fs/fusefs/xattr.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.
 */

/* Tests for all things relating to extended attributes and FUSE */

extern "C" {
#include <sys/types.h>
#include <sys/extattr.h>
#include <sys/wait.h>
#include <semaphore.h>
#include <signal.h>
#include <string.h>
}

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

using namespace testing;

const char FULLPATH[] = "mountpoint/some_file.txt";
const char RELPATH[] = "some_file.txt";
static sem_t killer_semaphore;

void* killer(void* target) {
	pid_t pid = *(pid_t*)target;
	sem_wait(&killer_semaphore);
	if (verbosity > 1)
		printf("Killing! pid %d\n", pid);
	kill(pid, SIGINT);

	return(NULL);
}

class Xattr: public FuseTest {
public:
void expect_listxattr(uint64_t ino, uint32_t size, ProcessMockerT r,
    Sequence *seq = NULL)
{
	if (seq == NULL) {
		EXPECT_CALL(*m_mock, process(
			ResultOf([=](auto in) {
				return (in.header.opcode == FUSE_LISTXATTR &&
					in.header.nodeid == ino &&
					in.body.listxattr.size == size);
			}, Eq(true)),
			_)
		).WillOnce(Invoke(r))
		.RetiresOnSaturation();
	} else {
		EXPECT_CALL(*m_mock, process(
			ResultOf([=](auto in) {
				return (in.header.opcode == FUSE_LISTXATTR &&
					in.header.nodeid == ino &&
					in.body.listxattr.size == size);
			}, Eq(true)),
			_)
		).InSequence(*seq)
		.WillOnce(Invoke(r))
		.RetiresOnSaturation();
	}
}

void expect_removexattr(uint64_t ino, const char *attr, int error)
{
	EXPECT_CALL(*m_mock, process(
		ResultOf([=](auto in) {
			const char *a = (const char*)in.body.bytes;
			return (in.header.opcode == FUSE_REMOVEXATTR &&
				in.header.nodeid == ino &&
				0 == strcmp(attr, a));
		}, Eq(true)),
		_)
	).WillOnce(Invoke(ReturnErrno(error)));
}

void expect_setxattr(uint64_t ino, const char *attr, const char *value,
	ProcessMockerT r)
{
	EXPECT_CALL(*m_mock, process(
		ResultOf([=](auto in) {
			const char *a = (const char*)in.body.bytes +
				sizeof(fuse_setxattr_in);
			const char *v = a + strlen(a) + 1;
			return (in.header.opcode == FUSE_SETXATTR &&
				in.header.nodeid == ino &&
				in.body.setxattr.size == (strlen(value) + 1) &&
				in.body.setxattr.setxattr_flags == 0 &&
				0 == strcmp(attr, a) &&
				0 == strcmp(value, v));
		}, Eq(true)),
		_)
	).WillOnce(Invoke(r));
}

};

class Xattr_7_32:public FuseTest {
public:
virtual void SetUp()
{
	m_kernel_minor_version = 32;
	FuseTest::SetUp();
}

void expect_setxattr_7_32(uint64_t ino, const char *attr, const char *value,
	ProcessMockerT r)
{
	EXPECT_CALL(*m_mock, process(
		ResultOf([=](auto in) {
			const char *a = (const char *)in.body.bytes +
				FUSE_COMPAT_SETXATTR_IN_SIZE;
			const char *v = a + strlen(a) + 1;
			return (in.header.opcode == FUSE_SETXATTR &&
				in.header.nodeid == ino &&
				in.body.setxattr.size == (strlen(value) + 1) &&
				0 == strcmp(attr, a) &&
				0 == strcmp(value, v));
		}, Eq(true)),
		_)
	).WillOnce(Invoke(r));
}
};

class Getxattr: public Xattr {};

class Listxattr: public Xattr {};

