[PATCH] cachefiles: modify inappropriate error return value in cachefiles_daemon_secctx

[Zizhi Wo]

In cachefiles_daemon_secctx(), if it is detected that secctx has been
written to the cache, the error code returned is -EINVAL, which is
inappropriate and does not distinguish the situation well.

Like cachefiles_daemon_dir(), fix this issue by return -EEXIST to the user
if it has already been defined once.

Fixes: 9ae326a69004 ("CacheFiles: A cache that backs onto a mounted filesystem")
Signed-off-by: Zizhi Wo <wozizhi@xxxxxxxxxx>
---
 fs/cachefiles/daemon.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/cachefiles/daemon.c b/fs/cachefiles/daemon.c
index 6465e2574230..1b14849804f3 100644
--- a/fs/cachefiles/daemon.c
+++ b/fs/cachefiles/daemon.c
@@ -586,7 +586,7 @@ static int cachefiles_daemon_secctx(struct cachefiles_cache *cache, char *args)
 
 	if (cache->secctx) {
 		pr_err("Second security context specified\n");
-		return -EINVAL;
+		return -EEXIST;
 	}
 
 	secctx = kstrdup(args, GFP_KERNEL);
-- 
2.39.2