn_to_page(persistent_gnt->pfn)); - tmp = persistent_gnt; - n = persistent_gnt->node.next; - if (n) - persistent_gnt = llist_entry(n, typeof(*(persistent_gnt)), node); - else - persistent_gnt = NULL; - kfree(tmp); + kfree(persistent_gnt); } - info->persistent_gnts_c = 0; } + BUG_ON(info->persistent_gnts_c != 0); /* No more gnttab callback work. */ gnttab_cancel_free_callback(&info->callback); @@ -875,7 +898,7 @@ static void blkif_completion(struct blk_shadow *s, struct blkfront_info *info, } /* Add the persistent grant into the list of free grants */ for (i = 0; i < s->req.u.rw.nr_segments; i++) { - llist_add(&s->grants_used[i]->node, &info->persistent_gnts); + list_add(&s->grants_used[i]->node, &info->persistent_gnts); info->persistent_gnts_c++; } } @@ -1013,6 +1036,12 @@ static int setup_blkring(struct xenbus_device *dev, sg_init_table(info->sg, BLKIF_MAX_SEGMENTS_PER_REQUEST); + /* Allocate memory for grants */ + err = fill_grant_buffer(info, BLK_RING_SIZE * + BLKIF_MAX_SEGMENTS_PER_REQUEST); + if (err) + goto fail; + err = xenbus_grant_ring(dev, virt_to_mfn(info->ring.sring)); if (err < 0) { free_page((unsigned long)sring); @@ -1171,7 +1200,7 @@ static int blkfront_probe(struct xenbus_device *dev, spin_lock_init(&info->io_lock); info->xbdev = dev; info->vdevice = vdevice; - init_llist_head(&info->persistent_gnts); + INIT_LIST_HEAD(&info->persistent_gnts); info->persistent_gnts_c = 0; info->connected = BLKIF_STATE_DISCONNECTED; INIT_WORK(&info->work, blkif_restart_queue); @@ -1203,11 +1232,10 @@ static int blkif_recover(struct blkfront_info *info) int j; /* Stage 1: Make a safe copy of the shadow state. */ - copy = kmalloc(sizeof(info->shadow), + copy = kmemdup(info->shadow, sizeof(info->shadow), GFP_NOIO | __GFP_REPEAT | __GFP_HIGH); if (!copy) return -ENOMEM; - memcpy(copy, info->shadow, sizeof(info->shadow)); /* Stage 2: Set up free list. */ memset(&info->shadow, 0, sizeof(info->shadow)); @@ -1236,7 +1264,7 @@ static int blkif_recover(struct blkfront_info *info) gnttab_grant_foreign_access_ref( req->u.rw.seg[j].gref, info->xbdev->otherend_id, - pfn_to_mfn(info->shadow[req->u.rw.id].frame[j]), + pfn_to_mfn(copy[i].grants_used[j]->pfn), 0); } info->shadow[req->u.rw.id].req = *req; @@ -1589,7 +1617,7 @@ out: return err; } -static int blkif_release(struct gendisk *disk, fmode_t mode) +static void blkif_release(struct gendisk *disk, fmode_t mode) { struct blkfront_info *info = disk->private_data; struct block_device *bdev; @@ -1630,7 +1658,6 @@ static int blkif_release(struct gendisk *disk, fmode_t mode) out: bdput(bdev); mutex_unlock(&blkfront_mutex); - return 0; } static const struct block_device_operations xlvbd_block_fops = |