* [Qemu-devel] [PATCH v2 0/2] virtio-scsi: Fix assertion failure on dataplane handlers
@ 2017-03-14 15:36 Fam Zheng
2017-03-14 15:36 ` [Qemu-devel] [PATCH v2 1/2] virtio-scsi: Make virtio_scsi_acquire/release public Fam Zheng
2017-03-14 15:36 ` [Qemu-devel] [PATCH v2 2/2] virtio-scsi: Fix acquire/release in dataplane handlers Fam Zheng
0 siblings, 2 replies; 10+ messages in thread
From: Fam Zheng @ 2017-03-14 15:36 UTC (permalink / raw)
To: qemu-devel; +Cc: Paolo Bonzini
v2: Use virtio_scsi_acquire/release. [Paolo]
Fam Zheng (2):
virtio-scsi: Make virtio_scsi_acquire/release public
virtio-scsi: Fix acquire/release in dataplane handlers
hw/scsi/virtio-scsi-dataplane.c | 20 ++++++++++++++++----
hw/scsi/virtio-scsi.c | 40 ++++++++++++++--------------------------
include/hw/virtio/virtio-scsi.h | 14 ++++++++++++++
3 files changed, 44 insertions(+), 30 deletions(-)
--
2.9.3
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Qemu-devel] [PATCH v2 1/2] virtio-scsi: Make virtio_scsi_acquire/release public
2017-03-14 15:36 [Qemu-devel] [PATCH v2 0/2] virtio-scsi: Fix assertion failure on dataplane handlers Fam Zheng
@ 2017-03-14 15:36 ` Fam Zheng
2017-03-14 15:36 ` [Qemu-devel] [PATCH v2 2/2] virtio-scsi: Fix acquire/release in dataplane handlers Fam Zheng
1 sibling, 0 replies; 10+ messages in thread
From: Fam Zheng @ 2017-03-14 15:36 UTC (permalink / raw)
To: qemu-devel; +Cc: Paolo Bonzini
They will be used in virtio-scsi-dataplane.c as well, so move them to
header.
Signed-off-by: Fam Zheng <famz@redhat.com>
---
hw/scsi/virtio-scsi.c | 14 --------------
include/hw/virtio/virtio-scsi.h | 14 ++++++++++++++
2 files changed, 14 insertions(+), 14 deletions(-)
diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c
index 1dbc4bc..e7466d3 100644
--- a/hw/scsi/virtio-scsi.c
+++ b/hw/scsi/virtio-scsi.c
@@ -422,20 +422,6 @@ static void virtio_scsi_handle_ctrl_req(VirtIOSCSI *s, VirtIOSCSIReq *req)
}
}
-static inline void virtio_scsi_acquire(VirtIOSCSI *s)
-{
- if (s->ctx) {
- aio_context_acquire(s->ctx);
- }
-}
-
-static inline void virtio_scsi_release(VirtIOSCSI *s)
-{
- if (s->ctx) {
- aio_context_release(s->ctx);
- }
-}
-
bool virtio_scsi_handle_ctrl_vq(VirtIOSCSI *s, VirtQueue *vq)
{
VirtIOSCSIReq *req;
diff --git a/include/hw/virtio/virtio-scsi.h b/include/hw/virtio/virtio-scsi.h
index f536f77..8ae0aca 100644
--- a/include/hw/virtio/virtio-scsi.h
+++ b/include/hw/virtio/virtio-scsi.h
@@ -121,6 +121,20 @@ typedef struct VirtIOSCSIReq {
} req;
} VirtIOSCSIReq;
+static inline void virtio_scsi_acquire(VirtIOSCSI *s)
+{
+ if (s->ctx) {
+ aio_context_acquire(s->ctx);
+ }
+}
+
+static inline void virtio_scsi_release(VirtIOSCSI *s)
+{
+ if (s->ctx) {
+ aio_context_release(s->ctx);
+ }
+}
+
void virtio_scsi_common_realize(DeviceState *dev, Error **errp,
VirtIOHandleOutput ctrl, VirtIOHandleOutput evt,
VirtIOHandleOutput cmd);
--
2.9.3
^ permalink raw reply related [flat|nested] 10+ messages in thread
* [Qemu-devel] [PATCH v2 2/2] virtio-scsi: Fix acquire/release in dataplane handlers
2017-03-14 15:36 [Qemu-devel] [PATCH v2 0/2] virtio-scsi: Fix assertion failure on dataplane handlers Fam Zheng
2017-03-14 15:36 ` [Qemu-devel] [PATCH v2 1/2] virtio-scsi: Make virtio_scsi_acquire/release public Fam Zheng
@ 2017-03-14 15:36 ` Fam Zheng
2017-03-15 17:25 ` Ed Swierk
` (3 more replies)
1 sibling, 4 replies; 10+ messages in thread
From: Fam Zheng @ 2017-03-14 15:36 UTC (permalink / raw)
To: qemu-devel; +Cc: Paolo Bonzini
After the AioContext lock push down, there is a race between
virtio_scsi_dataplane_start and those "assert(s->ctx &&
s->dataplane_started)", because the latter doesn't isn't wrapped in
aio_context_acquire.
