[PATCH 06/11] nfs: use store_release_wake_up() for clearing d_fsdata

NeilBrown
2024-12-06T02:19:34Z

The barrier provided by smp_store_release() is before the store, while
wake_up_var() needs a full barrier *after* the store.

The new store_release_wake_up() interface encodes all the barriers
making this sort of bug harder to write.

Signed-off-by: NeilBrown <neilb@suse.de>
---
fs/nfs/dir.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 492cffd9d3d8..ded86facef8f 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);
}

/*
--
2.47.0