From: "J. Bruce Fields" <bfields@xxxxxxxxxx>
The following fix up some problems that can cause crashes or silently
broken lock guarantees in the reexport case.
Note:
- patches 1-5 are server side
- patches 6-7 are client side
- patch 8 affects both
Simplest might be for Trond or Anna to ACK 6-8, if they look OK, and
then submit them all through the server. But those three sets of
patches are all independent if you'd rather split them up.
Not fixed:
- Attempts to reclaim locks after a reboot of the reexport
server will fail. This at least seems like an improvement
over the current situation, which is that they'll succeed even
in cases where they shouldn't. Complete support for reboot
recovery is a bigger job.
- NFSv4.1+ lock nofications don't work. So, clients have to
poll as they do with NFSv4.0, which is suboptimal, but correct
(and an improvement over the current situation, which is a
kernel oops).
So what we have at this point is a suboptimal lock implementation that
doesn't support lock recovery.
Another alternative might be to turn off file locking entirely in the
re-export case. I'd rather take the incremental improvement and fix the
oopses.
Change since v2:
- keep nlmsvc_file_inode a static inline to address build
failure identified by the kernel test robot
Changes since v1:
- Use ENOGRACE instead of returning NFS-specific error from vfs lock
method.
- Take write opens for write locks in the NLM case (as we always
have in the NFSv4 case).
- Don't block NLM threads waiting for blocking locks.
With those changes I'm passing connecthon tests for NFSv3-4.2 reexports
of an NFSv4.0 filesystem.
--b.
J. Bruce Fields (8):
lockd: lockd server-side shouldn't set fl_ops
nlm: minor nlm_lookup_file argument change
nlm: minor refactoring
lockd: update nlm_lookup_file reexport comment
Keep read and write fds with each nlm_file
nfs: don't atempt blocking locks on nfs reexports
lockd: don't attempt blocking locks on nfs reexports
nfs: don't allow reexport reclaims
fs/lockd/svc4proc.c | 6 +-
fs/lockd/svclock.c | 80 ++++++++++++++----------
fs/lockd/svcproc.c | 6 +-
fs/lockd/svcsubs.c | 117 +++++++++++++++++++++++++-----------
fs/nfs/export.c | 2 +-
fs/nfs/file.c | 3 +
fs/nfsd/lockd.c | 8 ++-
fs/nfsd/nfs4state.c | 11 +++-
fs/nfsd/nfsproc.c | 1 +
include/linux/errno.h | 1 +
include/linux/exportfs.h | 2 +
include/linux/fs.h | 1 +
include/linux/lockd/bind.h | 3 +-
include/linux/lockd/lockd.h | 11 +++-
14 files changed, 170 insertions(+), 82 deletions(-)
--
2.31.1
