projfs_new accepts FUSE args, and initial proj opt

We need to avoid wait_mount in tests so its stat(2) doesn't trigger
projection and clear the projection bit.

configure.ac

@@ -39,24 +39,6 @@ AC_SYS_LARGEFILE
 
 AX_COMPILER_FLAGS()
 
-AC_ARG_ENABLE([debug],
-  [AS_HELP_STRING([--enable-debug],
-    [Enable libprojfs debugging output])]
-)dnl
-
-AS_IF([test ":$enable_debug" = ":yes"],
-  [AC_DEFINE(PROJFS_DEBUG, 1, [Enable libprojfs debugging output])]
-)dnl
-
-AC_ARG_ENABLE([fuse_debug],
-  [AS_HELP_STRING([--enable-fuse-debug],
-    [Enable FUSE library debugging output])]
-)dnl
-
-AS_IF([test ":$enable_fuse_debug" = ":yes"],
-  [AC_DEFINE(PROJFS_FUSE_DEBUG, 1, [Enable FUSE library debugging output])]
-)dnl
-
 AC_CHECK_PROGS([DIFF], [diff])
 AC_ARG_VAR([DIFF], [File comparison tool])
 

docker/VFSForGit

@@ -1 +1 @@
-Subproject commit 3a2b9dfa9f66dec893c3e9fb08db25c1a546fee5
+Subproject commit 91fb51e235852e4c45b1fcf09ad1ab77d90c6058

include/projfs.h

@@ -104,7 +104,8 @@ struct projfs_handlers {
  */
 struct projfs *projfs_new(const char *lowerdir, const char *mountdir,
 			  const struct projfs_handlers *handlers,
-			  size_t handlers_size, void *user_data);
+			  size_t handlers_size, void *user_data,
+			  int argc, const char **argv);
 
 /**
  * Retrieve the private user data from a projfs handle.

lib/projfs.c

@@ -37,6 +37,7 @@
 #include <sys/syscall.h>
 #include <attr/xattr.h>
 #include <unistd.h>
+#include <stddef.h>
 
 #include "fdtable.h"
 #include "projfs.h"
@@ -46,6 +47,17 @@
 // TODO: make this value configurable
 #define PROJ_WAIT_MSEC 5000
 
+struct projfs_config {
+	int initial;
+};
+
+#define PROJFS_OPT(t, p, v) { t, offsetof(struct projfs_config, p), v }
+
+static struct fuse_opt projfs_opts[] = {
+	PROJFS_OPT("initial",	initial, 1),
+	FUSE_OPT_END
+};
+
 struct projfs {
 	char *lowerdir;
 	char *mountdir;
@@ -57,6 +69,8 @@ struct projfs {
 	pthread_t thread_id;
 	struct fdtable *fdtable;
 	int error;
+	struct fuse_args args;
+	struct projfs_config config;
 };
 
 typedef int (*projfs_handler_t)(struct projfs_event *);
@@ -583,9 +597,11 @@ static int projfs_op_getattr(char const *path, struct stat *attr,
 		res = fstat(fi->fh, attr);
 	else {
 		path = make_relative_path(path);
-		res = project_dir("getattr", path, 1);
-		if (res)
-			return -res;
+		if (strcmp(path, ".") != 0) {
+			res = project_dir("getattr", path, 1);
+			if (res)
+				return -res;
+		}
 		res = fstatat(get_fuse_context_lowerdir_fd(), path, attr,
 			      AT_SYMLINK_NOFOLLOW);
 	}
@@ -1319,14 +1335,6 @@ static struct fuse_operations projfs_ops = {
 	// copy_file_range
 };
 