Reproducer is simply booting a Fedora guest with an empty
virtio-scsi-dataplane controller:
qemu-system-x86_64 \
-drive if=none,id=root,format=raw,file=Fedora-Cloud-Base-25-1.3.x86_64.raw \
-device virtio-scsi \
-device scsi-disk,drive=root,bootindex=1 \
-object iothread,id=io \
-device virtio-scsi-pci,iothread=io \
-net user,hostfwd=tcp::10022-:22 -net nic,model=virtio -m 2048 \
--enable-kvm
Fix this by moving acquire/release pairs from virtio_scsi_handle_*_vq to
their callers - and wrap the broken assertions in.
Signed-off-by: Fam Zheng <famz@redhat.com>
---
hw/scsi/virtio-scsi-dataplane.c | 20 ++++++++++++++++----
hw/scsi/virtio-scsi.c | 26 ++++++++++++++------------
2 files changed, 30 insertions(+), 16 deletions(-)
diff --git a/hw/scsi/virtio-scsi-dataplane.c b/hw/scsi/virtio-scsi-dataplane.c
index 74c95e0..944ea4e 100644
--- a/hw/scsi/virtio-scsi-dataplane.c
+++ b/hw/scsi/virtio-scsi-dataplane.c
@@ -52,28 +52,40 @@ void virtio_scsi_dataplane_setup(VirtIOSCSI *s, Error **errp)
static bool virtio_scsi_data_plane_handle_cmd(VirtIODevice *vdev,
VirtQueue *vq)
{
- VirtIOSCSI *s = (VirtIOSCSI *)vdev;
+ bool progress;
+ VirtIOSCSI *s = VIRTIO_SCSI(vdev);
+ virtio_scsi_acquire(s);
assert(s->ctx && s->dataplane_started);
- return virtio_scsi_handle_cmd_vq(s, vq);
+ progress = virtio_scsi_handle_cmd_vq(s, vq);
+ virtio_scsi_release(s);
+ return progress;
}
static bool virtio_scsi_data_plane_handle_ctrl(VirtIODevice *vdev,
VirtQueue *vq)
{
+ bool progress;
VirtIOSCSI *s = VIRTIO_SCSI(vdev);
+ virtio_scsi_acquire(s);
assert(s->ctx && s->dataplane_started);
- return virtio_scsi_handle_ctrl_vq(s, vq);
+ progress = virtio_scsi_handle_ctrl_vq(s, vq);
+ virtio_scsi_release(s);
+ return progress;
}
static bool virtio_scsi_data_plane_handle_event(VirtIODevice *vdev,
VirtQueue *vq)
{
+ bool progress;
VirtIOSCSI *s = VIRTIO_SCSI(vdev);
+ virtio_scsi_acquire(s);
assert(s->ctx && s->dataplane_started);
- return virtio_scsi_handle_event_vq(s, vq);
+ progress = virtio_scsi_handle_event_vq(s, vq);
+ virtio_scsi_release(s);
+ return progress;
}
static int virtio_scsi_vring_init(VirtIOSCSI *s, VirtQueue *vq, int n,
diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c
index e7466d3..4939f1f 100644
--- a/hw/scsi/virtio-scsi.c
+++ b/hw/scsi/virtio-scsi.c
@@ -427,12 +427,10 @@ bool virtio_scsi_handle_ctrl_vq(VirtIOSCSI *s, VirtQueue *vq)
VirtIOSCSIReq *req;
bool progress = false;
- virtio_scsi_acquire(s);
while ((req = virtio_scsi_pop_req(s, vq))) {
progress = true;
virtio_scsi_handle_ctrl_req(s, req);
}
- virtio_scsi_release(s);
return progress;
}
@@ -446,7 +444,9 @@ static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
return;
}
}
+ virtio_scsi_acquire(s);
virtio_scsi_handle_ctrl_vq(s, vq);
+ virtio_scsi_release(s);
}
static void virtio_scsi_complete_cmd_req(VirtIOSCSIReq *req)
@@ -590,7 +590,6 @@ bool virtio_scsi_handle_cmd_vq(VirtIOSCSI *s, VirtQueue *vq)
QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs);
- virtio_scsi_acquire(s);
do {
virtio_queue_set_notification(vq, 0);
@@ -618,7 +617,6 @@ bool virtio_scsi_handle_cmd_vq(VirtIOSCSI *s, VirtQueue *vq)
QTAILQ_FOREACH_SAFE(req, &reqs, next, next) {
virtio_scsi_handle_cmd_req_submit(s, req);
}
- virtio_scsi_release(s);
return progress;
}
@@ -633,7 +631,9 @@ static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq)
return;
}
}
+ virtio_scsi_acquire(s);
virtio_scsi_handle_cmd_vq(s, vq);
+ virtio_scsi_release(s);
}
static void virtio_scsi_get_config(VirtIODevice *vdev,
@@ -709,12 +709,10 @@ void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
return;
}
- virtio_scsi_acquire(s);
-
req = virtio_scsi_pop_req(s, vs->event_vq);
if (!req) {
s->events_dropped = true;
- goto out;
+ return;
}
if (s->events_dropped) {
@@ -724,7 +722,7 @@ void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
if (virtio_scsi_parse_req(req, 0, sizeof(VirtIOSCSIEvent))) {
virtio_scsi_bad_req(req);
- goto out;
+ return;
}
evt = &req->resp.event;
@@ -744,19 +742,15 @@ void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
evt->lun[3] = dev->lun & 0xFF;
}
virtio_scsi_complete_req(req);
-out:
- virtio_scsi_release(s);
}
bool virtio_scsi_handle_event_vq(VirtIOSCSI *s, VirtQueue *vq)
{
- virtio_scsi_acquire(s);
if (s->events_dropped) {
virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
virtio_scsi_release(s);
return true;
}
- virtio_scsi_release(s);
