diff options
| -rw-r--r-- | src/libstore/build/hook-instance.cc | 1 | ||||
| -rw-r--r-- | src/libstore/crypto.cc | 1 | ||||
| -rw-r--r-- | src/libstore/lock.cc | 1 | ||||
| -rw-r--r-- | src/libstore/ssh.hh | 1 | ||||
| -rw-r--r-- | src/libutil/archive.cc | 1 | ||||
| -rw-r--r-- | src/libutil/archive.hh | 1 | ||||
| -rw-r--r-- | src/libutil/canon-path.cc | 2 | ||||
| -rw-r--r-- | src/libutil/cgroup.cc | 1 | ||||
| -rw-r--r-- | src/libutil/config.cc | 1 | ||||
| -rw-r--r-- | src/libutil/file-system.cc | 678 | ||||
| -rw-r--r-- | src/libutil/file-system.hh | 270 | ||||
| -rw-r--r-- | src/libutil/filesystem.cc | 176 | ||||
| -rw-r--r-- | src/libutil/hash.hh | 1 | ||||
| -rw-r--r-- | src/libutil/input-accessor.hh | 6 | ||||
| -rw-r--r-- | src/libutil/meson.build | 3 | ||||
| -rw-r--r-- | src/libutil/namespaces.cc | 1 | ||||
| -rw-r--r-- | src/libutil/source-path.hh | 2 | ||||
| -rw-r--r-- | src/libutil/tarfile.cc | 1 | ||||
| -rw-r--r-- | src/libutil/util.cc | 501 | ||||
| -rw-r--r-- | src/libutil/util.hh | 239 | ||||
| -rw-r--r-- | src/nix-collect-garbage/nix-collect-garbage.cc | 1 | ||||
| -rw-r--r-- | tests/unit/libstore/machines.cc | 1 | ||||
| -rw-r--r-- | tests/unit/libutil-support/tests/characterization.hh | 2 | ||||
| -rw-r--r-- | tests/unit/libutil/tests.cc | 1 |
24 files changed, 974 insertions, 919 deletions
diff --git a/src/libstore/build/hook-instance.cc b/src/libstore/build/hook-instance.cc index ea4c2e508..108722cfb 100644 --- a/src/libstore/build/hook-instance.cc +++ b/src/libstore/build/hook-instance.cc @@ -1,3 +1,4 @@ +#include "file-system.hh" #include "globals.hh" #include "hook-instance.hh" diff --git a/src/libstore/crypto.cc b/src/libstore/crypto.cc index 1027469c9..1e29a812b 100644 --- a/src/libstore/crypto.cc +++ b/src/libstore/crypto.cc @@ -1,5 +1,6 @@ #include "crypto.hh" #include "util.hh" +#include "file-system.hh" #include "globals.hh" #include <sodium.h> diff --git a/src/libstore/lock.cc b/src/libstore/lock.cc index 80c75eaa5..b52e87ae0 100644 --- a/src/libstore/lock.cc +++ b/src/libstore/lock.cc @@ -1,4 +1,5 @@ #include "lock.hh" +#include "file-system.hh" #include "globals.hh" #include "pathlocks.hh" diff --git a/src/libstore/ssh.hh b/src/libstore/ssh.hh index 94b952af9..0802c6cc0 100644 --- a/src/libstore/ssh.hh +++ b/src/libstore/ssh.hh @@ -1,6 +1,7 @@ #pragma once ///@file +#include "file-system.hh" #include "util.hh" #include "sync.hh" diff --git a/src/libutil/archive.cc b/src/libutil/archive.cc index a18c54ebf..c3f39d4b3 100644 --- a/src/libutil/archive.cc +++ b/src/libutil/archive.cc @@ -12,6 +12,7 @@ #include <fcntl.h> #include "archive.hh" +#include "file-system.hh" #include "util.hh" #include "config.hh" #include "signals.hh" diff --git a/src/libutil/archive.hh b/src/libutil/archive.hh index 017b6633c..f163a1947 100644 --- a/src/libutil/archive.hh +++ b/src/libutil/archive.hh @@ -3,6 +3,7 @@ #include "types.hh" #include "serialise.hh" +#include "file-system.hh" namespace nix { diff --git a/src/libutil/canon-path.cc b/src/libutil/canon-path.cc index 040464532..f678fae94 100644 --- a/src/libutil/canon-path.cc +++ b/src/libutil/canon-path.cc @@ -1,5 +1,5 @@ #include "canon-path.hh" -#include "util.hh" +#include "file-system.hh" namespace nix { diff --git a/src/libutil/cgroup.cc b/src/libutil/cgroup.cc index 9320d2371..aa7802f79 100644 --- a/src/libutil/cgroup.cc +++ b/src/libutil/cgroup.cc @@ -2,6 +2,7 @@ #include "cgroup.hh" #include "util.hh" +#include "file-system.hh" #include "finally.hh" #include <chrono> diff --git a/src/libutil/config.cc b/src/libutil/config.cc index 81efcd507..f6f14878a 100644 --- a/src/libutil/config.cc +++ b/src/libutil/config.cc @@ -2,6 +2,7 @@ #include "args.hh" #include "abstract-setting-to-json.hh" #include "experimental-features.hh" +#include "file-system.hh" #include "config-impl.hh" diff --git a/src/libutil/file-system.cc b/src/libutil/file-system.cc new file mode 100644 index 000000000..e5ba42eb6 --- /dev/null +++ b/src/libutil/file-system.cc @@ -0,0 +1,678 @@ +#include <sys/time.h> +#include <filesystem> +#include <atomic> + +#include "environment-variables.hh" +#include "file-system.hh" +#include "finally.hh" +#include "serialise.hh" +#include "util.hh" +#include "signals.hh" +#include "types.hh" + +namespace fs = std::filesystem; + +namespace nix { + +Path absPath(Path path, std::optional<PathView> dir, bool resolveSymlinks) +{ + if (path.empty() || path[0] != '/') { + if (!dir) { +#ifdef __GNU__ + /* GNU (aka. GNU/Hurd) doesn't have any limitation on path + lengths and doesn't define `PATH_MAX'. */ + char *buf = getcwd(NULL, 0); + if (buf == NULL) +#else + char buf[PATH_MAX]; + if (!getcwd(buf, sizeof(buf))) +#endif + throw SysError("cannot get cwd"); + path = concatStrings(buf, "/", path); +#ifdef __GNU__ + free(buf); +#endif + } else + path = concatStrings(*dir, "/", path); + } + return canonPath(path, resolveSymlinks); +} + + +Path canonPath(PathView path, bool resolveSymlinks) +{ + assert(path != ""); + + std::string s; + s.reserve(256); + + if (path[0] != '/') + throw Error("not an absolute path: '%1%'", path); + + std::string temp; + + /* Count the number of times we follow a symlink and stop at some + arbitrary (but high) limit to prevent infinite loops. */ + unsigned int followCount = 0, maxFollow = 1024; + + while (1) { + + /* Skip slashes. */ + while (!path.empty() && path[0] == '/') path.remove_prefix(1); + if (path.empty()) break; + + /* Ignore `.'