linux-kernel - [PATCH] nfs/localio: use read_seqbegin() rather than read_seqbegin_or

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Message-ID: <20250731081038.3478-1-lirongqing@baidu.com>
Date: Thu, 31 Jul 2025 16:10:38 +0800
From: lirongqing <lirongqing@...du.com>
To: <trondmy@...nel.org>, <anna@...nel.org>, <linux-nfs@...r.kernel.org>,
	<linux-kernel@...r.kernel.org>
CC: Li RongQing <lirongqing@...du.com>
Subject: [PATCH] nfs/localio: use read_seqbegin() rather than read_seqbegin_or_lock()

From: Li RongQing <lirongqing@...du.com>

The usage of read_seqbegin_or_lock() in nfs_copy_boot_verifier()
is wrong. "seq" is always even and thus "or_lock" has no effect.

nfs_copy_boot_verifier() just copies 8 bytes and is supposed to be
very rare operation, so we do not need the adaptive locking in this case.

Signed-off-by: Li RongQing <lirongqing@...du.com>
---
 fs/nfs/localio.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/fs/nfs/localio.c b/fs/nfs/localio.c
index 510d0a1..bd5fca2 100644
--- a/fs/nfs/localio.c
+++ b/fs/nfs/localio.c
@@ -500,14 +500,13 @@ nfs_copy_boot_verifier(struct nfs_write_verifier *verifier, struct inode *inode)
 {
 	struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
 	u32 *verf = (u32 *)verifier->data;
-	int seq = 0;
+	unsigned int seq;
 
 	do {
-		read_seqbegin_or_lock(&clp->cl_boot_lock, &seq);
+		seq = read_seqbegin(&clp->cl_boot_lock);
 		verf[0] = (u32)clp->cl_nfssvc_boot.tv_sec;
 		verf[1] = (u32)clp->cl_nfssvc_boot.tv_nsec;
-	} while (need_seqretry(&clp->cl_boot_lock, seq));
-	done_seqretry(&clp->cl_boot_lock, seq);
+	} while (read_seqretry(&clp->cl_boot_lock, seq));
 }
 
 static void
-- 
2.9.4