/* Listxattr tests that need to use a signal */
class ListxattrSig: public Listxattr {
public:
pthread_t m_killer_th;
pid_t m_child;

void SetUp() {
	/*
	 * Mount with -o nointr so the mount can't get interrupted while
	 * waiting for a response from the server
	 */
	m_nointr = true;
	FuseTest::SetUp();

	ASSERT_EQ(0, sem_init(&killer_semaphore, 0, 0)) << strerror(errno);
}

void TearDown() {
	if (m_killer_th != NULL) {
		pthread_join(m_killer_th, NULL);
	}

	sem_destroy(&killer_semaphore);

	FuseTest::TearDown();
}
};

class Removexattr: public Xattr {};
class Setxattr: public Xattr {};
class Setxattr_7_32:public Xattr_7_32 {};
class RofsXattr: public Xattr {
public:
virtual void SetUp() {
	m_ro = true;
	Xattr::SetUp();
}
};

/*
 * If the extended attribute does not exist on this file, the daemon should
 * return ENOATTR (ENODATA on Linux, but it's up to the daemon to choose the
 * correct errror code)
 */
TEST_F(Getxattr, enoattr)
{
	char data[80];
	uint64_t ino = 42;
	int ns = EXTATTR_NAMESPACE_USER;
	ssize_t r;

	expect_lookup(RELPATH, ino, S_IFREG | 0644, 0, 1);
	expect_getxattr(ino, "user.foo", ReturnErrno(ENOATTR));

	r = extattr_get_file(FULLPATH, ns, "foo", data, sizeof(data));
	ASSERT_EQ(-1, r);
	ASSERT_EQ(ENOATTR, errno);
}

/*
 * If the filesystem returns ENOSYS, then it will be treated as a permanent
 * failure and all future VOP_GETEXTATTR calls will fail with EOPNOTSUPP
 * without querying the filesystem daemon
 */
TEST_F(Getxattr, enosys)
{
	char data[80];
	uint64_t ino = 42;
	int ns = EXTATTR_NAMESPACE_USER;
	ssize_t r;

	expect_lookup(RELPATH, ino, S_IFREG | 0644, 0, 2);
	expect_getxattr(ino, "user.foo", ReturnErrno(ENOSYS));

	r = extattr_get_file(FULLPATH, ns, "foo", data, sizeof(data));
	ASSERT_EQ(-1, r);
	EXPECT_EQ(EOPNOTSUPP, errno);

	/* Subsequent attempts should not query the filesystem at all */
	r = extattr_get_file(FULLPATH, ns, "foo", data, sizeof(data));
	ASSERT_EQ(-1, r);
	EXPECT_EQ(EOPNOTSUPP, errno);
}

/*
 * On FreeBSD, if the user passes an insufficiently large buffer then the
 * filesystem is supposed to copy as much of the attribute's value as will fit.
 *
 * On Linux, however, the filesystem is supposed to return ERANGE.
 *
 * libfuse specifies the Linux behavior.  However, that's probably an error.
 * It would probably be correct for the filesystem to use platform-dependent
 * behavior.
 *
 * This test case covers a filesystem that uses the Linux behavior
 * TODO: require FreeBSD Behavior.
 */
TEST_F(Getxattr, erange)
{
	char data[10];
	uint64_t ino = 42;
	int ns = EXTATTR_NAMESPACE_USER;
	ssize_t r;

	expect_lookup(RELPATH, ino, S_IFREG | 0644, 0, 1);
	expect_getxattr(ino, "user.foo", ReturnErrno(ERANGE));

	r = extattr_get_file(FULLPATH, ns, "foo", data, sizeof(data));
	ASSERT_EQ(-1, r);
	ASSERT_EQ(ERANGE, errno);
}

/*
 * If the user passes a 0-length buffer, then the daemon should just return the
 * size of the attribute
 */
TEST_F(Getxattr, size_only)
{
	uint64_t ino = 42;
	int ns = EXTATTR_NAMESPACE_USER;

	expect_lookup(RELPATH, ino, S_IFREG | 0644, 0, 1);
	expect_getxattr(ino, "user.foo",
		ReturnImmediate([](auto in __unused, auto& out) {
			SET_OUT_HEADER_LEN(out, getxattr);
			out.body.getxattr.size = 99;
		})
	);

