Add fstat64 and open64 functions; enhance close_range and fd management (9a2a38f5) · Commits · hpc / gekkofs

src/client/gkfs_libc.cpp

+127 −20

Original line number	Diff line number	Diff line
		@@ -188,6 +188,8 @@ DLSYM_WRAPPER(int, stat, (int ver, const char* path, struct stat* buf),
		(ver, path, buf), "__xstat")
		DLSYM_WRAPPER(int, fstat, (int ver, int fd, struct stat* buf), (ver, fd, buf),
		"__fxstat")
		DLSYM_WRAPPER(int, fstat64, ( int fd,struct stat64* buf), ( fd, buf),
		"__fxstat64")
		DLSYM_WRAPPER(int, fxstatat,
		(int ver, int dfd, const char* path, struct stat* buf, int flags),
		(ver, dfd, path, buf, flags), "__fxstatat")
		@@ -329,7 +331,7 @@ resolve_gkfs_path(int dirfd, const char* path, std::string& resolved,
		auto res = std::mismatch(CTX->mountdir().begin(), CTX->mountdir().end(),
		std::string(path).begin());

		if(res.first != CTX->mountdir().end()) {
		if(res.first != CTX->mountdir().end() and dirfd==AT_FDCWD) {
		return PathStatus::External;
		}

		@@ -433,6 +435,16 @@ open64(const char* path, int flags, ...) {
		GKFS_FALLBACK(open64, const_cast<char*>(path), flags, mode)
		}

		int
		open64(const char* path, int flags, mode_t mode) {


		initializeGekko();
		GKFS_PATH_OPERATION(open, AT_FDCWD, path, mode, flags)
		GKFS_FALLBACK(open64, const_cast<char*>(path), flags, mode)
		}



		int
		openat(int dirfd, const char* path, int flags, ...) {
		@@ -465,24 +477,94 @@ close(int fd) {
		GKFS_FALLBACK(close, fd);
		}


		std::vector<int>
		get_open_fds() {
		std::vector<int> fds;
		const std::string fd_path = "/proc/self/fd";

		DIR* dir = dlsym_opendir(fd_path.c_str());
		if(!dir) {
		perror("opendir() failed");
		return fds;
		}

		struct dirent* entry;
		while((entry = dlsym_readdir(dir))) {
		// Skip "." and ".." entries
		if(entry->d_type == DT_DIR)
		continue;

		try {
		int fd = std::stoi(entry->d_name);
		// Skip the directory FD itself
		if(fd != dirfd(dir)) {
		fds.push_back(fd);
		}
		} catch(const std::exception&) {
		// Ignore non-integer entries
		}
		}

		dlsym_closedir(dir);

		fds.erase(std::remove_if(fds.begin(), fds.end(),
		[](int fd) { return fcntl(fd, F_GETFD) < 0; }),
		fds.end());

		return fds;
		}


		int
		close_range(unsigned low, unsigned high, int flags) {

		LOG(DEBUG, "close_range({}, {}, {})", low, high, flags);
		//return 0;
		auto fds = get_open_fds();
		if(flags & CLOSE_RANGE_UNSHARE) {
		// Unshare the file descriptor table
		LOG(DEBUG, "close_range with CLOSE_RANGE_UNSHARE");
		if(unshare(CLONE_FILES) == -1) {
		perror("unshare() failed");
		return -1;
		}
		}
		if(flags & CLOSE_RANGE_CLOEXEC) {
		// Close all file descriptors in the range
		LOG(DEBUG, "close_range with CLOSE_RANGE_CLOEXEC");
		}
		// Is fd from gekkofs ?
		initializeGekko();
		if(CTX->interception_enabled()) {
		for(unsigned int i = low; i <= high; i++) {
		if(i > GKFS_MAX_OPEN_FDS)
		break;
		for(unsigned int i : fds) {
		if(i < low \|\| i > high)
		continue;

		if(is_gkfs_fd(i)) {
		LOG_DEBUG("[GKFS] Closing fd {}", i);
		gkfs::syscall::gkfs_close(i);
		} else {
		LOG_DEBUG("[NONGKFS] Closing fd {}", i);
		close(i);
		}
		}
		// Fall back to close the original range (it may not be a good idea)
		return 0;
		} else {

		std::cout << "Not in gekko: close_range" << std::endl;
		for(unsigned int i : fds) {
		if(i < low \|\| i > high)
		continue;