-#ifdef PROJFS_DEBUG
-#define DEBUG_ARGV "--debug",
-#define DEBUG_ARGC 1
-#else
-#define DEBUG_ARGV
-#define DEBUG_ARGC 0
-#endif
-
 static void projfs_set_session(struct projfs *fs, struct fuse_session *se)
 {
 	if (fs == NULL)
@@ -1339,10 +1347,12 @@ static void projfs_set_session(struct projfs *fs, struct fuse_session *se)
 
 struct projfs *projfs_new(const char *lowerdir, const char *mountdir,
 		const struct projfs_handlers *handlers,
-		size_t handlers_size, void *user_data)
+		size_t handlers_size, void *user_data,
+		int argc, const char **argv)
 {
 	struct projfs *fs;
 	size_t len;
+	int i;
 
 	// TODO: prevent failure with relative lowerdir
 	if (lowerdir == NULL) {
@@ -1401,8 +1411,30 @@ struct projfs *projfs_new(const char *lowerdir, const char *mountdir,
 		goto out_mutex;
 	}
 
+	if (fuse_opt_add_arg(&fs->args, "projfs") != 0) {
+		fprintf(stderr, "projfs: failed to allocate argument\n");
+		goto out_fdtable;
+	}
+
+	for (i = 0; i < argc; ++i) {
+		if (fuse_opt_add_arg(&fs->args, argv[i]) != 0) {
+			fprintf(stderr, "projfs: failed to allocate "
+					"argument\n");
+			goto out_fdtable;
+		}
+	}
+
+	if (fuse_opt_parse(&fs->args, &fs->config, projfs_opts, NULL) == -1) {
+		fprintf(stderr, "projfs: unable to parse arguments\n");
+		goto out_fdtable;
+	}
+
 	return fs;
 
+out_fdtable:
+	fuse_opt_free_args(&fs->args);
+	fdtable_destroy(fs->fdtable);
+
 out_mutex:
 	pthread_mutex_destroy(&fs->mutex);
 out_mount:
@@ -1420,37 +1452,6 @@ void *projfs_get_user_data(struct projfs *fs)
 	return fs->user_data;
 }
 
-/**
- * @return 1 if dir is empty, 0 if not, -1 if an error occurred (errno set)
- */
-static int check_dir_empty(const char *path)
-{
-	int err, is_empty = 1;
-	struct dirent *e;
-	DIR *d = opendir(path);
-	if (!d)
-		return -1;
-
-	while (1) {
-		errno = 0;
-		e = readdir(d);
-		if (e == NULL) {
-			err = errno;
-			closedir(d);
-			if (err == 0)
-				return is_empty;
-			errno = err;
-			return -1;
-		}
-
-		if (strcmp(e->d_name, ".") == 0 ||
-				strcmp(e->d_name, "..") == 0)
-			; /* ignore */
-		else
-			is_empty = 0;
-	}
-}
-
 #define SPARSE_TEST_FILENAME ".libprojfs-sparse-test"
 #define SPARSE_TEST_SIZE_BYTES 1048576
 
@@ -1509,9 +1510,6 @@ close:
 static void *projfs_loop(void *data)
 {
 	struct projfs *fs = (struct projfs *)data;
-	const char *argv[] = { "projfs", DEBUG_ARGV NULL };
-	int argc = 1 + DEBUG_ARGC;
-	struct fuse_args args = FUSE_ARGS_INIT(argc, (char **)argv);
 	struct fuse_loop_config loop;
 	struct fuse *fuse;
 	struct fuse_session *se;
@@ -1541,20 +1539,20 @@ static void *projfs_loop(void *data)
 		goto out_close;
 	}
 
-	/* mark lowerdir as needing projection if it's empty (because the
-	 * provider creates it for us before we start running) -- probably want
-	 * to modify this behaviour in the future */
-	res = check_dir_empty(fs->lowerdir);
+	res = test_sparse_support(fs->lowerdir_fd);
 	if (res == -1) {
-		fprintf(stderr, "projfs: could not check if lowerdir "
-		                "is empty: %s: %s\n",
-			fs->lowerdir, strerror(errno));
+		fprintf(stderr, "projfs: unable to test sparse file support: "
+				"%s/%s: %s\n",
+			fs->lowerdir, SPARSE_TEST_FILENAME, strerror(errno));
 		res = 3;
 		goto out_close;
-	}
+	} else if (res == 0)
+		fprintf(stderr, "projfs: sparse files may not be supported by "
+		                "lower filesystem: %s\n", fs->lowerdir);
+	else if (res == 1)
+		res = 0;
 
