From: Trond Myklebust <trond.myklebust@hammerspace.com>
Date: Fri, 18 Jul 2025 23:15:27 +0000 (-0700)
Subject: NFS: Fix wakeup of __nfs_lookup_revalidate() in unblock_revalidate()
X-Git-Tag: v6.12.42~87
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=bb96d6dbd005c928516895e834c05f2c96fd1286;p=thirdparty%2Fkernel%2Fstable.git

NFS: Fix wakeup of __nfs_lookup_revalidate() in unblock_revalidate()

[ Upstream commit 1db3a48e83bb64a70bf27263b7002585574a9c2d ]

Use store_release_wake_up() to add the appropriate memory barrier before
calling wake_up_var(&dentry->d_fsdata).

Reported-by: Lukáš Hejtmánek<xhejtman@ics.muni.cz>
Suggested-by: Santosh Pradhan <santosh.pradhan@gmail.com>
Link: https://lore.kernel.org/all/18945D18-3EDB-4771-B019-0335CE671077@ics.muni.cz/
Fixes: 99bc9f2eb3f7 ("NFS: add barriers when testing for NFS_FSDATA_BLOCKED")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index f9f4a92f63e92..bbc625e742aa3 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1837,9 +1837,7 @@ static void block_revalidate(struct dentry *dentry)
 
 static void unblock_revalidate(struct dentry *dentry)
 {
-	/* store_release ensures wait_var_event() sees the update */
-	smp_store_release(&dentry->d_fsdata, NULL);
-	wake_up_var(&dentry->d_fsdata);
+	store_release_wake_up(&dentry->d_fsdata, NULL);
 }
 
 /*