return false;
}
@@ -770,7 +764,9 @@ static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
return;
}
}
+ virtio_scsi_acquire(s);
virtio_scsi_handle_event_vq(s, vq);
+ virtio_scsi_release(s);
}
static void virtio_scsi_change(SCSIBus *bus, SCSIDevice *dev, SCSISense sense)
@@ -780,8 +776,10 @@ static void virtio_scsi_change(SCSIBus *bus, SCSIDevice *dev, SCSISense sense)
if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_CHANGE) &&
dev->type != TYPE_ROM) {
+ virtio_scsi_acquire(s);
virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_PARAM_CHANGE,
sense.asc | (sense.ascq << 8));
+ virtio_scsi_release(s);
}
}
@@ -803,9 +801,11 @@ static void virtio_scsi_hotplug(HotplugHandler *hotplug_dev, DeviceState *dev,
}
if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
+ virtio_scsi_acquire(s);
virtio_scsi_push_event(s, sd,
VIRTIO_SCSI_T_TRANSPORT_RESET,
VIRTIO_SCSI_EVT_RESET_RESCAN);
+ virtio_scsi_release(s);
}
}
@@ -817,9 +817,11 @@ static void virtio_scsi_hotunplug(HotplugHandler *hotplug_dev, DeviceState *dev,
SCSIDevice *sd = SCSI_DEVICE(dev);
if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
+ virtio_scsi_acquire(s);
virtio_scsi_push_event(s, sd,
VIRTIO_SCSI_T_TRANSPORT_RESET,
VIRTIO_SCSI_EVT_RESET_REMOVED);
+ virtio_scsi_release(s);
}
qdev_simple_device_unplug_cb(hotplug_dev, dev, errp);
--
2.9.3
^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: [Qemu-devel] [PATCH v2 2/2] virtio-scsi: Fix acquire/release in dataplane handlers
2017-03-14 15:36 ` [Qemu-devel] [PATCH v2 2/2] virtio-scsi: Fix acquire/release in dataplane handlers Fam Zheng
@ 2017-03-15 17:25 ` Ed Swierk
2017-03-16 1:22 ` Fam Zheng
` (2 subsequent siblings)
3 siblings, 0 replies; 10+ messages in thread
From: Ed Swierk @ 2017-03-15 17:25 UTC (permalink / raw)
To: Fam Zheng; +Cc: qemu-devel, Paolo Bonzini
On Tue, Mar 14, 2017 at 8:36 AM, Fam Zheng <famz@redhat.com> wrote:
> After the AioContext lock push down, there is a race between
> virtio_scsi_dataplane_start and those "assert(s->ctx &&
> s->dataplane_started)", because the latter doesn't isn't wrapped in
> aio_context_acquire.
>
> Reproducer is simply booting a Fedora guest with an empty
> virtio-scsi-dataplane controller:
>
> qemu-system-x86_64 \
> -drive if=none,id=root,format=raw,file=Fedora-Cloud-Base-25-1.3.x86_64.raw \
> -device virtio-scsi \
> -device scsi-disk,drive=root,bootindex=1 \
> -object iothread,id=io \
> -device virtio-scsi-pci,iothread=io \
> -net user,hostfwd=tcp::10022-:22 -net nic,model=virtio -m 2048 \
> --enable-kvm
>
> Fix this by moving acquire/release pairs from virtio_scsi_handle_*_vq to
> their callers - and wrap the broken assertions in.
>
> Signed-off-by: Fam Zheng <famz@redhat.com>
Verified this fixes the assertion failure on 2.9.0-rc0.
Tested-by: Ed Swierk <eswierk@skyportsystems.com>
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [Qemu-devel] [PATCH v2 2/2] virtio-scsi: Fix acquire/release in dataplane handlers
2017-03-14 15:36 ` [Qemu-devel] [PATCH v2 2/2] virtio-scsi: Fix acquire/release in dataplane handlers Fam Zheng
2017-03-15 17:25 ` Ed Swierk
@ 2017-03-16 1:22 ` Fam Zheng
2017-03-16 23:48 ` Ed Swierk
2017-03-17 0:26 ` Ed Swierk
3 siblings, 0 replies; 10+ messages in thread
From: Fam Zheng @ 2017-03-16 1:22 UTC (permalink / raw)
To: qemu-devel; +Cc: Paolo Bonzini
On Tue, 03/14 23:36, Fam Zheng wrote:
> After the AioContext lock push down, there is a race between
> virtio_scsi_dataplane_start and those "assert(s->ctx &&
> s->dataplane_started)", because the latter doesn't isn't wrapped in
s/doesn't//
> aio_context_acquire.
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [Qemu-devel] [PATCH v2 2/2] virtio-scsi: Fix acquire/release in dataplane handlers
2017-03-14 15:36 ` [Qemu-devel] [PATCH v2 2/2] virtio-scsi: Fix acquire/release in dataplane handlers Fam Zheng
2017-03-15 17:25 ` Ed Swierk
2017-03-16 1:22 ` Fam Zheng
@ 2017-03-16 23:48 ` Ed Swierk
2017-03-17 1:34 ` Fam Zheng
2017-03-17 0:26 ` Ed Swierk
3 siblings, 1 reply; 10+ messages in thread
From: Ed Swierk @ 2017-03-16 23:48 UTC (permalink / raw)
To: Fam Zheng; +Cc: qemu-devel, Paolo Bonzini
On Tue, Mar 14, 2017 at 8:36 AM, Fam Zheng <famz@redhat.com> wrote:
> diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c
> index e7466d3..4939f1f 100644
> --- a/hw/scsi/virtio-scsi.c
> +++ b/hw/scsi/virtio-scsi.c
> ...
