Add support for more detailed error codes from main loop

ChangeLog.rst

@@ -7,6 +7,10 @@ UNRELEASED CHANGES
 
 * Added documentation for FUSE_CAP_FLOCK_LOCKS.
 
+* fuse_loop(), fuse_loop_mt(), fuse_session_loop() and
+  fuse_session_loop_mt() now return -errno instead of -1 in case of
+  failure.
+
 FUSE 3.0.0-rc2 (2016-11-06)
 ===========================
 

include/fuse.h

@@ -828,7 +828,7 @@ void fuse_destroy(struct fuse *f);
  * operations are called.
  *
  * @param f the FUSE handle
- * @return 0 if no error occurred, -1 otherwise
+ * @return 0 if no error occurred, -errno otherwise
  *
  * See also: fuse_loop()
  */
@@ -871,7 +871,7 @@ void fuse_exit(struct fuse *f);
  * @param f the FUSE handle
  * @param clone_fd whether to use separate device fds for each thread
  *                 (may increase performance)
- * @return 0 if no error occurred, -1 otherwise
+ * @return 0 if no error occurred, -errno otherwise
  *
  * See also: fuse_loop()
  */

include/fuse_lowlevel.h

@@ -1783,7 +1783,7 @@ int fuse_session_mount(struct fuse_session *se, const char *mountpoint);
  *   fuse_set_signal_handlers() first.
  *
  * @param se the session
- * @return 0 on success, -1 on error
+ * @return 0 on success, -errno on failure
  */
 int fuse_session_loop(struct fuse_session *se);
 
@@ -1793,7 +1793,7 @@ int fuse_session_loop(struct fuse_session *se);
  * @param se the session
  * @param clone_fd whether to use separate device fds for each thread
  *                 (may increase performance)
- * @return 0 on success, -1 on error
+ * @return 0 on success, -errno on failure
  */
 int fuse_session_loop_mt(struct fuse_session *se, int clone_fd);
 

lib/fuse_i.h

@@ -63,6 +63,7 @@ struct fuse_session {
 	uint64_t notify_ctr;
 	struct fuse_notify_req notify_list;
 	size_t bufsize;
+	int error;
 };
 
 struct fuse_chan {

lib/fuse_loop.c

@@ -35,6 +35,8 @@ int fuse_session_loop(struct fuse_session *se)
 	}
 
 	free(fbuf.mem);
+	if(se->error != 0)
+		res = se->error;
 	fuse_session_reset(se);
-	return res < 0 ? -1 : 0;
+	return res;
 }

lib/fuse_loop_mt.c

@@ -339,6 +339,8 @@ int fuse_session_loop_mt(struct fuse_session *se, int clone_fd)
 
 	pthread_mutex_destroy(&mt.lock);
 	sem_destroy(&mt.finish);
+	if(se->error != 0)
+		err = se->error;
 	fuse_session_reset(se);
 	return err;
 }

lib/fuse_lowlevel.c

@@ -2940,6 +2940,7 @@ void fuse_session_exit(struct fuse_session *se)
 void fuse_session_reset(struct fuse_session *se)
 {
 	se->exited = 0;
+	se->error = 0;
 }
 
 int fuse_session_exited(struct fuse_session *se)