	ASSERT_EQ(99, extattr_get_file(FULLPATH, ns, "foo", NULL, 0))
		<< strerror(errno);;
}

/*
 * Successfully get an attribute from the system namespace
 */
TEST_F(Getxattr, system)
{
	uint64_t ino = 42;
	char data[80];
	const char value[] = "whatever";
	ssize_t value_len = strlen(value) + 1;
	int ns = EXTATTR_NAMESPACE_SYSTEM;
	ssize_t r;

	expect_lookup(RELPATH, ino, S_IFREG | 0644, 0, 1);
	expect_getxattr(ino, "system.foo",
		ReturnImmediate([&](auto in __unused, auto& out) {
			memcpy((void*)out.body.bytes, value, value_len);
			out.header.len = sizeof(out.header) + value_len;
		})
	);

	r = extattr_get_file(FULLPATH, ns, "foo", data, sizeof(data));
	ASSERT_EQ(value_len, r)  << strerror(errno);
	EXPECT_STREQ(value, data);
}

/*
 * Successfully get an attribute from the user namespace
 */
TEST_F(Getxattr, user)
{
	uint64_t ino = 42;
	char data[80];
	const char value[] = "whatever";
	ssize_t value_len = strlen(value) + 1;
	int ns = EXTATTR_NAMESPACE_USER;
	ssize_t r;

	expect_lookup(RELPATH, ino, S_IFREG | 0644, 0, 1);
	expect_getxattr(ino, "user.foo",
		ReturnImmediate([&](auto in __unused, auto& out) {
			memcpy((void*)out.body.bytes, value, value_len);
			out.header.len = sizeof(out.header) + value_len;
		})
	);

	r = extattr_get_file(FULLPATH, ns, "foo", data, sizeof(data));
	ASSERT_EQ(value_len, r)  << strerror(errno);
	EXPECT_STREQ(value, data);
}

/*
 * If the filesystem returns ENOSYS, then it will be treated as a permanent
 * failure and all future VOP_LISTEXTATTR calls will fail with EOPNOTSUPP
 * without querying the filesystem daemon
 */
TEST_F(Listxattr, enosys)
{
	uint64_t ino = 42;
	int ns = EXTATTR_NAMESPACE_USER;

	expect_lookup(RELPATH, ino, S_IFREG | 0644, 0, 2);
	expect_listxattr(ino, 0, ReturnErrno(ENOSYS));

	ASSERT_EQ(-1, extattr_list_file(FULLPATH, ns, NULL, 0));
	EXPECT_EQ(EOPNOTSUPP, errno);

	/* Subsequent attempts should not query the filesystem at all */
	ASSERT_EQ(-1, extattr_list_file(FULLPATH, ns, NULL, 0));
	EXPECT_EQ(EOPNOTSUPP, errno);
}

/*
 * Listing extended attributes failed because they aren't configured on this
 * filesystem
 */
TEST_F(Listxattr, enotsup)
{
	uint64_t ino = 42;
	int ns = EXTATTR_NAMESPACE_USER;

	expect_lookup(RELPATH, ino, S_IFREG | 0644, 0, 1);
	expect_listxattr(ino, 0, ReturnErrno(ENOTSUP));

	ASSERT_EQ(-1, extattr_list_file(FULLPATH, ns, NULL, 0));
	ASSERT_EQ(ENOTSUP, errno);
}

