This is a note to let you know that I've just added the patch titled
NFSv4: Fix dropped lock for racing OPEN and delegation return
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
nfsv4-fix-dropped-lock-for-racing-open-and-delegation-return.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 1cbc11aaa01f80577b67ae02c73ee781112125fd Mon Sep 17 00:00:00 2001
From: Benjamin Coddington <bcodding@xxxxxxxxxx>
Date: Fri, 30 Jun 2023 09:18:13 -0400
Subject: NFSv4: Fix dropped lock for racing OPEN and delegation return
From: Benjamin Coddington <bcodding@xxxxxxxxxx>
commit 1cbc11aaa01f80577b67ae02c73ee781112125fd upstream.
Commmit f5ea16137a3f ("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@xxxxxxxxxxxxxxx>
Signed-off-by: Benjamin Coddington <bcodding@xxxxxxxxxx>
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/nfs/nfs4proc.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -7152,8 +7152,15 @@ static void nfs4_lock_done(struct rpc_ta
} 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) {
Patches currently in stable-queue which might be from bcodding@xxxxxxxxxx are
queue-5.15/nfsv4-fix-out-path-in-__nfs4_get_acl_uncached.patch
queue-5.15/nfsv4.2-fix-error-handling-in-nfs42_proc_getxattr.patch
queue-5.15/nfsv4-fix-dropped-lock-for-racing-open-and-delegation-return.patch
