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[Qemu-devel] [PULL 01/15] scsi: revert change to scsi_req_cancel_async a
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PULL 01/15] scsi: revert change to scsi_req_cancel_async and add assertions |
Date: |
Fri, 15 Jan 2016 17:04:16 +0100 |
Fam Zheng noticed that the change in commit 36896bf ("scsi: always call
notifier on async cancellation", 2015-12-16) could cause a leak of
the request; scsi_req_cancel_async now calls scsi_req_ref
multiple times for multiple cancellations, but there is only
one call to scsi_req_cancel_complete.
So revert the patch and instead assert that the problematic case (a call
to scsi_req_cancel_async after the aiocb has been completed) cannot
happen.
Signed-off-by: Paolo Bonzini <address@hidden>
---
hw/scsi/scsi-bus.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/hw/scsi/scsi-bus.c b/hw/scsi/scsi-bus.c
index 00bddc9..378bf4d 100644
--- a/hw/scsi/scsi-bus.c
+++ b/hw/scsi/scsi-bus.c
@@ -1759,6 +1759,15 @@ void scsi_req_cancel_async(SCSIRequest *req, Notifier
*notifier)
if (notifier) {
notifier_list_add(&req->cancel_notifiers, notifier);
}
+ if (req->io_canceled) {
+ /* A blk_aio_cancel_async is pending; when it finishes,
+ * scsi_req_cancel_complete will be called and will
+ * call the notifier we just added. Just wait for that.
+ */
+ assert(req->aiocb);
+ return;
+ }
+ /* Dropped in scsi_req_cancel_complete. */
scsi_req_ref(req);
scsi_req_dequeue(req);
req->io_canceled = true;
@@ -1775,6 +1784,8 @@ void scsi_req_cancel(SCSIRequest *req)
if (!req->enqueued) {
return;
}
+ assert(!req->io_canceled);
+ /* Dropped in scsi_req_cancel_complete. */
scsi_req_ref(req);
scsi_req_dequeue(req);
req->io_canceled = true;
--
1.8.3.1
- [Qemu-devel] [PULL 00/15] NBD, chardev, SCSI patches for 2015-01-15, Paolo Bonzini, 2016/01/15
- [Qemu-devel] [PULL 02/15] target-i386: do not duplicate page protection checks, Paolo Bonzini, 2016/01/15
- [Qemu-devel] [PULL 01/15] scsi: revert change to scsi_req_cancel_async and add assertions,
Paolo Bonzini <=
- [Qemu-devel] [PULL 04/15] scsi: initialise info object with appropriate size, Paolo Bonzini, 2016/01/15
- [Qemu-devel] [PULL] i386: avoid null pointer dereference, Paolo Bonzini, 2016/01/15
- [Qemu-devel] [PULL 05/15] vmw_pvscsi: x-disable-pcie, x-old-pci-configuration back-compat props are 2.5 specific, Paolo Bonzini, 2016/01/15
- [Qemu-devel] [PULL 07/15] iscsi: send readcapacity10 when readcapacity16 failed, Paolo Bonzini, 2016/01/15
- [Qemu-devel] [PULL 03/15] i386: avoid null pointer dereference, Paolo Bonzini, 2016/01/15
[Qemu-devel] [PULL 12/15] nbd-server: do not check request length except for reads and writes, Paolo Bonzini, 2016/01/15