/*
 * On FreeBSD, if the user passes an insufficiently large buffer to
 * extattr_list_file(2) or VOP_LISTEXTATTR(9), then the file system is supposed
 * to copy as much of the attribute's value as will fit.
 *
 * On Linux, however, the file system is supposed to return ERANGE if an
 * insufficiently large buffer is passed to listxattr(2).
 *
 * fusefs(4) must guarantee the usual FreeBSD behavior.
 */
TEST_F(Listxattr, erange)
{
	uint64_t ino = 42;
	int ns = EXTATTR_NAMESPACE_USER;
	char attrs[9] = "user.foo";
	char expected[3] = {3, 'f', 'o'};
	char buf[3];

	expect_lookup(RELPATH, ino, S_IFREG | 0644, 0, 1);
	expect_listxattr(ino, 0, ReturnImmediate([](auto i __unused, auto& out)
	{
		out.body.listxattr.size = sizeof(attrs);
		SET_OUT_HEADER_LEN(out, listxattr);
	}));
	expect_listxattr(ino, sizeof(attrs),
	ReturnImmediate([&](auto in __unused, auto& out) {
		memcpy((void*)out.body.bytes, attrs, sizeof(attrs));
		out.header.len = sizeof(fuse_out_header) + sizeof(attrs);
	}));


	ASSERT_EQ(static_cast<ssize_t>(sizeof(buf)),
		  extattr_list_file(FULLPATH, ns, buf, sizeof(buf)));
	ASSERT_EQ(0, memcmp(expected, buf, sizeof(buf)));
}

/*
 * A buggy or malicious file system always returns ERANGE, even if we pass an
 * appropriately sized buffer.  That will send the kernel into an infinite
 * loop.  This test will ensure that the loop is interruptible by killing the
 * blocked process with SIGINT.
 */
TEST_F(ListxattrSig, erange_forever)
{
	uint64_t ino = 42;
	uint32_t lie_size = 10;
	int status;

	fork(false, &status, [&] {
		EXPECT_LOOKUP(FUSE_ROOT_ID, RELPATH)
		.WillRepeatedly(Invoke(
			ReturnImmediate([=](auto in __unused, auto& out) {
			SET_OUT_HEADER_LEN(out, entry);
			out.body.entry.attr.mode = S_IFREG | 0644;
			out.body.entry.nodeid = ino;
			out.body.entry.attr.nlink = 1;
			out.body.entry.attr_valid = UINT64_MAX;
			out.body.entry.entry_valid = UINT64_MAX;
		})));
		EXPECT_CALL(*m_mock, process(
			ResultOf([=](auto in) {
				return (in.header.opcode == FUSE_LISTXATTR &&
					in.header.nodeid == ino &&
					in.body.listxattr.size == 0);
			}, Eq(true)),
			_)
		).WillRepeatedly(ReturnImmediate([=](auto i __unused, auto& out)
		{
			/* The file system requests 10 bytes, but it's a lie */
			out.body.listxattr.size = lie_size;
			SET_OUT_HEADER_LEN(out, listxattr);
			/*
			 * We can send the signal any time after fusefs enters
			 * VOP_LISTEXTATTR
			 */
			sem_post(&killer_semaphore);
		}));
		/*
		 * Even though the kernel faithfully respects our size request,
		 * we'll return ERANGE anyway.
		 */
		EXPECT_CALL(*m_mock, process(
			ResultOf([=](auto in) {
				return (in.header.opcode == FUSE_LISTXATTR &&
					in.header.nodeid == ino &&
					in.body.listxattr.size == lie_size);
			}, Eq(true)),
			_)
		).WillRepeatedly(ReturnErrno(ERANGE));

		ASSERT_EQ(0, pthread_create(&m_killer_th, NULL, killer,
					    &m_mock->m_child_pid))
			<< strerror(errno);

	}, [] {
		/* Child process will block until it gets signaled */
		int ns = EXTATTR_NAMESPACE_USER;
		char buf[3];
		extattr_list_file(FULLPATH, ns, buf, sizeof(buf));
		return 0;
	}
	);

