refactor resolve path (c009d4b0) · Commits · hpc / gekkofs

include/client/path.hpp

+3 −0

Original line number	Diff line number	Diff line
		@@ -36,6 +36,9 @@ unsigned int
		match_components(const std::string& path, unsigned int& path_components,
		const std::vector<std::string>& components);

		std::pair<bool, std::string>
		resolve_new(const std::string& path, std::string mountdir);

		bool
		resolve(const std::string& path, std::string& resolved,
		bool resolve_last_link = true);

src/client/path.cpp

+74 −1

Original line number	Diff line number	Diff line
		@@ -34,6 +34,8 @@

		#include <common/path_util.hpp>

		#include <stack>
		#include <utility>
		#include <vector>
		#include <string>
		#include <cassert>
		@@ -100,6 +102,77 @@ match_components(const string& path, unsigned int& path_components,
		return matched;
		}

		string
		follow_symlinks(const string& path) {
		struct stat st {};
		if(lstat(path.c_str(), &st) < 0) {
		LOG(DEBUG, "path \"{}\" does not exist", path);
		return path;
		}
		if(S_ISLNK(st.st_mode)) {
		auto link_resolved = ::unique_ptr<char[]>(new char[PATH_MAX]);
		if(realpath(path.c_str(), link_resolved.get()) == nullptr) {

		LOG(ERROR,
		"Failed to get realpath for link \"{}\". "
		"Error: {}",
		path, ::strerror(errno));
		return path;
		}
		// substituute resolved with new link path
		return link_resolved.get();
		}
		return path;
		}

		pair<bool, string>
		resolve_new(const string& path, string mountdir) {
		LOG(DEBUG, "path: \"{}\", mountdir: \"{}\"", path, mountdir);
		string resolved = "";
		stack<size_t> last_component_pos;

		for(size_t start = 0; start < path.size(); start++) {
		size_t end = path.find(path::separator, start);
		size_t comp_size = end - start;
		if(comp_size == 1 && path.at(start) == path::separator) {
		// should I use same while loop as in the original here?
		continue;
		}
		if(comp_size == 1 && path.at(start) == '.') {
		// component is '.', we skip it
		continue;
		}
		if(comp_size == 2 && path.at(start) == '.' &&
		path.at(start + 1) == '.') {
		// component is '..', we skip it
		assert(!last_component_pos.empty());
		resolved.erase(last_component_pos.top());
		last_component_pos.pop();
		continue;
		}
		// add `/<component>` to the reresolved path
		resolved.push_back(path::separator);
		last_component_pos.push(resolved.size() - 1);
		resolved.append(path, start, comp_size);

		#ifdef GKFS_FOLLOW_SYMLINKS // HAS_SYMLINKS ???
		resolved = follow_symlinks(resolved);
		#endif
		}

		if(resolved.substr(0, mountdir.size()) == mountdir) {
		resolved.erase(1, CTX->mountdir().size());
		LOG(DEBUG, "internal: \"{}\"", resolved);
		return make_pair(true, resolved);
		}

		if(resolved.empty()) {
		resolved.push_back(path::separator);
		}
		LOG(DEBUG, "external: \"{}\"", resolved);
		return make_pair(false, resolved);
		}

		/** Resolve path to its canonical representation
		*
		* Populate `resolved` with the canonical representation of `path`.

tests/unit/test_path.cpp

0 → 100644

+102 −0

Original line number	Diff line number	Diff line
		/*
		Copyright 2018-2024, Barcelona Supercomputing Center (BSC), Spain
		Copyright 2015-2024, Johannes Gutenberg Universitaet Mainz, Germany

		This software was partially supported by the
		EC H2020 funded project NEXTGenIO (Project ID: 671951, www.nextgenio.eu).

		This software was partially supported by the
		ADA-FS project under the SPPEXA project funded by the DFG.

		This file is part of GekkoFS.

		GekkoFS is free software: you can redistribute it and/or modify
		it under the terms of the GNU General Public License as published by
		the Free Software Foundation, either version 3 of the License, or
		(at your option) any later version.

		GekkoFS is distributed in the hope that it will be useful,
		but WITHOUT ANY WARRANTY; without even the implied warranty of
		MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
		GNU General Public License for more details.

		You should have received a copy of the GNU General Public License
		along with GekkoFS. If not, see <https://www.gnu.org/licenses/>.

		SPDX-License-Identifier: GPL-3.0-or-later
		*/

		#include <catch2/catch.hpp>
		#include <client/path.hpp>
		#include <utility>

		SCENARIO(" resolve fn should handle empty path ",
		"[test_path][empty]") {

		GIVEN(" a mount path ") {

		std::string mntpath = "/tmp/gkfs_mount";

		WHEN(" resolve with empty path ") {
		THEN(" / should be returned ") {
		REQUIRE(gkfs::path::resolve_new("", mntpath).second == "/");
		}
		}
		}
		}

		// TODO check pair.first is true
		SCENARIO(" resolve fn should handle internal paths ",
		"[test_path][external paths]") {

		GIVEN(" a mount path ") {

		std::string mntpath = "/tmp/gkfs_mount";

		WHEN(" resolve with relative path ") {
		THEN(" iwas ") {
		REQUIRE(gkfs::path::resolve_new("/home/foo/../../tmp/./gkfs_mount/bar/./", mntpath).second == "/bar/");
		}
		THEN(" iwas ") {
		REQUIRE(gkfs::path::resolve_new("/tmp/../tmp/gkfs_mount/bar/./", mntpath).second == "/bar/");
		}
		THEN(" iwas ") {
		REQUIRE(gkfs::path::resolve_new("/tmp/./gkfs_mount/bar/./", mntpath).second == "/bar/");
		}
		THEN(" iwas ") {
		REQUIRE(gkfs::path::resolve_new("/tmp/gkfs_mount/bar/./", mntpath).second == "/bar/");
		}
		THEN(" iwas ") {
		REQUIRE(gkfs::path::resolve_new("/home/foo/../.././tmp/gkfs_mount/", mntpath).second == "/");
		}
		}
		}
		}

		// TODO check pair.first is false
		SCENARIO(" resolve fn should handle external paths ",
		"[test_path][external paths]") {

		GIVEN(" a mount path ") {

		std::string mntpath = "/tmp/gkfs_mount";

		WHEN(" resolve with relative path ") {
		THEN(" iwas ") {
		REQUIRE(gkfs::path::resolve_new("/home/foo/../bar/./", mntpath).second == "/home/bar/");
		}
		THEN(" iwas ") {
		REQUIRE(gkfs::path::resolve_new("/home/foo/../bar/../", mntpath).second == "/home/");
		}
		THEN(" iwas ") {
		REQUIRE(gkfs::path::resolve_new("/home/foo/../../", mntpath).second == "/");
		}
		THEN(" iwas ") {
		REQUIRE(gkfs::path::resolve_new("/home/foo/./bar/../", mntpath).second == "/home/foo/");
		}
		THEN(" iwas ") {
		REQUIRE(gkfs::path::resolve_new("/home/./../tmp/", mntpath).second == "/tmp/");
		}
		}
		}
		}