NFS/localio: nfs_uuid_put() fix the wake up after unlinking the file

Trond Myklebust · Trond Myklebust · commit 4ec752ce6deb · 2025-08-05T16:45:40.000-07:00
Use store_release_wake_up() instead of wake_up_var_locked(), because the waiter cannot retake the nfs_uuid->lock. Acked-by: Mike Snitzer <snitzer@kernel.org> Tested-by: Mike Snitzer <snitzer@kernel.org> Suggested-by: NeilBrown <neil@brown.name> Link: https://lore.kernel.org/all/175262948827.2234665.1891349021754495573@noble.neil.brown.name/ Fixes: 21fb440 ("nfs_localio: protect race between nfs_uuid_put() and nfs_close_local_fh()") Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
diff --git a/fs/nfs_common/nfslocalio.c b/fs/nfs_common/nfslocalio.c
@@ -198,8 +198,7 @@ static bool nfs_uuid_put(nfs_uuid_t *nfs_uuid)
 		/* Now we can allow racing nfs_close_local_fh() to
 		 * skip the locking.
 		 */
-		RCU_INIT_POINTER(nfl->nfs_uuid, NULL);
-		wake_up_var_locked(&nfl->nfs_uuid, &nfs_uuid->lock);
+		store_release_wake_up(&nfl->nfs_uuid, RCU_INITIALIZER(NULL));
 	}
 
 	/* Remove client from nn->local_clients */

Original file line number	Diff line number	Diff line change
`@@ -198,8 +198,7 @@ static bool nfs_uuid_put(nfs_uuid_t *nfs_uuid)`
`198`	`198`	`/* Now we can allow racing nfs_close_local_fh() to`
`199`	`199`	`* skip the locking.`
`200`	`200`	`*/`
`201`		`- RCU_INIT_POINTER(nfl->nfs_uuid, NULL);`
`202`		`- wake_up_var_locked(&nfl->nfs_uuid, &nfs_uuid->lock);`
	`201`	`+ store_release_wake_up(&nfl->nfs_uuid, RCU_INITIALIZER(NULL));`
`203`	`202`	`}`
`204`	`203`
`205`	`204`	`/* Remove client from nn->local_clients */`