| From: |
| Jeuk Kim <jeuk20.kim-AT-gmail.com> |
| To: |
| Trond Myklebust <trondmy-AT-kernel.org>, Anna Schumaker <anna-AT-kernel.org> |
| Subject: |
| [PATCH 0/2] NFSv4/flexfiles: support loosely coupled data servers |
| Date: |
| Wed, 08 Jul 2026 16:44:31 +0900 |
| Message-ID: |
| <20260708074433.390161-1-jeuk20.kim@samsung.com> |
| Cc: |
| linux-nfs-AT-vger.kernel.org, linux-kernel-AT-vger.kernel.org, Tigran Mkrtchyan <tigran.mkrtchyan-AT-desy.de>, hui81.qi-AT-samsung.com, j-young.choi-AT-samsung.com, peng.yun-AT-samsung.com, qian01.li-AT-samsung.com, xing1.he-AT-samsung.com, jeuk20.kim-AT-samsung.com |
| Archive-link: |
| Article |
RFC 8435 allows a flexfiles data server to be loosely coupled, i.e. an
NFS server that does not advertise EXCHGID4_FLAG_USE_PNFS_DS via
EXCHANGE_ID. The client currently ignores the ffdv_tightly_coupled flag
and treats every DS as tightly coupled, so NFSv4.1+ I/O to a loosely
coupled DS fails during DS setup.
Patch 2 threads the decoded tightly_coupled flag down to the DS connect
path and, when it is false, skips the NFS_CS_PNFS flag and the
is_ds_client() check.
Patch 1 fixes pre-existing NFSv4.0 DS crashes on the same path (the DS
client has no session).
Jeuk Kim (2):
NFSv4/flexfiles: fix NULL dereference for NFSv4.0 data servers
NFSv4/flexfiles: support loosely coupled data servers
fs/nfs/filelayout/filelayoutdev.c | 2 +-
fs/nfs/flexfilelayout/flexfilelayout.c | 3 ++-
fs/nfs/flexfilelayout/flexfilelayoutdev.c | 3 ++-
fs/nfs/internal.h | 3 ++-
fs/nfs/nfs4client.c | 5 +++--
fs/nfs/nfs4session.c | 21 ++++++++++++++-------
fs/nfs/nfs4session.h | 3 ++-
fs/nfs/pnfs.h | 3 ++-
fs/nfs/pnfs_nfs.c | 14 +++++++++-----
9 files changed, 37 insertions(+), 20 deletions(-)
--
2.43.0
