* [PATCH] hw/nvme: fix control flow statement
@ 2022-04-15 19:27 Dmitry Tikhov
2022-04-15 19:35 ` Keith Busch
0 siblings, 1 reply; 5+ messages in thread
From: Dmitry Tikhov @ 2022-04-15 19:27 UTC (permalink / raw)
To: qemu-devel; +Cc: kbusch, its, ddtikhov, qemu-block, linux
Since there is no else after nvme_dsm_cb invocation, metadata associated
with non-zero block range is currently zeroed. Also this behaviour leads
to segfault since we schedule iocb->bh two times. First when entering
nvme_dsm_cb with iocb->idx == iocb->nr and second on call stack unwinding
by calling blk_aio_pwrite_zeroes and subsequent nvme_dsm_cb callback
because of missing else statement.
Signed-off-by: Dmitry Tikhov <d.tihov@yadro.com>
---
hw/nvme/ctrl.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/hw/nvme/ctrl.c b/hw/nvme/ctrl.c
index 03760ddeae..7ebd2aa326 100644
--- a/hw/nvme/ctrl.c
+++ b/hw/nvme/ctrl.c
@@ -2372,11 +2372,12 @@ static void nvme_dsm_md_cb(void *opaque, int ret)
}
nvme_dsm_cb(iocb, 0);
+ } else {
+ iocb->aiocb = blk_aio_pwrite_zeroes(ns->blkconf.blk, nvme_moff(ns, slba),
+ nvme_m2b(ns, nlb), BDRV_REQ_MAY_UNMAP,
+ nvme_dsm_cb, iocb);
}
- iocb->aiocb = blk_aio_pwrite_zeroes(ns->blkconf.blk, nvme_moff(ns, slba),
- nvme_m2b(ns, nlb), BDRV_REQ_MAY_UNMAP,
- nvme_dsm_cb, iocb);
return;
done:
--
2.35.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] hw/nvme: fix control flow statement
2022-04-15 19:27 [PATCH] hw/nvme: fix control flow statement Dmitry Tikhov
@ 2022-04-15 19:35 ` Keith Busch
2022-04-15 19:42 ` Klaus Jensen
0 siblings, 1 reply; 5+ messages in thread
From: Keith Busch @ 2022-04-15 19:35 UTC (permalink / raw)
To: Dmitry Tikhov; +Cc: its, ddtikhov, qemu-devel, qemu-block, linux
On Fri, Apr 15, 2022 at 10:27:21PM +0300, Dmitry Tikhov wrote:
> Since there is no else after nvme_dsm_cb invocation, metadata associated
> with non-zero block range is currently zeroed. Also this behaviour leads
> to segfault since we schedule iocb->bh two times. First when entering
> nvme_dsm_cb with iocb->idx == iocb->nr and second on call stack unwinding
> by calling blk_aio_pwrite_zeroes and subsequent nvme_dsm_cb callback
> because of missing else statement.
>
> Signed-off-by: Dmitry Tikhov <d.tihov@yadro.com>
> ---
> hw/nvme/ctrl.c | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/hw/nvme/ctrl.c b/hw/nvme/ctrl.c
> index 03760ddeae..7ebd2aa326 100644
> --- a/hw/nvme/ctrl.c
> +++ b/hw/nvme/ctrl.c
> @@ -2372,11 +2372,12 @@ static void nvme_dsm_md_cb(void *opaque, int ret)
> }
>
> nvme_dsm_cb(iocb, 0);
> + } else {
> + iocb->aiocb = blk_aio_pwrite_zeroes(ns->blkconf.blk, nvme_moff(ns, slba),
> + nvme_m2b(ns, nlb), BDRV_REQ_MAY_UNMAP,
> + nvme_dsm_cb, iocb);
> }
Instead of the 'else', just insert an early 'return;' after nvme_dsm_cb() like
the earlier condition above here. Otherwise, looks good, and thanks for the
fix.
