Merge tag 'for-linus-4.2-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git...

[uclinux-h8/linux.git] / drivers / block / xen-blkback / blkback.c

diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index 713fc9f..ced9677 100644 (file)
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -84,6 +84,13 @@ MODULE_PARM_DESC(max_persistent_grants,
                  "Maximum number of grants to map persistently");
 
 /*
+ * Maximum order of pages to be used for the shared ring between front and
+ * backend, 4KB page granularity is used.
+ */
+unsigned int xen_blkif_max_ring_order = XENBUS_MAX_RING_PAGE_ORDER;
+module_param_named(max_ring_page_order, xen_blkif_max_ring_order, int, S_IRUGO);
+MODULE_PARM_DESC(max_ring_page_order, "Maximum order of pages to be used for the shared ring");
+/*
  * The LRU mechanism to clean the lists of persistent grants needs to
  * be executed periodically. The time interval between consecutive executions
  * of the purge mechanism is set in ms.
@@ -729,7 +736,7 @@ static void xen_blkbk_unmap_and_respond(struct pending_req *req)
        struct grant_page **pages = req->segments;
        unsigned int invcount;
 
-       invcount = xen_blkbk_unmap_prepare(blkif, pages, req->nr_pages,
+       invcount = xen_blkbk_unmap_prepare(blkif, pages, req->nr_segs,
                                           req->unmap, req->unmap_pages);
 
        work->data = req;
@@ -915,7 +922,7 @@ static int xen_blkbk_map_seg(struct pending_req *pending_req)
        int rc;
 
        rc = xen_blkbk_map(pending_req->blkif, pending_req->segments,
-                          pending_req->nr_pages,
+                          pending_req->nr_segs,
                           (pending_req->operation != BLKIF_OP_READ));
 
        return rc;
@@ -931,7 +938,7 @@ static int xen_blkbk_parse_indirect(struct blkif_request *req,
        int indirect_grefs, rc, n, nseg, i;
        struct blkif_request_segment *segments = NULL;
 
-       nseg = pending_req->nr_pages;
+       nseg = pending_req->nr_segs;
        indirect_grefs = INDIRECT_PAGES(nseg);
        BUG_ON(indirect_grefs > BLKIF_MAX_INDIRECT_PAGES_PER_REQUEST);
 
@@ -1251,7 +1258,7 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif,
        pending_req->id        = req->u.rw.id;
        pending_req->operation = req_operation;
        pending_req->status    = BLKIF_RSP_OKAY;
-       pending_req->nr_pages  = nseg;
+       pending_req->nr_segs   = nseg;
 
        if (req->operation != BLKIF_OP_INDIRECT) {
                preq.dev               = req->u.rw.handle;
@@ -1372,7 +1379,7 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif,
 
  fail_flush:
        xen_blkbk_unmap(blkif, pending_req->segments,
-                       pending_req->nr_pages);
+                       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);
@@ -1438,6 +1445,12 @@ static int __init xen_blkif_init(void)
        if (!xen_domain())
                return -ENODEV;
 
+       if (xen_blkif_max_ring_order > XENBUS_MAX_RING_PAGE_ORDER) {
+               pr_info("Invalid max_ring_order (%d), will use default max: %d.\n",
+                       xen_blkif_max_ring_order, XENBUS_MAX_RING_PAGE_ORDER);
+               xen_blkif_max_ring_order = XENBUS_MAX_RING_PAGE_ORDER;
+       }
+
        rc = xen_blkif_interface_init();
        if (rc)
                goto failed_init;