[PATCH v2 0/2] nfsd: sanely handle inabilty to fetch pre/post attributes

[Jeff Layton]

Boyang reported tripping the BUG_ON in set_change_info. While we
couldn't confirm it, one way this could happen would be for nfsd_lookup
to succeed and then for fh_fill_both_attrs to fail.

This patchset attempts to (sanely) fix this, usually by aborting the
operation if fetching the pre attributes fails. Post-op attribute fetch
handling is more difficult to deal with however since we've already done
the operation, so this has it just fudge the change_info4 if that
occurs.

Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
Changes in v2:
- make fh_fill_*_attrs return an error and have the callers handle it
- rework of set_change_info, to better handle missing pre/post attrs

---
Jeff Layton (2):
      nfsd: handle failure to collect pre/post-op attrs more sanely
      nfsd: remove unsafe BUG_ON from set_change_info

 fs/nfsd/nfs3proc.c |  4 +++-
 fs/nfsd/nfs4proc.c | 45 +++++++++++++++++++++++++++++++++------
 fs/nfsd/nfsfh.c    | 26 ++++++++++++++---------
 fs/nfsd/nfsfh.h    |  6 +++---
 fs/nfsd/vfs.c      | 62 ++++++++++++++++++++++++++++++++++--------------------
 fs/nfsd/xdr4.h     | 11 ----------
 6 files changed, 100 insertions(+), 54 deletions(-)
---
base-commit: 070f391ca4d48e1750ee6108eb44f751a9e9448e
change-id: 20230720-bz2223560-9c4690a8217b

Best regards,
-- 
Jeff Layton <jlayton@xxxxxxxxxx>