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authorPaolo Bonzini <pbonzini@redhat.com>2011-10-25 12:53:33 +0200
committerKevin Wolf <kwolf@redhat.com>2011-10-28 19:25:52 +0200
commite88c591d63ed1bc8520f4f276bebd77c22e4ec72 (patch)
tree5c12cbd48d40a4f27a7ea04dd4a2b04ef1485e8a
parent63db0f0eee3c0b2cc3a06b36daf50c4e7801ea1b (diff)
scsi: do not call transfer_data after canceling a request
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 <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
-rw-r--r--hw/scsi-bus.c23
-rw-r--r--hw/scsi.h1
-rw-r--r--trace-events1
3 files changed, 21 insertions, 4 deletions
diff --git a/hw/scsi-bus.c b/hw/scsi-bus.c
index 3cf571eea..dfce5fbee 100644
--- a/hw/scsi-bus.c
+++ b/hw/scsi-bus.c
@@ -1107,8 +1107,12 @@ 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)
@@ -1173,11 +1177,15 @@ 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);
}
@@ -1186,10 +1194,17 @@ 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 8ea744a39..fcc345581 100644
--- a/hw/scsi.h
+++ b/hw/scsi.h
@@ -51,6 +51,7 @@ 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 a8880550b..56443af72 100644
--- a/trace-events
+++ b/trace-events
@@ -278,6 +278,7 @@ usb_host_claim_port(int bus, int hub, int port) "bus %d, hub addr %d, port %d"
# hw/scsi-bus.c
scsi_req_alloc(int target, int lun, int tag) "target %d lun %d tag %d"
scsi_req_data(int target, int lun, int tag, int len) "target %d lun %d tag %d len %d"
+scsi_req_data_canceled(int target, int lun, int tag, int len) "target %d lun %d tag %d len %d"
scsi_req_dequeue(int target, int lun, int tag) "target %d lun %d tag %d"
scsi_req_continue(int target, int lun, int tag) "target %d lun %d tag %d"
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"