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] hw/nvme: fix control flow statement
2022-04-15 19:35 ` Keith Busch
@ 2022-04-15 19:42 ` Klaus Jensen
2022-04-15 20:23 ` Dmitry Tikhov
0 siblings, 1 reply; 5+ messages in thread
From: Klaus Jensen @ 2022-04-15 19:42 UTC (permalink / raw)
To: Keith Busch; +Cc: ddtikhov, linux, Dmitry Tikhov, qemu-block, qemu-devel
[-- Attachment #1: Type: text/plain, Size: 1564 bytes --]
On Apr 15 13:35, Keith Busch wrote:
> On Fri, Apr 15, 2022 at 10:27:21PM +0300, Dmitry Tikhov wrote:
> > Since there is no else after nvme_dsm_cb invocation, metadata associated
> > with non-zero block range is currently zeroed. Also this behaviour leads
> > to segfault since we schedule iocb->bh two times. First when entering
> > nvme_dsm_cb with iocb->idx == iocb->nr and second on call stack unwinding
> > by calling blk_aio_pwrite_zeroes and subsequent nvme_dsm_cb callback
> > because of missing else statement.
> >
> > Signed-off-by: Dmitry Tikhov <d.tihov@yadro.com>
> > ---
> > hw/nvme/ctrl.c | 7 ++++---
> > 1 file changed, 4 insertions(+), 3 deletions(-)
> >
> > diff --git a/hw/nvme/ctrl.c b/hw/nvme/ctrl.c
> > index 03760ddeae..7ebd2aa326 100644
> > --- a/hw/nvme/ctrl.c
> > +++ b/hw/nvme/ctrl.c
> > @@ -2372,11 +2372,12 @@ static void nvme_dsm_md_cb(void *opaque, int ret)
> > }
> >
> > nvme_dsm_cb(iocb, 0);
> > + } else {
> > + iocb->aiocb = blk_aio_pwrite_zeroes(ns->blkconf.blk, nvme_moff(ns, slba),
> > + nvme_m2b(ns, nlb), BDRV_REQ_MAY_UNMAP,
> > + nvme_dsm_cb, iocb);
> > }
>
> Instead of the 'else', just insert an early 'return;' after nvme_dsm_cb() like
> the earlier condition above here. Otherwise, looks good, and thanks for the
> fix.
Dmitry,
Agree with Keith - also, please add
Fixes: d7d1474fd85d ("hw/nvme: reimplement dsm to allow cancellation")
Thanks again!
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^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] hw/nvme: fix control flow statement
2022-04-15 19:42 ` Klaus Jensen
@ 2022-04-15 20:23 ` Dmitry Tikhov
2022-04-15 20:27 ` Klaus Jensen
0 siblings, 1 reply; 5+ messages in thread
From: Dmitry Tikhov @ 2022-04-15 20:23 UTC (permalink / raw)
To: Klaus Jensen; +Cc: Keith Busch, ddtikhov, qemu-devel, qemu-block, linux
On Fri, Apr 15, 2022 at 21:42:05, Klaus Jensen wrote:
> On Apr 15 13:35, Keith Busch wrote:
> > On Fri, Apr 15, 2022 at 10:27:21PM +0300, Dmitry Tikhov wrote:
> > > Since there is no else after nvme_dsm_cb invocation, metadata associated
> > > with non-zero block range is currently zeroed. Also this behaviour leads
> > > to segfault since we schedule iocb->bh two times. First when entering
> > > nvme_dsm_cb with iocb->idx == iocb->nr and second on call stack unwinding
> > > by calling blk_aio_pwrite_zeroes and subsequent nvme_dsm_cb callback
> > > because of missing else statement.
> > >
> > > Signed-off-by: Dmitry Tikhov <d.tihov@yadro.com>
> > > ---
> > > hw/nvme/ctrl.c | 7 ++++---
> > > 1 file changed, 4 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/hw/nvme/ctrl.c b/hw/nvme/ctrl.c
> > > index 03760ddeae..7ebd2aa326 100644
> > > --- a/hw/nvme/ctrl.c
> > > +++ b/hw/nvme/ctrl.c
> > > @@ -2372,11 +2372,12 @@ static void nvme_dsm_md_cb(void *opaque, int ret)
> > > }
> > >
> > > nvme_dsm_cb(iocb, 0);
> > > + } else {
> > > + iocb->aiocb = blk_aio_pwrite_zeroes(ns->blkconf.blk, nvme_moff(ns, slba),
> > > + nvme_m2b(ns, nlb), BDRV_REQ_MAY_UNMAP,
> > > + nvme_dsm_cb, iocb);
> > > }
> >
> > Instead of the 'else', just insert an early 'return;' after nvme_dsm_cb() like
> > the earlier condition above here. Otherwise, looks good, and thanks for the
> > fix.
