/*-
 * 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/ioctl.h>
#include <sys/filio.h>

#include <fcntl.h>
}

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

using namespace testing;

const static char FULLPATH[] = "mountpoint/foo";
const static char RELPATH[] = "foo";

class Bmap: public FuseTest,
            public WithParamInterface<tuple<int, int>>
{
public:
virtual void SetUp() {
        m_maxreadahead = UINT32_MAX;
        m_init_flags |= get<0>(GetParam());
        FuseTest::SetUp();
}
void expect_bmap(uint64_t ino, uint64_t lbn, uint32_t blocksize, uint64_t pbn)
{
        EXPECT_CALL(*m_mock, process(
                ResultOf([=](auto in) {
                        return (in.header.opcode == FUSE_BMAP &&
                                in.header.nodeid == ino &&
                                in.body.bmap.block == lbn &&
                                in.body.bmap.blocksize == blocksize);
                }, Eq(true)),
                _)
        ).WillOnce(Invoke(ReturnImmediate([=](auto i __unused, auto& out) {
                SET_OUT_HEADER_LEN(out, bmap);
                out.body.bmap.block = pbn;
        })));
}
        
void expect_lookup(const char *relpath, uint64_t ino, off_t size)
{
        FuseTest::expect_lookup(relpath, ino, S_IFREG | 0644, size, 1,
                UINT64_MAX);
}
};

class BmapEof: public Bmap {};

/*
 * Test FUSE_BMAP
 */
TEST_P(Bmap, bmap)
{
        struct fiobmap2_arg arg;
        /*
         * Pick fsize and lbn large enough that max length runs won't reach
         * either beginning or end of file
         */
        const off_t filesize = 1 << 30;
        int64_t lbn = 100;
        int64_t pbn = 12345;
        const ino_t ino = 42;
        int fd;

        expect_lookup(RELPATH, 42, filesize);
        expect_open(ino, 0, 1);
        expect_bmap(ino, lbn, m_maxbcachebuf, pbn);

        fd = open(FULLPATH, O_RDWR);
        ASSERT_LE(0, fd) << strerror(errno);

        arg.bn = lbn;
        arg.runp = -1;
        arg.runb = -1;
        ASSERT_EQ(0, ioctl(fd, FIOBMAP2, &arg)) << strerror(errno);
        EXPECT_EQ(arg.bn, pbn);
       /*
        * XXX The FUSE protocol does not include the runp and runb variables,
        * so those must be guessed in-kernel.  There's no "right" answer, so
        * just check that they're within reasonable limits.
        */
        EXPECT_LE(arg.runb, lbn);
        EXPECT_LE((unsigned long)arg.runb, m_maxreadahead / m_maxbcachebuf);
        EXPECT_LE((unsigned long)arg.runb, m_maxphys / m_maxbcachebuf);
        EXPECT_GT(arg.runb, 0);
        EXPECT_LE(arg.runp, filesize / m_maxbcachebuf - lbn);
        EXPECT_LE((unsigned long)arg.runp, m_maxreadahead / m_maxbcachebuf);
        EXPECT_LE((unsigned long)arg.runp, m_maxphys / m_maxbcachebuf);
        EXPECT_GT(arg.runp, 0);

        leak(fd);
}

/* 
 * If the daemon does not implement VOP_BMAP, fusefs should return sensible
 * defaults.
 */
TEST_P(Bmap, default_)
{
        struct fiobmap2_arg arg;
        const off_t filesize = 1 << 30;
        const ino_t ino = 42;
        int64_t lbn;
        int fd;

        expect_lookup(RELPATH, 42, filesize);
        expect_open(ino, 0, 1);
        EXPECT_CALL(*m_mock, process(
                ResultOf([=](auto in) {
                        return (in.header.opcode == FUSE_BMAP);
                }, Eq(true)),
                _)
        ).WillOnce(Invoke(ReturnErrno(ENOSYS)));

        fd = open(FULLPATH, O_RDWR);
        ASSERT_LE(0, fd) << strerror(errno);