> bool virtio_scsi_handle_event_vq(VirtIOSCSI *s, VirtQueue *vq)
> {
> - virtio_scsi_acquire(s);
> if (s->events_dropped) {
> virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
> virtio_scsi_release(s);
Did you intend to leave this virtio_scsi_release() call?
> return true;
> }
> - virtio_scsi_release(s);
> return false;
> }
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [Qemu-devel] [PATCH v2 2/2] virtio-scsi: Fix acquire/release in dataplane handlers
2017-03-14 15:36 ` [Qemu-devel] [PATCH v2 2/2] virtio-scsi: Fix acquire/release in dataplane handlers Fam Zheng
` (2 preceding siblings ...)
2017-03-16 23:48 ` Ed Swierk
@ 2017-03-17 0:26 ` Ed Swierk
2017-03-17 6:02 ` Fam Zheng
3 siblings, 1 reply; 10+ messages in thread
From: Ed Swierk @ 2017-03-17 0:26 UTC (permalink / raw)
To: Fam Zheng; +Cc: qemu-devel, Paolo Bonzini
On Tue, Mar 14, 2017 at 8:36 AM, Fam Zheng <famz@redhat.com> wrote:
> After the AioContext lock push down, there is a race between
> virtio_scsi_dataplane_start and those "assert(s->ctx &&
> s->dataplane_started)", because the latter doesn't isn't wrapped in
> aio_context_acquire.
>
> Reproducer is simply booting a Fedora guest with an empty
> virtio-scsi-dataplane controller:
>
> qemu-system-x86_64 \
> -drive if=none,id=root,format=raw,file=Fedora-Cloud-Base-25-1.3.x86_64.raw \
> -device virtio-scsi \
> -device scsi-disk,drive=root,bootindex=1 \
> -object iothread,id=io \
> -device virtio-scsi-pci,iothread=io \
> -net user,hostfwd=tcp::10022-:22 -net nic,model=virtio -m 2048 \
> --enable-kvm
>
> Fix this by moving acquire/release pairs from virtio_scsi_handle_*_vq to
> their callers - and wrap the broken assertions in.
>
> Signed-off-by: Fam Zheng <famz@redhat.com>
With this change on top of 2.9.0-rc0, I am able to boot a Linux guest
from a virtio-scsi drive with an iothread, e.g.
qemu-system-x86_64 -nographic -enable-kvm -monitor
telnet:0.0.0.0:1234,server,nowait -m 1024 -object
iothread,id=iothread1 -device
virtio-scsi-pci,iothread=iothread1,id=scsi0 -drive
file=/x/drive.qcow2,format=qcow2,if=none,id=drive0,cache=directsync,aio=native
-device scsi-hd,drive=drive0,bootindex=1
But when I try to take a snapshot by running this in the monitor
snapshot_blkdev drive0 /x/snap1.qcow2
qemu bombs with
qemu-system-x86_64: /x/qemu/include/block/aio.h:457:
aio_enable_external: Assertion `ctx->external_disable_cnt > 0' failed.
This does not occur if I don't use the iothread.
I instrumented the code a bit, printing the value of bs,
bdrv_get_aio_context(bs), and
bdrv_get_aio_context(bs)->external_disable_cnt before and after
aio_{disable,enable}_external() in bdrv_drained_{begin,end}().
Without the iothread, nested calls to these functions cause the
counter to increase and decrease as you'd expect, and the context is
the same in each call.
bdrv_drained_begin 0 bs=0x7fe9f5ad65a0 ctx=0x7fe9f5abc7b0 cnt=0
bdrv_drained_begin 1 bs=0x7fe9f5ad65a0 ctx=0x7fe9f5abc7b0 cnt=1
bdrv_drained_begin 0 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=1
bdrv_drained_begin 1 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=2
bdrv_drained_end 0 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=2
bdrv_drained_end 1 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=1
bdrv_drained_begin 0 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=1
bdrv_drained_begin 1 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=2
bdrv_drained_begin 0 bs=0x7fe9f67cfde0 ctx=0x7fe9f5abc7b0 cnt=2
bdrv_drained_begin 1 bs=0x7fe9f67cfde0 ctx=0x7fe9f5abc7b0 cnt=3
bdrv_drained_end 0 bs=0x7fe9f67cfde0 ctx=0x7fe9f5abc7b0 cnt=3
bdrv_drained_end 1 bs=0x7fe9f67cfde0 ctx=0x7fe9f5abc7b0 cnt=2
bdrv_drained_end 0 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=2
bdrv_drained_end 1 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=1
bdrv_drained_begin 0 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=1
bdrv_drained_begin 1 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=2
bdrv_drained_begin 0 bs=0x7fe9f67cfde0 ctx=0x7fe9f5abc7b0 cnt=2
bdrv_drained_begin 1 bs=0x7fe9f67cfde0 ctx=0x7fe9f5abc7b0 cnt=3
bdrv_drained_end 0 bs=0x7fe9f67cfde0 ctx=0x7fe9f5abc7b0 cnt=3
bdrv_drained_end 1 bs=0x7fe9f67cfde0 ctx=0x7fe9f5abc7b0 cnt=2
bdrv_drained_end 0 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=2
bdrv_drained_end 1 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=1
bdrv_drained_begin 0 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=1
bdrv_drained_begin 1 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=2
bdrv_drained_end 0 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=2
bdrv_drained_end 1 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=1
bdrv_drained_end 0 bs=0x7fe9f5ad65a0 ctx=0x7fe9f5abc7b0 cnt=1
bdrv_drained_end 1 bs=0x7fe9f5ad65a0 ctx=0x7fe9f5abc7b0 cnt=0
But with the iothread, there are at least two different context
pointers, and there is one extra call to bdrv_drained_end() without a
matching bdrv_drained_begin(). That last call comes from
external_snapshot_clean().
