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[Qemu-devel] [PULL 33/39] scsi: Unify request unref in scsi_req_cancel
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PULL 33/39] scsi: Unify request unref in scsi_req_cancel |
Date: |
Tue, 30 Sep 2014 14:25:13 +0200 |
From: Fam Zheng <address@hidden>
Before, scsi_req_cancel will take ownership of the canceled request and unref
it. We did this because we didn't know whether AIO CB will be called or not
during the cancelling, so we set the io_canceled flag before calling it, and
skip unref in the potentially called callbacks, which is not very nice.
Now, bdrv_aio_cancel has a stricter contract that the completion callbacks are
always called, so we can remove the checks of req->io_canceled and just unref
it in callbacks.
It will also make implementing asynchronous cancellation easier.
Signed-off-by: Fam Zheng <address@hidden>
Signed-off-by: Paolo Bonzini <address@hidden>
---
hw/scsi/scsi-disk.c | 37 ++++++++-----------------------------
hw/scsi/scsi-generic.c | 13 ++-----------
2 files changed, 10 insertions(+), 40 deletions(-)
diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c
index 9645d01..2e45752 100644
--- a/hw/scsi/scsi-disk.c
+++ b/hw/scsi/scsi-disk.c
@@ -113,11 +113,6 @@ 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);
}
r->req.aiocb = NULL;
}
@@ -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)
@@ -246,9 +239,7 @@ 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)
@@ -280,9 +271,7 @@ 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)
@@ -320,9 +309,7 @@ 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. */
@@ -363,9 +350,7 @@ 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. */
@@ -481,9 +466,7 @@ 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)
@@ -1582,9 +1565,7 @@ 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);
}
@@ -1678,9 +1659,7 @@ 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 2a73a43..e92b418 100644
--- a/hw/scsi/scsi-generic.c
+++ b/hw/scsi/scsi-generic.c
@@ -137,9 +137,7 @@ static void scsi_command_complete(void *opaque, int ret)
scsi_req_complete(&r->req, status);
done:
- if (!r->req.io_canceled) {
- scsi_req_unref(&r->req);
- }
+ scsi_req_unref(&r->req);
}
/* Cancel a pending data transfer. */
@@ -150,11 +148,6 @@ 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 independent of whether bdrv_aio_cancel completes the request
- * or not. */
- scsi_req_unref(&r->req);
}
r->req.aiocb = NULL;
}
@@ -214,9 +207,7 @@ 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);
}
}
--
1.8.3.1
- [Qemu-devel] [PULL 23/39] virtio-scsi: Add VirtIOSCSIVring in VirtIOSCSIReq, (continued)
- [Qemu-devel] [PULL 23/39] virtio-scsi: Add VirtIOSCSIVring in VirtIOSCSIReq, Paolo Bonzini, 2014/09/30
- [Qemu-devel] [PULL 22/39] virtio-scsi: Add 'iothread' property to virtio-scsi, Paolo Bonzini, 2014/09/30
- [Qemu-devel] [PULL 24/39] virtio-scsi-dataplane: Code to run virtio-scsi on iothread, Paolo Bonzini, 2014/09/30
- [Qemu-devel] [PULL 25/39] virtio-scsi: Hook up with dataplane, Paolo Bonzini, 2014/09/30
- [Qemu-devel] [PULL 26/39] virtio-scsi: Add migration state notifier for dataplane code, Paolo Bonzini, 2014/09/30
- [Qemu-devel] [PULL 27/39] virtio-scsi: Two stages processing of cmd request, Paolo Bonzini, 2014/09/30
- [Qemu-devel] [PULL 28/39] virtio-scsi: Batched prepare for cmd reqs, Paolo Bonzini, 2014/09/30
- [Qemu-devel] [PULL 29/39] virtio-scsi: Call bdrv_io_plug/bdrv_io_unplug in cmd request handling, Paolo Bonzini, 2014/09/30
- [Qemu-devel] [PULL 30/39] virtio-scsi: Process ".iothread" property, Paolo Bonzini, 2014/09/30
- [Qemu-devel] [PULL 31/39] scsi: Drop scsi_req_abort, Paolo Bonzini, 2014/09/30
- [Qemu-devel] [PULL 33/39] scsi: Unify request unref in scsi_req_cancel,
Paolo Bonzini <=
- [Qemu-devel] [PULL 32/39] scsi-generic: Handle canceled request in scsi_command_complete, Paolo Bonzini, 2014/09/30
- [Qemu-devel] [PULL 34/39] scsi: Drop SCSIReqOps.cancel_io, Paolo Bonzini, 2014/09/30
- [Qemu-devel] [PULL 35/39] scsi: Introduce scsi_req_cancel_complete, Paolo Bonzini, 2014/09/30
- [Qemu-devel] [PULL 38/39] util: introduce bitmap_try_new, Paolo Bonzini, 2014/09/30
- [Qemu-devel] [PULL 39/39] block/iscsi: handle failure on malloc of the allocationmap, Paolo Bonzini, 2014/09/30
- [Qemu-devel] [PULL 36/39] scsi: Introduce scsi_req_cancel_async, Paolo Bonzini, 2014/09/30
- [Qemu-devel] [PULL 37/39] virtio-scsi: Handle TMF request cancellation asynchronously, Paolo Bonzini, 2014/09/30
- Re: [Qemu-devel] [PULL 00/39] SCSI changes for 2014-09-23, Peter Maydell, 2014/09/30