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NFSv4: Fix dropped lock for racing OPEN and delegation return
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commit 1cbc11a upstream.

Commmit f5ea161 ("NFSv4: Retry LOCK on OLD_STATEID during delegation
return") attempted to solve this problem by using nfs4's generic async error
handling, but introduced a regression where v4.0 lock recovery would hang.
The additional complexity introduced by overloading that error handling is
not necessary for this case.  This patch expects that commit to be
reverted.

The problem as originally explained in the above commit is:

    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 using the old_stateid refresh helpers if the server replies
with OLD_STATEID.

Suggested-by: Trond Myklebust <trondmy@hammerspace.com>
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Benjamin Coddington authored and Greg Kroah-Hartman committed Aug 30, 2023
1 parent ed29b5f commit ed2e9e1
Showing 1 changed file with 8 additions and 1 deletion.
9 changes: 8 additions & 1 deletion fs/nfs/nfs4proc.c
Original file line number Diff line number Diff line change
Expand Up @@ -7180,8 +7180,15 @@ static void nfs4_lock_done(struct rpc_task *task, void *calldata)
} else if (!nfs4_update_lock_stateid(lsp, &data->res.stateid))
goto out_restart;
break;
case -NFS4ERR_BAD_STATEID:
case -NFS4ERR_OLD_STATEID:
if (data->arg.new_lock_owner != 0 &&
nfs4_refresh_open_old_stateid(&data->arg.open_stateid,
lsp->ls_state))
goto out_restart;
if (nfs4_refresh_lock_old_stateid(&data->arg.lock_stateid, lsp))
goto out_restart;
fallthrough;
case -NFS4ERR_BAD_STATEID:
case -NFS4ERR_STALE_STATEID:
case -NFS4ERR_EXPIRED:
if (data->arg.new_lock_owner != 0) {
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