	ASSERT_TRUE(WIFSIGNALED(status));
}

/*
 * Get the size of the list that it would take to list no extended attributes
 */
TEST_F(Listxattr, size_only_empty)
{
	uint64_t ino = 42;
	int ns = EXTATTR_NAMESPACE_USER;

	expect_lookup(RELPATH, ino, S_IFREG | 0644, 0, 1);
	expect_listxattr(ino, 0, ReturnImmediate([](auto i __unused, auto& out) {
		out.body.listxattr.size = 0;
		SET_OUT_HEADER_LEN(out, listxattr);
	}));

	ASSERT_EQ(0, extattr_list_file(FULLPATH, ns, NULL, 0))
		<< strerror(errno);
}

/*
 * Get the size of the list that it would take to list some extended
 * attributes.  Due to the format differences between a FreeBSD and a
 * Linux/FUSE extended attribute list, fuse(4) will actually allocate a buffer
 * and get the whole list, then convert it, just to figure out its size.
 */
TEST_F(Listxattr, size_only_nonempty)
{
	uint64_t ino = 42;
	int ns = EXTATTR_NAMESPACE_USER;
	char attrs[9] = "user.foo";

	expect_lookup(RELPATH, ino, S_IFREG | 0644, 0, 1);
	expect_listxattr(ino, 0, ReturnImmediate([](auto i __unused, auto& out)
	{
		out.body.listxattr.size = sizeof(attrs);
		SET_OUT_HEADER_LEN(out, listxattr);
	}));

	expect_listxattr(ino, sizeof(attrs),
		ReturnImmediate([=](auto in __unused, auto& out) {
			size_t l = sizeof(attrs);
			strlcpy((char*)out.body.bytes, attrs, l);
			out.header.len = sizeof(fuse_out_header) + l;
		})
	);

	ASSERT_EQ(4, extattr_list_file(FULLPATH, ns, NULL, 0))
		<< strerror(errno);
}

/*
 * The list of extended attributes grows in between the server's two calls to
 * FUSE_LISTXATTR.
 */
TEST_F(Listxattr, size_only_race_bigger)
{
	uint64_t ino = 42;
	int ns = EXTATTR_NAMESPACE_USER;
	char attrs0[9] = "user.foo";
	char attrs1[18] = "user.foo\0user.bar";
	Sequence seq;

	EXPECT_LOOKUP(FUSE_ROOT_ID, RELPATH)
	.WillRepeatedly(Invoke(
		ReturnImmediate([=](auto in __unused, auto& out) {
		SET_OUT_HEADER_LEN(out, entry);
		out.body.entry.attr.mode = S_IFREG | 0644;
		out.body.entry.nodeid = ino;
		out.body.entry.attr.nlink = 1;
		out.body.entry.attr_valid = UINT64_MAX;
		out.body.entry.entry_valid = UINT64_MAX;
	})));
	expect_listxattr(ino, 0, ReturnImmediate([](auto i __unused, auto& out)
	{
		out.body.listxattr.size = sizeof(attrs0);
		SET_OUT_HEADER_LEN(out, listxattr);
	}), &seq);

	/*
	 * After the first FUSE_LISTXATTR the list grew, so the second
	 * operation returns ERANGE.
	 */
	expect_listxattr(ino, sizeof(attrs0), ReturnErrno(ERANGE), &seq);

	/* And now the kernel retries */
	expect_listxattr(ino, 0, ReturnImmediate([](auto i __unused, auto& out)
	{
		out.body.listxattr.size = sizeof(attrs1);
		SET_OUT_HEADER_LEN(out, listxattr);
	}), &seq);
	expect_listxattr(ino, sizeof(attrs1),
		ReturnImmediate([&](auto in __unused, auto& out) {
			memcpy((char*)out.body.bytes, attrs1, sizeof(attrs1));
			out.header.len = sizeof(fuse_out_header) +
			    sizeof(attrs1);
		}), &seq
	);

	/* Userspace should never know about the retry */
	ASSERT_EQ(8, extattr_list_file(FULLPATH, ns, NULL, 0))
		<< strerror(errno);
}

