conn->want conversion: Fix fuse_apply_conn_info_opts()

fuse_apply_conn_info_opts() was applying to 'want_ext',
which would cause conflicts with 'want' if the application
applied its own flags to 'conn->want'.

Solution is:
    - to move fuse_{set,unset,get}_feature_flag and
      convert_to_conn_want_ext() to fuse_lowlevel.c and
      to define them as part of the public API, although
      convert_to_conn_want_ext() should not be used - it is
      currently needed to be a public function due as it needs
      to be defined for the tests.

Related to https://github.com/libfuse/libfuse/issues/1171 and
https://github.com/libfuse/libfuse/pull/1172.

Closes: https://github.com/libfuse/libfuse/issues/1171
Signed-off-by: Bernd Schubert <bschubert@ddn.com>
(cherry picked from commit baadab0492a495fda98216b351976d2e5d6d0866)

1 files changed, 7 insertions, 31 deletions

diff --git a/lib/fuse_i.h b/lib/fuse_i.h
index bf5e2ca..718fa14 100644
--- a/lib/fuse_i.h
+++ b/lib/fuse_i.h
@@ -85,6 +85,13 @@ struct fuse_session {
 
 	/* true if reading requests from /dev/fuse are handled internally */
 	bool buf_reallocable;
+
+	/*
+	 * conn->want and conn_want_ext options set by libfuse , needed
+	 * to correctly convert want to want_ext
+	 */
+	uint32_t conn_want;
+	uint64_t conn_want_ext;
 };
 
 struct fuse_chan {
@@ -227,34 +234,3 @@ int fuse_loop_cfg_verify(struct fuse_loop_config *config);
 /* room needed in buffer to accommodate header */
 #define FUSE_BUFFER_HEADER_SIZE 0x1000
 
-/**
- * Get the wanted capability flags, converting from old format if necessary
- */
-static inline int convert_to_conn_want_ext(struct fuse_conn_info *conn,
-					   uint64_t want_ext_default,
-					   uint32_t want_default)
-{
-	/*
-	 * Convert want to want_ext if necessary.
-	 * For the high level interface this function might be called
-	 * twice, once from the high level interface and once from the
-	 * low level interface. Both, with different want_ext_default and
-	 * want_default values. In order to suppress a failure for the
-	 * second call, we check if the lower 32 bits of want_ext are
-	 * already set to the value of want.
-	 */
-	if (conn->want != want_default &&
-	    fuse_lower_32_bits(conn->want_ext) != conn->want) {
-		if (conn->want_ext != want_ext_default)
-			return -EINVAL;
-
-		/* high bits from want_ext, low bits from want */
-		conn->want_ext = fuse_higher_32_bits(conn->want_ext) |
-				 conn->want;
-	}
-
-	/* ensure there won't be a second conversion */
-	conn->want = fuse_lower_32_bits(conn->want_ext);
-
-	return 0;
-}