From cb38fa23c17519faf46a76d2f71a8430705fe474 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Fri, 2 May 2008 21:50:45 -0500 Subject: [PATCH] virtio: de-structify virtio_block status byte Ron Minnich points out that a struct containing a char is not always sizeof(char); simplest to remove the structure to avoid confusion. Cc: "ron minnich" Signed-off-by: Rusty Russell --- Documentation/lguest/lguest.c | 12 ++++++------ drivers/block/virtio_blk.c | 6 +++--- include/linux/virtio_blk.h | 7 +------ 3 files changed, 10 insertions(+), 15 deletions(-) diff --git a/Documentation/lguest/lguest.c b/Documentation/lguest/lguest.c index 4c1fc65a8b..5cd705c3d7 100644 --- a/Documentation/lguest/lguest.c +++ b/Documentation/lguest/lguest.c @@ -1398,7 +1398,7 @@ static bool service_io(struct device *dev) struct vblk_info *vblk = dev->priv; unsigned int head, out_num, in_num, wlen; int ret; - struct virtio_blk_inhdr *in; + u8 *in; struct virtio_blk_outhdr *out; struct iovec iov[dev->vq->vring.num]; off64_t off; @@ -1416,7 +1416,7 @@ static bool service_io(struct device *dev) head, out_num, in_num); out = convert(&iov[0], struct virtio_blk_outhdr); - in = convert(&iov[out_num+in_num-1], struct virtio_blk_inhdr); + in = convert(&iov[out_num+in_num-1], u8); off = out->sector * 512; /* The block device implements "barriers", where the Guest indicates @@ -1430,7 +1430,7 @@ static bool service_io(struct device *dev) * It'd be nice if we supported eject, for example, but we don't. */ if (out->type & VIRTIO_BLK_T_SCSI_CMD) { fprintf(stderr, "Scsi commands unsupported\n"); - in->status = VIRTIO_BLK_S_UNSUPP; + *in = VIRTIO_BLK_S_UNSUPP; wlen = sizeof(*in); } else if (out->type & VIRTIO_BLK_T_OUT) { /* Write */ @@ -1453,7 +1453,7 @@ static bool service_io(struct device *dev) errx(1, "Write past end %llu+%u", off, ret); } wlen = sizeof(*in); - in->status = (ret >= 0 ? VIRTIO_BLK_S_OK : VIRTIO_BLK_S_IOERR); + *in = (ret >= 0 ? VIRTIO_BLK_S_OK : VIRTIO_BLK_S_IOERR); } else { /* Read */ @@ -1466,10 +1466,10 @@ static bool service_io(struct device *dev) verbose("READ from sector %llu: %i\n", out->sector, ret); if (ret >= 0) { wlen = sizeof(*in) + ret; - in->status = VIRTIO_BLK_S_OK; + *in = VIRTIO_BLK_S_OK; } else { wlen = sizeof(*in); - in->status = VIRTIO_BLK_S_IOERR; + *in = VIRTIO_BLK_S_IOERR; } } diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 0cfbe8c594..fb283af380 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -35,7 +35,7 @@ struct virtblk_req struct list_head list; struct request *req; struct virtio_blk_outhdr out_hdr; - struct virtio_blk_inhdr in_hdr; + u8 status; }; static void blk_done(struct virtqueue *vq) @@ -48,7 +48,7 @@ static void blk_done(struct virtqueue *vq) spin_lock_irqsave(&vblk->lock, flags); while ((vbr = vblk->vq->vq_ops->get_buf(vblk->vq, &len)) != NULL) { int uptodate; - switch (vbr->in_hdr.status) { + switch (vbr->status) { case VIRTIO_BLK_S_OK: uptodate = 1; break; @@ -101,7 +101,7 @@ static bool do_req(struct request_queue *q, struct virtio_blk *vblk, sg_init_table(vblk->sg, VIRTIO_MAX_SG); sg_set_buf(&vblk->sg[0], &vbr->out_hdr, sizeof(vbr->out_hdr)); num = blk_rq_map_sg(q, vbr->req, vblk->sg+1); - sg_set_buf(&vblk->sg[num+1], &vbr->in_hdr, sizeof(vbr->in_hdr)); + sg_set_buf(&vblk->sg[num+1], &vbr->status, sizeof(vbr->status)); if (rq_data_dir(vbr->req) == WRITE) { vbr->out_hdr.type |= VIRTIO_BLK_T_OUT; diff --git a/include/linux/virtio_blk.h b/include/linux/virtio_blk.h index bca0b10d79..c75a9e82b9 100644 --- a/include/linux/virtio_blk.h +++ b/include/linux/virtio_blk.h @@ -41,13 +41,8 @@ struct virtio_blk_outhdr __u64 sector; }; +/* And this is the final byte of the write scatter-gather list. */ #define VIRTIO_BLK_S_OK 0 #define VIRTIO_BLK_S_IOERR 1 #define VIRTIO_BLK_S_UNSUPP 2 - -/* This is the first element of the write scatter-gather list */ -struct virtio_blk_inhdr -{ - unsigned char status; -}; #endif /* _LINUX_VIRTIO_BLK_H */ -- 2.39.5