>
> Dmitry,
>
> Agree with Keith - also, please add
>
> Fixes: d7d1474fd85d ("hw/nvme: reimplement dsm to allow cancellation")
>
> Thanks again!
Ok, will do. Can i change patch subject text or it should stay
the same between submissions?
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] hw/nvme: fix control flow statement
2022-04-15 20:23 ` Dmitry Tikhov
@ 2022-04-15 20:27 ` Klaus Jensen
0 siblings, 0 replies; 5+ messages in thread
From: Klaus Jensen @ 2022-04-15 20:27 UTC (permalink / raw)
To: Dmitry Tikhov; +Cc: Keith Busch, ddtikhov, qemu-devel, qemu-block, linux
[-- Attachment #1: Type: text/plain, Size: 1943 bytes --]
On Apr 15 23:23, Dmitry Tikhov wrote:
> On Fri, Apr 15, 2022 at 21:42:05, Klaus Jensen wrote:
> > On Apr 15 13:35, Keith Busch wrote:
> > > On Fri, Apr 15, 2022 at 10:27:21PM +0300, Dmitry Tikhov wrote:
> > > > Since there is no else after nvme_dsm_cb invocation, metadata associated
> > > > with non-zero block range is currently zeroed. Also this behaviour leads
> > > > to segfault since we schedule iocb->bh two times. First when entering
> > > > nvme_dsm_cb with iocb->idx == iocb->nr and second on call stack unwinding
> > > > by calling blk_aio_pwrite_zeroes and subsequent nvme_dsm_cb callback
> > > > because of missing else statement.
> > > >
> > > > Signed-off-by: Dmitry Tikhov <d.tihov@yadro.com>
> > > > ---
> > > > hw/nvme/ctrl.c | 7 ++++---
> > > > 1 file changed, 4 insertions(+), 3 deletions(-)
> > > >
> > > > diff --git a/hw/nvme/ctrl.c b/hw/nvme/ctrl.c
> > > > index 03760ddeae..7ebd2aa326 100644
> > > > --- a/hw/nvme/ctrl.c
> > > > +++ b/hw/nvme/ctrl.c
> > > > @@ -2372,11 +2372,12 @@ static void nvme_dsm_md_cb(void *opaque, int ret)
> > > > }
> > > >
> > > > nvme_dsm_cb(iocb, 0);
> > > > + } else {
> > > > + iocb->aiocb = blk_aio_pwrite_zeroes(ns->blkconf.blk, nvme_moff(ns, slba),
> > > > + nvme_m2b(ns, nlb), BDRV_REQ_MAY_UNMAP,
> > > > + nvme_dsm_cb, iocb);
> > > > }
> > >
> > > Instead of the 'else', just insert an early 'return;' after nvme_dsm_cb() like
> > > the earlier condition above here. Otherwise, looks good, and thanks for the
> > > fix.
> >
> > Dmitry,
> >
> > Agree with Keith - also, please add
> >
> > Fixes: d7d1474fd85d ("hw/nvme: reimplement dsm to allow cancellation")
> >
> > Thanks again!
>
> Ok, will do. Can i change patch subject text or it should stay
> the same between submissions?
Changing it is ok :)
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^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2022-04-15 21:13 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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2022-04-15 19:27 [PATCH] hw/nvme: fix control flow statement Dmitry Tikhov
2022-04-15 19:35 ` Keith Busch
2022-04-15 19:42 ` Klaus Jensen
2022-04-15 20:23 ` Dmitry Tikhov
2022-04-15 20:27 ` Klaus Jensen
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