bmap.cc

/*-
 * 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:
virtual void SetUp() {
	m_maxreadahead = UINT32_MAX;
	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, public WithParamInterface<int> {};

/*
 * Test FUSE_BMAP
 */
TEST_F(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_F(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_F(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_F(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 = 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);
}

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