Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751303Ab3C0LNz (ORCPT ); Wed, 27 Mar 2013 07:13:55 -0400 Received: from smtp.eu.citrix.com ([46.33.159.39]:22412 "EHLO SMTP.EU.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752135Ab3C0LM0 (ORCPT ); Wed, 27 Mar 2013 07:12:26 -0400 X-IronPort-AV: E=Sophos;i="4.84,917,1355097600"; d="scan'208";a="2955626" From: Roger Pau Monne To: , CC: Roger Pau Monne , Konrad Rzeszutek Wilk Subject: [PATCH v1 6/7] xen-blkback: expand map/unmap functions Date: Wed, 27 Mar 2013 12:10:42 +0100 Message-ID: <1364382643-3711-7-git-send-email-roger.pau@citrix.com> X-Mailer: git-send-email 1.7.7.5 (Apple Git-26) In-Reply-To: <1364382643-3711-1-git-send-email-roger.pau@citrix.com> References: <1364382643-3711-1-git-send-email-roger.pau@citrix.com> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 9709 Lines: 288 Preparatory change for implementing indirect descriptors. Change xen_blkbk_{map/unmap} in order to be able to map/unmap a random amount of grants (previously it was limited to BLKIF_MAX_SEGMENTS_PER_REQUEST). Also, remove the usage of pending_req in the map/unmap functions, so we can map/unmap grants without needing to pass a pending_req. Signed-off-by: Roger Pau Monné Cc: Konrad Rzeszutek Wilk Cc: xen-devel@lists.xen.org --- drivers/block/xen-blkback/blkback.c | 133 ++++++++++++++++++++++------------- 1 files changed, 84 insertions(+), 49 deletions(-) diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c index a1c9dad..f8c838e 100644 --- a/drivers/block/xen-blkback/blkback.c +++ b/drivers/block/xen-blkback/blkback.c @@ -181,10 +181,6 @@ static inline void shrink_free_pagepool(struct xen_blkif *blkif, int num) #define vaddr(page) ((unsigned long)pfn_to_kaddr(page_to_pfn(page))) -#define pending_handle(_req, _seg) \ - (_req->grant_handles[_seg]) - - static int do_block_io_op(struct xen_blkif *blkif); static int dispatch_rw_block_io(struct xen_blkif *blkif, struct blkif_request *req, @@ -643,50 +639,57 @@ struct seg_buf { * Unmap the grant references, and also remove the M2P over-rides * used in the 'pending_req'. */ -static void xen_blkbk_unmap(struct pending_req *req) +static void xen_blkbk_unmap(struct xen_blkif *blkif, + grant_handle_t handles[], + struct page *pages[], + struct persistent_gnt *persistent_gnts[], + int num) { struct gnttab_unmap_grant_ref unmap[BLKIF_MAX_SEGMENTS_PER_REQUEST]; - struct page *pages[BLKIF_MAX_SEGMENTS_PER_REQUEST]; + struct page *unmap_pages[BLKIF_MAX_SEGMENTS_PER_REQUEST]; unsigned int i, invcount = 0; - grant_handle_t handle; - struct xen_blkif *blkif = req->blkif; int ret; - for (i = 0; i < req->nr_pages; i++) { - if (req->persistent_gnts[i] != NULL) { - put_persistent_gnt(blkif, req->persistent_gnts[i]); + for (i = 0; i < num; i++) { + if (persistent_gnts[i] != NULL) { + put_persistent_gnt(blkif, persistent_gnts[i]); continue; } - handle = pending_handle(req, i); - pages[invcount] = req->pages[i]; - if (handle == BLKBACK_INVALID_HANDLE) + if (handles[i] == BLKBACK_INVALID_HANDLE) continue; - gnttab_set_unmap_op(&unmap[invcount], vaddr(pages[invcount]), - GNTMAP_host_map, handle); - pending_handle(req, i) = BLKBACK_INVALID_HANDLE; - invcount++; + unmap_pages[invcount] = pages[i]; + gnttab_set_unmap_op(&unmap[invcount], vaddr(pages[i]), + GNTMAP_host_map, handles[i]); + handles[i] = BLKBACK_INVALID_HANDLE; + if (++invcount == BLKIF_MAX_SEGMENTS_PER_REQUEST) { + ret = gnttab_unmap_refs(unmap, NULL, unmap_pages, + invcount); + BUG_ON(ret); + put_free_pages(blkif, unmap_pages, invcount); + invcount = 0; + } + } + if (invcount) { + ret = gnttab_unmap_refs(unmap, NULL, unmap_pages, invcount); + BUG_ON(ret); + put_free_pages(blkif, unmap_pages, invcount); } - - ret = gnttab_unmap_refs(unmap, NULL, pages, invcount); - BUG_ON(ret); - put_free_pages(blkif, pages, invcount); } -static int xen_blkbk_map(struct blkif_request *req, - struct pending_req *pending_req, - struct seg_buf seg[], - struct page *pages[]) +static int xen_blkbk_map(struct xen_blkif *blkif, grant_ref_t grefs[], + struct persistent_gnt *persistent_gnts[], + grant_handle_t handles[], + struct page *pages[], + int num, bool ro) { struct gnttab_map_grant_ref map[BLKIF_MAX_SEGMENTS_PER_REQUEST]; struct page *pages_to_gnt[BLKIF_MAX_SEGMENTS_PER_REQUEST]; - struct persistent_gnt **persistent_gnts = pending_req->persistent_gnts; struct persistent_gnt *persistent_gnt = NULL; - struct xen_blkif *blkif = pending_req->blkif; phys_addr_t addr = 0; int i, j; - int nseg = req->u.rw.nr_segments; int segs_to_map = 0; int ret = 0; + int last_map = 0, map_until = 0; int use_persistent_gnts; use_persistent_gnts = (blkif->vbd.feature_gnt_persistent); @@ -696,13 +699,14 @@ static int xen_blkbk_map(struct blkif_request *req, * assign map[..] with the PFN of the page in our domain with the * corresponding grant reference for each page. */ - for (i = 0; i < nseg; i++) { +again: + for (i = map_until; i < num; i++) { uint32_t flags; if (use_persistent_gnts) persistent_gnt = get_persistent_gnt( blkif, - req->u.rw.seg[i].gref); + grefs[i]); if (persistent_gnt) { /* @@ -718,13 +722,15 @@ static int xen_blkbk_map(struct blkif_request *req, pages_to_gnt[segs_to_map] = pages[i]; persistent_gnts[i] = NULL; flags = GNTMAP_host_map; - if (!use_persistent_gnts && - (pending_req->operation != BLKIF_OP_READ)) + if (!use_persistent_gnts && ro) flags |= GNTMAP_readonly; gnttab_set_map_op(&map[segs_to_map++], addr, - flags, req->u.rw.seg[i].gref, + flags, grefs[i], blkif->domid); } + map_until = i + 1; + if (segs_to_map == BLKIF_MAX_SEGMENTS_PER_REQUEST) + break; } if (segs_to_map) { @@ -737,22 +743,20 @@ static int xen_blkbk_map(struct blkif_request *req, * so that when we access vaddr(pending_req,i) it has the contents of * the page from the other domain. */ - for (i = 0, j = 0; i < nseg; i++) { + for (i = last_map, j = 0; i < map_until; i++) { if (!persistent_gnts[i]) { /* This is a newly mapped grant */ BUG_ON(j >= segs_to_map); if (unlikely(map[j].status != 0)) { pr_debug(DRV_PFX "invalid buffer -- could not remap it\n"); - pending_handle(pending_req, i) = - BLKBACK_INVALID_HANDLE; + handles[i] = BLKBACK_INVALID_HANDLE; ret |= 1; - j++; - continue; + goto next; } - pending_handle(pending_req, i) = map[j].handle; + handles[i] = map[j].handle; } if (persistent_gnts[i]) - goto