/*
 * The list of extended attributes shrinks in between the server's two calls to
 * FUSE_LISTXATTR
 */
TEST_F(Listxattr, size_only_race_smaller)
{
	uint64_t ino = 42;
	int ns = EXTATTR_NAMESPACE_USER;
	char attrs0[18] = "user.foo\0user.bar";
	char attrs1[9] = "user.foo";

	expect_lookup(RELPATH, ino, S_IFREG | 0644, 0, 1);
	expect_listxattr(ino, 0, ReturnImmediate([](auto i __unused, auto& out)
	{
		out.body.listxattr.size = sizeof(attrs0);
		SET_OUT_HEADER_LEN(out, listxattr);
	}));
	expect_listxattr(ino, sizeof(attrs0),
		ReturnImmediate([&](auto in __unused, auto& out) {
			memcpy((char*)out.body.bytes, attrs1, sizeof(attrs1));
			out.header.len = sizeof(fuse_out_header) +
			    sizeof(attrs1);
		})
	);

	ASSERT_EQ(4, extattr_list_file(FULLPATH, ns, NULL, 0))
		<< strerror(errno);
}

TEST_F(Listxattr, size_only_really_big)
{
	uint64_t ino = 42;
	int ns = EXTATTR_NAMESPACE_USER;

	expect_lookup(RELPATH, ino, S_IFREG | 0644, 0, 1);
	expect_listxattr(ino, 0, ReturnImmediate([](auto i __unused, auto& out) {
		out.body.listxattr.size = 16000;
		SET_OUT_HEADER_LEN(out, listxattr);
	}));

	expect_listxattr(ino, 16000,
		ReturnImmediate([](auto in __unused, auto& out) {
			const char l[16] = "user.foobarbang";
			for (int i=0; i < 1000; i++) {
				memcpy(&out.body.bytes[16 * i], l, 16);
			}
			out.header.len = sizeof(fuse_out_header) + 16000;
		})
	);

	ASSERT_EQ(11000, extattr_list_file(FULLPATH, ns, NULL, 0))
		<< strerror(errno);
}

/*
 * List all of the user attributes of a file which has both user and system
 * attributes
 */
TEST_F(Listxattr, user)
{
	uint64_t ino = 42;
	int ns = EXTATTR_NAMESPACE_USER;
	char data[80];
	char expected[9] = {3, 'f', 'o', 'o', 4, 'b', 'a', 'n', 'g'};
	char attrs[28] = "user.foo\0system.x\0user.bang";

	expect_lookup(RELPATH, ino, S_IFREG | 0644, 0, 1);
	expect_listxattr(ino, 0,
		ReturnImmediate([&](auto in __unused, auto& out) {
			out.body.listxattr.size = sizeof(attrs);
			SET_OUT_HEADER_LEN(out, listxattr);
		})
	);

	expect_listxattr(ino, sizeof(attrs),
	ReturnImmediate([&](auto in __unused, auto& out) {
		memcpy((void*)out.body.bytes, attrs, sizeof(attrs));
		out.header.len = sizeof(fuse_out_header) + sizeof(attrs);
	}));

	ASSERT_EQ(static_cast<ssize_t>(sizeof(expected)),
		extattr_list_file(FULLPATH, ns, data, sizeof(data)))
		<< strerror(errno);
	ASSERT_EQ(0, memcmp(expected, data, sizeof(expected)));
}

