Message ID | 55F91755.1010704@cn.fujitsu.com |
---|---|
State | New |
Headers | show |
On 16/09/2015 09:16, Wen Congyang wrote: > If the socket fd is shutdown, there may be some data which is received before > shutdown. We will read the data and do read/write in nbd_trip(). But the exp's > blk is NULL, and it will cause qemu crashed. > > Reported-by: Li Zhijian <lizhijian@cn.fujitsu.com> > Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> > --- > nbd.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/nbd.c b/nbd.c > index 06b501b..d8586a1 100644 > --- a/nbd.c > +++ b/nbd.c > @@ -1132,6 +1132,7 @@ void nbd_export_close(NBDExport *exp) > nbd_export_set_name(exp, NULL); > nbd_export_put(exp); > if (exp->blk) { > + bdrv_drain(blk_bs(exp->blk)); > blk_remove_aio_context_notifier(exp->blk, blk_aio_attached, > blk_aio_detach, exp); > blk_unref(exp->blk); I think a better fix is to move the whole "if" to nbd_export_put. In fact, nbd_export_close is wrong because exp can be freed by nbd_export_close's call to nbd_export_put. > @@ -1305,6 +1306,14 @@ static void nbd_trip(void *opaque) > goto invalid_request; > } > > + if (client->closing) { > + /* > + * The client may be closed when we are blocked in > + * nbd_co_receive_request() > + */ > + goto done; > + } This is okay. Paolo > switch (command) { > case NBD_CMD_READ: > TRACE("Request type is READ"); >
On 09/16/2015 04:17 PM, Paolo Bonzini wrote: > > > On 16/09/2015 09:16, Wen Congyang wrote: >> If the socket fd is shutdown, there may be some data which is received before >> shutdown. We will read the data and do read/write in nbd_trip(). But the exp's >> blk is NULL, and it will cause qemu crashed. >> >> Reported-by: Li Zhijian <lizhijian@cn.fujitsu.com> >> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> >> --- >> nbd.c | 9 +++++++++ >> 1 file changed, 9 insertions(+) >> >> diff --git a/nbd.c b/nbd.c >> index 06b501b..d8586a1 100644 >> --- a/nbd.c >> +++ b/nbd.c >> @@ -1132,6 +1132,7 @@ void nbd_export_close(NBDExport *exp) >> nbd_export_set_name(exp, NULL); >> nbd_export_put(exp); >> if (exp->blk) { >> + bdrv_drain(blk_bs(exp->blk)); >> blk_remove_aio_context_notifier(exp->blk, blk_aio_attached, >> blk_aio_detach, exp); >> blk_unref(exp->blk); > > I think a better fix is to move the whole "if" to nbd_export_put. In > fact, nbd_export_close is wrong because exp can be freed by > nbd_export_close's call to nbd_export_put. OK, I will fix it in the next version. Thanks Wen Congyang > >> @@ -1305,6 +1306,14 @@ static void nbd_trip(void *opaque) >> goto invalid_request; >> } >> >> + if (client->closing) { >> + /* >> + * The client may be closed when we are blocked in >> + * nbd_co_receive_request() >> + */ >> + goto done; >> + } > > This is okay. > > Paolo > >> switch (command) { >> case NBD_CMD_READ: >> TRACE("Request type is READ"); >> > . >
On 16/09/2015 10:22, Wen Congyang wrote: >>> >> if (exp->blk) { >>> >> + bdrv_drain(blk_bs(exp->blk)); >>> >> blk_remove_aio_context_notifier(exp->blk, blk_aio_attached, >>> >> blk_aio_detach, exp); >>> >> blk_unref(exp->blk); >> > >> > I think a better fix is to move the whole "if" to nbd_export_put. In >> > fact, nbd_export_close is wrong because exp can be freed by >> > nbd_export_close's call to nbd_export_put. > OK, I will fix it in the next version. To be clear, the bug is pre-existing (commit 38b54b6, "nbd: use BlockDriverState refcnt", 2013-08-23). Paolo
diff --git a/nbd.c b/nbd.c index 06b501b..d8586a1 100644 --- a/nbd.c +++ b/nbd.c @@ -1132,6 +1132,7 @@ void nbd_export_close(NBDExport *exp) nbd_export_set_name(exp, NULL); nbd_export_put(exp); if (exp->blk) { + bdrv_drain(blk_bs(exp->blk)); blk_remove_aio_context_notifier(exp->blk, blk_aio_attached, blk_aio_detach, exp); blk_unref(exp->blk); @@ -1305,6 +1306,14 @@ static void nbd_trip(void *opaque) goto invalid_request; } + if (client->closing) { + /* + * The client may be closed when we are blocked in + * nbd_co_receive_request() + */ + goto done; + } + switch (command) { case NBD_CMD_READ: TRACE("Request type is READ");
If the socket fd is shutdown, there may be some data which is received before shutdown. We will read the data and do read/write in nbd_trip(). But the exp's blk is NULL, and it will cause qemu crashed. Reported-by: Li Zhijian <lizhijian@cn.fujitsu.com> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> --- nbd.c | 9 +++++++++ 1 file changed, 9 insertions(+)