From 97baee7ffa5c7cdc57fb47d37bf56e49940e0c97 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Wed, 22 Feb 2012 14:11:46 +0100 Subject: [PATCH 030/109] scsi: do not call transfer_data after canceling a request RH-Author: Paolo Bonzini Message-id: <1329919979-20948-30-git-send-email-pbonzini@redhat.com> Patchwork-id: 37510 O-Subject: [RHEL 6.3 qemu-kvm PATCH v2 029/102] scsi: do not call transfer_data after canceling a request Bugzilla: 782029 RH-Acked-by: Laszlo Ersek RH-Acked-by: Orit Wasserman RH-Acked-by: Gerd Hoffmann Otherwise, if cancellation is "faked" by the AIO layer and goes through qemu_aio_flush, the whole request is completed synchronously during scsi_req_cancel. Using the enqueued flag would work here, but not in the next patches, so I'm introducing a new io_canceled flag. That's because scsi_req_data is a synchronous callback and the enqueued flag might be reset by the time it returns. scsi-disk cannot unref the request until after calling scsi_req_data. Signed-off-by: Paolo Bonzini Signed-off-by: Kevin Wolf (cherry picked from e88c591d63ed1bc8520f4f276bebd77c22e4ec72) Conflicts: trace-events (add back disable markers) --- hw/scsi-bus.c | 23 +++++++++++++++++++---- hw/scsi.h | 1 + trace-events | 1 + 3 files changed, 21 insertions(+), 4 deletions(-) Signed-off-by: Michal Novotny --- hw/scsi-bus.c | 23 +++++++++++++++++++---- hw/scsi.h | 1 + trace-events | 1 + 3 files changed, 21 insertions(+), 4 deletions(-) diff --git a/hw/scsi-bus.c b/hw/scsi-bus.c index 1905da2..97a5deb 100644 --- a/hw/scsi-bus.c +++ b/hw/scsi-bus.c @@ -1096,8 +1096,12 @@ void scsi_req_continue(SCSIRequest *req) Once it completes, calling scsi_req_continue will restart I/O. */ void scsi_req_data(SCSIRequest *req, int len) { - trace_scsi_req_data(req->dev->id, req->lun, req->tag, len); - req->bus->info->transfer_data(req, len); + if (req->io_canceled) { + trace_scsi_req_data_canceled(req->dev->id, req->lun, req->tag, len); + } else { + trace_scsi_req_data(req->dev->id, req->lun, req->tag, len); + req->bus->info->transfer_data(req, len); + } } void scsi_req_print(SCSIRequest *req) @@ -1158,11 +1162,15 @@ void scsi_req_complete(SCSIRequest *req, int status) void scsi_req_cancel(SCSIRequest *req) { - if (req->ops->cancel_io) { - req->ops->cancel_io(req); + if (!req->enqueued) { + return; } scsi_req_ref(req); scsi_req_dequeue(req); + req->io_canceled = true; + if (req->ops->cancel_io) { + req->ops->cancel_io(req); + } if (req->bus->info->cancel) { req->bus->info->cancel(req); } @@ -1171,10 +1179,17 @@ void scsi_req_cancel(SCSIRequest *req) void scsi_req_abort(SCSIRequest *req, int status) { + if (!req->enqueued) { + return; + } + scsi_req_ref(req); + scsi_req_dequeue(req); + req->io_canceled = true; if (req->ops->cancel_io) { req->ops->cancel_io(req); } scsi_req_complete(req, status); + scsi_req_unref(req); } void scsi_device_purge_requests(SCSIDevice *sdev, SCSISense sense) diff --git a/hw/scsi.h b/hw/scsi.h index 483c9ae..6c922c5 100644 --- a/hw/scsi.h +++ b/hw/scsi.h @@ -52,6 +52,7 @@ struct SCSIRequest { uint8_t sense[SCSI_SENSE_BUF_SIZE]; uint32_t sense_len; bool enqueued; + bool io_canceled; void *hba_private; QTAILQ_ENTRY(SCSIRequest) next; }; diff --git a/trace-events b/trace-events index 1959d48..bb9f332 100644 --- a/trace-events +++ b/trace-events @@ -129,6 +129,7 @@ disable usb_set_device_feature(int addr, int feature, int ret) "dev %d, feature # hw/scsi-bus.c disable scsi_req_alloc(int target, int lun, int tag) "target %d lun %d tag %d" disable scsi_req_data(int target, int lun, int tag, int len) "target %d lun %d tag %d len %d" +disable scsi_req_data_canceled(int target, int lun, int tag, int len) "target %d lun %d tag %d len %d" disable scsi_req_dequeue(int target, int lun, int tag) "target %d lun %d tag %d" disable scsi_req_continue(int target, int lun, int tag) "target %d lun %d tag %d" disable scsi_req_parsed(int target, int lun, int tag, int cmd, int mode, int xfer) "target %d lun %d tag %d command %d dir %d length %d" -- 1.7.7.6