[PATCH 2/2] NFSv4/pNFS: defer LAYOUTRETURN after an unsuccessful OLD_STATEID refresh

[Lucheng Bao <lubao@everpuredata.com>]

Commit c16467dc03db ("pnfs: Fix handling of NFS4ERR_OLD_STATEID replies
to layoutreturn") made stateid refresh fail while newer layout segments
remain busy. The standalone LAYOUTRETURN handler still treats this as a
completed return, potentially discarding a pending LAYOUTCOMMIT.

Set rpc_status to -EAGAIN before the existing completion handling so the
release callback defers the return for a live inode. Leave successful
refreshes and inode-teardown behavior unchanged.

On 6.8.0, this change applies without commit bbbff6d5edd1 ("NFSv4/pNFS:
Retry the layout return later in case of a timeout or reboot"), but that
commit and its prerequisites are required for the deferred-release
behavior.

Fixes: c16467dc03db ("pnfs: Fix handling of NFS4ERR_OLD_STATEID replies to layoutreturn")
Cc: stable@vger.kernel.org # See commit message for prerequisites
Signed-off-by: Lucheng Bao <lubao@everpuredata.com>
---
 fs/nfs/nfs4proc.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 1ae047a062b8..9993e4d29d72 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -9867,6 +9867,7 @@ static void nfs4_layoutreturn_done(struct rpc_task *task, void *calldata)
 					&lrp->args.range,
 					lrp->args.inode))
 			goto out_restart;
+		lrp->rpc_status = -EAGAIN;
 		fallthrough;
 	default:
 		task->tk_status = 0;
-- 
2.34.1