Date: Wed, 4 Sep 2013 23:32:49 +0000 (UTC) From: "Justin T. Gibbs" <gibbs@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r255218 - head/sys/dev/xen/blkback Message-ID: <201309042332.r84NWndg040721@svn.freebsd.org>
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Author: gibbs Date: Wed Sep 4 23:32:49 2013 New Revision: 255218 URL: http://svnweb.freebsd.org/changeset/base/255218 Log: Correct blkback handling of the BLKIF_OP_FLUSH_DISKCACHE opcode. Properly round-trip the "operation code" for client requests. sys/dev/xen/blkback/blkback.c: In xbb_dispatch_dev() when processing a flush request, correctly set bio->bio_caller1 to the request list (not bare request) for the operation, as is expected by the completion handler xbb_bio_done(). In xbb_get_resources(), initialize "operation" in the driver's internal request object from the client's "ring request", so it is correct when used to populate the reply when this operation completes. Submitted by: Roger Pau Monné Sponsored by: Citrix Systems R&D Reviewed by: gibbs Modified: head/sys/dev/xen/blkback/blkback.c Modified: head/sys/dev/xen/blkback/blkback.c ============================================================================== --- head/sys/dev/xen/blkback/blkback.c Wed Sep 4 23:31:29 2013 (r255217) +++ head/sys/dev/xen/blkback/blkback.c Wed Sep 4 23:32:49 2013 (r255218) @@ -230,7 +230,7 @@ struct xbb_xen_reqlist { int num_children; /** - * Number of I/O requests dispatched to the backend. + * Number of I/O requests still pending on the backend. */ int pendcnt; @@ -327,13 +327,6 @@ struct xbb_xen_req { int nr_512b_sectors; /** - * The number of struct bio requests still outstanding for this - * request on the backend device. This field is only used for - * device (rather than file) backed I/O. - */ - int pendcnt; - - /** * BLKIF_OP code for this request. */ int operation; @@ -1240,6 +1233,7 @@ xbb_get_resources(struct xbb_softc *xbb, nreq->reqlist = *reqlist; nreq->req_ring_idx = ring_idx; nreq->id = ring_req->id; + nreq->operation = ring_req->operation; if (xbb->abi != BLKIF_PROTOCOL_NATIVE) { bcopy(ring_req, &nreq->ring_req_storage, sizeof(*ring_req)); @@ -2062,7 +2056,6 @@ xbb_dispatch_dev(struct xbb_softc *xbb, { struct xbb_dev_data *dev_data; struct bio *bios[XBB_MAX_SEGMENTS_PER_REQLIST]; - struct xbb_xen_req *nreq; off_t bio_offset; struct bio *bio; struct xbb_sg *xbb_sg; @@ -2080,7 +2073,6 @@ xbb_dispatch_dev(struct xbb_softc *xbb, bio_idx = 0; if (operation == BIO_FLUSH) { - nreq = STAILQ_FIRST(&reqlist->contig_req_list); bio = g_new_bio(); if (__predict_false(bio == NULL)) { DPRINTF("Unable to allocate bio for BIO_FLUSH\n"); @@ -2094,10 +2086,10 @@ xbb_dispatch_dev(struct xbb_softc *xbb, bio->bio_offset = 0; bio->bio_data = 0; bio->bio_done = xbb_bio_done; - bio->bio_caller1 = nreq; + bio->bio_caller1 = reqlist; bio->bio_pblkno = 0; - nreq->pendcnt = 1; + reqlist->pendcnt = 1; SDT_PROBE1(xbb, kernel, xbb_dispatch_dev, flush, device_get_unit(xbb->dev));
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