bdrv_drained_begin 0 bs=0x7fe4437545c0 ctx=0x7fe443749a00 cnt=0
bdrv_drained_begin 1 bs=0x7fe4437545c0 ctx=0x7fe443749a00 cnt=1
bdrv_drained_begin 0 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=0
bdrv_drained_begin 1 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=1
bdrv_drained_end 0 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=1
bdrv_drained_end 1 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=0
bdrv_drained_begin 0 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=0
bdrv_drained_begin 1 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=1
bdrv_drained_begin 0 bs=0x7fe44444de20 ctx=0x7fe44373a7b0 cnt=1
bdrv_drained_begin 1 bs=0x7fe44444de20 ctx=0x7fe44373a7b0 cnt=2
bdrv_drained_end 0 bs=0x7fe44444de20 ctx=0x7fe44373a7b0 cnt=2
bdrv_drained_end 1 bs=0x7fe44444de20 ctx=0x7fe44373a7b0 cnt=1
bdrv_drained_end 0 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=1
bdrv_drained_end 1 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=0
bdrv_drained_begin 0 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=0
bdrv_drained_begin 1 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=1
bdrv_drained_begin 0 bs=0x7fe44444de20 ctx=0x7fe44373a7b0 cnt=1
bdrv_drained_begin 1 bs=0x7fe44444de20 ctx=0x7fe44373a7b0 cnt=2
bdrv_drained_end 0 bs=0x7fe44444de20 ctx=0x7fe44373a7b0 cnt=2
bdrv_drained_end 1 bs=0x7fe44444de20 ctx=0x7fe44373a7b0 cnt=1
bdrv_drained_end 0 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=1
bdrv_drained_end 1 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=0
bdrv_drained_begin 0 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=0
bdrv_drained_begin 1 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=1
bdrv_drained_end 0 bs=0x7fe443990a00 ctx=0x7fe443749a00 cnt=1
bdrv_drained_end 1 bs=0x7fe443990a00 ctx=0x7fe443749a00 cnt=0
bdrv_drained_end 0 bs=0x7fe4437545c0 ctx=0x7fe443749a00 cnt=0
qemu-system-x86_64: /x/qemu/include/block/aio.h:457:
aio_enable_external: Assertion `ctx->external_disable_cnt > 0' failed.
I didn't have much luck bisecting the bug, since about 200 commits
prior to 2.9.0-rc0 qemu bombs immediately on boot, and after that I
get the assertion addressed by your patch. I have to go farther back
to find a working version.
Any help would be appreciated.
--Ed
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [Qemu-devel] [PATCH v2 2/2] virtio-scsi: Fix acquire/release in dataplane handlers
2017-03-16 23:48 ` Ed Swierk
@ 2017-03-17 1:34 ` Fam Zheng
0 siblings, 0 replies; 10+ messages in thread
From: Fam Zheng @ 2017-03-17 1:34 UTC (permalink / raw)
To: Ed Swierk; +Cc: qemu-devel, Paolo Bonzini
On Thu, 03/16 16:48, Ed Swierk wrote:
> On Tue, Mar 14, 2017 at 8:36 AM, Fam Zheng <famz@redhat.com> wrote:
> > diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c
> > index e7466d3..4939f1f 100644
> > --- a/hw/scsi/virtio-scsi.c
> > +++ b/hw/scsi/virtio-scsi.c
> > ...
> > bool virtio_scsi_handle_event_vq(VirtIOSCSI *s, VirtQueue *vq)
> > {
> > - virtio_scsi_acquire(s);
> > if (s->events_dropped) {
> > virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
> > virtio_scsi_release(s);
>
> Did you intend to leave this virtio_scsi_release() call?
Oops, no, we should drop it.
Fam
>
> > return true;
> > }
> > - virtio_scsi_release(s);
> > return false;
> > }
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [Qemu-devel] [PATCH v2 2/2] virtio-scsi: Fix acquire/release in dataplane handlers
2017-03-17 0:26 ` Ed Swierk
@ 2017-03-17 6:02 ` Fam Zheng
2017-03-17 6:13 ` Ed Swierk
0 siblings, 1 reply; 10+ messages in thread
From: Fam Zheng @ 2017-03-17 6:02 UTC (permalink / raw)
To: Ed Swierk; +Cc: Paolo Bonzini, qemu-devel
On Thu, 03/16 17:26, Ed Swierk wrote:
> On Tue, Mar 14, 2017 at 8:36 AM, Fam Zheng <famz@redhat.com> wrote:
> > After the AioContext lock push down, there is a race between
> > virtio_scsi_dataplane_start and those "assert(s->ctx &&
> > s->dataplane_started)", because the latter doesn't isn't wrapped in
> > aio_context_acquire.
