On Wed, Feb 10 2021 at 1:12P -0500,
Mike Snitzer <snit...@redhat.com> wrote:
> On Fri, Jan 22 2021 at 10:25am -0500,
> Nikos Tsironis <ntsiro...@arrikto.com> wrote:
>
> > The device metadata are resized in era_ctr(), so the metadata resize
> > operation in era_preresume() never runs.
> >
> > Also, note, that if the operation did ever run it would deadlock, since
> > the worker has not been started at this point.
It wouldn't have deadlocked, it'd have queued the work (see wake_worker)
> >
> > Fixes: eec40579d84873 ("dm: add era target")
> > Cc: sta...@vger.kernel.org # v3.15+
> > Signed-off-by: Nikos Tsironis <ntsiro...@arrikto.com>
> > ---
> > drivers/md/dm-era-target.c | 9 ---------
> > 1 file changed, 9 deletions(-)
> >
> > diff --git a/drivers/md/dm-era-target.c b/drivers/md/dm-era-target.c
> > index 104fb110cd4e..c40e132e50cd 100644
> > --- a/drivers/md/dm-era-target.c
> > +++ b/drivers/md/dm-era-target.c
> > @@ -1567,15 +1567,6 @@ static int era_preresume(struct dm_target *ti)
> > {
> > int r;
> > struct era *era = ti->private;
> > - dm_block_t new_size = calc_nr_blocks(era);
> > -
> > - if (era->nr_blocks != new_size) {
> > - r = in_worker1(era, metadata_resize, &new_size);
> > - if (r)
> > - return r;
> > -
> > - era->nr_blocks = new_size;
> > - }
> >
> > start_worker(era);
> >
> > --
> > 2.11.0
> >
>
> Resize shouldn't actually happen in the ctr. The ctr loads a temporary
> (inactive) table that will only become active upon resume. That is why
> resize should always be done in terms of resume.
>
> I'll look closer but ctr shouldn't do the actual resize, and the
> start_worker() should be moved above the resize code you've removed
> above.
Does this work for you? If so I'll get it staged (like I've just
staged all your other dm-era fixes for 5.12).
drivers/md/dm-era-target.c | 13 ++-----------
1 file changed, 2 insertions(+), 11 deletions(-)
diff --git a/drivers/md/dm-era-target.c b/drivers/md/dm-era-target.c
index d0e75fd31c1e..ec198e9cdafb 100644
--- a/drivers/md/dm-era-target.c
+++ b/drivers/md/dm-era-target.c
@@ -1501,15 +1501,6 @@ static int era_ctr(struct dm_target *ti, unsigned argc,
char **argv)
}
era->md = md;
- era->nr_blocks = calc_nr_blocks(era);
-
- r = metadata_resize(era->md, &era->nr_blocks);
- if (r) {
- ti->error = "couldn't resize metadata";
- era_destroy(era);
- return -ENOMEM;
- }
-
era->wq = alloc_ordered_workqueue("dm-" DM_MSG_PREFIX, WQ_MEM_RECLAIM);
if (!era->wq) {
ti->error = "could not create workqueue for metadata object";
@@ -1583,6 +1574,8 @@ static int era_preresume(struct dm_target *ti)
struct era *era = ti->private;
dm_block_t new_size = calc_nr_blocks(era);
+ start_worker(era);
+
if (era->nr_blocks != new_size) {
r = in_worker1(era, metadata_resize, &new_size);
if (r)
@@ -1591,8 +1584,6 @@ static int era_preresume(struct dm_target *ti)
era->nr_blocks = new_size;
}
- start_worker(era);
-
r = in_worker0(era, metadata_era_rollover);
if (r) {
DMERR("%s: metadata_era_rollover failed", __func__);
--
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