-	if (res == 1) {
-		/* dir is empty */
+	if (fs->config.initial == 1) {
 		if (set_proj_state_xattr(fs->lowerdir_fd,
 					 PROJ_STATE_EMPTY, 0) == -1) {
 			fprintf(stderr, "projfs: could not set projection "
@@ -1565,22 +1563,9 @@ static void *projfs_loop(void *data)
 		}
 	}
 
-	res = test_sparse_support(fs->lowerdir_fd);
-	if (res == -1) {
-		fprintf(stderr, "projfs: unable to test sparse file support: "
-				"%s/%s: %s\n",
-			fs->lowerdir, SPARSE_TEST_FILENAME, strerror(errno));
-		res = 5;
-		goto out_close;
-	} else if (res == 0)
-		fprintf(stderr, "projfs: sparse files may not be supported by "
-		                "lower filesystem: %s\n", fs->lowerdir);
-	else if (res == 1)
-		res = 0;
-
-	fuse = fuse_new(&args, &projfs_ops, sizeof(projfs_ops), fs);
+	fuse = fuse_new(&fs->args, &projfs_ops, sizeof(projfs_ops), fs);
 	if (fuse == NULL) {
-		res = 6;
+		res = 5;
 		goto out_close;
 	}
 
@@ -1589,13 +1574,13 @@ static void *projfs_loop(void *data)
 
 	// TODO: defer all signal handling to user, once we remove FUSE
 	if (fuse_set_signal_handlers(se) != 0) {
-		res = 7;
+		res = 6;
 		goto out_session;
 	}
 
 	// TODO: mount with x-gvfs-hide option and maybe others for KDE, etc.
 	if (fuse_mount(fuse, fs->mountdir) != 0) {
-		res = 8;
+		res = 7;
 		goto out_signal;
 	}
 
@@ -1607,7 +1592,7 @@ static void *projfs_loop(void *data)
 	if ((err = fuse_loop_mt(fuse, &loop)) != 0) {
 		if (err > 0)
 			fprintf(stderr, "projfs: %s signal\n", strsignal(err));
-		res = 9;
+		res = 8;
 	}
 
 	fuse_session_unmount(se);
@@ -1690,6 +1675,8 @@ void *projfs_stop(struct projfs *fs)
 		        fs->error);
 	}
 
+	fuse_opt_free_args(&fs->args);
+
 	fdtable_destroy(fs->fdtable);
 
 	pthread_mutex_destroy(&fs->mutex);

t/Makefile.am

@@ -27,12 +27,14 @@ test_common = test_common.c \
 	      $(top_srcdir)/include/projfs_notify.h
 
 check_PROGRAMS = get_strerror \
+		 test_args \
 		 test_fdtable \
 		 test_handlers \
 		 test_simple \
 		 wait_mount
 
 get_strerror_SOURCES = get_strerror.c $(test_common)
+test_args_SOURCES = test_args.c $(test_common)
 test_fdtable_SOURCES = test_fdtable.c $(test_common) \
 		       ../lib/fdtable.c ../lib/fdtable.h
 test_handlers_SOURCES = test_handlers.c $(test_common)
@@ -53,7 +55,8 @@ TESTS = t000-mirror-read.t \
 	t202-event-deny.t \
 	t203-event-null.t \
 	t204-event-allow.t \
-	t205-event-locking.t
+	t205-event-locking.t \
+	t300-args-initial.t
 
 EXTRA_DIST = README.md chainlint.sed clean_test_dirs.sh \
 	     test-lib.sh test-lib-event.sh test-lib-functions.sh $(TESTS)

t/t205-event-locking.t

@@ -25,9 +25,6 @@ given path.
 
