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));
_______________________________________________
svn-src-head@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/svn-src-head
To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
