/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2019 The FreeBSD Foundation
 *
 * This software was developed by BFF Storage Systems, LLC under sponsorship
 * from the FreeBSD Foundation.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

extern "C" {
#include <sys/param.h>
#include <sys/mount.h>
#include <semaphore.h>
}

#include "mockfs.hh"
#include "utils.hh"

using namespace testing;

class Statfs: public FuseTest {};

TEST_F(Statfs, eio)
{
        struct statfs statbuf;

        EXPECT_CALL(*m_mock, process(
                ResultOf([](auto in) {
                        return (in.header.opcode == FUSE_STATFS);
                }, Eq(true)),
                _)
        ).WillOnce(Invoke(ReturnErrno(EIO)));

        ASSERT_NE(0, statfs("mountpoint", &statbuf));
        ASSERT_EQ(EIO, errno);
}

/*
 * When the daemon is dead but the filesystem is still mounted, fuse(4) fakes
 * the statfs(2) response, which is necessary for unmounting.
 */
TEST_F(Statfs, enotconn)
{
        struct statfs statbuf;
        char mp[PATH_MAX];

        m_mock->kill_daemon();

        ASSERT_NE(nullptr, getcwd(mp, PATH_MAX)) << strerror(errno);
        strlcat(mp, "/mountpoint", PATH_MAX);
        ASSERT_EQ(0, statfs("mountpoint", &statbuf)) << strerror(errno);

        EXPECT_EQ(getuid(), statbuf.f_owner);
        EXPECT_EQ(0, strcmp("fusefs", statbuf.f_fstypename));
        EXPECT_EQ(0, strcmp("/dev/fuse", statbuf.f_mntfromname));
        EXPECT_EQ(0, strcmp(mp, statbuf.f_mntonname));
}

static void* statfs_th(void* arg) {
        ssize_t r;
        struct statfs *sb = (struct statfs*)arg;

        r = statfs("mountpoint", sb);
        if (r >= 0)
                return 0;
        else
                return (void*)(intptr_t)errno;
}

/*
 * Like the enotconn test, but in this case the daemon dies after we send the
 * FUSE_STATFS operation but before we get a response.
 */
TEST_F(Statfs, enotconn_while_blocked)
{
        struct statfs statbuf;
        void *thr0_value;
        pthread_t th0;
        char mp[PATH_MAX];
        sem_t sem;

        ASSERT_EQ(0, sem_init(&sem, 0, 0)) << strerror(errno);

        EXPECT_CALL(*m_mock, process(
                ResultOf([](auto in) {
                        return (in.header.opcode == FUSE_STATFS);
                }, Eq(true)),
                _)
        ).WillOnce(Invoke([&](auto in __unused, auto &out __unused) {
                sem_post(&sem);
                /* Just block until the daemon dies */
        }));

        ASSERT_NE(nullptr, getcwd(mp, PATH_MAX)) << strerror(errno);
        strlcat(mp, "/mountpoint", PATH_MAX);
        ASSERT_EQ(0, pthread_create(&th0, NULL, statfs_th, (void*)&statbuf))
                << strerror(errno);

        ASSERT_EQ(0, sem_wait(&sem)) << strerror(errno);
        m_mock->kill_daemon();

        pthread_join(th0, &thr0_value);
        ASSERT_EQ(0, (intptr_t)thr0_value);

        EXPECT_EQ(getuid(), statbuf.f_owner);
        EXPECT_EQ(0, strcmp("fusefs", statbuf.f_fstypename));
        EXPECT_EQ(0, strcmp("/dev/fuse", statbuf.f_mntfromname));
        EXPECT_EQ(0, strcmp(mp, statbuf.f_mntonname));
}

TEST_F(Statfs, ok)
{
        struct statfs statbuf;
        char mp[PATH_MAX];

        EXPECT_CALL(*m_mock, process(
                ResultOf([](auto in) {
                        return (in.header.opcode == FUSE_STATFS);
                }, Eq(true)),
                _)
        ).WillOnce(Invoke(ReturnImmediate([=](auto in __unused, auto& out) {
                SET_OUT_HEADER_LEN(out, statfs);
                out.body.statfs.st.blocks = 1000;
                out.body.statfs.st.bfree = 100;
                out.body.statfs.st.bavail = 200;
                out.body.statfs.st.files = 5;
                out.body.statfs.st.ffree = 6;
                out.body.statfs.st.namelen = 128;
                out.body.statfs.st.frsize = 1024;
        })));

        ASSERT_NE(nullptr, getcwd(mp, PATH_MAX)) << strerror(errno);
        strlcat(mp, "/mountpoint", PATH_MAX);
        ASSERT_EQ(0, statfs("mountpoint", &statbuf)) << strerror(errno);
        EXPECT_EQ(1024ul, statbuf.f_bsize);
        /* 
         * fuse(4) ignores the filesystem's reported optimal transfer size, and
         * chooses a size that works well with the rest of the system instead
         */
        EXPECT_EQ(1000ul, statbuf.f_blocks);
        EXPECT_EQ(100ul, statbuf.f_bfree);
        EXPECT_EQ(200l, statbuf.f_bavail);
        EXPECT_EQ(5ul, statbuf.f_files);
        EXPECT_EQ(6l, statbuf.f_ffree);
        EXPECT_EQ(128u, statbuf.f_namemax);
        EXPECT_EQ(getuid(), statbuf.f_owner);
        EXPECT_EQ(0, strcmp("fusefs", statbuf.f_fstypename));
        EXPECT_EQ(0, strcmp("/dev/fuse", statbuf.f_mntfromname));
        EXPECT_EQ(0, strcmp(mp, statbuf.f_mntonname));
}