| Message ID | 20210416080911.83197-3-vsementsov@virtuozzo.com |
|---|---|
| State | New |
| Headers | show |
| Series | block/nbd: rework client connection | expand |
On Fri, Apr 16, 2021 at 11:08:40AM +0300, Vladimir Sementsov-Ogievskiy wrote: > We have two "return error" paths in nbd_open() after > nbd_process_options(). Actually we should call nbd_clear_bdrvstate() > on these paths. Interesting that nbd_process_options() calls > nbd_clear_bdrvstate() by itself. > > Let's fix leaks and refactor things to be more obvious: > > - intialize yank at top of nbd_open() > - move yank cleanup to nbd_clear_bdrvstate() > - refactor nbd_open() so that all failure paths except for > yank-register goes through nbd_clear_bdrvstate() > > Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> > --- > block/nbd.c | 36 ++++++++++++++++++------------------ > 1 file changed, 18 insertions(+), 18 deletions(-) > > diff --git a/block/nbd.c b/block/nbd.c > index 739ae2941f..a407a3814b 100644 > --- a/block/nbd.c > +++ b/block/nbd.c > @@ -152,8 +152,12 @@ static void nbd_co_establish_connection_cancel(BlockDriverState *bs, > static int nbd_client_handshake(BlockDriverState *bs, Error **errp); > static void nbd_yank(void *opaque); > > -static void nbd_clear_bdrvstate(BDRVNBDState *s) > +static void nbd_clear_bdrvstate(BlockDriverState *bs) > { > + BDRVNBDState *s = (BDRVNBDState *)bs->opaque; > + > + yank_unregister_instance(BLOCKDEV_YANK_INSTANCE(bs->node_name)); > + > object_unref(OBJECT(s->tlscreds)); > qapi_free_SocketAddress(s->saddr); > s->saddr = NULL; > @@ -2279,9 +2283,6 @@ static int nbd_process_options(BlockDriverState *bs, QDict *options, > ret = 0; > > error: > - if (ret < 0) { > - nbd_clear_bdrvstate(s); > - } > qemu_opts_del(opts); > return ret; > } > @@ -2292,11 +2293,6 @@ static int nbd_open(BlockDriverState *bs, QDict *options, int flags, > int ret; > BDRVNBDState *s = (BDRVNBDState *)bs->opaque; > > - ret = nbd_process_options(bs, options, errp); > - if (ret < 0) { > - return ret; > - } > - > s->bs = bs; > qemu_co_mutex_init(&s->send_mutex); > qemu_co_queue_init(&s->free_sema); > @@ -2305,20 +2301,23 @@ static int nbd_open(BlockDriverState *bs, QDict *options, int flags, > return -EEXIST; > } > > + ret = nbd_process_options(bs, options, errp); > + if (ret < 0) { > + goto fail; > + } > + > /* > * establish TCP connection, return error if it fails > * TODO: Configurable retry-until-timeout behaviour. > */ > if (nbd_establish_connection(bs, s->saddr, errp) < 0) { > - yank_unregister_instance(BLOCKDEV_YANK_INSTANCE(bs->node_name)); > - return -ECONNREFUSED; > + ret = -ECONNREFUSED; > + goto fail; > } > > ret = nbd_client_handshake(bs, errp); Not that this was introduced by this patch, but once you're at it: AFAICT nbd_client_handshake() calls yank_unregister_instance() on some error path(s); I assume this needs to go too, otherwise it's called twice (and asserts). Roman. > if (ret < 0) { > - yank_unregister_instance(BLOCKDEV_YANK_INSTANCE(bs->node_name)); > - nbd_clear_bdrvstate(s); > - return ret; > + goto fail; > } > /* successfully connected */ > s->state = NBD_CLIENT_CONNECTED; > @@ -2330,6 +2329,10 @@ static int nbd_open(BlockDriverState *bs, QDict *options, int flags, > aio_co_schedule(bdrv_get_aio_context(bs), s->connection_co); > > return 0; > + > +fail: > + nbd_clear_bdrvstate(bs); > + return ret; > } > > static int nbd_co_flush(BlockDriverState *bs) > @@ -2373,11 +2376,8 @@ static void nbd_refresh_limits(BlockDriverState *bs, Error **errp) > > static void nbd_close(BlockDriverState *bs) > { > - BDRVNBDState *s = bs->opaque; > - > nbd_client_close(bs); > - yank_unregister_instance(BLOCKDEV_YANK_INSTANCE(bs->node_name)); > - nbd_clear_bdrvstate(s); > + nbd_clear_bdrvstate(bs); > } > > /*
