[PATCH AUTOSEL 4.19 1/4] NFSv4: Retry LOCK on OLD_STATEID during delegation return

[Sasha Levin]

From: Benjamin Coddington <bcodding@xxxxxxxxxx>

[ Upstream commit f5ea16137a3fa2858620dc9084466491c128535f ]

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@xxxxxxxxxx>
Signed-off-by: Benjamin Coddington <bcodding@xxxxxxxxxx>
Signed-off-by: Anna Schumaker <Anna.Schumaker@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 fs/nfs/nfs4proc.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index f9f76594b866..9a0f48f7f2b8 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -6613,6 +6613,7 @@ static void nfs4_lock_done(struct rpc_task *task, void *calldata)
 {
 	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__);
 
@@ -6622,8 +6623,7 @@ static void nfs4_lock_done(struct rpc_task *task, void *calldata)
 	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)
@@ -6644,6 +6644,8 @@ static void nfs4_lock_done(struct rpc_task *task, void *calldata)
 			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;
-- 
2.35.1