> >
> > Reproducer is simply booting a Fedora guest with an empty
> > virtio-scsi-dataplane controller:
> >
> > qemu-system-x86_64 \
> > -drive if=none,id=root,format=raw,file=Fedora-Cloud-Base-25-1.3.x86_64.raw \
> > -device virtio-scsi \
> > -device scsi-disk,drive=root,bootindex=1 \
> > -object iothread,id=io \
> > -device virtio-scsi-pci,iothread=io \
> > -net user,hostfwd=tcp::10022-:22 -net nic,model=virtio -m 2048 \
> > --enable-kvm
> >
> > Fix this by moving acquire/release pairs from virtio_scsi_handle_*_vq to
> > their callers - and wrap the broken assertions in.
> >
> > Signed-off-by: Fam Zheng <famz@redhat.com>
>
> With this change on top of 2.9.0-rc0, I am able to boot a Linux guest
> from a virtio-scsi drive with an iothread, e.g.
>
> qemu-system-x86_64 -nographic -enable-kvm -monitor
> telnet:0.0.0.0:1234,server,nowait -m 1024 -object
> iothread,id=iothread1 -device
> virtio-scsi-pci,iothread=iothread1,id=scsi0 -drive
> file=/x/drive.qcow2,format=qcow2,if=none,id=drive0,cache=directsync,aio=native
> -device scsi-hd,drive=drive0,bootindex=1
>
> But when I try to take a snapshot by running this in the monitor
>
> snapshot_blkdev drive0 /x/snap1.qcow2
>
> qemu bombs with
>
> qemu-system-x86_64: /x/qemu/include/block/aio.h:457:
> aio_enable_external: Assertion `ctx->external_disable_cnt > 0' failed.
>
> This does not occur if I don't use the iothread.
>
> I instrumented the code a bit, printing the value of bs,
> bdrv_get_aio_context(bs), and
> bdrv_get_aio_context(bs)->external_disable_cnt before and after
> aio_{disable,enable}_external() in bdrv_drained_{begin,end}().
>
> Without the iothread, nested calls to these functions cause the
> counter to increase and decrease as you'd expect, and the context is
> the same in each call.
>
> bdrv_drained_begin 0 bs=0x7fe9f5ad65a0 ctx=0x7fe9f5abc7b0 cnt=0
> bdrv_drained_begin 1 bs=0x7fe9f5ad65a0 ctx=0x7fe9f5abc7b0 cnt=1
> bdrv_drained_begin 0 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=1
> bdrv_drained_begin 1 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=2
> bdrv_drained_end 0 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=2
> bdrv_drained_end 1 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=1
> bdrv_drained_begin 0 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=1
> bdrv_drained_begin 1 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=2
> bdrv_drained_begin 0 bs=0x7fe9f67cfde0 ctx=0x7fe9f5abc7b0 cnt=2
> bdrv_drained_begin 1 bs=0x7fe9f67cfde0 ctx=0x7fe9f5abc7b0 cnt=3
> bdrv_drained_end 0 bs=0x7fe9f67cfde0 ctx=0x7fe9f5abc7b0 cnt=3
> bdrv_drained_end 1 bs=0x7fe9f67cfde0 ctx=0x7fe9f5abc7b0 cnt=2
> bdrv_drained_end 0 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=2
> bdrv_drained_end 1 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=1
> bdrv_drained_begin 0 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=1
> bdrv_drained_begin 1 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=2
> bdrv_drained_begin 0 bs=0x7fe9f67cfde0 ctx=0x7fe9f5abc7b0 cnt=2
> bdrv_drained_begin 1 bs=0x7fe9f67cfde0 ctx=0x7fe9f5abc7b0 cnt=3
> bdrv_drained_end 0 bs=0x7fe9f67cfde0 ctx=0x7fe9f5abc7b0 cnt=3
> bdrv_drained_end 1 bs=0x7fe9f67cfde0 ctx=0x7fe9f5abc7b0 cnt=2
> bdrv_drained_end 0 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=2
> bdrv_drained_end 1 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=1
> bdrv_drained_begin 0 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=1
> bdrv_drained_begin 1 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=2
> bdrv_drained_end 0 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=2
> bdrv_drained_end 1 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=1
> bdrv_drained_end 0 bs=0x7fe9f5ad65a0 ctx=0x7fe9f5abc7b0 cnt=1
> bdrv_drained_end 1 bs=0x7fe9f5ad65a0 ctx=0x7fe9f5abc7b0 cnt=0
>
> But with the iothread, there are at least two different context
> pointers, and there is one extra call to bdrv_drained_end() without a
> matching bdrv_drained_begin(). That last call comes from
> external_snapshot_clean().