/*
 * List all of the system attributes of a file which has both user and system
 * attributes
 */
TEST_F(Listxattr, system)
{
	uint64_t ino = 42;
	int ns = EXTATTR_NAMESPACE_SYSTEM;
	char data[80];
	char expected[2] = {1, 'x'};
	char attrs[28] = "user.foo\0system.x\0user.bang";

	expect_lookup(RELPATH, ino, S_IFREG | 0644, 0, 1);
	expect_listxattr(ino, 0,
		ReturnImmediate([&](auto in __unused, auto& out) {
			out.body.listxattr.size = sizeof(attrs);
			SET_OUT_HEADER_LEN(out, listxattr);
		})
	);

	expect_listxattr(ino, sizeof(attrs),
	ReturnImmediate([&](auto in __unused, auto& out) {
		memcpy((void*)out.body.bytes, attrs, sizeof(attrs));
		out.header.len = sizeof(fuse_out_header) + sizeof(attrs);
	}));

	ASSERT_EQ(static_cast<ssize_t>(sizeof(expected)),
		extattr_list_file(FULLPATH, ns, data, sizeof(data)))
		<< strerror(errno);
	ASSERT_EQ(0, memcmp(expected, data, sizeof(expected)));
}

/* Fail to remove a nonexistent attribute */
TEST_F(Removexattr, enoattr)
{
	uint64_t ino = 42;
	int ns = EXTATTR_NAMESPACE_USER;

	expect_lookup(RELPATH, ino, S_IFREG | 0644, 0, 1);
	expect_removexattr(ino, "user.foo", ENOATTR);

	ASSERT_EQ(-1, extattr_delete_file(FULLPATH, ns, "foo"));
	ASSERT_EQ(ENOATTR, errno);
}

/*
 * If the filesystem returns ENOSYS, then it will be treated as a permanent
 * failure and all future VOP_DELETEEXTATTR calls will fail with EOPNOTSUPP
 * without querying the filesystem daemon
 */
TEST_F(Removexattr, enosys)
{
	uint64_t ino = 42;
	int ns = EXTATTR_NAMESPACE_USER;

	expect_lookup(RELPATH, ino, S_IFREG | 0644, 0, 2);
	expect_removexattr(ino, "user.foo", ENOSYS);

	ASSERT_EQ(-1, extattr_delete_file(FULLPATH, ns, "foo"));
	EXPECT_EQ(EOPNOTSUPP, errno);

	/* Subsequent attempts should not query the filesystem at all */
	ASSERT_EQ(-1, extattr_delete_file(FULLPATH, ns, "foo"));
	EXPECT_EQ(EOPNOTSUPP, errno);
}

/* Successfully remove a user xattr */
TEST_F(Removexattr, user)
{
	uint64_t ino = 42;
	int ns = EXTATTR_NAMESPACE_USER;

	expect_lookup(RELPATH, ino, S_IFREG | 0644, 0, 1);
	expect_removexattr(ino, "user.foo", 0);

	ASSERT_EQ(0, extattr_delete_file(FULLPATH, ns, "foo"))
		<< strerror(errno);
}

/* Successfully remove a system xattr */
TEST_F(Removexattr, system)
{
	uint64_t ino = 42;
	int ns = EXTATTR_NAMESPACE_SYSTEM;

	expect_lookup(RELPATH, ino, S_IFREG | 0644, 0, 1);
	expect_removexattr(ino, "system.foo", 0);

	ASSERT_EQ(0, extattr_delete_file(FULLPATH, ns, "foo"))
		<< strerror(errno);
}


/*
 * If the filesystem returns ENOSYS, then it will be treated as a permanent
 * failure and all future VOP_SETEXTATTR calls will fail with EOPNOTSUPP
 * without querying the filesystem daemon
 */
TEST_F(Setxattr, enosys)
{
	uint64_t ino = 42;
	const char value[] = "whatever";
	ssize_t value_len = strlen(value) + 1;
	int ns = EXTATTR_NAMESPACE_USER;
	ssize_t r;

	expect_lookup(RELPATH, ino, S_IFREG | 0644, 0, 2);
	expect_setxattr(ino, "user.foo", value, ReturnErrno(ENOSYS));

	r = extattr_set_file(FULLPATH, ns, "foo", (const void*)value,
		value_len);
	ASSERT_EQ(-1, r);
	EXPECT_EQ(EOPNOTSUPP, errno);