		std::cout << "Not in gekko: close_range " << i << std::endl;
		close(i);
		}
		GKFS_FALLBACK(close_range, low, high, flags);
		}
		// We are not in gekko just do it...
		// GKFS_FALLBACK(close_range, low, high, flags);
		return 0;
		}


		int
		creat(const char* path, mode_t mode) {
		@@ -752,7 +834,7 @@ stat64(const char* path, struct stat64* buf) {
		std::string resolved;
		switch(resolve_gkfs_path(AT_FDCWD, path, resolved)) {
		case PathStatus::Internal: {
		LOG(DEBUG, "[GKFS] {}", CTX->file_map()->get(fd)->path());
		LOG(DEBUG, "[GKFS] {}", resolved);
		auto res = gkfs::syscall::gkfs_stat(resolved, &st);
		convert(&st, buf);
		return res;
		@@ -787,7 +869,7 @@ fstatat(int dfd, const char* path, struct stat* buf, int flags) {
		std::string resolved;
		switch(resolve_gkfs_path(dfd, path, resolved)) {
		case PathStatus::Internal: {
		LOG(DEBUG, "[GKFS] {}", CTX->file_map()->get(fd)->path());
		LOG(DEBUG, "[GKFS] {}", resolved);
		auto res = gkfs::syscall::gkfs_stat(resolved, buf);
		return res;
		}
		@@ -866,13 +948,12 @@ fork(void) {
		int
		pipe(int pipefd[2]) {
		initializeGekko();
		if(is_gkfs_fd(pipefd[0])) {
		LOG(DEBUG, "[GKFS] 0 {}", pipefd[0]);
		}
		if(is_gkfs_fd(pipefd[1])) {
		LOG(DEBUG, "[GKFS] 1 {}", pipefd[1]);
		}
		GKFS_FALLBACK(pipe, pipefd);

		auto res = dlsym_pipe(pipefd);
		LOG(DEBUG, "pipe {} <---> {}", pipefd[0], pipefd[1]);

		// GKFS_FALLBACK(pipe, pipefd);
		return res;
		}

		int
		@@ -885,7 +966,20 @@ dup(int fd) {
		int
		dup2(int fd, int fd2) {
		initializeGekko();
		GKFS_OPERATION(dup2, fd, fd2);
		if(is_gkfs_fd(fd) && is_gkfs_fd(fd2)) {
		LOG(DEBUG, "[GKFS] DUP2 G{} --> G{}", fd, fd2);
		return gkfs::syscall::gkfs_dup2(fd, fd2);
		}else
		if(is_gkfs_fd(fd2)) {
		LOG(DEBUG, "[GKFS-NON] DUP2 {} --> G{}", fd, fd2);
		return gkfs::syscall::gkfs_dup(fd);
		}else
		if(is_gkfs_fd(fd)) {
		LOG(DEBUG, "[GKFS-NON] DUP2 G{} --> {}", fd, fd2);
		return gkfs::syscall::gkfs_dup2(fd, fd2);
		}

		//GKFS_OPERATION(dup2, fd, fd2);
		GKFS_FALLBACK(dup2, fd, fd2);
		}

		@@ -1032,7 +1126,7 @@ realpath(const char* path, char* resolved_path) {
		return nullptr;

		case gkfs::preload::RelativizeStatus::internal:
		LOG(DEBUG, "[GKFS] {}", resolved);
		LOG(DEBUG, "[GKFS] {} --> {}", resolved, path);
		if(resolved_path == nullptr) {
		resolved_path =
		static_cast<char*>(malloc(resolved.size() + 1));
		@@ -1287,8 +1381,21 @@ fdopen(int fd, const char* mode) {

		if(CTX->interception_enabled()) {
		if(is_gkfs_fd(fd)) {
		FILE* ret;
		ret = dlsym_fopen("/dev/null", mode);
		FILE* ret = static_cast<FILE*>(malloc(sizeof(FILE)));
		if(ret == NULL) {
		errno = ENOMEM;
		return NULL;
		}
		ret->_mode = 0666;
		ret->_flags = 0;
		if(strchr(mode, 'r') != NULL)
		ret->_flags \|= O_RDONLY;
		if(strchr(mode, 'w'))
		ret->_flags = O_WRONLY \| O_CREAT \| O_TRUNC;
		if(strchr(mode, 'a'))
		ret->_flags = O_WRONLY \| O_CREAT \| O_APPEND;
		if(strchr(mode, '+'))
		ret->_flags = O_RDWR \| O_CREAT;
		ret->_fileno = fd;
		return ret;
		}