This patch add a simple functional test for the "abort" file in fusectlfs (/sys/fs/fuse/connections/ID/about).
A simple fuse daemon is added for testing.
Related discussion can be found in the link below.
Link: https://lore.kernel.org/all/CAOQ4uxjKFXOKQxPpxtS6G_nR0tpw95w0GiO68UcWg_OBhmS... Signed-off-by: Chen Linxuan chenlinxuan@uniontech.com Acked-by: Shuah Khan skhan@linuxfoundation.org Reviewed-by: Amir Goldstein amir73il@gmail.com Co-developed-by: Miklos Szeredi miklos@szeredi.hu Reviewed-by: Miklos Szeredi miklos@szeredi.hu --- Changes in v4: - Apply patch suggested by Miklos Szeredi - Setting up a userns environment for testing - Fix a EBUSY on umount/rmdir - Link to v3: https://lore.kernel.org/all/20250610021007.2800329-2-chenlinxuan@uniontech.c... Changes in v3: - Apply changes suggested by Amir Goldstein - Rename the test subdir to filesystems/fuse - Verify errno when connection is aborted - Apply changes suggested by Shuah Khan - Update commit message - Link to v2: https://lore.kernel.org/all/20250517012350.10317-2-chenlinxuan@uniontech.com... Changes in v2: - Apply changes suggested by Amir Goldstein - Check errno - Link to v1: https://lore.kernel.org/all/20250515073449.346774-2-chenlinxuan@uniontech.co... --- MAINTAINERS | 1 + tools/testing/selftests/Makefile | 1 + .../selftests/filesystems/fuse/.gitignore | 3 + .../selftests/filesystems/fuse/Makefile | 21 +++ .../selftests/filesystems/fuse/fuse_mnt.c | 146 ++++++++++++++++++ .../selftests/filesystems/fuse/fusectl_test.c | 140 +++++++++++++++++ 6 files changed, 312 insertions(+) create mode 100644 tools/testing/selftests/filesystems/fuse/.gitignore create mode 100644 tools/testing/selftests/filesystems/fuse/Makefile create mode 100644 tools/testing/selftests/filesystems/fuse/fuse_mnt.c create mode 100644 tools/testing/selftests/filesystems/fuse/fusectl_test.c
diff --git a/MAINTAINERS b/MAINTAINERS index a92290fffa163..04d90432c1841 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -9901,6 +9901,7 @@ T: git git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse.git F: Documentation/filesystems/fuse* F: fs/fuse/ F: include/uapi/linux/fuse.h +F: tools/testing/selftests/filesystems/fuse/
FUTEX SUBSYSTEM M: Thomas Gleixner tglx@linutronix.de diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile index 339b31e6a6b59..c37a76a8ca214 100644 --- a/tools/testing/selftests/Makefile +++ b/tools/testing/selftests/Makefile @@ -36,6 +36,7 @@ TARGETS += filesystems/fat TARGETS += filesystems/overlayfs TARGETS += filesystems/statmount TARGETS += filesystems/mount-notify +TARGETS += filesystems/fuse TARGETS += firmware TARGETS += fpu TARGETS += ftrace diff --git a/tools/testing/selftests/filesystems/fuse/.gitignore b/tools/testing/selftests/filesystems/fuse/.gitignore new file mode 100644 index 0000000000000..3e72e742d08e8 --- /dev/null +++ b/tools/testing/selftests/filesystems/fuse/.gitignore @@ -0,0 +1,3 @@ +# SPDX-License-Identifier: GPL-2.0-only +fuse_mnt +fusectl_test diff --git a/tools/testing/selftests/filesystems/fuse/Makefile b/tools/testing/selftests/filesystems/fuse/Makefile new file mode 100644 index 0000000000000..612aad69a93aa --- /dev/null +++ b/tools/testing/selftests/filesystems/fuse/Makefile @@ -0,0 +1,21 @@ +# SPDX-License-Identifier: GPL-2.0-or-later + +CFLAGS += -Wall -O2 -g $(KHDR_INCLUDES) + +TEST_GEN_PROGS := fusectl_test +TEST_GEN_FILES := fuse_mnt + +include ../../lib.mk + +VAR_CFLAGS := $(shell pkg-config fuse --cflags 2>/dev/null) +ifeq ($(VAR_CFLAGS),) +VAR_CFLAGS := -D_FILE_OFFSET_BITS=64 -I/usr/include/fuse +endif + +VAR_LDLIBS := $(shell pkg-config fuse --libs 2>/dev/null) +ifeq ($(VAR_LDLIBS),) +VAR_LDLIBS := -lfuse -pthread +endif + +$(OUTPUT)/fuse_mnt: CFLAGS += $(VAR_CFLAGS) +$(OUTPUT)/fuse_mnt: LDLIBS += $(VAR_LDLIBS) diff --git a/tools/testing/selftests/filesystems/fuse/fuse_mnt.c b/tools/testing/selftests/filesystems/fuse/fuse_mnt.c new file mode 100644 index 0000000000000..d12b17f30fadc --- /dev/null +++ b/tools/testing/selftests/filesystems/fuse/fuse_mnt.c @@ -0,0 +1,146 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * fusectl test file-system + * Creates a simple FUSE filesystem with a single read-write file (/test) + */ + +#define FUSE_USE_VERSION 26 + +#include <fuse.h> +#include <stdio.h> +#include <string.h> +#include <errno.h> +#include <fcntl.h> +#include <stdlib.h> +#include <unistd.h> + +#define MAX(a, b) ((a) > (b) ? (a) : (b)) + +static char *content; +static size_t content_size = 0; +static const char test_path[] = "/test"; + +static int test_getattr(const char *path, struct stat *st) +{ + memset(st, 0, sizeof(*st)); + + if (!strcmp(path, "/")) { + st->st_mode = S_IFDIR | 0755; + st->st_nlink = 2; + return 0; + } + + if (!strcmp(path, test_path)) { + st->st_mode = S_IFREG | 0664; + st->st_nlink = 1; + st->st_size = content_size; + return 0; + } + + return -ENOENT; +} + +static int test_readdir(const char *path, void *buf, fuse_fill_dir_t filler, + off_t offset, struct fuse_file_info *fi) +{ + if (strcmp(path, "/")) + return -ENOENT; + + filler(buf, ".", NULL, 0); + filler(buf, "..", NULL, 0); + filler(buf, test_path + 1, NULL, 0); + + return 0; +} + +static int test_open(const char *path, struct fuse_file_info *fi) +{ + if (strcmp(path, test_path)) + return -ENOENT; + + return 0; +} + +static int test_read(const char *path, char *buf, size_t size, off_t offset, + struct fuse_file_info *fi) +{ + if (strcmp(path, test_path) != 0) + return -ENOENT; + + if (!content || content_size == 0) + return 0; + + if (offset >= content_size) + return 0; + + if (offset + size > content_size) + size = content_size - offset; + + memcpy(buf, content + offset, size); + + return size; +} + +static int test_write(const char *path, const char *buf, size_t size, + off_t offset, struct fuse_file_info *fi) +{ + size_t new_size; + + if (strcmp(path, test_path) != 0) + return -ENOENT; + + if(offset > content_size) + return -EINVAL; + + new_size = MAX(offset + size, content_size); + + if (new_size > content_size) + content = realloc(content, new_size); + + content_size = new_size; + + if (!content) + return -ENOMEM; + + memcpy(content + offset, buf, size); + + return size; +} + +static int test_truncate(const char *path, off_t size) +{ + if (strcmp(path, test_path) != 0) + return -ENOENT; + + if (size == 0) { + free(content); + content = NULL; + content_size = 0; + return 0; + } + + content = realloc(content, size); + + if (!content) + return -ENOMEM; + + if (size > content_size) + memset(content + content_size, 0, size - content_size); + + content_size = size; + return 0; +} + +static struct fuse_operations memfd_ops = { + .getattr = test_getattr, + .readdir = test_readdir, + .open = test_open, + .read = test_read, + .write = test_write, + .truncate = test_truncate, +}; + +int main(int argc, char *argv[]) +{ + return fuse_main(argc, argv, &memfd_ops, NULL); +} diff --git a/tools/testing/selftests/filesystems/fuse/fusectl_test.c b/tools/testing/selftests/filesystems/fuse/fusectl_test.c new file mode 100644 index 0000000000000..8d124d1cacb26 --- /dev/null +++ b/tools/testing/selftests/filesystems/fuse/fusectl_test.c @@ -0,0 +1,140 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +// Copyright (c) 2025 Chen Linxuan chenlinxuan@uniontech.com + +#define _GNU_SOURCE + +#include <errno.h> +#include <fcntl.