Re: [PATCH] nvdimm/pmem: Fix an error handling path in 'pmem_attach_disk()'

From: Marion & Christophe JAILLET
Date: Sun Nov 07 2021 - 13:19:42 EST




Le 07/11/2021 à 18:25, Marion & Christophe JAILLET a écrit :


Le 07/11/2021 à 18:20, Christophe JAILLET a écrit :
Le 07/11/2021 à 18:11, Ira Weiny a écrit :
On Sat, Nov 06, 2021 at 06:27:11PM +0100, Christophe JAILLET wrote:
If 'devm_init_badblocks()' fails, a previous 'blk_alloc_disk()' call must
be undone.

I think this is a problem...


Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
---
This patch is speculative. Several fixes on error handling paths have been
done recently, but this one has been left as-is. There was maybe a good
reason that I have missed for that. So review with care!

I've not been able to identify a Fixes tag that please me :(
---
  drivers/nvdimm/pmem.c | 5 +++--
  1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index fe7ece1534e1..c37a1e6750b3 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -490,8 +490,9 @@ static int pmem_attach_disk(struct device *dev,
      nvdimm_namespace_disk_name(ndns, disk->disk_name);
      set_capacity(disk, (pmem->size - pmem->pfn_pad - pmem->data_offset)
              / 512);
-    if (devm_init_badblocks(dev, &pmem->bb))
-        return -ENOMEM;
+    rc = devm_init_badblocks(dev, &pmem->bb);
+    if (rc)
+        goto out;

But I don't see this 'out' label in the function currently?  Was that part of
your patch missing?

Hi,
the patch is based on the latest linux-next.
See [1]. The 'out' label exists there and is already used.

In fact, I run an own-made coccinelle script which tries to spot mix-up between return and goto.
In this case, we have a 'return -ENOMEM' after a 'goto out' which looks spurious. Hence, my patch.

[1]:https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/drivers/nvdimm/pmem.c#n512

Lol, the #n512 above is in fact another place that should be updated as well. I missed it and only fixed #n494!

In fact, no, line 512 should be left as-is. The clean-up wilol be made by 'pmem_release_disk()'.

The patch attached at the very first mail of this thread looks good to me.

CJ


CJ


CJ


Ira

      nvdimm_badblocks_populate(nd_region, &pmem->bb, &bb_range);
      disk->bb = &pmem->bb;
--
2.30.2