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Correct blkback handling of the BLKIF_OP_FLUSH_DISKCACHE opcode.

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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
This commit is contained in:
gibbs 2013-09-04 23:32:49 +00:00
parent 23ba68da73
commit ceb5fa1b16
1 changed files with 4 additions and 12 deletions
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16
sys/dev/xen/blkback/blkback.c
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@ -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;
@ -326,13 +326,6 @@ 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.
*/
@ -1240,6 +1233,7 @@ xbb_get_resources(struct xbb_softc *xbb, struct xbb_xen_reqlist **reqlist,
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_xen_reqlist *reqlist,
{
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, struct xbb_xen_reqlist *reqlist,
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, struct xbb_xen_reqlist *reqlist,
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));