>
> bdrv_drained_begin 0 bs=0x7fe4437545c0 ctx=0x7fe443749a00 cnt=0
> bdrv_drained_begin 1 bs=0x7fe4437545c0 ctx=0x7fe443749a00 cnt=1
> bdrv_drained_begin 0 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=0
> bdrv_drained_begin 1 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=1
> bdrv_drained_end 0 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=1
> bdrv_drained_end 1 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=0
> bdrv_drained_begin 0 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=0
> bdrv_drained_begin 1 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=1
> bdrv_drained_begin 0 bs=0x7fe44444de20 ctx=0x7fe44373a7b0 cnt=1
> bdrv_drained_begin 1 bs=0x7fe44444de20 ctx=0x7fe44373a7b0 cnt=2
> bdrv_drained_end 0 bs=0x7fe44444de20 ctx=0x7fe44373a7b0 cnt=2
> bdrv_drained_end 1 bs=0x7fe44444de20 ctx=0x7fe44373a7b0 cnt=1
> bdrv_drained_end 0 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=1
> bdrv_drained_end 1 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=0
> bdrv_drained_begin 0 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=0
> bdrv_drained_begin 1 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=1
> bdrv_drained_begin 0 bs=0x7fe44444de20 ctx=0x7fe44373a7b0 cnt=1
> bdrv_drained_begin 1 bs=0x7fe44444de20 ctx=0x7fe44373a7b0 cnt=2
> bdrv_drained_end 0 bs=0x7fe44444de20 ctx=0x7fe44373a7b0 cnt=2
> bdrv_drained_end 1 bs=0x7fe44444de20 ctx=0x7fe44373a7b0 cnt=1
> bdrv_drained_end 0 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=1
> bdrv_drained_end 1 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=0
> bdrv_drained_begin 0 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=0
> bdrv_drained_begin 1 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=1
> bdrv_drained_end 0 bs=0x7fe443990a00 ctx=0x7fe443749a00 cnt=1
> bdrv_drained_end 1 bs=0x7fe443990a00 ctx=0x7fe443749a00 cnt=0
> bdrv_drained_end 0 bs=0x7fe4437545c0 ctx=0x7fe443749a00 cnt=0
> qemu-system-x86_64: /x/qemu/include/block/aio.h:457:
> aio_enable_external: Assertion `ctx->external_disable_cnt > 0' failed.
This may indeed come from the left-behind virtio_scsi_release() you pointed out,
I'll fix it in v3 and please see if it helps.
Fam
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [Qemu-devel] [PATCH v2 2/2] virtio-scsi: Fix acquire/release in dataplane handlers
2017-03-17 6:02 ` Fam Zheng
@ 2017-03-17 6:13 ` Ed Swierk
0 siblings, 0 replies; 10+ messages in thread
From: Ed Swierk @ 2017-03-17 6:13 UTC (permalink / raw)
To: Fam Zheng; +Cc: qemu-devel, Paolo Bonzini
On Mar 16, 2017 23:02, "Fam Zheng" <famz@redhat.com> wrote:
On Thu, 03/16 17:26, Ed Swierk wrote:
> On Tue, Mar 14, 2017 at 8:36 AM, Fam Zheng <famz@redhat.com> wrote:
> > After the AioContext lock push down, there is a race between
> > virtio_scsi_dataplane_start and those "assert(s->ctx &&
> > s->dataplane_started)", because the latter doesn't isn't wrapped in
> > aio_context_acquire.
> >
> > Reproducer is simply booting a Fedora guest with an empty
> > virtio-scsi-dataplane controller:
> >
> > qemu-system-x86_64 \
> > -drive if=none,id=root,format=raw,file=Fedora-Cloud-Base-25-1.3.x86_64.raw
\
> > -device virtio-scsi \
> > -device scsi-disk,drive=root,bootindex=1 \
> > -object iothread,id=io \
> > -device virtio-scsi-pci,iothread=io \
> > -net user,hostfwd=tcp::10022-:22 -net nic,model=virtio -m 2048 \
> > --enable-kvm
> >
> > Fix this by moving acquire/release pairs from virtio_scsi_handle_*_vq to
> > their callers - and wrap the broken assertions in.
> >
> > Signed-off-by: Fam Zheng <famz@redhat.com>
>
> With this change on top of 2.9.0-rc0, I am able to boot a Linux guest
> from a virtio-scsi drive with an iothread, e.g.
>
> qemu-system-x86_64 -nographic -enable-kvm -monitor
> telnet:0.0.0.0:1234,server,nowait -m 1024 -object
> iothread,id=iothread1 -device
> virtio-scsi-pci,iothread=iothread1,id=scsi0 -drive
> file=/x/drive.qcow2,format=qcow2,if=none,id=drive0,cache=
directsync,aio=native
> -device scsi-hd,drive=drive0,bootindex=1
>
> But when I try to take a snapshot by running this in the monitor
>
> snapshot_blkdev drive0 /x/snap1.qcow2
>
> qemu bombs with
>
> qemu-system-x86_64: /x/qemu/include/block/aio.h:457:
> aio_enable_external: Assertion `ctx->external_disable_cnt > 0' failed.
>
> This does not occur if I don't use the iothread.
>
> I instrumented the code a bit, printing the value of bs,
> bdrv_get_aio_context(bs), and
> bdrv_get_aio_context(bs)->external_disable_cnt before and after
> aio_{disable,enable}_external() in bdrv_drained_{begin,end}().
>
> Without the iothread, nested calls to these functions cause the
> counter to increase and decrease as you'd expect, and the context is
> the same in each call.