	/* Subsequent attempts should not query the filesystem at all */
	r = extattr_set_file(FULLPATH, ns, "foo", (const void*)value,
		value_len);
	ASSERT_EQ(-1, r);
	EXPECT_EQ(EOPNOTSUPP, errno);
}

/*
 * SETXATTR will return ENOTSUP if the namespace is invalid or the filesystem
 * as currently configured doesn't support extended attributes.
 */
TEST_F(Setxattr, enotsup)
{
	uint64_t ino = 42;
	const char value[] = "whatever";
	ssize_t value_len = strlen(value) + 1;
	int ns = EXTATTR_NAMESPACE_USER;
	ssize_t r;

	expect_lookup(RELPATH, ino, S_IFREG | 0644, 0, 1);
	expect_setxattr(ino, "user.foo", value, ReturnErrno(ENOTSUP));

	r = extattr_set_file(FULLPATH, ns, "foo", (const void*)value,
		value_len);
	ASSERT_EQ(-1, r);
	EXPECT_EQ(ENOTSUP, errno);
}

/*
 * Successfully set a user attribute.
 */
TEST_F(Setxattr, user)
{
	uint64_t ino = 42;
	const char value[] = "whatever";
	ssize_t value_len = strlen(value) + 1;
	int ns = EXTATTR_NAMESPACE_USER;
	ssize_t r;

	expect_lookup(RELPATH, ino, S_IFREG | 0644, 0, 1);
	expect_setxattr(ino, "user.foo", value, ReturnErrno(0));

	r = extattr_set_file(FULLPATH, ns, "foo", (const void*)value,
		value_len);
	ASSERT_EQ(value_len, r) << strerror(errno);
}

/*
 * Successfully set a system attribute.
 */
TEST_F(Setxattr, system)
{
	uint64_t ino = 42;
	const char value[] = "whatever";
	ssize_t value_len = strlen(value) + 1;
	int ns = EXTATTR_NAMESPACE_SYSTEM;
	ssize_t r;

	expect_lookup(RELPATH, ino, S_IFREG | 0644, 0, 1);
	expect_setxattr(ino, "system.foo", value, ReturnErrno(0));

	r = extattr_set_file(FULLPATH, ns, "foo", (const void*)value,
		value_len);
	ASSERT_EQ(value_len, r) << strerror(errno);
}


TEST_F(Setxattr_7_32, ok)
{
	uint64_t ino = 42;
	const char value[] = "whatever";
	ssize_t value_len = strlen(value) + 1;
	int ns = EXTATTR_NAMESPACE_USER;
	ssize_t r;

	expect_lookup(RELPATH, ino, S_IFREG | 0644, 0, 1);
	expect_setxattr_7_32(ino, "user.foo", value, ReturnErrno(0));

	r = extattr_set_file(FULLPATH, ns, "foo", (const void *)value,
		value_len);
	ASSERT_EQ(value_len, r) << strerror(errno);
}

TEST_F(RofsXattr, deleteextattr_erofs)
{
	uint64_t ino = 42;
	int ns = EXTATTR_NAMESPACE_USER;

	expect_lookup(RELPATH, ino, S_IFREG | 0644, 0, 1);

	ASSERT_EQ(-1, extattr_delete_file(FULLPATH, ns, "foo"));
	ASSERT_EQ(EROFS, errno);
}

TEST_F(RofsXattr, setextattr_erofs)
{
	uint64_t ino = 42;
	const char value[] = "whatever";
	ssize_t value_len = strlen(value) + 1;
	int ns = EXTATTR_NAMESPACE_USER;
	ssize_t r;

	expect_lookup(RELPATH, ino, S_IFREG | 0644, 0, 1);

	r = extattr_set_file(FULLPATH, ns, "foo", (const void*)value,
		value_len);
	ASSERT_EQ(-1, r);
	EXPECT_EQ(EROFS, errno);
}