. */ + if (path == "." || path.substr(0, 2) == "./") + path.remove_prefix(1); + + /* If `..', delete the last component. */ + else if (path == ".." || path.substr(0, 3) == "../") + { + if (!s.empty()) s.erase(s.rfind('/')); + path.remove_prefix(2); + } + + /* Normal component; copy it. */ + else { + s += '/'; + if (const auto slash = path.find('/'); slash == std::string::npos) { + s += path; + path = {}; + } else { + s += path.substr(0, slash); + path = path.substr(slash); + } + + /* If s points to a symlink, resolve it and continue from there */ + if (resolveSymlinks && isLink(s)) { + if (++followCount >= maxFollow) + throw Error("infinite symlink recursion in path '%1%'", path); + temp = concatStrings(readLink(s), path); + path = temp; + if (!temp.empty() && temp[0] == '/') { + s.clear(); /* restart for symlinks pointing to absolute path */ + } else { + s = dirOf(s); + if (s == "/") { // we don’t want trailing slashes here, which dirOf only produces if s = / + s.clear(); + } + } + } + } + } + + return s.empty() ? "/" : std::move(s); +} + +void chmodPath(const Path & path, mode_t mode) +{ + if (chmod(path.c_str(), mode) == -1) + throw SysError("setting permissions on '%s'", path); +} + +Path dirOf(const PathView path) +{ + Path::size_type pos = path.rfind('/'); + if (pos == std::string::npos) + return "."; + return pos == 0 ? "/" : Path(path, 0, pos); +} + + +std::string_view baseNameOf(std::string_view path) +{ + if (path.empty()) + return ""; + + auto last = path.size() - 1; + if (path[last] == '/' && last > 0) + last -= 1; + + auto pos = path.rfind('/', last); + if (pos == std::string::npos) + pos = 0; + else + pos += 1; + + return path.substr(pos, last - pos + 1); +} + + +std::string expandTilde(std::string_view path) +{ + // TODO: expand ~user ? + auto tilde = path.substr(0, 2); + if (tilde == "~/" || tilde == "~") + return getHome() + std::string(path.substr(1)); + else + return std::string(path); +} + + +bool isInDir(std::string_view path, std::string_view dir) +{ + return path.substr(0, 1) == "/" + && path.substr(0, dir.size()) == dir + && path.size() >= dir.size() + 2 + && path[dir.size()] == '/'; +} + + +bool isDirOrInDir(std::string_view path, std::string_view dir) +{ + return path == dir || isInDir(path, dir); +} + + +struct stat stat(const Path & path) +{ + struct stat st; + if (stat(path.c_str(), &st)) + throw SysError("getting status of '%1%'", path); + return st; +} + + +struct stat lstat(const Path & path) +{ + struct stat st; + if (lstat(path.c_str(), &st)) + throw SysError("getting status of '%1%'", path); + return st; +} + +std::optional<struct stat> maybeLstat(const Path & path) +{ + std::optional<struct stat> st{std::in_place}; + if (lstat(path.c_str(), &*st)) + { + if (errno == ENOENT || errno == ENOTDIR) + st.reset(); + else + throw SysError("getting status of '%s'", path); + } + return st; +} + +bool pathExists(const Path & path) +{ + return maybeLstat(path).has_value(); +} + +bool pathAccessible(const Path & path) +{ + try { + return pathExists(path); + } catch (SysError & e) { + // swallow EPERM + if (e.errNo == EPERM) return false; + throw; + } +} + + +Path readLink(const Path & path) +{ + checkInterrupt(); + std::vector<char> buf; + for (ssize_t bufSize = PATH_MAX/4; true; bufSize += bufSize/2) { + buf.resize(bufSize); + ssize_t rlSize = readlink(path.c_str(), buf.data(), bufSize); + if (rlSize == -1) + if (errno == EINVAL) + throw Error("'%1%' is not a symlink", path); + else + throw SysError("reading symbolic link '%1%'", path); + else if (rlSize < bufSize) + return std::string(buf.data(), rlSize); + } +} + + +bool isLink(const Path & path) +{ + struct stat st = lstat(path); + return S_ISLNK(st.st_mode); +} + + +DirEntries readDirectory(DIR *dir, const Path & path) +{ + DirEntries entries; + entries.reserve(64); + + struct dirent * dirent; + while (errno = 0, dirent = readdir(dir)) { /* sic */ + checkInterrupt(); + std::string name = dirent->d_name; + if (name == "." || name == "..") continue; + entries.emplace_back(name, dirent->d_ino, +#ifdef HAVE_STRUCT_DIRENT_D_TYPE + dirent->d_type +#else + DT_UNKNOWN +#endif + ); + } + if (errno) throw SysError("reading directory '%1%'", path); + + return entries; +} + +DirEntries readDirectory(const Path & path) +{ + AutoCloseDir dir(opendir(path.c_str())); + if (!dir) throw SysError("opening directory '%1%'", path); + + return readDirectory(dir.get(), path); +} + + +unsigned char getFileType(const Path & path) +{ + struct stat st = lstat(path); + if (S_ISDIR(st.st_mode)) return DT_DIR; + if (S_ISLNK(st.st_mode)) return DT_LNK; + if (S_ISREG(st.st_mode)) return DT_REG; + return DT_UNKNOWN; +} + + +std::string readFile(int fd) +{ + struct stat st; + if (fstat(fd, &st) == -1) + throw SysError("statting file"); + + return drainFD(fd, true, st.st_size); +} + + +std::string readFile(const Path & path) +{ + AutoCloseFD fd{open(path.c_str(), O_RDONLY | O_CLOEXEC)}; + if (!fd) + throw SysError("opening file '%1%'", path); + return readFile(fd.get()); +} + + +void readFile(const Path & path, Sink & sink) +{ + AutoCloseFD fd{open(path.c_str(), O_RDONLY | O_CLOEXEC)}; + if (!fd) + throw SysError("opening file '%s'", path); + drainFD(fd.get(), sink); +} + + +void writeFile(const Path & path, std::string_view s, mode_t mode, bool sync) +{ + AutoCloseFD fd{open(path.c_str(), O_WRONLY | O_TRUNC | O_CREAT | O_CLOEXEC, mode)}; + if (!fd) + throw SysError("opening file '%1%'", path); + try { + writeFull(fd.get(), s); + } catch (Error & e) { + e.addTrace({}, "writing file '%1%'", path); + throw; + } + if (sync) + fd.fsync(); + // Explicitly close to make sure exceptions are propagated. + fd.close(); + if (sync) + syncParent(path); +} + + +void writeFile(const Path & path, Source & source, mode_t mode, bool sync) +{ + AutoCloseFD fd{open(path.c_str(), O_WRONLY | O_TRUNC | O_CREAT | O_CLOEXEC, mode)}; + if (!fd) + throw SysError("opening file '%1%'", path); + + std::vector<char> buf(64 * 1024); + + try { + while (true) { + try { + auto n = source.read(buf.data(), buf.size()); + writeFull(fd.get(), {buf.data(), n}); + } catch (EndOfFile &) { break; } + } + } catch (Error & e) { + e.addTrace({}, "writing file '%1%'", path); + throw; + } + if (sync) + fd.fsync(); + // Explicitly close to make sure exceptions are propagated. + fd.close(); + if (sync) + syncParent(path); +} + +void syncParent(const Path & path) +{ + AutoCloseFD fd{open(dirOf(path).c_str(), O_RDONLY, 0)}; + if (!fd) + throw SysError("opening file '%1%'", path); + fd.fsync(); +} + +static void _deletePath(int parentfd, const Path & path, uint64_t & bytesFreed) +{ + checkInterrupt(); + + std::string name(baseNameOf(path)); + + struct stat st; + if (fstatat(parentfd, name.c_str(), &st, AT_SYMLINK_NOFOLLOW) == -1) { + if (errno == ENOENT) return; + throw SysError("getting status of '%1%'", path); + } + + if (!S_ISDIR(st.st_mode)) { + /* We are about to delete a file. Will it likely free space? */ + + switch (st.st_nlink) { + /* Yes: last link. */ + case 1: + bytesFreed += st.st_size; + break; + /* Maybe: yes, if 'auto-optimise-store' or manual optimisation + was performed. Instead of checking for real let's assume + it's an optimised file and space will be freed. + + In worst case we will double count on freed space for files + with exactly two hardlinks for unoptimised packages. + */ + case 2: + bytesFreed += st.st_size; + break; + /* No: 3+ links. */ + default: + break; + } + } + + if (S_ISDIR(st.st_mode)) { + /* Make the directory accessible. */ + const auto PERM_MASK = S_IRUSR | S_IWUSR | S_IXUSR; + if ((st.st_mode & PERM_MASK) != PERM_MASK) { + if (fchmodat(parentfd, name.c_str(), st.st_mode | PERM_MASK, 0) == -1) + throw SysError("chmod '%1%'", path); + } + + int fd = openat(parentfd, path.c_str(), O_RDONLY); + if (fd == -1) + throw SysError("opening directory '%1%'", path); + AutoCloseDir dir(fdopendir(fd)); + if (!dir) + throw SysError("opening directory '%1%'", path); + for (auto & i : readDirectory(dir.get(), path)) + _deletePath(dirfd(dir.get()), path + "/" + i.name, bytesFreed); + } + + int flags = S_ISDIR(st.st_mode) ? AT_REMOVEDIR : 0; + if (unlinkat(parentfd, name.c_str(), flags) == -1) { + if (errno == ENOENT) return; + throw SysError("cannot unlink '%1%'", path); + } +} + +static void _deletePath(const Path & path, uint64_t & bytesFreed) +{ + Path dir = dirOf(path); + if (dir == "") + dir = "/"; + + AutoCloseFD dirfd{open(dir.c_str(), O_RDONLY)}; + if (!dirfd) { + if (errno == ENOENT) return; + throw SysError("opening directory '%1%'", path); + } + + _deletePath(dirfd.get(), path, bytesFreed); +} + + +void deletePath(const Path & path) +{ + uint64_t dummy; + deletePath(path, dummy); +} + + +void deletePath(const Path & path, uint64_t & bytesFreed) +{ + //Activity act(*logger, lvlDebug, "recursively deleting path '%1%'", path); + bytesFreed = 0; + _deletePath(path, bytesFreed); +} + +Paths createDirs(const Path & path) +{ + Paths created; + if (path == "/") return created; + + struct stat st; + if (lstat(path.c_str(), &st) == -1) { + created = createDirs(dirOf(path)); + if (mkdir(path.c_str(), 0777) == -1 && errno != EEXIST) + throw SysError("creating directory '%1%'", path); + st = lstat(path); + created.push_back(path); + } + + if (S_ISLNK(st.st_mode) && stat(path.c_str(), &st) == -1) + throw SysError("statting symlink '%1%'", path); + + if (!S_ISDIR(st.st_mode)) throw Error("'%1%' is not a directory", path); + + return created; +} + + +////////////////////////////////////////////////////////////////////// + +AutoDelete::AutoDelete() : del{false} {} + +AutoDelete::AutoDelete(const std::string & p, bool recursive) : path(p) +{ + del = true; + this->recursive = recursive; +} + +AutoDelete::~AutoDelete() +{ + try { + if (del) { + if (recursive) + deletePath(path); + else { + if (remove(path.c_str()) == -1) + throw SysError("cannot unlink '%1%'", path); + } + } + } catch (...) { + ignoreException(); + } +} + +void AutoDelete::cancel() +{ + del = false; +} + +void AutoDelete::reset(const Path & p, bool recursive) { + path = p; + this->recursive = recursive; + del = true; +} + +////////////////////////////////////////////////////////////////////// + +static Path tempName(Path tmpRoot, const Path & prefix, bool includePid, + std::atomic<unsigned int> & counter) +{ + tmpRoot = canonPath(tmpRoot.empty() ? getEnv("TMPDIR").value_or("/tmp") : tmpRoot, true); + if (includePid) + return fmt("%1%/%2%-%3%-%4%", tmpRoot, prefix, getpid(), counter++); + else + return fmt("%1%/%2%-%3%", tmpRoot, prefix, counter++); +} + +Path createTempDir(const Path & tmpRoot, const Path & prefix, + bool includePid, bool useGlobalCounter, mode_t mode) +{ + static std::atomic<unsigned int> globalCounter = 0; + std::atomic<unsigned int> localCounter = 0; + auto & counter(useGlobalCounter ? globalCounter : localCounter); + + while (1) { + checkInterrupt(); + Path tmpDir = tempName(tmpRoot, prefix, includePid, counter); + if (mkdir(tmpDir.c_str(), mode) == 0) { +#if __FreeBSD__ + /* Explicitly set the group of the directory. This is to + work around around problems caused by BSD's group + ownership semantics (directories inherit the group of + the parent). For instance, the group of /tmp on + FreeBSD is "wheel", so all directories created in /tmp + will be owned by "wheel"; but if the user is not in + "wheel", then "tar" will fail to unpack archives that + have the setgid bit set on directories. */ + if (chown(tmpDir.c_str(), (uid_t) -1, getegid()) != 0) + throw SysError("setting group of directory '%1%'", tmpDir); +#endif + return tmpDir; + } + if (errno != EEXIST) + throw SysError("creating directory '%1%'", tmpDir); + } +} + + +std::pair<AutoCloseFD, Path> createTempFile(const Path & prefix) +{ + Path tmpl(getEnv("TMPDIR").value_or("/tmp") + "/" + prefix + ".XXXXXX"); + // Strictly speaking, this is UB, but who cares... + // FIXME: use O_TMPFILE. + AutoCloseFD fd(mkstemp((char *) tmpl.c_str())); + if (!fd) + throw SysError("creating temporary file '%s'", tmpl); + closeOnExec(fd.get()); + return {std::move(fd), tmpl}; +} + +void createSymlink(const Path & target, const Path & link) +{ + if (symlink(target.c_str(), link.c_str())) + throw SysError("creating symlink from '%1%' to '%2%'", link, target); +} + +void replaceSymlink(const Path & target, const Path & link) +{ + for (unsigned int n = 0; true; n++) { + Path tmp = canonPath(fmt("%s/.