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+// Copyright 2010 The Kyua Authors.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+// * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+// * 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.
+// * Neither the name of Google Inc. nor the names of its contributors
+// may be used to endorse or promote products derived from this software
+// without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT
+// OWNER 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.
+
+#include "utils/fs/operations.hpp"
+
+#if defined(HAVE_CONFIG_H)
+# include "config.h"
+#endif
+
+extern "C" {
+#include <sys/param.h>
+#if defined(HAVE_SYS_MOUNT_H)
+# include <sys/mount.h>
+#endif
+#include <sys/stat.h>
+#if defined(HAVE_SYS_STATVFS_H) && defined(HAVE_STATVFS)
+# include <sys/statvfs.h>
+#endif
+#if defined(HAVE_SYS_VFS_H)
+# include <sys/vfs.h>
+#endif
+#include <sys/wait.h>
+
+#include <unistd.h>
+}
+
+#include <cerrno>
+#include <cstdlib>
+#include <cstring>
+#include <fstream>
+#include <iostream>
+#include <sstream>
+#include <string>
+
+#include "utils/auto_array.ipp"
+#include "utils/defs.hpp"
+#include "utils/env.hpp"
+#include "utils/format/macros.hpp"
+#include "utils/fs/directory.hpp"
+#include "utils/fs/exceptions.hpp"
+#include "utils/fs/path.hpp"
+#include "utils/logging/macros.hpp"
+#include "utils/optional.ipp"
+#include "utils/sanity.hpp"
+#include "utils/units.hpp"
+
+namespace fs = utils::fs;
+namespace units = utils::units;
+
+using utils::optional;
+
+
+namespace {
+
+
+/// Operating systems recognized by the code below.
+enum os_type {
+ os_unsupported = 0,
+ os_freebsd,
+ os_linux,
+ os_netbsd,
+ os_sunos,
+};
+
+
+/// The current operating system.
+static enum os_type current_os =
+#if defined(__FreeBSD__)
+ os_freebsd
+#elif defined(__linux__)
+ os_linux
+#elif defined(__NetBSD__)
+ os_netbsd
+#elif defined(__SunOS__)
+ os_sunos
+#else
+ os_unsupported
+#endif
+ ;
+
+
+/// Specifies if a real unmount(2) is available.
+///
+/// We use this as a constant instead of a macro so that we can compile both
+/// versions of the unmount code unconditionally. This is a way to prevent
+/// compilation bugs going unnoticed for long.
+static const bool have_unmount2 =
+#if defined(HAVE_UNMOUNT)
+ true;
+#else
+ false;
+#endif
+
+
+#if !defined(UMOUNT)
+/// Fake replacement value to the path to umount(8).
+# define UMOUNT "do-not-use-this-value"
+#else
+# if defined(HAVE_UNMOUNT)
+# error "umount(8) detected when unmount(2) is also available"
+# endif
+#endif
+
+
+#if !defined(HAVE_UNMOUNT)
+/// Fake unmount(2) function for systems without it.
+///
+/// This is only provided to allow our code to compile in all platforms
+/// regardless of whether they actually have an unmount(2) or not.
+///
+/// \return -1 to indicate error, although this should never happen.
+static int
+unmount(const char* /* path */,
+ const int /* flags */)
+{
+ PRE(false);
+ return -1;
+}
+#endif
+
+
+/// Error code returned by subprocess to indicate a controlled failure.
+const int exit_known_error = 123;
+
+
+static void run_mount_tmpfs(const fs::path&, const uint64_t) UTILS_NORETURN;
+
+
+/// Executes 'mount -t tmpfs' (or a similar variant).
+///
+/// This function must be called from a subprocess as it never returns.
+///
+/// \param mount_point Location on which to mount a tmpfs.
+/// \param size The size of the tmpfs to mount. If 0, use unlimited.
