Store CWD in environment to surivive across exec (176c04a7) · Commits · David Auer / gekkofs

ifs/include/preload/resolve.hpp

+7 −0

Original line number	Diff line number	Diff line
		@@ -3,3 +3,10 @@
		bool resolve_path (const std::string& path, std::string& resolved);

		std::string get_sys_cwd();
		void set_sys_cwd(const std::string& path);

		void set_env_cwd(const std::string& path);
		void unset_env_cwd();

		void init_cwd();
		void set_cwd(const std::string& path, bool internal);

ifs/src/preload/intcp_functions.cpp

+11 −18

Original line number	Diff line number	Diff line
		@@ -1298,8 +1298,8 @@ int chdir(const char* path){

		CTX->log()->trace("{}() called with path '{}'", __func__, path);
		std::string rel_path;
		const char* fake_path;
		if (CTX->relativize_path(path, rel_path)) {
		bool internal = CTX->relativize_path(path, rel_path);
		if (internal) {
		//path falls in our namespace
		struct stat st;
		if(adafs_stat(rel_path, &st) != 0) {
		@@ -1312,7 +1312,6 @@ int chdir(const char* path){
		errno = ENOTDIR;
		return -1;
		}
		fake_path = CTX->mountdir().c_str();
		//TODO get complete path from relativize_path instead of
		// removing mountdir and then adding again here
		rel_path.insert(0, CTX->mountdir());
		@@ -1320,17 +1319,12 @@ int chdir(const char* path){
		// open_dir is '/'
		rel_path.pop_back();
		}
		} else {
		fake_path = rel_path.c_str();
		}

		if(LIBC_FUNC(chdir, fake_path)) {
		CTX->log()->error("{}() failed to change dir: {}",
		__func__, std::strerror(errno));
		try {
		set_cwd(rel_path, internal);
		} catch (const std::system_error& se) {
		return -1;
		}

		CTX->cwd(rel_path);
		return 0;
		}

		@@ -1351,23 +1345,22 @@ int fchdir(int fd) {
		return -1;
		}

		if (LIBC_FUNC(chdir, CTX->mountdir().c_str())) {
		CTX->log()->error("{}() failed to change dir: {}",
		__func__, std::strerror(errno));
		return -1;
		}

		std::string new_path = CTX->mountdir() + open_dir->path();
		if (has_trailing_slash(new_path)) {
		// open_dir is '/'
		new_path.pop_back();
		}
		CTX->cwd(new_path);
		try {
		set_cwd(new_path, true);
		} catch (const std::system_error& se) {
		return -1;
		}
		} else {
		if(LIBC_FUNC(fchdir, fd) != 0) {
		CTX->log()->error("{}() failed to change dir: {}",
		__func__, std::strerror(errno));
		}
		unset_env_cwd();
		CTX->cwd(get_sys_cwd());
		}
		return 0;

ifs/src/preload/preload.cpp

+19 −2

Original line number	Diff line number	Diff line
		@@ -11,6 +11,8 @@
		#include <preload/passthrough.hpp>
		#include <preload/preload_util.hpp>

		#include <fstream>

		enum class Margo_mode {
		RPC, IPC
		};
		@@ -300,6 +302,20 @@ void init_logging() {
		CTX->log(spdlog::get(logger_names.at(0)));
		}

		void log_prog_name() {
		std::string line;
		std::ifstream cmdline("/proc/self/cmdline");
		if (!cmdline.is_open()) {
		CTX->log()->error("Unable to open cmdline file");
		throw runtime_error("Unable to open cmdline file");
		}
		if(!getline(cmdline, line)) {
		throw runtime_error("Unable to read cmdline file");
		}
		CTX->log()->info("Command to itercept: '{}'", line);
		cmdline.close();
		}

		/**
		* Called initially ONCE when preload library is used with the LD_PRELOAD environment variable
		*/
		@@ -307,7 +323,8 @@ void init_preload() {
		init_passthrough_if_needed();
		init_logging();
		CTX->log()->debug("Initialized logging subsystem");
		CTX->cwd(get_sys_cwd());
		log_prog_name();
		init_cwd();
		CTX->log()->debug("Current working directory: '{}'", CTX->cwd());
		if (get_daemon_pid() == -1 \|\| CTX->mountdir().empty()) {
		cerr << "ADA-FS daemon not running or mountdir could not be loaded. Check adafs_preload.log" << endl;

ifs/src/preload/resolve.cpp

+53 −0

Original line number	Diff line number	Diff line
		@@ -109,3 +109,56 @@ std::string get_sys_cwd() {
		}
		return {temp};
		}

		void set_sys_cwd(const std::string& path) {
		CTX->log()->debug("{}() to '{}'", __func__, path);
		if (LIBC_FUNC(chdir, path.c_str())) {
		CTX->log()->error("{}() failed to set system current working directory: {}",
		__func__, std::strerror(errno));
		throw std::system_error(errno,
		std::system_category(),
		"Failed to set system current working directory");
		}
		}

		void set_env_cwd(const std::string& path) {
		CTX->log()->debug("{}() to '{}'", __func__, path);
		if(setenv("ADAFS_CWD", path.c_str(), 1)) {
		CTX->log()->error("{}() failed to set environment current working directory: {}",
		__func__, std::strerror(errno));
		throw std::system_error(errno,
		std::system_category(),
		"Failed to set environment current working directory");
		}
		}

		void unset_env_cwd() {
		CTX->log()->debug("{}()", __func__);
		if(unsetenv("ADAFS_CWD")) {
		CTX->log()->error("{}() failed to unset environment current working directory: {}",
		__func__, std::strerror(errno));
		throw std::system_error(errno,
		std::system_category(),
		"Failed to unset environment current working directory");
		}
		}

		void init_cwd() {
		const char* env_cwd = std::getenv("ADAFS_CWD");
		if (env_cwd != nullptr) {
		CTX->cwd(env_cwd);
		} else {
		CTX->cwd(get_sys_cwd());
		}
		}

		void set_cwd(const std::string& path, bool internal) {
		if(internal) {
		set_sys_cwd(CTX->mountdir());
		set_env_cwd(path);
		} else {
		set_sys_cwd(path);
		unset_env_cwd();
		}
		CTX->cwd(path);
		}