%d_%s", dirOf(link), n, baseNameOf(link))); + + try { + createSymlink(target, tmp); + } catch (SysError & e) { + if (e.errNo == EEXIST) continue; + throw; + } + + renameFile(tmp, link); + + break; + } +} + +void setWriteTime(const fs::path & p, const struct stat & st) +{ + struct timeval times[2]; + times[0] = { + .tv_sec = st.st_atime, + .tv_usec = 0, + }; + times[1] = { + .tv_sec = st.st_mtime, + .tv_usec = 0, + }; + if (lutimes(p.c_str(), times) != 0) + throw SysError("changing modification time of '%s'", p); +} + +void copy(const fs::directory_entry & from, const fs::path & to, CopyFileFlags flags) +{ + // TODO: Rewrite the `is_*` to use `symlink_status()` + auto statOfFrom = lstat(from.path().c_str()); + auto fromStatus = from.symlink_status(); + + // Mark the directory as writable so that we can delete its children + if (flags.deleteAfter && fs::is_directory(fromStatus)) { + fs::permissions(from.path(), fs::perms::owner_write, fs::perm_options::add | fs::perm_options::nofollow); + } + + + if (fs::is_symlink(fromStatus) || fs::is_regular_file(fromStatus)) { + auto opts = fs::copy_options::overwrite_existing; + + if (!flags.followSymlinks) { + opts |= fs::copy_options::copy_symlinks; + } + + fs::copy(from.path(), to, opts); + } else if (fs::is_directory(fromStatus)) { + fs::create_directory(to); + for (auto & entry : fs::directory_iterator(from.path())) { + copy(entry, to / entry.path().filename(), flags); + } + } else { + throw Error("file '%s' has an unsupported type", from.path()); + } + + setWriteTime(to, statOfFrom); + if (flags.deleteAfter) { + if (!fs::is_symlink(fromStatus)) + fs::permissions(from.path(), fs::perms::owner_write, fs::perm_options::add | fs::perm_options::nofollow); + fs::remove(from.path()); + } +} + + +void copyFile(const Path & oldPath, const Path & newPath, CopyFileFlags flags) +{ + return copy(fs::directory_entry(fs::path(oldPath)), fs::path(newPath), flags); +} + +void renameFile(const Path & oldName, const Path & newName) +{ + fs::rename(oldName, newName); +} + +void moveFile(const Path & oldName, const Path & newName) +{ + try { + renameFile(oldName, newName); + } catch (fs::filesystem_error & e) { + auto oldPath = fs::path(oldName); + auto newPath = fs::path(newName); + // For the move to be as atomic as possible, copy to a temporary + // directory + fs::path temp = createTempDir(newPath.parent_path(), "rename-tmp"); + Finally removeTemp = [&]() { fs::remove(temp); }; + auto tempCopyTarget = temp / "copy-target"; + if (e.code().value() == EXDEV) { + fs::remove(newPath); + warn("Can’t rename %s as %s, copying instead", oldName, newName); + copy(fs::directory_entry(oldPath), tempCopyTarget, { .deleteAfter = true }); + renameFile(tempCopyTarget, newPath); + } + } +} + +} diff --git a/src/libutil/file-system.hh b/src/libutil/file-system.hh new file mode 100644 index 000000000..1d91ef334 --- /dev/null +++ b/src/libutil/file-system.hh @@ -0,0 +1,270 @@ +#pragma once +/** + * @file + * + * Utiltities for working with the file sytem and file paths. + */ + +#include "types.hh" +#include "util.hh" + +#include <sys/types.h> +#include <sys/stat.h> +#include <dirent.h> +#include <unistd.h> + +#include <boost/lexical_cast.hpp> + +#include <functional> +#include <optional> + +#ifndef HAVE_STRUCT_DIRENT_D_TYPE +#define DT_UNKNOWN 0 +#define DT_REG 1 +#define DT_LNK 2 +#define DT_DIR 3 +#endif + +namespace nix { + +struct Sink; +struct Source; + +/** + * @return An absolutized path, resolving paths relative to the + * specified directory, or the current directory otherwise. The path + * is also canonicalised. + */ +Path absPath(Path path, + std::optional<PathView> dir = {}, + bool resolveSymlinks = false); + +/** + * Canonicalise a path by removing all `.` or `..` components and + * double or trailing slashes. Optionally resolves all symlink + * components such that each component of the resulting path is *not* + * a symbolic link. + */ +Path canonPath(PathView path, bool resolveSymlinks = false); + +/** + * Change the permissions of a path + * Not called `chmod` as it shadows and could be confused with + * `int chmod(char *, mode_t)`, which does not handle errors + */ +void chmodPath(const Path & path, mode_t mode); + +/** + * @return The directory part of the given canonical path, i.e., + * everything before the final `/`. If the path is the root or an + * immediate child thereof (e.g., `/foo`), this means `/` + * is returned. + */ +Path dirOf(const PathView path); + +/** + * @return the base name of the given canonical path, i.e., everything + * following the final `/` (trailing slashes are removed). + */ +std::string_view baseNameOf(std::string_view path); + +/** + * Perform tilde expansion on a path. + */ +std::string expandTilde(std::string_view path); + +/** + * Check whether 'path' is a descendant of 'dir'. Both paths must be + * canonicalized. + */ +bool