 projfs_start test_handlers source target --timeout 1 --lock-file lock || exit 1
 
-# wait_mount will trigger a projection, so we need to reset it to empty
-setfattr -n user.projection.empty -v y source
-
 test_expect_success 'test concurrent access does not trigger failure' '
 	projfs_run_twice ls target
 '

t/t300-args-initial.t

@@ -0,0 +1,42 @@
+#!/bin/sh
+#
+# Copyright (C) 2019 GitHub, Inc.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see http://www.gnu.org/licenses/ .
+
+test_description='projfs argument passthrough test
+
+Check that arguments are interpeted and passed through correctly.
+'
+
+. ./test-lib.sh
+
+projfs_start test_args source target || exit 1
+
+test_expect_success 'mount without args does not mark initial' '
+	test_must_fail getfattr -n user.projection.empty source
+'
+
+projfs_stop || exit 1
+
+projfs_start test_args source target -o initial || exit 1
+
+test_expect_success 'mount with initial arg does mark initial' '
+	getfattr -n user.projection.empty source
+'
+
+projfs_stop || exit 1
+
+test_done
+

t/test_args.c

@@ -0,0 +1,43 @@
+/* Linux Projected Filesystem
+   Copyright (C) 2018-2019 GitHub, Inc.
+
+   See the NOTICE file distributed with this library for additional
+   information regarding copyright ownership.
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with this library, in the file COPYING; if not,
+   see <http://www.gnu.org/licenses/>.
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "test_common.h"
+
+int main(int argc, const char **argv)
+{
+	struct projfs *fs;
+	if (argc < 3) {
+		fprintf(stderr, "usage: %s [OPTIONS ...] "
+				"<lower-path> <mount-path>\n", argv[0]);
+		exit(EXIT_FAILURE);
+	}
+	
+	fs = test_start_mount(argv[argc - 2], argv[argc - 1], NULL, 0, NULL,
+	                      argc - 3, argv + 1);
+	test_wait_signal();
+	test_stop_mount(fs);
+
+	exit(EXIT_SUCCESS);
+}
+

t/test_common.c

@@ -425,12 +425,13 @@ unsigned int test_get_opts(unsigned int opt_flags, ...)
 
 struct projfs *test_start_mount(const char *lowerdir, const char *mountdir,
 				const struct projfs_handlers *handlers,
-				size_t handlers_size, void *user_data)
+				size_t handlers_size, void *user_data,
+				int argc, const char **argv)
 {
 	struct projfs *fs;
 
 	fs = projfs_new(lowerdir, mountdir, handlers, handlers_size,
-			user_data);
+			user_data, argc, argv);
 
 	if (fs == NULL)
 		errx(EXIT_FAILURE, "unable to create filesystem");

t/test_common.h

@@ -62,7 +62,8 @@ unsigned int test_get_opts(unsigned int opt_flags, ...);
 
 struct projfs *test_start_mount(const char *lowerdir, const char *mountdir,
 				const struct projfs_handlers *handlers,
-				size_t handlers_size, void *user_data);
+				size_t handlers_size, void *user_data,
+				int argc, const char **argv);
 
 void *test_stop_mount(struct projfs *fs);
 

t/test_handlers.c

@@ -117,7 +117,7 @@ int main(int argc, char *const argv[])
 	handlers.handle_perm_event = &test_perm_event;
 
 	fs = test_start_mount(lower_path, mount_path,
-			      &handlers, sizeof(handlers), NULL);
+			      &handlers, sizeof(handlers), NULL, 0, NULL);
 	test_wait_signal();
 	test_stop_mount(fs);
 

t/test_simple.c

@@ -32,7 +32,7 @@ int main(int argc, char *const argv[])
 	test_parse_mount_opts(argc, argv, TEST_OPT_NONE,
 			      &lower_path, &mount_path);
 
-	fs = test_start_mount(lower_path, mount_path, NULL, 0, 0);
+	fs = test_start_mount(lower_path, mount_path, NULL, 0, NULL, 0, NULL);
 	test_wait_signal();
 	test_stop_mount(fs);