From 921bf46a3f40baddf3ed040f59cfe96c0316cc17 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Wed, 22 Feb 2012 14:11:51 +0100 Subject: [PATCH 035/109] scsi-disk: commonize iovec creation between reads and writes RH-Author: Paolo Bonzini Message-id: <1329919979-20948-35-git-send-email-pbonzini@redhat.com> Patchwork-id: 37512 O-Subject: [RHEL 6.3 qemu-kvm PATCH v2 034/102] scsi-disk: commonize iovec creation between reads and writes Bugzilla: 782029 RH-Acked-by: Laszlo Ersek RH-Acked-by: Orit Wasserman RH-Acked-by: Gerd Hoffmann Also, consistently use qiov.size instead of iov.iov_len. Signed-off-by: Paolo Bonzini Signed-off-by: Kevin Wolf (cherry picked from 103b40f51e4012b3b0ad20f615562a1806d7f49a) Conflicts: hw/scsi-disk.c --- hw/scsi-disk.c | 43 ++++++++++++++++++------------------------- 1 files changed, 18 insertions(+), 25 deletions(-) Signed-off-by: Michal Novotny --- hw/scsi-disk.c | 43 ++++++++++++++++++------------------------- 1 files changed, 18 insertions(+), 25 deletions(-) diff --git a/hw/scsi-disk.c b/hw/scsi-disk.c index 29ff20c..bc0625f 100644 --- a/hw/scsi-disk.c +++ b/hw/scsi-disk.c @@ -113,6 +113,13 @@ static void scsi_cancel_io(SCSIRequest *req) r->req.aiocb = NULL; } +static uint32_t scsi_init_iovec(SCSIDiskReq *r) +{ + r->iov.iov_len = MIN(r->sector_count * 512, SCSI_DMA_BUF_SIZE); + qemu_iovec_init_external(&r->qiov, &r->iov, 1); + return r->qiov.size / 512; +} + static void scsi_read_complete(void * opaque, int ret) { SCSIDiskReq *r = (SCSIDiskReq *)opaque; @@ -130,12 +137,12 @@ static void scsi_read_complete(void * opaque, int ret) } } - DPRINTF("Data ready tag=0x%x len=%zd\n", r->req.tag, r->iov.iov_len); + DPRINTF("Data ready tag=0x%x len=%zd\n", r->req.tag, r->qiov.size); - n = r->iov.iov_len / 512; + n = r->qiov.size / 512; r->sector += n; r->sector_count -= n; - scsi_req_data(&r->req, r->iov.iov_len); + scsi_req_data(&r->req, r->qiov.size); done: if (!r->req.io_canceled) { @@ -198,18 +205,11 @@ static void scsi_read_data(SCSIRequest *req) return; } - n = r->sector_count; - if (n > SCSI_DMA_BUF_SIZE / 512) - n = SCSI_DMA_BUF_SIZE / 512; - if (s->tray_open) { scsi_read_complete(r, -ENOMEDIUM); return; } - - r->iov.iov_len = n * 512; - qemu_iovec_init_external(&r->qiov, &r->iov, 1); - + n = scsi_init_iovec(r); bdrv_acct_start(s->bs, &r->acct, n * BDRV_SECTOR_SIZE, BDRV_ACCT_READ); r->req.aiocb = bdrv_aio_readv(s->bs, r->sector, &r->qiov, n, scsi_read_complete, r); @@ -269,7 +269,6 @@ static void scsi_write_complete(void * opaque, int ret) { SCSIDiskReq *r = (SCSIDiskReq *)opaque; SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev); - uint32_t len; uint32_t n; if (r->req.aiocb != NULL) { @@ -283,19 +282,15 @@ static void scsi_write_complete(void * opaque, int ret) } } - n = r->iov.iov_len / 512; + n = r->qiov.size / 512; r->sector += n; r->sector_count -= n; if (r->sector_count == 0) { scsi_req_complete(&r->req, GOOD); } else { - len = r->sector_count * 512; - if (len > SCSI_DMA_BUF_SIZE) { - len = SCSI_DMA_BUF_SIZE; - } - r->iov.iov_len = len; - DPRINTF("Write complete tag=0x%x more=%d\n", r->req.tag, len); - scsi_req_data(&r->req, len); + scsi_init_iovec(r); + DPRINTF("Write complete tag=0x%x more=%d\n", r->req.tag, r->qiov.size); + scsi_req_data(&r->req, r->qiov.size); } done: @@ -321,22 +316,20 @@ static void scsi_write_data(SCSIRequest *req) return; } - n = r->iov.iov_len / 512; + n = r->qiov.size / 512; if (n) { if (s->tray_open) { scsi_write_complete(r, -ENOMEDIUM); return; } - qemu_iovec_init_external(&r->qiov, &r->iov, 1); - bdrv_acct_start(s->bs, &r->acct, n * BDRV_SECTOR_SIZE, BDRV_ACCT_WRITE); r->req.aiocb = bdrv_aio_writev(s->bs, r->sector, &r->qiov, n, - scsi_write_complete, r); + scsi_write_complete, r); if (r->req.aiocb == NULL) { scsi_write_complete(r, -ENOMEM); } } else { - /* Invoke completion routine to fetch data from host. */ + /* Called for the first time. Ask the driver to send us more data. */ scsi_write_complete(r, 0); } } -- 1.7.7.6