isInDir(std::string_view path, std::string_view dir); + +/** + * Check whether 'path' is equal to 'dir' or a descendant of + * 'dir'. Both paths must be canonicalized. + */ +bool isDirOrInDir(std::string_view path, std::string_view dir); + +/** + * Get status of `path`. + */ +struct stat stat(const Path & path); +struct stat lstat(const Path & path); + +/** + * `lstat` the given path if it exists. + * @return std::nullopt if the path doesn't exist, or an optional containing the result of `lstat` otherwise + */ +std::optional<struct stat> maybeLstat(const Path & path); + +/** + * @return true iff the given path exists. + */ +bool pathExists(const Path & path); + +/** + * A version of pathExists that returns false on a permission error. + * Useful for inferring default paths across directories that might not + * be readable. + * @return true iff the given path can be accessed and exists + */ +bool pathAccessible(const Path & path); + +/** + * Read the contents (target) of a symbolic link. The result is not + * in any way canonicalised. + */ +Path readLink(const Path & path); + +bool isLink(const Path & path); + +/** + * Read the contents of a directory. The entries `.` and `..` are + * removed. + */ +struct DirEntry +{ + std::string name; + ino_t ino; + /** + * one of DT_* + */ + unsigned char type; + DirEntry(std::string name, ino_t ino, unsigned char type) + : name(std::move(name)), ino(ino), type(type) { } +}; + +typedef std::vector<DirEntry> DirEntries; + +DirEntries readDirectory(const Path & path); + +unsigned char getFileType(const Path & path); + +/** + * Read the contents of a file into a string. + */ +std::string readFile(int fd); +std::string readFile(const Path & path); +void readFile(const Path & path, Sink & sink); + +/** + * Write a string to a file. + */ +void writeFile(const Path & path, std::string_view s, mode_t mode = 0666, bool sync = false); + +void writeFile(const Path & path, Source & source, mode_t mode = 0666, bool sync = false); + +/** + * Flush a file's parent directory to disk + */ +void syncParent(const Path & path); + +/** + * Delete a path; i.e., in the case of a directory, it is deleted + * recursively. It's not an error if the path does not exist. The + * second variant returns the number of bytes and blocks freed. + */ +void deletePath(const Path & path); + +void deletePath(const Path & path, uint64_t & bytesFreed); + +/** + * Create a directory and all its parents, if necessary. Returns the + * list of created directories, in order of creation. + */ +Paths createDirs(const Path & path); +inline Paths createDirs(PathView path) +{ + return createDirs(Path(path)); +} + +/** + * Create a symlink. + */ +void createSymlink(const Path & target, const Path & link); + +/** + * Atomically create or replace a symlink. + */ +void replaceSymlink(const Path & target, const Path & link); + +void renameFile(const Path & src, const Path & dst); + +/** + * Similar to 'renameFile', but fallback to a copy+remove if `src` and `dst` + * are on a different filesystem. + * + * Beware that this might not be atomic because of the copy that happens behind + * the scenes + */ +void moveFile(const Path & src, const Path & dst); + +struct CopyFileFlags +{ + /** + * Delete the file after copying. + */ + bool deleteAfter = false; + + /** + * Follow symlinks and copy the eventual target. + */ + bool followSymlinks = false; +}; + +/** + * Recursively copy the content of `oldPath` to `newPath`. If `andDelete` is + * `true`, then also remove `oldPath` (making this equivalent to `moveFile`, but + * with the guaranty that the destination will be “fresh”, with no stale inode + * or file descriptor pointing to it). + */ +void copyFile(const Path & oldPath, const Path & newPath, CopyFileFlags flags); + +/** + * Automatic cleanup of resources. + */ + + +class AutoDelete +{ + Path path; + bool del; + bool recursive; +public: + AutoDelete(); + AutoDelete(const Path & p, bool recursive = true); + ~AutoDelete(); + void cancel(); + void reset(const Path & p, bool recursive = true); + operator Path() const { return path; } + operator PathView() const { return path; } +}; + +struct DIRDeleter +{ + void operator()(DIR * dir) const { + closedir(dir); + } +}; + +typedef std::unique_ptr<DIR, DIRDeleter> AutoCloseDir; + +/** + * Create a temporary directory. + */ +Path createTempDir(const Path & tmpRoot = "", const Path & prefix = "nix", + bool includePid = true, bool useGlobalCounter = true, mode_t mode = 0755); + +/** + * Create a temporary file, returning a file handle and its path. + */ +std::pair<AutoCloseFD, Path> createTempFile(const Path & prefix = "nix"); + +/** + * Used in various places. + */ +typedef std::function<bool(const Path & path)> PathFilter; + +extern PathFilter defaultPathFilter; + +} diff --git a/src/libutil/filesystem.cc b/src/libutil/filesystem.cc deleted file mode 100644 index 85871870c..000000000 --- a/src/libutil/filesystem.cc +++ /dev/null @@ -1,176 +0,0 @@ -#include <sys/time.h> -#include <filesystem> -#include <atomic> - -#include "environment-variables.hh" -#include "finally.hh" -#include "util.hh" -#include "signals.hh" -#include "types.hh" - -namespace fs = std::filesystem; - -namespace nix { - -static Path tempName(Path tmpRoot, const Path & prefix, bool includePid, - std::atomic<unsigned int> & counter) -{ - tmpRoot = canonPath(tmpRoot.empty() ? getEnv("TMPDIR").value_or("/tmp") : tmpRoot, true); - if (includePid) - return fmt("%1%/%2%-%3%-%4%", tmpRoot, prefix, getpid(), counter++); - else - return fmt("%1%/%2%-%3%", tmpRoot, prefix, counter++); -} - -Path createTempDir(const Path & tmpRoot, const Path & prefix, - bool includePid, bool useGlobalCounter, mode_t