21.04.2021 17:00, Roman Kagan wrote: > On Fri, Apr 16, 2021 at 11:08:40AM +0300, Vladimir Sementsov-Ogievskiy wrote: >> We have two "return error" paths in nbd_open() after >> nbd_process_options(). Actually we should call nbd_clear_bdrvstate() >> on these paths. Interesting that nbd_process_options() calls >> nbd_clear_bdrvstate() by itself. >> >> Let's fix leaks and refactor things to be more obvious: >> >> - intialize yank at top of nbd_open() >> - move yank cleanup to nbd_clear_bdrvstate() >> - refactor nbd_open() so that all failure paths except for >> yank-register goes through nbd_clear_bdrvstate() >> >> Signed-off-by: Vladimir Sementsov-Ogievskiy<vsementsov@virtuozzo.com> >> --- >> block/nbd.c | 36 ++++++++++++++++++------------------ >> 1 file changed, 18 insertions(+), 18 deletions(-) >> >> diff --git a/block/nbd.c b/block/nbd.c >> index 739ae2941f..a407a3814b 100644 >> --- a/block/nbd.c >> +++ b/block/nbd.c >> @@ -152,8 +152,12 @@ static void nbd_co_establish_connection_cancel(BlockDriverState *bs, >> static int nbd_client_handshake(BlockDriverState *bs, Error **errp); >> static void nbd_yank(void *opaque); >> >> -static void nbd_clear_bdrvstate(BDRVNBDState *s) >> +static void nbd_clear_bdrvstate(BlockDriverState *bs) >> { >> + BDRVNBDState *s = (BDRVNBDState *)bs->opaque; >> + >> + yank_unregister_instance(BLOCKDEV_YANK_INSTANCE(bs->node_name)); >> + >> object_unref(OBJECT(s->tlscreds)); >> qapi_free_SocketAddress(s->saddr); >> s->saddr = NULL; >> @@ -2279,9 +2283,6 @@ static int nbd_process_options(BlockDriverState *bs, QDict *options, >> ret = 0; >> >> error: >> - if (ret < 0) { >> - nbd_clear_bdrvstate(s); >> - } >> qemu_opts_del(opts); >> return ret; >> } >> @@ -2292,11 +2293,6 @@ static int nbd_open(BlockDriverState *bs, QDict *options, int flags, >> int ret; >> BDRVNBDState *s = (BDRVNBDState *)bs->opaque; >> >> - ret = nbd_process_options(bs, options, errp); >> - if (ret < 0) { >> - return ret; >> - } >> - >> s->bs = bs; >> qemu_co_mutex_init(&s->send_mutex); >> qemu_co_queue_init(&s->free_sema); >> @@ -2305,20 +2301,23 @@ static int nbd_open(BlockDriverState *bs, QDict *options, int flags, >> return -EEXIST; >> } >> >> + ret = nbd_process_options(bs, options, errp); >> + if (ret < 0) { >> + goto fail; >> + } >> + >> /* >> * establish TCP connection, return error if it fails >> * TODO: Configurable retry-until-timeout behaviour. >> */ >> if (nbd_establish_connection(bs, s->saddr, errp) < 0) { >> - yank_unregister_instance(BLOCKDEV_YANK_INSTANCE(bs->node_name)); >> - return -ECONNREFUSED; >> + ret = -ECONNREFUSED; >> + goto fail; >> } >> >> ret = nbd_client_handshake(bs, errp); > Not that this was introduced by this patch, but once you're at it: > AFAICT nbd_client_handshake() calls yank_unregister_instance() on some > error path(s); I assume this needs to go too, otherwise it's called > twice (and asserts). > > Roman. > No, nbd_client_handshake() only calls yank_unregister_function(), not instance.