+static void
+run_mount_tmpfs(const fs::path& mount_point, const uint64_t size)
+{
+ const char* mount_args[16];
+ std::string size_arg;
+
+ std::size_t last = 0;
+ switch (current_os) {
+ case os_freebsd:
+ mount_args[last++] = "mount";
+ mount_args[last++] = "-ttmpfs";
+ if (size > 0) {
+ size_arg = F("-osize=%s") % size;
+ mount_args[last++] = size_arg.c_str();
+ }
+ mount_args[last++] = "tmpfs";
+ mount_args[last++] = mount_point.c_str();
+ break;
+
+ case os_linux:
+ mount_args[last++] = "mount";
+ mount_args[last++] = "-ttmpfs";
+ if (size > 0) {
+ size_arg = F("-osize=%s") % size;
+ mount_args[last++] = size_arg.c_str();
+ }
+ mount_args[last++] = "tmpfs";
+ mount_args[last++] = mount_point.c_str();
+ break;
+
+ case os_netbsd:
+ mount_args[last++] = "mount";
+ mount_args[last++] = "-ttmpfs";
+ if (size > 0) {
+ size_arg = F("-o-s%s") % size;
+ mount_args[last++] = size_arg.c_str();
+ }
+ mount_args[last++] = "tmpfs";
+ mount_args[last++] = mount_point.c_str();
+ break;
+
+ case os_sunos:
+ mount_args[last++] = "mount";
+ mount_args[last++] = "-Ftmpfs";
+ if (size > 0) {
+ size_arg = F("-o-s%s") % size;
+ mount_args[last++] = size_arg.c_str();
+ }
+ mount_args[last++] = "tmpfs";
+ mount_args[last++] = mount_point.c_str();
+ break;
+
+ default:
+ std::cerr << "Don't know how to mount a temporary file system in this "
+ "host operating system\n";
+ std::exit(exit_known_error);
+ }
+ mount_args[last] = NULL;
+
+ const char** arg;
+ std::cout << "Mounting tmpfs onto " << mount_point << " with:";
+ for (arg = &mount_args[0]; *arg != NULL; arg++)
+ std::cout << " " << *arg;
+ std::cout << "\n";
+
+ const int ret = ::execvp(mount_args[0],
+ UTILS_UNCONST(char* const, mount_args));
+ INV(ret == -1);
+ std::cerr << "Failed to exec " << mount_args[0] << "\n";
+ std::exit(EXIT_FAILURE);
+}
+
+
+/// Unmounts a file system using unmount(2).
+///
+/// \pre unmount(2) must be available; i.e. have_unmount2 must be true.
+///
+/// \param mount_point The file system to unmount.
+///
+/// \throw fs::system_error If the call to unmount(2) fails.
+static void
+unmount_with_unmount2(const fs::path& mount_point)
+{
+ PRE(have_unmount2);
+
+ if (::unmount(mount_point.c_str(), 0) == -1) {
+ const int original_errno = errno;
+ throw fs::system_error(F("unmount(%s) failed") % mount_point,
+ original_errno);
+ }
+}
+
+
+/// Unmounts a file system using umount(8).
+///
+/// \pre umount(2) must not be available; i.e. have_unmount2 must be false.
+///
+/// \param mount_point The file system to unmount.
+///
+/// \throw fs::error If the execution of umount(8) fails.
+static void
+unmount_with_umount8(const fs::path& mount_point)
+{
+ PRE(!have_unmount2);
+
+ const pid_t pid = ::fork();
+ if (pid == -1) {
+ const int original_errno = errno;
+ throw fs::system_error("Cannot fork to execute unmount tool",
+ original_errno);
+ } else if (pid == 0) {
+ const int ret = ::execlp(UMOUNT, "umount", mount_point.c_str(), NULL);
+ INV(ret == -1);
+ std::cerr << "Failed to exec " UMOUNT "\n";
+ std::exit(EXIT_FAILURE);
+ }
+
+ int status;
+retry:
+ if (::waitpid(pid, &status, 0) == -1) {
+ const int original_errno = errno;
+ if (errno == EINTR)
+ goto retry;
+ throw fs::system_error("Failed to wait for unmount subprocess",
+ original_errno);
+ }
+
+ if (WIFEXITED(status)) {
+ if (WEXITSTATUS(status) == EXIT_SUCCESS)
+ return;
+ else
+ throw fs::error(F("Failed to unmount %s; returned exit code %s")
+ % mount_point % WEXITSTATUS(status));
+ } else
+ throw fs::error(F("Failed to unmount %s; unmount tool received signal")
+ % mount_point);
+}
+
+
+/// Stats a file, without following links.
