freebsd-dev/tests/sys/fs/fusefs/forget.cc
Alan Somers 3227325366 fusefs: fix two bugs regarding VOP_RECLAIM of the root inode
* We never send FUSE_LOOKUP for the root inode, since its inode number
  is hard-coded to 1.  Therefore, we should not send FUSE_FORGET for it,
  lest the server see its lookup count fall below 0.

* During VOP_RECLAIM, if we are reclaiming the root inode, we must clear
  the file system's vroot pointer.  Otherwise it will be left pointing
  at a reclaimed vnode, which will cause future VOP_LOOKUP operations to
  fail.  Previously we only cleared that pointer during VFS_UMOUNT.  I
  don't know of any real-world way to trigger this bug.

MFC after:	2 weeks
Reviewed by:	pfg
Differential Revision: https://reviews.freebsd.org/D34753
2022-04-06 16:16:52 -06:00

181 lines
5.2 KiB
C++

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* 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.
*
* $FreeBSD$
*/
extern "C" {
#include <sys/types.h>
#include <sys/mount.h>
#include <sys/sysctl.h>
#include <fcntl.h>
#include <semaphore.h>
#include <unistd.h>
}
#include "mockfs.hh"
#include "utils.hh"
using namespace testing;
class Forget: public FuseTest {
public:
void SetUp() {
if (geteuid() != 0)
GTEST_SKIP() << "Only root may use " << reclaim_mib;
FuseTest::SetUp();
}
};
/*
* When a fusefs vnode is reclaimed, it should send a FUSE_FORGET operation.
*/
TEST_F(Forget, ok)
{
const char FULLPATH[] = "mountpoint/some_file.txt";
const char RELPATH[] = "some_file.txt";
uint64_t ino = 42;
mode_t mode = S_IFREG | 0755;
sem_t sem;
ASSERT_EQ(0, sem_init(&sem, 0, 0)) << strerror(errno);
EXPECT_LOOKUP(FUSE_ROOT_ID, RELPATH)
.Times(3)
.WillRepeatedly(Invoke(
ReturnImmediate([=](auto in __unused, auto& out) {
SET_OUT_HEADER_LEN(out, entry);
out.body.entry.attr.mode = mode;
out.body.entry.nodeid = ino;
out.body.entry.attr.nlink = 1;
out.body.entry.attr_valid = UINT64_MAX;
})));
expect_forget(ino, 3, &sem);
/*
* access(2) the file to force a lookup. Access it twice to double its
* lookup count.
*/
ASSERT_EQ(0, access(FULLPATH, F_OK)) << strerror(errno);
ASSERT_EQ(0, access(FULLPATH, F_OK)) << strerror(errno);
reclaim_vnode(FULLPATH);
sem_wait(&sem);
sem_destroy(&sem);
}
/*
* When a directory is reclaimed, the names of its entries vanish from the
* namecache
*/
TEST_F(Forget, invalidate_names)
{
const char FULLFPATH[] = "mountpoint/some_dir/some_file.txt";
const char FULLDPATH[] = "mountpoint/some_dir";
const char DNAME[] = "some_dir";
const char FNAME[] = "some_file.txt";
uint64_t dir_ino = 42;
uint64_t file_ino = 43;
EXPECT_LOOKUP(FUSE_ROOT_ID, DNAME)
.Times(2)
.WillRepeatedly(Invoke(
ReturnImmediate([=](auto in __unused, auto& out) {
SET_OUT_HEADER_LEN(out, entry);
out.body.entry.attr.mode = S_IFDIR | 0755;
out.body.entry.nodeid = dir_ino;
out.body.entry.attr.nlink = 2;
out.body.entry.attr_valid = UINT64_MAX;
out.body.entry.entry_valid = UINT64_MAX;
})));
/*
* Even though we don't reclaim FNAME and its entry is cacheable, we
* should get two lookups because the reclaim of DNAME will invalidate
* the cached FNAME entry.
*/
EXPECT_LOOKUP(dir_ino, FNAME)
.Times(2)
.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 = file_ino;
out.body.entry.attr.nlink = 1;
out.body.entry.attr_valid = UINT64_MAX;
out.body.entry.entry_valid = UINT64_MAX;
})));
expect_forget(dir_ino, 1);
/* Access the file to cache its name */
ASSERT_EQ(0, access(FULLFPATH, F_OK)) << strerror(errno);
/* Reclaim the directory, invalidating its children from namecache */
reclaim_vnode(FULLDPATH);
/* Access the file again, causing another lookup */
ASSERT_EQ(0, access(FULLFPATH, F_OK)) << strerror(errno);
}
/*
* Reclaiming the root inode should not send a FUSE_FORGET request, nor should
* it interfere with further lookup operations.
*/
TEST_F(Forget, root)
{
const char FULLPATH[] = "mountpoint/some_file.txt";
const char RELPATH[] = "some_file.txt";
uint64_t ino = 42;
mode_t mode = S_IFREG | 0755;
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 = mode;
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;
})));
/* access(2) the file to force a lookup. */
ASSERT_EQ(0, access(FULLPATH, F_OK)) << strerror(errno);
reclaim_vnode("mountpoint");
nap();
/* Access it again, to make sure it's still possible. */
ASSERT_EQ(0, access(FULLPATH, F_OK)) << strerror(errno);
}