[RFC,0/2] nfsd: simplify and improve nfsd write verifier handling

Message

Jeff Layton Feb. 7, 2023, 5:41 p.m. UTC

While looking at the recent problems with the fsync during nfsd_file
cleanup, it occured to me that we could greatly simplify and improve
the server's write verifier handling.

Instead of trying to check for errors via fsync and resetting the write
verifier when we get one, we can just fold the current value of the
inode's errseq_t into the hashed verifier that is generated at startup
time.

This is only lightly tested so far. It's a bit difficult to test these
sorts of error handling changes though, since these should be infrequent
events.

Trond, you originally added the code to make it reset the verifier on a
writeback error. Do you have a good way to test that?

Jeff Layton (2):
  errseq: add a new errseq_fetch helper
  nfsd: simplify write verifier handling

 fs/nfsd/filecache.c    | 22 +--------------------
 fs/nfsd/netns.h        |  4 ----
 fs/nfsd/nfs4proc.c     | 17 +++++++---------
 fs/nfsd/nfsctl.c       |  1 -
 fs/nfsd/nfssvc.c       | 44 +++++++++++-------------------------------
 fs/nfsd/trace.h        | 28 ---------------------------
 fs/nfsd/vfs.c          | 28 +++++----------------------
 fs/nfsd/vfs.h          |  1 +
 include/linux/errseq.h |  1 +
 lib/errseq.c           | 33 ++++++++++++++++++++++++++++++-
 10 files changed, 58 insertions(+), 121 deletions(-)