>
> bdrv_drained_begin 0 bs=0x7fe9f5ad65a0 ctx=0x7fe9f5abc7b0 cnt=0
> bdrv_drained_begin 1 bs=0x7fe9f5ad65a0 ctx=0x7fe9f5abc7b0 cnt=1
> bdrv_drained_begin 0 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=1
> bdrv_drained_begin 1 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=2
> bdrv_drained_end 0 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=2
> bdrv_drained_end 1 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=1
> bdrv_drained_begin 0 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=1
> bdrv_drained_begin 1 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=2
> bdrv_drained_begin 0 bs=0x7fe9f67cfde0 ctx=0x7fe9f5abc7b0 cnt=2
> bdrv_drained_begin 1 bs=0x7fe9f67cfde0 ctx=0x7fe9f5abc7b0 cnt=3
> bdrv_drained_end 0 bs=0x7fe9f67cfde0 ctx=0x7fe9f5abc7b0 cnt=3
> bdrv_drained_end 1 bs=0x7fe9f67cfde0 ctx=0x7fe9f5abc7b0 cnt=2
> bdrv_drained_end 0 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=2
> bdrv_drained_end 1 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=1
> bdrv_drained_begin 0 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=1
> bdrv_drained_begin 1 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=2
> bdrv_drained_begin 0 bs=0x7fe9f67cfde0 ctx=0x7fe9f5abc7b0 cnt=2
> bdrv_drained_begin 1 bs=0x7fe9f67cfde0 ctx=0x7fe9f5abc7b0 cnt=3
> bdrv_drained_end 0 bs=0x7fe9f67cfde0 ctx=0x7fe9f5abc7b0 cnt=3
> bdrv_drained_end 1 bs=0x7fe9f67cfde0 ctx=0x7fe9f5abc7b0 cnt=2
> bdrv_drained_end 0 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=2
> bdrv_drained_end 1 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=1
> bdrv_drained_begin 0 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=1
> bdrv_drained_begin 1 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=2
> bdrv_drained_end 0 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=2
> bdrv_drained_end 1 bs=0x7fe9f5d12a00 ctx=0x7fe9f5abc7b0 cnt=1
> bdrv_drained_end 0 bs=0x7fe9f5ad65a0 ctx=0x7fe9f5abc7b0 cnt=1
> bdrv_drained_end 1 bs=0x7fe9f5ad65a0 ctx=0x7fe9f5abc7b0 cnt=0
>
> But with the iothread, there are at least two different context
> pointers, and there is one extra call to bdrv_drained_end() without a
> matching bdrv_drained_begin(). That last call comes from
> external_snapshot_clean().
>
> bdrv_drained_begin 0 bs=0x7fe4437545c0 ctx=0x7fe443749a00 cnt=0
> bdrv_drained_begin 1 bs=0x7fe4437545c0 ctx=0x7fe443749a00 cnt=1
> bdrv_drained_begin 0 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=0
> bdrv_drained_begin 1 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=1
> bdrv_drained_end 0 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=1
> bdrv_drained_end 1 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=0
> bdrv_drained_begin 0 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=0
> bdrv_drained_begin 1 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=1
> bdrv_drained_begin 0 bs=0x7fe44444de20 ctx=0x7fe44373a7b0 cnt=1
> bdrv_drained_begin 1 bs=0x7fe44444de20 ctx=0x7fe44373a7b0 cnt=2
> bdrv_drained_end 0 bs=0x7fe44444de20 ctx=0x7fe44373a7b0 cnt=2
> bdrv_drained_end 1 bs=0x7fe44444de20 ctx=0x7fe44373a7b0 cnt=1
> bdrv_drained_end 0 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=1
> bdrv_drained_end 1 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=0
> bdrv_drained_begin 0 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=0
> bdrv_drained_begin 1 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=1
> bdrv_drained_begin 0 bs=0x7fe44444de20 ctx=0x7fe44373a7b0 cnt=1
> bdrv_drained_begin 1 bs=0x7fe44444de20 ctx=0x7fe44373a7b0 cnt=2
> bdrv_drained_end 0 bs=0x7fe44444de20 ctx=0x7fe44373a7b0 cnt=2
> bdrv_drained_end 1 bs=0x7fe44444de20 ctx=0x7fe44373a7b0 cnt=1
> bdrv_drained_end 0 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=1
> bdrv_drained_end 1 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=0
> bdrv_drained_begin 0 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=0
> bdrv_drained_begin 1 bs=0x7fe443990a00 ctx=0x7fe44373a7b0 cnt=1
> bdrv_drained_end 0 bs=0x7fe443990a00 ctx=0x7fe443749a00 cnt=1
> bdrv_drained_end 1 bs=0x7fe443990a00 ctx=0x7fe443749a00 cnt=0
> bdrv_drained_end 0 bs=0x7fe4437545c0 ctx=0x7fe443749a00 cnt=0
> qemu-system-x86_64: /x/qemu/include/block/aio.h:457:
> aio_enable_external: Assertion `ctx->external_disable_cnt > 0' failed.
This may indeed come from the left-behind virtio_scsi_release() you pointed
out,
I'll fix it in v3 and please see if it helps.
Fam
I tried that, but the 'ctx->external_disable_cnt > 0' assertion still
occurs.
--Ed
^ permalink raw reply [flat|nested] 10+ messages in thread
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2017-03-14 15:36 [Qemu-devel] [PATCH v2 0/2] virtio-scsi: Fix assertion failure on dataplane handlers Fam Zheng
2017-03-14 15:36 ` [Qemu-devel] [PATCH v2 1/2] virtio-scsi: Make virtio_scsi_acquire/release public Fam Zheng
2017-03-14 15:36 ` [Qemu-devel] [PATCH v2 2/2] virtio-scsi: Fix acquire/release in dataplane handlers Fam Zheng
2017-03-15 17:25 ` Ed Swierk
2017-03-16 1:22 ` Fam Zheng
2017-03-16 23:48 ` Ed Swierk
2017-03-17 1:34 ` Fam Zheng
2017-03-17 0:26 ` Ed Swierk
2017-03-17 6:02 ` Fam Zheng
2017-03-17 6:13 ` Ed Swierk
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