        /* First block */
        lbn = 0;
        arg.bn = lbn;
        arg.runp = -1;
        arg.runb = -1;
        ASSERT_EQ(0, ioctl(fd, FIOBMAP2, &arg)) << strerror(errno);
        EXPECT_EQ(arg.bn, 0);
        EXPECT_EQ((unsigned long )arg.runp, m_maxphys / m_maxbcachebuf - 1);
        EXPECT_EQ(arg.runb, 0);

        /* In the middle */
        lbn = filesize / m_maxbcachebuf / 2;
        arg.bn = lbn;
        arg.runp = -1;
        arg.runb = -1;
        ASSERT_EQ(0, ioctl(fd, FIOBMAP2, &arg)) << strerror(errno);
        EXPECT_EQ(arg.bn, lbn * m_maxbcachebuf / DEV_BSIZE);
        EXPECT_EQ((unsigned long )arg.runp, m_maxphys / m_maxbcachebuf - 1);
        EXPECT_EQ((unsigned long )arg.runb, m_maxphys / m_maxbcachebuf - 1);

        /* Last block */
        lbn = filesize / m_maxbcachebuf - 1;
        arg.bn = lbn;
        arg.runp = -1;
        arg.runb = -1;
        ASSERT_EQ(0, ioctl(fd, FIOBMAP2, &arg)) << strerror(errno);
        EXPECT_EQ(arg.bn, lbn * m_maxbcachebuf / DEV_BSIZE);
        EXPECT_EQ(arg.runp, 0);
        EXPECT_EQ((unsigned long )arg.runb, m_maxphys / m_maxbcachebuf - 1);

        leak(fd);
}

/*
 * The server returns an error for some reason for FUSE_BMAP.  fusefs should
 * faithfully report that error up to the caller.
 */
TEST_P(Bmap, einval)
{
        struct fiobmap2_arg arg;
        const off_t filesize = 1 << 30;
        int64_t lbn = 100;
        const ino_t ino = 42;
        int fd;

        expect_lookup(RELPATH, 42, filesize);
        expect_open(ino, 0, 1);
        EXPECT_CALL(*m_mock, process(
                ResultOf([=](auto in) {
                        return (in.header.opcode == FUSE_BMAP &&
                                in.header.nodeid == ino);
                }, Eq(true)),
                _)
        ).WillOnce(Invoke(ReturnErrno(EINVAL)));

        fd = open(FULLPATH, O_RDWR);
        ASSERT_LE(0, fd) << strerror(errno);

        arg.bn = lbn;
        arg.runp = -1;
        arg.runb = -1;
        ASSERT_EQ(-1, ioctl(fd, FIOBMAP2, &arg));
        EXPECT_EQ(EINVAL, errno);

        leak(fd);
}

/*
 * Even if the server returns EINVAL during VOP_BMAP, we should still be able
 * to successfully read a block.  This is a regression test for
 * https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=264196 .  The bug did not
 * lie in fusefs, but this is a convenient place for a regression test.
 */
TEST_P(Bmap, spurious_einval)
{
        const off_t filesize = 4ull << 30;
        const ino_t ino = 42;
        int fd, r;
        char buf[1];

        expect_lookup(RELPATH, 42, filesize);
        expect_open(ino, 0, 1);
        EXPECT_CALL(*m_mock, process(
                ResultOf([=](auto in) {
                        return (in.header.opcode == FUSE_BMAP &&
                                in.header.nodeid == ino);
                }, Eq(true)),
                _)
        ).WillRepeatedly(Invoke(ReturnErrno(EINVAL)));
        EXPECT_CALL(*m_mock, process(
        ResultOf([=](auto in) {
                return (in.header.opcode == FUSE_READ &&
                        in.header.nodeid == ino &&
                        in.body.read.offset == 0 &&
                        in.body.read.size == (uint64_t)m_maxbcachebuf);
                }, Eq(true)),
                _)
        ).WillOnce(Invoke(ReturnImmediate([=](auto in, auto& out) {
                size_t osize = in.body.read.size;

                assert(osize < sizeof(out.body.bytes));
                out.header.len = sizeof(struct fuse_out_header) + osize;
                bzero(out.body.bytes, osize);
        })));

        fd = open(FULLPATH, O_RDWR);
        ASSERT_LE(0, fd) << strerror(errno);

