| Message ID | 20210211142243.31062-1-ntsironis@arrikto.com (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Delegated to: | Mike Snitzer |
| Headers | show |
| Series | [v2] dm era: only resize metadata in preresume | expand |
On Thu, Feb 11 2021 at 9:22am -0500, Nikos Tsironis <ntsironis@arrikto.com> wrote: > Metadata resize shouldn't 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. Otherwise a load (ctr) > whose inactive table never becomes active will incorrectly resize the > metadata. > > Also, perform the resize directly in preresume, instead of using the > worker to do it. > > The worker might run other metadata operations, e.g., it could start > digestion, before resizing the metadata. These operations will end up > using the old size. > > This could lead to errors, like: > > device-mapper: era: metadata_digest_transcribe_writeset: dm_array_set_value failed > device-mapper: era: process_old_eras: digest step failed, stopping digestion > > The reason of the above error is that the worker started the digestion > of the archived writeset using the old, larger size. > > As a result, metadata_digest_transcribe_writeset tried to write beyond > the end of the era array. > > Fixes: eec40579d84873 ("dm: add era target") > Cc: stable@vger.kernel.org # v3.15+ > Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com> > --- > drivers/md/dm-era-target.c | 21 ++++++++++----------- > 1 file changed, 10 insertions(+), 11 deletions(-) Thanks, I replaced the patch I created (that used a worker to resize from preresume) with this. Now staged for 5.12. Mike -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel
diff --git a/drivers/md/dm-era-target.c b/drivers/md/dm-era-target.c index d0e75fd31c1e..d9ac7372108c 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"; @@ -1584,9 +1575,17 @@ static int era_preresume(struct dm_target *ti) 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) + r = metadata_resize(era->md, &new_size); + if (r) { + DMERR("%s: metadata_resize failed", __func__); return r; + } + + r = metadata_commit(era->md); + if (r) { + DMERR("%s: metadata_commit failed", __func__); + return r; + } era->nr_blocks = new_size; }
Metadata resize shouldn't 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. Otherwise a load (ctr) whose inactive table never becomes active will incorrectly resize the metadata. Also, perform the resize directly in preresume, instead of using the worker to do it. The worker might run other metadata operations, e.g., it could start digestion, before resizing the metadata. These operations will end up using the old size. This could lead to errors, like: device-mapper: era: metadata_digest_transcribe_writeset: dm_array_set_value failed device-mapper: era: process_old_eras: digest step failed, stopping digestion The reason of the above error is that the worker started the digestion of the archived writeset using the old, larger size. As a result, metadata_digest_transcribe_writeset tried to write beyond the end of the era array. Fixes: eec40579d84873 ("dm: add era target") Cc: stable@vger.kernel.org # v3.15+ Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com> --- drivers/md/dm-era-target.c | 21 ++++++++++----------- 1 file changed, 10 insertions(+), 11 deletions(-)