From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35794) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XKQzN-0001RC-30 for qemu-devel@nongnu.org; Thu, 21 Aug 2014 07:57:15 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XKQzG-0006Ds-TF for qemu-devel@nongnu.org; Thu, 21 Aug 2014 07:57:08 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54670) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XKQzG-0006Db-LV for qemu-devel@nongnu.org; Thu, 21 Aug 2014 07:57:02 -0400 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s7LBv2kY022614 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Thu, 21 Aug 2014 07:57:02 -0400 From: Fam Zheng Date: Thu, 21 Aug 2014 19:56:56 +0800 Message-Id: <1408622216-9578-10-git-send-email-famz@redhat.com> In-Reply-To: <1408622216-9578-1-git-send-email-famz@redhat.com> References: <1408622216-9578-1-git-send-email-famz@redhat.com> Subject: [Qemu-devel] [RFC PATCH 9/9] scsi: Cancel request asynchronously List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Kevin Wolf , Paolo Bonzini , Stefan Hajnoczi We are blocking the whole VM, which means that an irresponsive storage backend will hang the whole guest. Let's switch to bdrv_aio_cancel_async to improve this. Signed-off-by: Fam Zheng --- hw/scsi/scsi-bus.c | 6 ++---- hw/scsi/scsi-disk.c | 41 ++++++++++------------------------------- hw/scsi/scsi-generic.c | 21 ++++++--------------- 3 files changed, 18 insertions(+), 50 deletions(-) diff --git a/hw/scsi/scsi-bus.c b/hw/scsi/scsi-bus.c index 6f4462b..59ec9f9 100644 --- a/hw/scsi/scsi-bus.c +++ b/hw/scsi/scsi-bus.c @@ -1615,7 +1615,6 @@ void scsi_req_continue(SCSIRequest *req) { if (req->io_canceled) { trace_scsi_req_continue_canceled(req->dev->id, req->lun, req->tag); - return; } trace_scsi_req_continue(req->dev->id, req->lun, req->tag); if (req->cmd.mode == SCSI_XFER_TO_DEV) { @@ -1633,7 +1632,6 @@ void scsi_req_data(SCSIRequest *req, int len) uint8_t *buf; if (req->io_canceled) { trace_scsi_req_data_canceled(req->dev->id, req->lun, req->tag, len); - return; } trace_scsi_req_data(req->dev->id, req->lun, req->tag, len); assert(req->cmd.mode != SCSI_XFER_NONE); @@ -1721,7 +1719,7 @@ void scsi_req_complete(SCSIRequest *req, int status) void scsi_req_cancel(SCSIRequest *req) { trace_scsi_req_cancel(req->dev->id, req->lun, req->tag); - if (!req->enqueued) { + if (req->io_canceled) { return; } scsi_req_ref(req); @@ -1738,7 +1736,7 @@ void scsi_req_cancel(SCSIRequest *req) void scsi_req_abort(SCSIRequest *req, int status) { - if (!req->enqueued) { + if (req->io_canceled) { return; } scsi_req_ref(req); diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c index d55521d..46b1e53 100644 --- a/hw/scsi/scsi-disk.c +++ b/hw/scsi/scsi-disk.c @@ -112,14 +112,9 @@ static void scsi_cancel_io(SCSIRequest *req) DPRINTF("Cancel tag=0x%x\n", req->tag); if (r->req.aiocb) { - bdrv_aio_cancel(r->req.aiocb); - - /* This reference was left in by scsi_*_data. We take ownership of - * it the moment scsi_req_cancel is called, independent of whether - * bdrv_aio_cancel completes the request or not. */ - scsi_req_unref(&r->req); + assert(req->io_canceled); + bdrv_aio_cancel_async(r->req.aiocb); } - r->req.aiocb = NULL; } static uint32_t scsi_init_iovec(SCSIDiskReq *r, size_t size) @@ -197,9 +192,7 @@ static void scsi_aio_complete(void *opaque, int ret) scsi_req_complete(&r->req, GOOD); done: - if (!r->req.io_canceled) { - scsi_req_unref(&r->req); - } + scsi_req_unref(&r->req); } static bool scsi_is_cmd_fua(SCSICommand *cmd) @@ -245,9 +238,7 @@ static void scsi_write_do_fua(SCSIDiskReq *r) scsi_req_complete(&r->req, GOOD); done: - if (!r->req.io_canceled) { - scsi_req_unref(&r->req); - } + scsi_req_unref(&r->req); } static void scsi_dma_complete_noio(void *opaque, int ret) @@ -279,9 +270,7 @@ static void scsi_dma_complete_noio(void *opaque, int ret) } done: - if (!r->req.io_canceled) { - scsi_req_unref(&r->req); - } + scsi_req_unref(&r->req); } static void scsi_dma_complete(void *opaque, int ret) @@ -319,9 +308,7 @@ static void scsi_read_complete(void * opaque, int ret) scsi_req_data(&r->req, r->qiov.size); done: - if (!r->req.io_canceled) { - scsi_req_unref(&r->req); - } + scsi_req_unref(&r->req); } /* Actually issue a read to the block device. */ @@ -361,9 +348,7 @@ static void scsi_do_read(void *opaque, int ret) } done: - if (!r->req.io_canceled) { - scsi_req_unref(&r->req); - } + scsi_req_unref(&r->req); } /* Read more data from scsi device into buffer. */ @@ -478,9 +463,7 @@ static void scsi_write_complete(void * opaque, int ret) } done: - if (!r->req.io_canceled) { - scsi_req_unref(&r->req); - } + scsi_req_unref(&r->req); } static void scsi_write_data(SCSIRequest *req) @@ -1577,9 +1560,7 @@ static void scsi_unmap_complete(void *opaque, int ret) scsi_req_complete(&r->req, GOOD); done: - if (!r->req.io_canceled) { - scsi_req_unref(&r->req); - } + scsi_req_unref(&r->req); g_free(data); } @@ -1672,9 +1653,7 @@ static void scsi_write_same_complete(void *opaque, int ret) scsi_req_complete(&r->req, GOOD); done: - if (!r->req.io_canceled) { - scsi_req_unref(&r->req); - } + scsi_req_unref(&r->req); qemu_vfree(data->iov.iov_base); g_free(data); } diff --git a/hw/scsi/scsi-generic.c b/hw/scsi/scsi-generic.c index 0b2ff90..1c29ecb 100644 --- a/hw/scsi/scsi-generic.c +++ b/hw/scsi/scsi-generic.c @@ -132,27 +132,20 @@ static void scsi_command_complete(void *opaque, int ret) DPRINTF("Command complete 0x%p tag=0x%x status=%d\n", r, r->req.tag, status); - scsi_req_complete(&r->req, status); if (!r->req.io_canceled) { - scsi_req_unref(&r->req); + scsi_req_complete(&r->req, status); } + scsi_req_unref(&r->req); } /* Cancel a pending data transfer. */ static void scsi_cancel_io(SCSIRequest *req) { - SCSIGenericReq *r = DO_UPCAST(SCSIGenericReq, req, req); - DPRINTF("Cancel tag=0x%x\n", req->tag); - if (r->req.aiocb) { - bdrv_aio_cancel(r->req.aiocb); - - /* This reference was left in by scsi_*_data. We take ownership of - * it independent of whether bdrv_aio_cancel completes the request - * or not. */ - scsi_req_unref(&r->req); + if (req->aiocb) { + req->io_canceled = true; + bdrv_aio_cancel_async(req->aiocb); } - r->req.aiocb = NULL; } static int execute_command(BlockDriverState *bdrv, @@ -211,9 +204,7 @@ static void scsi_read_complete(void * opaque, int ret) bdrv_set_guest_block_size(s->conf.bs, s->blocksize); scsi_req_data(&r->req, len); - if (!r->req.io_canceled) { - scsi_req_unref(&r->req); - } + scsi_req_unref(&r->req); } } -- 2.0.3