| Message ID | 20180907161520.26349-12-kwolf@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | Fix some jobs/drain/aio_poll related hangs | expand |
On Fri, 09/07 18:15, Kevin Wolf wrote: > When starting an active commit job, other callbacks can run before > mirror_start_job() calls bdrv_ref() where needed and cause the nodes to > go away. Add another pair of bdrv_ref/unref() around it to protect > against this case. > > Signed-off-by: Kevin Wolf <kwolf@redhat.com> > --- > block/mirror.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/block/mirror.c b/block/mirror.c > index 6cc10df5c9..c42999eadf 100644 > --- a/block/mirror.c > +++ b/block/mirror.c > @@ -1679,6 +1679,11 @@ void commit_active_start(const char *job_id, BlockDriverState *bs, > > orig_base_flags = bdrv_get_flags(base); > > + /* bdrv_reopen() drains, which might make the BDSes go away before a > + * reference is taken in mirror_start_job(). */ > + bdrv_ref(bs); > + bdrv_ref(base); > + > if (bdrv_reopen(base, bs->open_flags, errp)) { Doesn't it need bdrv_unref's in this branch? > return; > } > @@ -1689,6 +1694,10 @@ void commit_active_start(const char *job_id, BlockDriverState *bs, > &commit_active_job_driver, false, base, auto_complete, > filter_node_name, false, MIRROR_COPY_MODE_BACKGROUND, > &local_err); > + > + bdrv_unref(bs); > + bdrv_unref(base); > + > if (local_err) { > error_propagate(errp, local_err); > goto error_restore_flags; > -- > 2.13.6 >
Am 11.09.2018 um 10:31 hat Fam Zheng geschrieben: > On Fri, 09/07 18:15, Kevin Wolf wrote: > > When starting an active commit job, other callbacks can run before > > mirror_start_job() calls bdrv_ref() where needed and cause the nodes to > > go away. Add another pair of bdrv_ref/unref() around it to protect > > against this case. > > > > Signed-off-by: Kevin Wolf <kwolf@redhat.com> > > --- > > block/mirror.c | 9 +++++++++ > > 1 file changed, 9 insertions(+) > > > > diff --git a/block/mirror.c b/block/mirror.c > > index 6cc10df5c9..c42999eadf 100644 > > --- a/block/mirror.c > > +++ b/block/mirror.c > > @@ -1679,6 +1679,11 @@ void commit_active_start(const char *job_id, BlockDriverState *bs, > > > > orig_base_flags = bdrv_get_flags(base); > > > > + /* bdrv_reopen() drains, which might make the BDSes go away before a > > + * reference is taken in mirror_start_job(). */ > > + bdrv_ref(bs); > > + bdrv_ref(base); > > + > > if (bdrv_reopen(base, bs->open_flags, errp)) { > > Doesn't it need bdrv_unref's in this branch? Yes, of course. Thanks for catching this! Kevin
diff --git a/block/mirror.c b/block/mirror.c index 6cc10df5c9..c42999eadf 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -1679,6 +1679,11 @@ void commit_active_start(const char *job_id, BlockDriverState *bs, orig_base_flags = bdrv_get_flags(base); + /* bdrv_reopen() drains, which might make the BDSes go away before a + * reference is taken in mirror_start_job(). */ + bdrv_ref(bs); + bdrv_ref(base); + if (bdrv_reopen(base, bs->open_flags, errp)) { return; } @@ -1689,6 +1694,10 @@ void commit_active_start(const char *job_id, BlockDriverState *bs, &commit_active_job_driver, false, base, auto_complete, filter_node_name, false, MIRROR_COPY_MODE_BACKGROUND, &local_err); + + bdrv_unref(bs); + bdrv_unref(base); + if (local_err) { error_propagate(errp, local_err); goto error_restore_flags;
When starting an active commit job, other callbacks can run before mirror_start_job() calls bdrv_ref() where needed and cause the nodes to go away. Add another pair of bdrv_ref/unref() around it to protect against this case. Signed-off-by: Kevin Wolf <kwolf@redhat.com> --- block/mirror.c | 9 +++++++++ 1 file changed, 9 insertions(+)