On Thu, Apr 22, 2021 at 01:27:22AM +0300, Vladimir Sementsov-Ogievskiy wrote: > 21.04.2021 17:00, Roman Kagan wrote: > > On Fri, Apr 16, 2021 at 11:08:40AM +0300, Vladimir Sementsov-Ogievskiy wrote: > > > @@ -2305,20 +2301,23 @@ static int nbd_open(BlockDriverState *bs, QDict *options, int flags, > > > return -EEXIST; > > > } > > > + ret = nbd_process_options(bs, options, errp); > > > + if (ret < 0) { > > > + goto fail; > > > + } > > > + > > > /* > > > * establish TCP connection, return error if it fails > > > * TODO: Configurable retry-until-timeout behaviour. > > > */ > > > if (nbd_establish_connection(bs, s->saddr, errp) < 0) { > > > - yank_unregister_instance(BLOCKDEV_YANK_INSTANCE(bs->node_name)); > > > - return -ECONNREFUSED; > > > + ret = -ECONNREFUSED; > > > + goto fail; > > > } > > > ret = nbd_client_handshake(bs, errp); > > Not that this was introduced by this patch, but once you're at it: > > AFAICT nbd_client_handshake() calls yank_unregister_instance() on some > > error path(s); I assume this needs to go too, otherwise it's called > > twice (and asserts). > > > > Roman. > > > > No, nbd_client_handshake() only calls yank_unregister_function(), not instance. Indeed. Sorry for confusion. Reviewed-by: Roman Kagan <rvkagan@yandex-team.ru>
On Fri, Apr 16, 2021 at 11:08:40AM +0300, Vladimir Sementsov-Ogievskiy wrote: > We have two "return error" paths in nbd_open() after > nbd_process_options(). Actually we should call nbd_clear_bdrvstate() > on these paths. Interesting that nbd_process_options() calls > nbd_clear_bdrvstate() by itself. > > Let's fix leaks and refactor things to be more obvious: > > - intialize yank at top of nbd_open() > - move yank cleanup to nbd_clear_bdrvstate() > - refactor nbd_open() so that all failure paths except for > yank-register goes through nbd_clear_bdrvstate() > > Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> > --- > block/nbd.c | 36 ++++++++++++++++++------------------ > 1 file changed, 18 insertions(+), 18 deletions(-) > Reviewed-by: Eric Blake <eblake@redhat.com> -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org
diff --git a/block/nbd.c b/block/nbd.c index 739ae2941f..a407a3814b 100644 --- a/block/nbd.c +++ b/block/nbd.c @@ -152,8 +152,12 @@ static void nbd_co_establish_connection_cancel(BlockDriverState *bs, static int nbd_client_handshake(BlockDriverState *bs, Error **errp); static void nbd_yank(void *opaque); -static void nbd_clear_bdrvstate(BDRVNBDState *s) +static void nbd_clear_bdrvstate(BlockDriverState *bs) { + BDRVNBDState *s = (BDRVNBDState *)bs->opaque; + + yank_unregister_instance(BLOCKDEV_YANK_INSTANCE(bs->node_name)); + object_unref(OBJECT(s->tlscreds)); qapi_free_SocketAddress(s->saddr); s->saddr = NULL; @@ -2279,9 +2283,6 @@ static int nbd_process_options(BlockDriverState *bs, QDict *options, ret = 0; error: - if (ret < 0) { - nbd_clear_bdrvstate(s); - } qemu_opts_del(opts); return ret; } @@ -2292,11 +2293,6 @@ static int nbd_open(BlockDriverState *bs, QDict *options, int flags, int ret; BDRVNBDState *s = (BDRVNBDState *)bs->opaque; - ret = nbd_process_options(bs, options, errp); - if (ret < 0) { - return ret; - } - s->bs = bs; qemu_co_mutex_init(&s->send_mutex); qemu_co_queue_init(&s->free_sema); @@ -2305,20 +2301,23 @@ static int nbd_open(BlockDriverState *bs, QDict *options, int flags, return -EEXIST; } + ret = nbd_process_options(bs, options, errp); + if (ret < 0) { + goto fail; + } + /* * establish TCP connection, return error if it fails * TODO: Configurable retry-until-timeout behaviour. */ if (nbd_establish_connection(bs, s->saddr, errp) < 0) { - yank_unregister_instance(BLOCKDEV_YANK_INSTANCE(bs->node_name)); - return -ECONNREFUSED; + ret = -ECONNREFUSED; + goto fail; } ret = nbd_client_handshake(bs, errp); if (ret < 0) { - yank_unregister_instance(BLOCKDEV_YANK_INSTANCE(bs->node_name)); - nbd_clear_bdrvstate(s); - return ret; + goto fail; } /* successfully connected */ s->state = NBD_CLIENT_CONNECTED; @@ -2330,6 +2329,10 @@ static int nbd_open(BlockDriverState *bs, QDict *options, int flags, aio_co_schedule(bdrv_get_aio_context(bs), s->connection_co); return 0; + +fail: + nbd_clear_bdrvstate(bs); + return ret; } static int nbd_co_flush(BlockDriverState *bs) @@ -2373,11 +2376,8 @@ static void nbd_refresh_limits(BlockDriverState *bs, Error **errp) static void nbd_close(BlockDriverState *bs) { - BDRVNBDState *s = bs->opaque; - nbd_client_close(bs); - yank_unregister_instance(BLOCKDEV_YANK_INSTANCE(bs->node_name)); - nbd_clear_bdrvstate(s); + nbd_clear_bdrvstate(bs); } /*
We have two "return error" paths in nbd_open() after nbd_process_options(). Actually we should call nbd_clear_bdrvstate() on these paths. Interesting that nbd_process_options() calls nbd_clear_bdrvstate() by itself. Let's fix leaks and refactor things to be more obvious: - intialize yank at top of nbd_open() - move yank cleanup to nbd_clear_bdrvstate() - refactor nbd_open() so that all failure paths except for yank-register goes through nbd_clear_bdrvstate() Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> --- block/nbd.c | 36 ++++++++++++++++++------------------ 1 file changed, 18 insertions(+), 18 deletions(-)