open: make RESOLVE_CACHED correctly test for O_TMPFILE

O_TMPFILE is actually __O_TMPFILE|O_DIRECTORY. This means that the old
fast-path check for RESOLVE_CACHED would reject all users passing
O_DIRECTORY with -EAGAIN, when in fact the intended test was to check
for __O_TMPFILE.

Cc: stable@vger.kernel.org # v5.12+
Fixes: 99668f618062 ("fs: expose LOOKUP_CACHED through openat2() RESOLVE_CACHED")
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Message-Id: <20230806-resolve_cached-o_tmpfile-v1-1-7ba16308465e@cyphar.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/fs/open.c b/fs/open.c
index 0c55c8e..e6ead0f 100644 (file)
--- a/fs/open.c
+++ b/fs/open.c
@@ -1322,7 +1322,7 @@ inline int build_open_flags(const struct open_how *how, struct open_flags *op)
                lookup_flags |= LOOKUP_IN_ROOT;
        if (how->resolve & RESOLVE_CACHED) {
                /* Don't bother even trying for create/truncate/tmpfile open */
-               if (flags & (O_TRUNC | O_CREAT | O_TMPFILE))
+               if (flags & (O_TRUNC | O_CREAT | __O_TMPFILE))
                        return -EAGAIN;
                lookup_flags |= LOOKUP_CACHED;
        }