These changes are the raw update to linux-4.4.6-rt14. Kernel sources

[kvmfornfv.git] / kernel / drivers / block / xen-blkback / blkback.c

diff --git a/kernel/drivers/block/xen-blkback/blkback.c b/kernel/drivers/block/xen-blkback/blkback.c
index 3e9ec95..41fb1a9 100644 (file)
--- a/kernel/drivers/block/xen-blkback/blkback.c
+++ b/kernel/drivers/block/xen-blkback/blkback.c
@@ -83,6 +83,13 @@ module_param_named(max_persistent_grants, xen_blkif_max_pgrants, int, 0644);
 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_GRANT_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
@@ -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);
 
@@ -943,6 +950,8 @@ static int xen_blkbk_parse_indirect(struct blkif_request *req,
                goto unmap;
 
        for (n = 0, i = 0; n < nseg; n++) {
+               uint8_t first_sect, last_sect;
+
                if ((n % SEGS_PER_INDIRECT_FRAME) == 0) {
                        /* Map indirect segments */
                        if (segments)
@@ -950,15 +959,18 @@ static int xen_blkbk_parse_indirect(struct blkif_request *req,
                        segments = kmap_atomic(pages[n/SEGS_PER_INDIRECT_FRAME]->page);
                }
                i = n % SEGS_PER_INDIRECT_FRAME;
+
                pending_req->segments[n]->gref = segments[i].gref;
-               seg[n].nsec = segments[i].last_sect -
-                       segments[i].first_sect + 1;
-               seg[n].offset = (segments[i].first_sect << 9);
-               if ((segments[i].last_sect >= (PAGE_SIZE >> 9)) ||
-                   (segments[i].last_sect < segments[i].first_sect)) {
+
+               first_sect = READ_ONCE(segments[i].first_sect);
+               last_sect = READ_ONCE(segments[i].last_sect);
+               if (last_sect >= (XEN_PAGE_SIZE >> 9) || last_sect < first_sect) {
                        rc = -EINVAL;
                        goto unmap;
                }
+
+               seg[n].nsec = last_sect - first_sect + 1;
+               seg[n].offset = first_sect << 9;
                preq->nr_sects += seg[n].nsec;
        }
 
@@ -1071,9 +1083,9 @@ static void __end_block_io_op(struct pending_req *pending_req, int error)
 /*
  * bio callback.
  */
-static void end_block_io_op(struct bio *bio, int error)
+static void end_block_io_op(struct bio *bio)
 {
-       __end_block_io_op(bio->bi_private, error);
+       __end_block_io_op(bio->bi_private, bio->bi_error);
        bio_put(bio);
 }
 
@@ -1203,6 +1215,7 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif,
 
        req_operation = req->operation == BLKIF_OP_INDIRECT ?
                        req->u.indirect.indirect_op : req->operation;
+
        if ((req->operation == BLKIF_OP_INDIRECT) &&
            (req_operation != BLKIF_OP_READ) &&
            (req_operation != BLKIF_OP_WRITE)) {
@@ -1251,7 +1264,7 @@ 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;
@@ -1261,7 +1274,7 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif,
                        seg[i].nsec = req->u.rw.seg[i].last_sect -
                                req->u.rw.seg[i].first_sect + 1;
                        seg[i].offset = (req->u.rw.seg[i].first_sect << 9);
-                       if ((req->u.rw.seg[i].last_sect >= (PAGE_SIZE >> 9)) ||
+                       if ((req->u.rw.seg[i].last_sect >= (XEN_PAGE_SIZE >> 9)) ||
                            (req->u.rw.seg[i].last_sect <
                             req->u.rw.seg[i].first_sect))
                                goto fail_response;
@@ -1372,7 +1385,7 @@ 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 +1451,12 @@ static int __init xen_blkif_init(void)
        if (!xen_domain())
                return -ENODEV;
 
+       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 = XENBUS_MAX_RING_GRANT_ORDER;
+       }
+
        rc = xen_blkif_interface_init();
        if (rc)
                goto failed_init;