+///
+/// \param path The file to stat.
+///
+/// \return The stat structure on success.
+///
+/// \throw system_error An error on failure.
+static struct ::stat
+safe_stat(const fs::path& path)
+{
+ struct ::stat sb;
+ if (::lstat(path.c_str(), &sb) == -1) {
+ const int original_errno = errno;
+ throw fs::system_error(F("Cannot get information about %s") % path,
+ original_errno);
+ }
+ return sb;
+}
+
+
+} // anonymous namespace
+
+
+/// Copies a file.
+///
+/// \param source The file to copy.
+/// \param target The destination of the new copy; must be a file name, not a
+/// directory.
+///
+/// \throw error If there is a problem copying the file.
+void
+fs::copy(const fs::path& source, const fs::path& target)
+{
+ std::ifstream input(source.c_str());
+ if (!input)
+ throw error(F("Cannot open copy source %s") % source);
+
+ std::ofstream output(target.c_str());
+ if (!output)
+ throw error(F("Cannot create copy target %s") % target);
+
+ char buffer[1024];
+ while (input.good()) {
+ input.read(buffer, sizeof(buffer));
+ if (input.good() || input.eof())
+ output.write(buffer, input.gcount());
+ }
+ if (!input.good() && !input.eof())
+ throw error(F("Error while reading input file %s") % source);
+}
+
+
+/// Queries the path to the current directory.
+///
+/// \return The path to the current directory.
+///
+/// \throw fs::error If there is a problem querying the current directory.
+fs::path
+fs::current_path(void)
+{
+ char* cwd;
+#if defined(HAVE_GETCWD_DYN)
+ cwd = ::getcwd(NULL, 0);
+#else
+ cwd = ::getcwd(NULL, MAXPATHLEN);
+#endif
+ if (cwd == NULL) {
+ const int original_errno = errno;
+ throw fs::system_error(F("Failed to get current working directory"),
+ original_errno);
+ }
+
+ try {
+ const fs::path result(cwd);
+ std::free(cwd);
+ return result;
+ } catch (...) {
+ std::free(cwd);
+ throw;
+ }
+}
+
+
+/// Checks if a file exists.
+///
+/// Be aware that this is racy in the same way as access(2) is.
+///
+/// \param path The file to check the existance of.
+///
+/// \return True if the file exists; false otherwise.
+bool
+fs::exists(const fs::path& path)
+{
+ return ::access(path.c_str(), F_OK) == 0;
+}
+
+
+/// Locates a file in the PATH.
+///
+/// \param name The file to locate.
+///
+/// \return The path to the located file or none if it was not found. The
+/// returned path is always absolute.
+optional< fs::path >
+fs::find_in_path(const char* name)
+{
+ const optional< std::string > current_path = utils::getenv("PATH");
+ if (!current_path || current_path.get().empty())
+ return none;
+
+ std::istringstream path_input(current_path.get() + ":");
+ std::string path_component;
+ while (std::getline(path_input, path_component, ':').good()) {
+ const fs::path candidate = path_component.empty() ?
+ fs::path(name) : (fs::path(path_component) / name);
+ if (exists(candidate)) {
+ if (candidate.is_absolute())
+ return utils::make_optional(candidate);
+ else
+ return utils::make_optional(candidate.to_absolute());
+ }
+ }
+ return none;
+}
+
+
+/// Calculates the free space in a given file system.
+///
+/// \param path Path to a file in the file system for which to check the free
+/// disk space.
+///
+/// \return The amount of free space usable by a non-root user.
+///
+/// \throw system_error If the call to statfs(2) fails.