        /*
         * Read the same block multiple times.  On a system affected by PR
         * 264196 , the second read will fail.
         */
        r = read(fd, buf, sizeof(buf));
        EXPECT_EQ(r, 1) << strerror(errno);
        r = read(fd, buf, sizeof(buf));
        EXPECT_EQ(r, 1) << strerror(errno);
        r = read(fd, buf, sizeof(buf));
        EXPECT_EQ(r, 1) << strerror(errno);
}

/*
 * VOP_BMAP should not query the server for the file's size, even if its cached
 * attributes have expired.
 * Regression test for https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=256937
 */
TEST_P(BmapEof, eof)
{
        /*
         * Outline:
         * 1) lookup the file, setting attr_valid=0
         * 2) Read more than one block, causing the kernel to issue VOP_BMAP to
         *    plan readahead.
         * 3) Nothing should panic
         * 4) Repeat the tests, truncating the file after different numbers of
         *    GETATTR operations.
         */
        Sequence seq;
        const off_t filesize = 2 * m_maxbcachebuf;
        const ino_t ino = 42;
        mode_t mode = S_IFREG | 0644;
        char *buf;
        int fd;
        int ngetattrs;

        ngetattrs = get<1>(GetParam());
        FuseTest::expect_lookup(RELPATH, ino, mode, filesize, 1, 0);
        expect_open(ino, 0, 1);
        // Depending on ngetattrs, FUSE_READ could be called with either
        // filesize or filesize / 2 .
        EXPECT_CALL(*m_mock, process(
        ResultOf([=](auto in) {
                return (in.header.opcode == FUSE_READ &&
                        in.header.nodeid == ino &&
                        in.body.read.offset == 0 &&
                        ( in.body.read.size == filesize ||
                          in.body.read.size == filesize / 2));
                }, Eq(true)),
                _)
        ).WillOnce(Invoke(ReturnImmediate([=](auto in, auto& out) {
                size_t osize = in.body.read.size;

                assert(osize < sizeof(out.body.bytes));
                out.header.len = sizeof(struct fuse_out_header) + osize;
                bzero(out.body.bytes, osize);
        })));
        EXPECT_CALL(*m_mock, process(
                ResultOf([](auto in) {
                        return (in.header.opcode == FUSE_GETATTR &&
                                in.header.nodeid == ino);
                }, Eq(true)),
                _)
        ).Times(Between(ngetattrs - 1, ngetattrs))
        .InSequence(seq)
        .WillRepeatedly(Invoke(ReturnImmediate([=](auto i __unused, auto& out) {
                SET_OUT_HEADER_LEN(out, attr);
                out.body.attr.attr_valid = 0;
                out.body.attr.attr.ino = ino;
                out.body.attr.attr.mode = S_IFREG | 0644;
                out.body.attr.attr.size = filesize;
        })));
        EXPECT_CALL(*m_mock, process(
                ResultOf([](auto in) {
                        return (in.header.opcode == FUSE_GETATTR &&
                                in.header.nodeid == ino);
                }, Eq(true)),
                _)
        ).InSequence(seq)
        .WillRepeatedly(Invoke(ReturnImmediate([=](auto i __unused, auto& out) {
                SET_OUT_HEADER_LEN(out, attr);
                out.body.attr.attr_valid = 0;
                out.body.attr.attr.ino = ino;
                out.body.attr.attr.mode = S_IFREG | 0644;
                out.body.attr.attr.size = filesize / 2;
        })));

        buf = new char[filesize]();
        fd = open(FULLPATH, O_RDWR);
        ASSERT_LE(0, fd) << strerror(errno);
        read(fd, buf, filesize);

        delete[] buf;
        leak(fd);
}

/*
 * Try with and without async reads, because it affects the type of vnode lock
 * on entry to fuse_vnop_bmap.
 */
INSTANTIATE_TEST_SUITE_P(B, Bmap, Values(
        tuple(0, 0),
        tuple(FUSE_ASYNC_READ, 0)
));

INSTANTIATE_TEST_SUITE_P(BE, BmapEof, Values(
        tuple(0, 1),
        tuple(0, 2),
        tuple(0, 3)
));