next; + continue; if (use_persistent_gnts && blkif->persistent_gnt_c < xen_blkif_max_pgrants) { /* @@ -767,7 +771,6 @@ static int xen_blkbk_map(struct blkif_request *req, * allocate the persistent_gnt struct * map this grant non-persistenly */ - j++; goto next; } persistent_gnt->gnt = map[j].ref; @@ -776,14 +779,12 @@ static int xen_blkbk_map(struct blkif_request *req, if (add_persistent_gnt(blkif, persistent_gnt)) { kfree(persistent_gnt); - j++; goto next; } persistent_gnts[i] = persistent_gnt; pr_debug(DRV_PFX " grant %u added to the tree of persistent grants, using %u/%u\n", persistent_gnt->gnt, blkif->persistent_gnt_c, xen_blkif_max_pgrants); - j++; goto next; } if (use_persistent_gnts && !blkif->vbd.overflow_max_grants) { @@ -791,10 +792,14 @@ static int xen_blkbk_map(struct blkif_request *req, pr_debug(DRV_PFX " domain %u, device %#x is using maximum number of persistent grants\n", blkif->domid, blkif->vbd.handle); } - j++; next: - seg[i].offset = (req->u.rw.seg[i].first_sect << 9); + j++; } + segs_to_map = 0; + last_map = map_until; + if (map_until != num) + goto again; + return ret; out_of_memory: @@ -803,6 +808,31 @@ out_of_memory: return -ENOMEM; } +static int xen_blkbk_map_seg(struct blkif_request *req, + struct pending_req *pending_req, + struct seg_buf seg[], + struct page *pages[]) +{ + int i, rc; + grant_ref_t grefs[BLKIF_MAX_SEGMENTS_PER_REQUEST]; + + for (i = 0; i < req->u.rw.nr_segments; i++) + grefs[i] = req->u.rw.seg[i].gref; + + rc = xen_blkbk_map(pending_req->blkif, grefs, + pending_req->persistent_gnts, + pending_req->grant_handles, pending_req->pages, + req->u.rw.nr_segments, + (pending_req->operation != BLKIF_OP_READ)); + if (rc) + return rc; + + for (i = 0; i < req->u.rw.nr_segments; i++) + seg[i].offset = (req->u.rw.seg[i].first_sect << 9); + + return 0; +} + static int dispatch_discard_io(struct xen_blkif *blkif, struct blkif_request *req) { @@ -889,7 +919,10 @@ static void __end_block_io_op(struct pending_req *pending_req, int error) * the proper response on the ring. */ if (atomic_dec_and_test(&pending_req->pendcnt)) { - xen_blkbk_unmap(pending_req); + xen_blkbk_unmap(pending_req->blkif, pending_req->grant_handles, + pending_req->pages, + pending_req->persistent_gnts, + pending_req->nr_pages); make_response(pending_req->blkif, pending_req->id, pending_req->operation, pending_req->status); xen_blkif_put(pending_req->blkif); @@ -1111,7 +1144,7 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif, * the hypercall to unmap the grants - that is all done in * xen_blkbk_unmap. */ - if (xen_blkbk_map(req, pending_req, seg, pages)) + if (xen_blkbk_map_seg(req, pending_req, seg, pages)) goto fail_flush; /* @@ -1172,7 +1205,9 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif, return 0; fail_flush: - xen_blkbk_unmap(pending_req); + xen_blkbk_unmap(blkif, pending_req->grant_handles, + pending_req->pages, pending_req->persistent_gnts, + pending_req->nr_pages); fail_response: /* Haven't submitted any bio's yet. */ make_response(blkif, req->u.rw.id, req->operation, BLKIF_RSP_ERROR); -- 1.7.7.5 (Apple Git-26) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/