+utils::units::bytes
+fs::free_disk_space(const fs::path& path)
+{
+#if defined(HAVE_STATVFS)
+ struct ::statvfs buf;
+ if (::statvfs(path.c_str(), &buf) == -1) {
+ const int original_errno = errno;
+ throw fs::system_error(F("Failed to stat file system for %s") % path,
+ original_errno);
+ }
+ return units::bytes(uint64_t(buf.f_bsize) * buf.f_bavail);
+#elif defined(HAVE_STATFS)
+ struct ::statfs buf;
+ if (::statfs(path.c_str(), &buf) == -1) {
+ const int original_errno = errno;
+ throw fs::system_error(F("Failed to stat file system for %s") % path,
+ original_errno);
+ }
+ return units::bytes(uint64_t(buf.f_bsize) * buf.f_bavail);
+#else
+# error "Don't know how to query free disk space"
+#endif
+}
+
+
+/// Checks if the given path is a directory or not.
+///
+/// \return True if the path is a directory; false otherwise.
+bool
+fs::is_directory(const fs::path& path)
+{
+ const struct ::stat sb = safe_stat(path);
+ return S_ISDIR(sb.st_mode);
+}
+
+
+/// Creates a directory.
+///
+/// \param dir The path to the directory to create.
+/// \param mode The permissions for the new directory.
+///
+/// \throw system_error If the call to mkdir(2) fails.
+void
+fs::mkdir(const fs::path& dir, const int mode)
+{
+ if (::mkdir(dir.c_str(), static_cast< mode_t >(mode)) == -1) {
+ const int original_errno = errno;
+ throw fs::system_error(F("Failed to create directory %s") % dir,
+ original_errno);
+ }
+}
+
+
+/// Creates a directory and any missing parents.
+///
+/// This is separate from the fs::mkdir function to clearly differentiate the
+/// libc wrapper from the more complex algorithm implemented here.
+///
+/// \param dir The path to the directory to create.
+/// \param mode The permissions for the new directories.
+///
+/// \throw system_error If any call to mkdir(2) fails.
+void
+fs::mkdir_p(const fs::path& dir, const int mode)
+{
+ try {
+ fs::mkdir(dir, mode);
+ } catch (const fs::system_error& e) {
+ if (e.original_errno() == ENOENT) {
+ fs::mkdir_p(dir.branch_path(), mode);
+ fs::mkdir(dir, mode);
+ } else if (e.original_errno() != EEXIST)
+ throw e;
+ }
+}
+
+
+/// Creates a temporary directory that is world readable/accessible.
+///
+/// The temporary directory is created using mkdtemp(3) using the provided
+/// template. This should be most likely used in conjunction with
+/// fs::auto_directory.
+///
+/// The temporary directory is given read and execute permissions to everyone
+/// and thus should not be used to protect data that may be subject to snooping.
+/// This goes together with the assumption that this function is used to create
+/// temporary directories for test cases, and that those test cases may
+/// sometimes be executed as an unprivileged user. In those cases, we need to
+/// support two different things:
+///
+/// - Allow the unprivileged code to write to files in the work directory by
+/// name (e.g. to write the results file, whose name is provided by the
+/// monitor code running as root). This requires us to grant search
+/// permissions.
+///
+/// - Allow the test cases themselves to call getcwd(3) at any point. At least
+/// on NetBSD 7.x, getcwd(3) requires both read and search permissions on all
+/// path components leading to the current directory. This requires us to
+/// grant both read and search permissions.
+///
+/// TODO(jmmv): A cleaner way to support this would be for the test executor to
+/// create two work directory hierarchies directly rooted under TMPDIR: one for
+/// root and one for the unprivileged user. However, that requires more
+/// bookkeeping for no real gain, because we are not really trying to protect
+/// the data within our temporary directories against attacks.
+///
+/// \param path_template The template for the temporary path, which is a
+/// basename that is created within the TMPDIR. Must contain the XXXXXX
+/// pattern, which is atomically replaced by a random unique string.
+///
+/// \return The generated path for the temporary directory.
+///
+/// \throw fs::system_error If the call to mkdtemp(3) fails.
