static int ioreq_parse(struct ioreq *ioreq) { struct XenBlkDev *blkdev = ioreq->blkdev; uintptr_t mem; size_t len; int i; xen_be_printf(&blkdev->xendev, 3, "op %d, nr %d, handle %d, id %" PRId64 ", sector %" PRId64 "\n", ioreq->req.operation, ioreq->req.nr_segments, ioreq->req.handle, ioreq->req.id, ioreq->req.sector_number); switch (ioreq->req.operation) { case BLKIF_OP_READ: ioreq->prot = PROT_WRITE; /* to memory */ if (ioreq->req.operation != BLKIF_OP_READ && blkdev->mode[0] != 'w') { xen_be_printf(&blkdev->xendev, 0, "error: write req for ro device\n"); goto err; } break; case BLKIF_OP_WRITE_BARRIER: if (!syncwrite) ioreq->presync = ioreq->postsync = 1; /* fall through */ case BLKIF_OP_WRITE: ioreq->prot = PROT_READ; /* from memory */ if (syncwrite) ioreq->postsync = 1; break; default: xen_be_printf(&blkdev->xendev, 0, "error: unknown operation (%d)\n", ioreq->req.operation); goto err; }; ioreq->start = ioreq->req.sector_number * blkdev->file_blk; for (i = 0; i < ioreq->req.nr_segments; i++) { if (i == BLKIF_MAX_SEGMENTS_PER_REQUEST) { xen_be_printf(&blkdev->xendev, 0, "error: nr_segments too big\n"); goto err; } if (ioreq->req.seg[i].first_sect > ioreq->req.seg[i].last_sect) { xen_be_printf(&blkdev->xendev, 0, "error: first > last sector\n"); goto err; } if (ioreq->req.seg[i].last_sect * BLOCK_SIZE >= XC_PAGE_SIZE) { xen_be_printf(&blkdev->xendev, 0, "error: page crossing\n"); goto err; } ioreq->domids[i] = blkdev->xendev.dom; ioreq->refs[i] = ioreq->req.seg[i].gref; mem = ioreq->req.seg[i].first_sect * blkdev->file_blk; len = (ioreq->req.seg[i].last_sect - ioreq->req.seg[i].first_sect + 1) * blkdev->file_blk; qemu_iovec_add(&ioreq->v, (void*)mem, len); } if (ioreq->start + ioreq->v.size > blkdev->file_size) { xen_be_printf(&blkdev->xendev, 0, "error: access beyond end of file\n"); goto err; } return 0; err: ioreq->status = BLKIF_RSP_ERROR; return -1; }
static int ioreq_parse(struct ioreq *ioreq) { struct XenBlkDev *blkdev = ioreq->blkdev; uintptr_t mem; size_t len; int i; xen_be_printf(&blkdev->xendev, 3, "op %d, nr %d, handle %d, id %" PRId64 ", sector %" PRId64 "\n", ioreq->req.operation, ioreq->req.nr_segments, ioreq->req.handle, ioreq->req.id, ioreq->req.sector_number); switch (ioreq->req.operation) { case BLKIF_OP_READ: ioreq->prot = PROT_WRITE;   if (ioreq->req.operation != BLKIF_OP_READ && blkdev->mode[0] != 'w') { xen_be_printf(&blkdev->xendev, 0, "error: write req for ro device\n"); goto err; } break; case BLKIF_OP_WRITE_BARRIER: if (!syncwrite) ioreq->presync = ioreq->postsync = 1;   case BLKIF_OP_WRITE: ioreq->prot = PROT_READ;   if (syncwrite) ioreq->postsync = 1; break; default: xen_be_printf(&blkdev->xendev, 0, "error: unknown operation (%d)\n", ioreq->req.operation); goto err; }; ioreq->start = ioreq->req.sector_number * blkdev->file_blk; for (i = 0; i < ioreq->req.nr_segments; i++) { if (i == BLKIF_MAX_SEGMENTS_PER_REQUEST) { xen_be_printf(&blkdev->xendev, 0, "error: nr_segments too big\n"); goto err; } if (ioreq->req.seg[i].first_sect > ioreq->req.seg[i].last_sect) { xen_be_printf(&blkdev->xendev, 0, "error: first > last sector\n"); goto err; } if (ioreq->req.seg[i].last_sect * BLOCK_SIZE >= XC_PAGE_SIZE) { xen_be_printf(&blkdev->xendev, 0, "error: page crossing\n"); goto err; } ioreq->domids[i] = blkdev->xendev.dom; ioreq->refs[i] = ioreq->req.seg[i].gref; mem = ioreq->req.seg[i].first_sect * blkdev->file_blk; len = (ioreq->req.seg[i].last_sect - ioreq->req.seg[i].first_sect + 1) * blkdev->file_blk; qemu_iovec_add(&ioreq->v, (void*)mem, len); } if (ioreq->start + ioreq->v.size > blkdev->file_size) { xen_be_printf(&blkdev->xendev, 0, "error: access beyond end of file\n"); goto err; } return 0; err: ioreq->status = BLKIF_RSP_ERROR; return -1; }