nfs: Skip pathconf probe when neither field is consumed

The PATHCONF RPC issued from nfs_probe_fsinfo() supplies two pieces of
information: max_namelen, used only when server->namelen has not been
pinned by mount options, and the case_insensitive / case_preserving
fields, used only by the NFSv2/NFSv3 path. NFSv4 receives its case
sensitivity caps from the FATTR4_CASE_* attributes during the
set_capabilities probe, and a non-zero server->namelen short-circuits
the only other field of interest.

When both conditions hold (NFSv4 with namelen pinned), the pathconf
reply is discarded in full but the round-trip is still on the mount
critical path. Gate the call on version < 4 || namelen == 0 so that
mounts which cannot benefit from the reply do not pay for it.

Reported-by: sashiko-bot <sashiko-bot@kernel.org>
Closes: https://sashiko.dev/#/patchset/20260507-case-sensitivity-v14-0-e62cc8200435@oracle.com?part=10
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Link: https://patch.msgid.link/20260515153515.362266-4-cel@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>

0 files changed, 0 insertions, 0 deletions