On Fri, Jul 21, 2023 at 07:42:47AM +1000, NeilBrown wrote: > On Fri, 21 Jul 2023, Jeff Layton wrote: > > 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. > > I think both v3 and v4 allow a reply that says "the operation was a > success but there are no post-op attrs". With v4 you can say "there is > no change-attr, but here are some other attrs". I think. If the protocols enable NFSD to avoid returning made-up values, I'm all for it. > Our xdr-encoding doesn't make that easy, but it is just a "simple matter > of coding". If you think it is worth it. > > NeilBrown > > > > > > 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> > > > > >
