[PATCH v2] nfsd: allow SC_STATUS_FREEABLE when searching via nfs4_lookup_stateid()

[Jeff Layton]

The pynfs DELEG8 test fails when run against nfsd. It acquires a
delegation and then lets the lease time out. It then tries to use the
deleg stateid and expects to see NFS4ERR_DELEG_REVOKED, but it gets
bad NFS4ERR_BAD_STATEID instead.

When a delegation is revoked, it's initially marked with
SC_STATUS_REVOKED, or SC_STATUS_ADMIN_REVOKED and later, it's marked
with the SC_STATUS_FREEABLE flag, which denotes that it is waiting for
s FREE_STATEID call.

nfs4_lookup_stateid() accepts a statusmask that includes the status
flags that a found stateid is allowed to have. Currently, that mask
never includes SC_STATUS_FREEABLE, which means that revoked delegations
are (almost) never found.

Add SC_STATUS_FREEABLE to the always-allowed status flags, and remove it
from nfsd4_delegreturn() since it's now always implied.

Fixes: 8dd91e8d31fe ("nfsd: fix race between laundromat and free_stateid")
Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
Changes in v2:
- remove SC_STATUS_FREEABLE from the mask passed in nfsd4_delegreturn()
- add note to changelog about pynfs test, and Fixes: tag
- Link to v1: https://lore.kernel.org/r/20250212-nfsd-fixes-v1-1-935e3a4919fc@xxxxxxxxxx
---
 fs/nfsd/nfs4state.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 153eeea2c7c999d003cd1f36cecb0dd4f6e049b8..83e078e52d3a5891f706023cf7d9fabdf26b6705 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -7051,7 +7051,7 @@ nfsd4_lookup_stateid(struct nfsd4_compound_state *cstate,
 		 */
 		statusmask |= SC_STATUS_REVOKED;
 
-	statusmask |= SC_STATUS_ADMIN_REVOKED;
+	statusmask |= SC_STATUS_ADMIN_REVOKED | SC_STATUS_FREEABLE;
 
 	if (ZERO_STATEID(stateid) || ONE_STATEID(stateid) ||
 		CLOSE_STATEID(stateid))
@@ -7706,9 +7706,7 @@ nfsd4_delegreturn(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 	if ((status = fh_verify(rqstp, &cstate->current_fh, S_IFREG, 0)))
 		return status;
 
-	status = nfsd4_lookup_stateid(cstate, stateid, SC_TYPE_DELEG,
-				      SC_STATUS_REVOKED | SC_STATUS_FREEABLE,
-				      &s, nn);
+	status = nfsd4_lookup_stateid(cstate, stateid, SC_TYPE_DELEG, SC_STATUS_REVOKED, &s, nn);
 	if (status)
 		goto out;
 	dp = delegstateid(s);

---
base-commit: 4990d098433db18c854e75fb0f90d941eb7d479e
change-id: 20250212-nfsd-fixes-fa8047082335

Best regards,
-- 
Jeff Layton <jlayton@xxxxxxxxxx>