+fs::path
+fs::mkdtemp_public(const std::string& path_template)
+{
+ PRE(path_template.find("XXXXXX") != std::string::npos);
+
+ const fs::path tmpdir(utils::getenv_with_default("TMPDIR", "/tmp"));
+ const fs::path full_template = tmpdir / path_template;
+
+ utils::auto_array< char > buf(new char[full_template.str().length() + 1]);
+ std::strcpy(buf.get(), full_template.c_str());
+ if (::mkdtemp(buf.get()) == NULL) {
+ const int original_errno = errno;
+ throw fs::system_error(F("Cannot create temporary directory using "
+ "template %s") % full_template,
+ original_errno);
+ }
+ const fs::path path(buf.get());
+
+ if (::chmod(path.c_str(), 0755) == -1) {
+ const int original_errno = errno;
+
+ try {
+ rmdir(path);
+ } catch (const fs::system_error& e) {
+ // This really should not fail. We just created the directory and
+ // have not written anything to it so there is no reason for this to
+ // fail. But better handle the failure just in case.
+ LW(F("Failed to delete just-created temporary directory %s")
+ % path);
+ }
+
+ throw fs::system_error(F("Failed to grant search permissions on "
+ "temporary directory %s") % path,
+ original_errno);
+ }
+
+ return path;
+}
+
+
+/// Creates a temporary file.
+///
+/// The temporary file is created using mkstemp(3) using the provided template.
+/// This should be most likely used in conjunction with fs::auto_file.
+///
+/// \param path_template The template for the temporary path, which is a
+/// basename that is created within the TMPDIR. Must contain the XXXXXX
+/// pattern, which is atomically replaced by a random unique string.
+///
+/// \return The generated path for the temporary directory.
+///
+/// \throw fs::system_error If the call to mkstemp(3) fails.
+fs::path
+fs::mkstemp(const std::string& path_template)
+{
+ PRE(path_template.find("XXXXXX") != std::string::npos);
+
+ const fs::path tmpdir(utils::getenv_with_default("TMPDIR", "/tmp"));
+ const fs::path full_template = tmpdir / path_template;
+
+ utils::auto_array< char > buf(new char[full_template.str().length() + 1]);
+ std::strcpy(buf.get(), full_template.c_str());
+ if (::mkstemp(buf.get()) == -1) {
+ const int original_errno = errno;
+ throw fs::system_error(F("Cannot create temporary file using template "
+ "%s") % full_template, original_errno);
+ }
+ return fs::path(buf.get());
+}
+
+
+/// Mounts a temporary file system with unlimited size.
+///
+/// \param in_mount_point The path on which the file system will be mounted.
+///
+/// \throw fs::system_error If the attempt to mount process fails.
+/// \throw fs::unsupported_operation_error If the code does not know how to
+/// mount a temporary file system in the current operating system.
+void
+fs::mount_tmpfs(const fs::path& in_mount_point)
+{
+ mount_tmpfs(in_mount_point, units::bytes());
+}
+
+
+/// Mounts a temporary file system.
+///
+/// \param in_mount_point The path on which the file system will be mounted.
+/// \param size The size of the tmpfs to mount. If 0, use unlimited.
+///
+/// \throw fs::system_error If the attempt to mount process fails.
+/// \throw fs::unsupported_operation_error If the code does not know how to
+/// mount a temporary file system in the current operating system.
+void
+fs::mount_tmpfs(const fs::path& in_mount_point, const units::bytes& size)
+{
+ // SunOS's mount(8) requires paths to be absolute. To err on the side of
+ // caution, let's make the mount point absolute in all cases.
+ const fs::path mount_point = in_mount_point.is_absolute() ?
