Feedback-ID: iac594737:Fastmail
From:   Demi Marie Obenour <demi@invisiblethingslab.com>
To:     Jens Axboe <axboe@kernel.dk>, Juergen Gross <jgross@suse.com>,
        =?UTF-8?q?Roger=20Pau=20Monn=C3=A9?= <roger.pau@citrix.com>
Cc:     Demi Marie Obenour <demi@invisiblethingslab.com>,
        =?UTF-8?q?Marek=20Marczykowski-G=C3=B3recki?= 
        <marmarek@invisiblethingslab.com>, xen-devel@lists.xenproject.org,
        linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [RFC PATCH 6/7] Minor blkback cleanups
Date:   Wed, 25 Jan 2023 22:33:57 -0500
Message-Id: <20230126033358.1880-6-demi@invisiblethingslab.com>
In-Reply-To: <20230126033358.1880-1-demi@invisiblethingslab.com>
References: <20230126033358.1880-1-demi@invisiblethingslab.com>
MIME-Version: 1.0
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No functional change intended.

Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
---
 drivers/block/xen-blkback/blkback.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index a5cf7f1e871c7f9ff397ab8ff1d7b9e3db686659..8a49cbe81d8895f89371bdf50d1b445c088c9b6a 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -1238,6 +1238,8 @@ static int dispatch_rw_block_io(struct xen_blkif_ring *ring,
 	nseg = req->operation == BLKIF_OP_INDIRECT ?
 	       req->u.indirect.nr_segments : req->u.rw.nr_segments;
 
+	BUILD_BUG_ON(offsetof(struct blkif_request, u.rw.id) != 8);
+	BUILD_BUG_ON(offsetof(struct blkif_request, u.indirect.id) != 8);
 	if (unlikely(nseg == 0 && operation_flags != REQ_PREFLUSH) ||
 	    unlikely((req->operation != BLKIF_OP_INDIRECT) &&
 		     (nseg > BLKIF_MAX_SEGMENTS_PER_REQUEST)) ||
@@ -1261,13 +1263,13 @@ static int dispatch_rw_block_io(struct xen_blkif_ring *ring,
 		preq.sector_number     = req->u.rw.sector_number;
 		for (i = 0; i < nseg; i++) {
 			pages[i]->gref = req->u.rw.seg[i].gref;
-			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 >= (XEN_PAGE_SIZE >> 9)) ||
 			    (req->u.rw.seg[i].last_sect <
 			     req->u.rw.seg[i].first_sect))
 				goto fail_response;
+			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);
 			preq.nr_sects += seg[i].nsec;
 		}
 	} else {
-- 
Sincerely,
Demi Marie Obenour (she/her/hers)
Invisible Things Lab