[PATCH] nfs/localio: use read_seqbegin() rather than read_seqbegin_or_lock()

From: lirongqing
Date: Thu Jul 31 2025 - 04:11:22 EST


From: Li RongQing <lirongqing@xxxxxxxxx>

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@xxxxxxxxx>
---
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