From: Benjamin Coddington <bcodding@redhat.com>
Date: Wed, 19 Oct 2022 12:09:18 -0400
Subject: [PATCH] NFSv4: Retry LOCK on OLD_STATEID during delegation return
Git-commit: f5ea16137a3fa2858620dc9084466491c128535f
Patch-mainline: v6.1
References: git-fixes

There's a small window where a LOCK sent during a delegation return can
race with another OPEN on client, but the open stateid has not yet been
updated.  In this case, the client doesn't handle the OLD_STATEID error
from the server and will lose this lock, emitting:
"nfs: nfs4_handle_delegation_recall_error: unhandled error -10024".

Fix this by sending the task through the nfs4 error handling in
nfs4_lock_done() when we may have to reconcile our stateid with what the
server believes it to be.  For this case, the result is a retry of the
LOCK operation with the updated stateid.

Reported-by: Gonzalo Siero Humet <gsierohu@redhat.com>
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Acked-by: NeilBrown <neilb@suse.com>

---
 fs/nfs/nfs4proc.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -7132,6 +7132,7 @@ static void nfs4_lock_done(struct rpc_ta
 {
 	struct nfs4_lockdata *data = calldata;
 	struct nfs4_lock_state *lsp = data->lsp;
+	struct nfs_server *server = NFS_SERVER(d_inode(data->ctx->dentry));
 
 	dprintk("%s: begin!\n", __func__);
 
@@ -7141,8 +7142,7 @@ static void nfs4_lock_done(struct rpc_ta
 	data->rpc_status = task->tk_status;
 	switch (task->tk_status) {
 	case 0:
-		renew_lease(NFS_SERVER(d_inode(data->ctx->dentry)),
-				data->timestamp);
+		renew_lease(server, data->timestamp);
 		if (data->arg.new_lock && !data->cancelled) {
 			data->fl.fl_flags &= ~(FL_SLEEP | FL_ACCESS);
 			if (locks_lock_inode_wait(lsp->ls_state->inode, &data->fl) < 0)
@@ -7163,6 +7163,8 @@ static void nfs4_lock_done(struct rpc_ta
 			if (!nfs4_stateid_match(&data->arg.open_stateid,
 						&lsp->ls_state->open_stateid))
 				goto out_restart;
+			else if (nfs4_async_handle_error(task, server, lsp->ls_state, NULL) == -EAGAIN)
+				goto out_restart;
 		} else if (!nfs4_stateid_match(&data->arg.lock_stateid,
 						&lsp->ls_stateid))
 				goto out_restart;