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/mount.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <sys/wait.h> +#include <unistd.h> +#include <dirent.h> +#include <sched.h> +#include <linux/limits.h> + +#include "../../kselftest_harness.h" + +#define FUSECTL_MOUNTPOINT "/sys/fs/fuse/connections" +#define FUSE_MOUNTPOINT "/tmp/fuse_mnt_XXXXXX" +#define FUSE_DEVICE "/dev/fuse" +#define FUSECTL_TEST_VALUE "1" + +static void write_file(struct __test_metadata *const _metadata, + const char *path, const char *val) +{ + int fd = open(path, O_WRONLY); + size_t len = strlen(val); + + ASSERT_GE(fd, 0); + ASSERT_EQ(write(fd, val, len), len); + ASSERT_EQ(close(fd), 0); +} + +FIXTURE(fusectl){ + char fuse_mountpoint[sizeof(FUSE_MOUNTPOINT)]; + int connection; +}; + +FIXTURE_SETUP(fusectl) +{ + const char *fuse_mnt_prog = "./fuse_mnt"; + int status, pid; + struct stat statbuf; + uid_t uid = getuid(); + gid_t gid = getgid(); + char buf[32]; + + /* Setup userns */ + ASSERT_EQ(unshare(CLONE_NEWNS|CLONE_NEWUSER), 0); + sprintf(buf, "0 %d 1", uid); + write_file(_metadata, "/proc/self/uid_map", buf); + write_file(_metadata, "/proc/self/setgroups", "deny"); + sprintf(buf, "0 %d 1", gid); + write_file(_metadata, "/proc/self/gid_map", buf); + ASSERT_EQ(mount("", "/", NULL, MS_REC|MS_PRIVATE, NULL), 0); + + strcpy(self->fuse_mountpoint, FUSE_MOUNTPOINT); + + if (!mkdtemp(self->fuse_mountpoint)) + SKIP(return, + "Failed to create FUSE mountpoint %s", + strerror(errno)); + + if (access(FUSECTL_MOUNTPOINT, F_OK)) + SKIP(return, + "FUSE control filesystem not mounted"); + + pid = fork(); + if (pid < 0) + SKIP(return, + "Failed to fork FUSE daemon process: %s", + strerror(errno)); + + if (pid == 0) { + execlp(fuse_mnt_prog, fuse_mnt_prog, self->fuse_mountpoint, NULL); + exit(errno); + } + + waitpid(pid, &status, 0); + if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) { + SKIP(return, + "Failed to start FUSE daemon %s", + strerror(WEXITSTATUS(status))); + } + + if (stat(self->fuse_mountpoint, &statbuf)) + SKIP(return, + "Failed to stat FUSE mountpoint %s", + strerror(errno)); + + self->connection = statbuf.st_dev; +} + +FIXTURE_TEARDOWN(fusectl) +{ + umount2(self->fuse_mountpoint, MNT_DETACH); + rmdir(self->fuse_mountpoint); +} + +TEST_F(fusectl, abort) +{ + char path_buf[PATH_MAX]; + int abort_fd, test_fd, ret; + + sprintf(path_buf, "/sys/fs/fuse/connections/%d/abort", self->connection); + + ASSERT_EQ(0, access(path_buf, F_OK)); + + abort_fd = open(path_buf, O_WRONLY); + ASSERT_GE(abort_fd, 0); + + sprintf(path_buf, "%s/test", self->fuse_mountpoint); + + test_fd = open(path_buf, O_RDWR); + ASSERT_GE(test_fd, 0); + + ret = read(test_fd, path_buf, sizeof(path_buf)); + ASSERT_EQ(ret, 0); + + ret = write(test_fd, "test", sizeof("test")); + ASSERT_EQ(ret, sizeof("test")); + + ret = lseek(test_fd, 0, SEEK_SET); + ASSERT_GE(ret, 0); + + ret = write(abort_fd, FUSECTL_TEST_VALUE, sizeof(FUSECTL_TEST_VALUE)); + ASSERT_GT(ret, 0); + + close(abort_fd); + + ret = read(test_fd, path_buf, sizeof(path_buf)); + ASSERT_EQ(ret, -1); + ASSERT_EQ(errno, ENOTCONN); +} + +TEST_HARNESS_MAIN