+ in_mount_point : in_mount_point.to_absolute();
+
+ const pid_t pid = ::fork();
+ if (pid == -1) {
+ const int original_errno = errno;
+ throw fs::system_error("Cannot fork to execute mount tool",
+ original_errno);
+ }
+ if (pid == 0)
+ run_mount_tmpfs(mount_point, size);
+
+ int status;
+retry:
+ if (::waitpid(pid, &status, 0) == -1) {
+ const int original_errno = errno;
+ if (errno == EINTR)
+ goto retry;
+ throw fs::system_error("Failed to wait for mount subprocess",
+ original_errno);
+ }
+
+ if (WIFEXITED(status)) {
+ if (WEXITSTATUS(status) == exit_known_error)
+ throw fs::unsupported_operation_error(
+ "Don't know how to mount a tmpfs on this operating system");
+ else if (WEXITSTATUS(status) == EXIT_SUCCESS)
+ return;
+ else
+ throw fs::error(F("Failed to mount tmpfs on %s; returned exit "
+ "code %s") % mount_point % WEXITSTATUS(status));
+ } else {
+ throw fs::error(F("Failed to mount tmpfs on %s; mount tool "
+ "received signal") % mount_point);
+ }
+}
+
+
+/// Recursively removes a directory.
+///
+/// This operation simulates a "rm -r". No effort is made to forcibly delete
+/// files and no attention is paid to mount points.
+///
+/// \param directory The directory to remove.
+///
+/// \throw fs::error If there is a problem removing any directory or file.
+void
+fs::rm_r(const fs::path& directory)
+{
+ const fs::directory dir(directory);
+
+ for (fs::directory::const_iterator iter = dir.begin(); iter != dir.end();
+ ++iter) {
+ if (iter->name == "." || iter->name == "..")
+ continue;
+
+ const fs::path entry = directory / iter->name;
+
+ if (fs::is_directory(entry)) {
+ LD(F("Descending into %s") % entry);
+ fs::rm_r(entry);
+ } else {
+ LD(F("Removing file %s") % entry);
+ fs::unlink(entry);
+ }
+ }
+
+ LD(F("Removing empty directory %s") % directory);
+ fs::rmdir(directory);
+}
+
+
+/// Removes an empty directory.
+///
+/// \param file The directory to remove.
+///
+/// \throw fs::system_error If the call to rmdir(2) fails.
+void
+fs::rmdir(const path& file)
+{
+ if (::rmdir(file.c_str()) == -1) {
+ const int original_errno = errno;
+ throw fs::system_error(F("Removal of %s failed") % file,
+ original_errno);
+ }
+}
+
+
+/// Obtains all the entries in a directory.
+///
+/// \param path The directory to scan.
+///
+/// \return The set of all directory entries in the given directory.
+///
+/// \throw fs::system_error If reading the directory fails for any reason.
+std::set< fs::directory_entry >
+fs::scan_directory(const fs::path& path)
+{
+ std::set< fs::directory_entry > contents;
+
+ fs::directory dir(path);
+ for (fs::directory::const_iterator iter = dir.begin(); iter != dir.end();
+ ++iter) {
+ contents.insert(*iter);
+ }
+
+ return contents;
+}
+
+
+/// Removes a file.
+///
+/// \param file The file to remove.
+///
+/// \throw fs::system_error If the call to unlink(2) fails.
+void
+fs::unlink(const path& file)
+{
+ if (::unlink(file.c_str()) == -1) {
+ const int original_errno = errno;
+ throw fs::system_error(F("Removal of %s failed") % file,
+ original_errno);
+ }
+}
+
+
+/// Unmounts a file system.
+///
+/// \param in_mount_point The file system to unmount.
+///
+/// \throw fs::error If the unmount fails.
+void
+fs::unmount(const fs::path& in_mount_point)
+{
+ // FreeBSD's unmount(2) requires paths to be absolute. To err on the side
+ // of caution, let's make it absolute in all cases.
+ const fs::path mount_point = in_mount_point.is_absolute() ?
+ in_mount_point : in_mount_point.to_absolute();
+
+ static const int unmount_retries = 3;
+ static const int unmount_retry_delay_seconds = 1;
+
+ int retries = unmount_retries;
+retry:
+ try {
+ if (have_unmount2) {
+ unmount_with_unmount2(mount_point);
+ } else {
+ unmount_with_umount8(mount_point);
+ }
+ } catch (const fs::system_error& error) {
+ if (error.original_errno() == EBUSY && retries > 0) {
+ LW(F("%s busy; unmount retries left %s") % mount_point % retries);
+ retries--;
+ ::sleep(unmount_retry_delay_seconds);
+ goto retry;
+ }
+ throw;
+ }
+}