mode) -{ - static std::atomic<unsigned int> globalCounter = 0; - std::atomic<unsigned int> localCounter = 0; - auto & counter(useGlobalCounter ? globalCounter : localCounter); - - while (1) { - checkInterrupt(); - Path tmpDir = tempName(tmpRoot, prefix, includePid, counter); - if (mkdir(tmpDir.c_str(), mode) == 0) { -#if __FreeBSD__ - /* Explicitly set the group of the directory. This is to - work around around problems caused by BSD's group - ownership semantics (directories inherit the group of - the parent). For instance, the group of /tmp on - FreeBSD is "wheel", so all directories created in /tmp - will be owned by "wheel"; but if the user is not in - "wheel", then "tar" will fail to unpack archives that - have the setgid bit set on directories. */ - if (chown(tmpDir.c_str(), (uid_t) -1, getegid()) != 0) - throw SysError("setting group of directory '%1%'", tmpDir); -#endif - return tmpDir; - } - if (errno != EEXIST) - throw SysError("creating directory '%1%'", tmpDir); - } -} - - -std::pair<AutoCloseFD, Path> createTempFile(const Path & prefix) -{ - Path tmpl(getEnv("TMPDIR").value_or("/tmp") + "/" + prefix + ".XXXXXX"); - // Strictly speaking, this is UB, but who cares... - // FIXME: use O_TMPFILE. - AutoCloseFD fd(mkstemp((char *) tmpl.c_str())); - if (!fd) - throw SysError("creating temporary file '%s'", tmpl); - closeOnExec(fd.get()); - return {std::move(fd), tmpl}; -} - -void createSymlink(const Path & target, const Path & link) -{ - if (symlink(target.c_str(), link.c_str())) - throw SysError("creating symlink from '%1%' to '%2%'", link, target); -} - -void replaceSymlink(const Path & target, const Path & link) -{ - for (unsigned int n = 0; true; n++) { - Path tmp = canonPath(fmt("%s/.%d_%s", dirOf(link), n, baseNameOf(link))); - - try { - createSymlink(target, tmp); - } catch (SysError & e) { - if (e.errNo == EEXIST) continue; - throw; - } - - renameFile(tmp, link); - - break; - } -} - -void setWriteTime(const fs::path & p, const struct stat & st) -{ - struct timeval times[2]; - times[0] = { - .tv_sec = st.st_atime, - .tv_usec = 0, - }; - times[1] = { - .tv_sec = st.st_mtime, - .tv_usec = 0, - }; - if (lutimes(p.c_str(), times) != 0) - throw SysError("changing modification time of '%s'", p); -} - -void copy(const fs::directory_entry & from, const fs::path & to, CopyFileFlags flags) -{ - // TODO: Rewrite the `is_*` to use `symlink_status()` - auto statOfFrom = lstat(from.path().c_str()); - auto fromStatus = from.symlink_status(); - - // Mark the directory as writable so that we can delete its children - if (flags.deleteAfter && fs::is_directory(fromStatus)) { - fs::permissions(from.path(), fs::perms::owner_write, fs::perm_options::add | fs::perm_options::nofollow); - } - - - if (fs::is_symlink(fromStatus) || fs::is_regular_file(fromStatus)) { - auto opts = fs::copy_options::overwrite_existing; - - if (!flags.followSymlinks) { - opts |= fs::copy_options::copy_symlinks; - } - - fs::copy(from.path(), to, opts); - } else if (fs::is_directory(fromStatus)) { - fs::create_directory(to); - for (auto & entry : fs::directory_iterator(from.path())) { - copy(entry, to / entry.path().filename(), flags); - } - } else { - throw Error("file '%s' has an unsupported type", from.path()); - } - - setWriteTime(to, statOfFrom); - if (flags.deleteAfter) { - if (!fs::is_symlink(fromStatus)) - fs::permissions(from.path(), fs::perms::owner_write, fs::perm_options::add | fs::perm_options::nofollow); - fs::remove(from.path()); - } -} - - -void copyFile(const Path & oldPath, const Path & newPath, CopyFileFlags flags) -{ - return copy(fs::directory_entry(fs::path(oldPath)), fs::path(newPath), flags); -} - -void renameFile(const Path & oldName, const Path & newName) -{ - fs::rename(oldName, newName); -} - -void moveFile(const Path & oldName, const Path & newName) -{ - try { - renameFile(oldName, newName); - } catch (fs::filesystem_error & e) { - auto oldPath = fs::path(oldName); - auto newPath = fs::path(newName); - // For the move to be as atomic as possible, copy to a temporary - // directory - fs::path temp = createTempDir(newPath.parent_path(), "rename-tmp"); - Finally removeTemp = [&]() { fs::remove(temp); }; - auto tempCopyTarget = temp / "copy-target"; - if (e.code().value() == EXDEV) { - fs::remove(newPath); - warn("Can’t rename %s as %s, copying instead", oldName, newName); - copy(fs::directory_entry(oldPath), tempCopyTarget, { .deleteAfter = true }); - renameFile(tempCopyTarget, newPath); - } - } -} - -} diff --git a/src/libutil/hash.hh b/src/libutil/hash.hh index ae3ee40f4..bb2a5e2a7 100644 --- a/src/libutil/hash.hh +++ b/src/libutil/hash.hh @@ -3,6 +3,7 @@ #include "types.hh" #include "serialise.hh" +#include "file-system.hh" namespace nix { diff --git a/src/libutil/input-accessor.hh b/src/libutil/input-accessor.hh index 740175af0..d8e17c9b1 100644 --- a/src/libutil/input-accessor.hh +++ b/src/libutil/input-accessor.hh @@ -1,8 +1,10 @@ #pragma once ///@file -#include "types.hh" -#include "archive.hh" + +#include <map> +#include <optional> +#include <string> namespace nix { diff --git a/src/libutil/meson.build b/src/libutil/meson.build index c890911e9..8af251d1b 100644 --- a/src/libutil/meson.build +++ b/src/libutil/meson.build @@ -13,7 +13,7 @@ libutil_sources = files( 'escape-string.cc', 'exit.cc', 'experimental-features.cc', - 'filesystem.cc', + 'file-system.cc', 'git.cc', 'hash.cc', 'hilite.cc', @@ -62,6 +62,7 @@ libutil_headers = files( 'exit.hh', 'experimental-features.hh', 'experimental-features-json.hh', + 'file-system.hh', 'finally.hh', 'fmt.hh', 'git.hh', diff --git a/src/libutil/namespaces.cc b/src/libutil/namespaces.cc index dec3a7189..4b539f342 100644 --- a/src/libutil/namespaces.cc +++ b/src/libutil/namespaces.cc @@ -1,5 +1,6 @@ #if __linux__ +#include "file-system.hh" #include "namespaces.hh" #include "util.hh" #include "finally.hh" diff --git a/src/libutil/source-path.hh b/src/libutil/source-path.hh index 4d4c51062..311e9f7a6 100644 --- a/src/libutil/source-path.hh +++ b/src/libutil/source-path.hh @@ -6,7 +6,9 @@ */ #include "ref.hh" +#include "archive.hh" #include "canon-path.hh" +#include "file-system.hh" #include "repair-flag.hh" #include "input-accessor.hh" diff --git a/src/libutil/tarfile.cc b/src/libutil/tarfile.cc index f3f04a936..cabb7af9b 100644 --- a/src/libutil/tarfile.cc +++ b/src/libutil/tarfile.cc @@ -1,6 +1,7 @@ #include <archive.h> #include <archive_entry.h> +#include "file-system.hh" #include "serialise.hh" #include "tarfile.hh" diff --git a/src/libutil/util.cc b/src/libutil/util.cc index 63d9e5248..ac3071ba8 100644 --- a/src/libutil/util.cc +++ b/src/libutil/util.cc @@ -5,6 +5,7 @@ #include "cgroup.hh" #include "signals.hh" #include "environment-variables.hh" +#include "file-system.hh" #include <array> #include <cctype> @@ -50,352 +51,6 @@ namespace nix { -Path absPath(Path path, std::optional<PathView> dir, bool resolveSymlinks) -{ - if (path.empty() || path[0] != '/') { - if (!dir) { -#ifdef __GNU__ - /* GNU (aka. GNU/Hurd) doesn't have any limitation on path - lengths and doesn't define `PATH_MAX'. */ - char *buf = getcwd(NULL, 0); - if (buf == NULL) -#else - char buf[PATH_MAX]; - if (!getcwd(buf, sizeof(buf))) -#endif - throw SysError("cannot get cwd"); - path = concatStrings(buf, "/", path); -#ifdef __GNU__ - free(buf); -#endif - } else - path = concatStrings(*dir, "/", path); - } - return canonPath(path, resolveSymlinks); -} - - -Path canonPath(PathView path, bool resolveSymlinks) -{ - assert(path != ""); - - std::string s; - s.reserve(256); - - if (path[0] != '/') - throw Error("not an absolute path: '%1%'", path); - - std::string temp; - - /* Count the number of times we follow a symlink and stop at some - arbitrary (but high) limit to prevent infinite loops. */ - unsigned int followCount = 0, maxFollow = 1024; - - while (1) { - - /* Skip slashes. */ - while (!path.empty() && path[0] == '/') path.remove_prefix(1); - if (path.empty()) break; - - /* Ignore `.'. */ - if (path == "." || path.substr(0, 2) == "./") - path.remove_prefix(1); - - /* If `..', delete the last component. */ - else if (path == ".." || path.substr(0, 3) == "../") - { - if (!s.empty()) s.erase(s.rfind('/')); - path.remove_prefix(2); - } - - /* Normal component; copy it. */ - else { - s += '/'; - if (const auto slash = path.find('/'); slash == std::string::npos) { - s += path; - path = {}; - } else { - s += path.substr(0, slash); - path = path.substr(slash); - } - - /* If s points to a symlink, resolve it and continue from there */ - if (resolveSymlinks && isLink(s)) { - if (++followCount >= maxFollow) - throw Error("infinite symlink recursion in path '%1%'", path); - temp = concatStrings(readLink(s), path); - path = temp; - if (!temp.empty() && temp[0] == '/') { - s.clear(); /* restart for symlinks pointing to absolute path */ - } else { - s = dirOf(s); - if (s == "/") { // we don’t want trailing slashes here, which dirOf only produces if s = / - s.clear(); - } - } - } - } - } - - return s.empty() ? "/" : std::move(s); -} - -void chmodPath(const Path & path, mode_t mode) -{ - if (chmod(path.c_str(), mode) == -1) - throw SysError("setting permissions on '%s'", path); -} - -Path dirOf(const PathView path) -{ - Path::size_type pos = path.rfind('/'); - if (pos == std::string::npos) - return "."; - return pos == 0 ? "/" : Path(path, 0, pos); -} - - -std::string_view baseNameOf(std::string_view path) -{ - if (path.empty()) - return ""; - - auto last = path.size() - 1; - if (path[last] == '/' && last > 0) - last -= 1; - - auto pos = path.rfind('/', last); - if (pos == std::string::npos) - pos = 0; - else - pos += 1; - - return path.substr(pos, last - pos + 1); -} - - -std::string expandTilde(std::string_view path) -{ - // TODO: expand ~user ? - auto tilde = path.substr(0, 2); - if (tilde == "~/" || tilde == "~") - return getHome() + std::string(path.substr(1)); - else - return std::string(path); -} - - -bool isInDir(std::string_view path, std::string_view dir) -{ - return path.substr(0, 1) == "/" - && path.substr(0, dir.size()) == dir - && path.size() >= dir.size() + 2 - && path[dir.size()] == '/'; -} - - -bool isDirOrInDir(std::string_view path, std::string_view dir) -{ - return path == dir || isInDir(path, dir); -} - - -struct stat stat(const Path & path) -{ - struct stat st; - if (stat(path.c_str(), &st)) - throw SysError("getting status of '%1%'", path); - return st; -} - - -struct stat lstat(const Path & path) -{ - struct stat st; - if (lstat(path.c_str(), &st)) - throw SysError("getting status of '%1%'", path); - return st; -} - -std::optional<struct stat> maybeLstat(const Path & path) -{ - std::optional<struct stat> st{std::in_place}; - if (lstat(path.c_str(), &*st)) - { - if (errno == ENOENT || errno == ENOTDIR) - st.reset(); - else - throw SysError("getting status of '%s'", path); - } - return st; -} - -bool pathExists(const Path & path) -{ - return maybeLstat(path).has_value(); -} - -bool pathAccessible(const Path & path) -{ - try { - return pathExists(path); - } catch (SysError & e) { - // swallow EPERM - if (e.errNo == EPERM) return false; - throw; - } -} - - -Path readLink(const Path & path) -{ - checkInterrupt(); - std::vector<char> buf; - for (ssize_t bufSize = PATH_MAX/4; true; bufSize += bufSize/2) { - buf.resize(bufSize); - ssize_t rlSize = readlink(path.c_str(), buf.data(), bufSize); - if (rlSize == -1) - if (errno == EINVAL) - throw Error("'%1%' is not a symlink", path); - else - throw SysError("reading symbolic link '%1%'", path); - else if (rlSize < bufSize) - return std::string(buf.data(), rlSize); - } -} - - -bool isLink(const Path & path) -{ - struct stat st = lstat(path); - return S_ISLNK(st.st_mode); -} - - -DirEntries readDirectory(DIR *dir, const Path & path) -{ - DirEntries entries; - entries.reserve(64); - - struct dirent * dirent; - while (errno = 0, dirent = readdir(dir)) { /* sic */ - checkInterrupt(); - std::string name = dirent->d_name; - if (name == "." || name == "..") continue; - entries.emplace_back(name, dirent->d_ino, -#ifdef HAVE_STRUCT_DIRENT_D_TYPE - dirent->d_type -#else - DT_UNKNOWN -#endif - ); - } - if (errno) throw SysError("reading directory '%1%'", path); - - return entries; -} - -DirEntries readDirectory(const Path & path) -{ - AutoCloseDir dir(opendir(path.c_str())); - if (!dir) throw SysError("opening directory '%1%'", path); - - return readDirectory(dir.get(), path); -} - - -unsigned char getFileType(const Path & path) -{ - struct stat st = lstat(path); - if (S_ISDIR(st.st_mode)) return DT_DIR; - if (S_ISLNK(st.st_mode)) return DT_LNK; - if (S_ISREG(st.st_mode)) return DT_REG; - return DT_UNKNOWN; -} - - -std::string readFile(int fd) -{ - struct stat st; - if (fstat(fd, &st) == -1) - throw SysError("statting file"); - - return drainFD(fd, true, st.st_size); -} - - -std::string readFile(const Path & path) -{ - AutoCloseFD fd{open(path.c_str(), O_RDONLY | O_CLOEXEC)}; - if (!fd) - throw SysError("opening file '%1%'", path); - return readFile(fd.get()); -} - - -void readFile(const Path & path, Sink & sink) -{ - AutoCloseFD fd{open(path.c_str(), O_RDONLY | O_CLOEXEC)}; - if (!fd) - throw SysError("opening file '%s'", path); - drainFD(fd.get(), sink); -} - - -void writeFile(const Path & path, std::string_view s, mode_t mode, bool sync) -{ - AutoCloseFD fd{open(path.c_str(), O_WRONLY | O_TRUNC | O_CREAT | O_CLOEXEC, mode)}; - if (!fd) - throw SysError("opening file '%1%'", path); - try { - writeFull(fd.get(), s); - } catch (Error & e) { - e.addTrace({}, "writing file '%1%'", path); - throw; - } - if (sync) - fd.fsync(); - // Explicitly close to make sure exceptions are propagated. - fd.close(); - if (sync) - syncParent(path); -} - - -void writeFile(const Path & path, Source & source, mode_t mode, bool sync) -{ - AutoCloseFD fd{open(path.c_str(), O_WRONLY | O_TRUNC | O_CREAT | O_CLOEXEC, mode)}; - if (!fd) - throw SysError("opening file '%1%'", path); - - std::vector<char> buf(64 * 1024); - - try { - while (true) { - try { - auto n = source.read(buf.data(), buf.size()); - writeFull(fd.get(), {buf.data(), n}); - } catch (EndOfFile &) { break; } - } - } catch (Error & e) { - e.addTrace({}, "writing file '%1%'", path); - throw; - } - if (sync) - fd.fsync(); - // Explicitly close to make sure exceptions are propagated. - fd.close(); - if (sync) - syncParent(path); -} - -void syncParent(const Path & path) -{ - AutoCloseFD fd{open(dirOf(path).c_str(), O_RDONLY, 0)}; - if (!fd) - throw SysError("opening file '%1%'", path); - fd.fsync(); -} std::string readLine(int fd) { @@ -425,98 +80,6 @@ void writeLine(int fd, std::string s) } -static void _deletePath(int parentfd, const Path & path, uint64_t & bytesFreed) -{ - checkInterrupt(); - - std::string name(baseNameOf(path)); - - struct stat st; - if (fstatat(parentfd, name.c_str(), &st, AT_SYMLINK_NOFOLLOW) == -1) { - if (errno == ENOENT) return; - throw SysError("getting status of '%1%'", path); - } - - if (!S_ISDIR(st.st_mode)) { - /* We are about to delete a file. Will it likely free space? */ - - switch (st.st_nlink) { - /* Yes: last link. */ - case 1: - bytesFreed += st.st_size; - break; - /* Maybe: yes, if 'auto-optimise-store' or manual optimisation - was performed. Instead of checking for real let's assume - it's an optimised file and space will be freed. - - In worst case we will double count on freed space for files - with exactly two hardlinks for unoptimised packages. - */ - case 2: - bytesFreed += st.st_size; - break; - /* No: 3+ links. */ - default: - break; - } - } - - if (S_ISDIR(st.st_mode)) { - /* Make the directory accessible. */ - const auto PERM_MASK = S_IRUSR | S_IWUSR | S_IXUSR; - if ((st.st_mode & PERM_MASK) != PERM_MASK) { - if (fchmodat(parentfd, name.c_str(), st.st_mode | PERM_MASK, 0) == -1) - throw SysError("chmod '%1%'", path); - } - - int fd = openat(parentfd, path.c_str(), O_RDONLY); - if (fd == -1) - throw SysError("opening directory '%1%'", path); - AutoCloseDir dir(fdopendir(fd)); - if (!dir) - throw SysError("opening directory '%1%'", path); - for (auto & i : readDirectory(dir.get(), path)) - _deletePath(dirfd(dir.get()), path + "/" + i.name, bytesFreed); - } - - int flags = S_ISDIR(st.st_mode) ? AT_REMOVEDIR : 0; - if (unlinkat(parentfd, name.c_str(), flags) == -1) { - if (errno == ENOENT) return; - throw SysError("cannot unlink '%1%'", path); - } -} - -static void _deletePath(const Path & path, uint64_t & bytesFreed) -{ - Path dir = dirOf(path); - if (dir == "") - dir = "/"; - - AutoCloseFD dirfd{open(dir.c_str(), O_RDONLY)}; - if (!dirfd) { - if (errno == ENOENT) return; - throw SysError("opening directory '%1%'", path); - } - - _deletePath(dirfd.get(), path, bytesFreed); -} - - -void deletePath(const Path & path) -{ - uint64_t dummy; - deletePath(path, dummy); -} - - -void deletePath(const Path & path, uint64_t & bytesFreed) -{ - //Activity act(*logger, lvlDebug, "recursively deleting path '%1%'", path); - bytesFreed = 0; - _deletePath(path, bytesFreed); -} - - std::string getUserName() { auto pw = getpwuid(geteuid()); @@ -632,28 +195,6 @@ std::optional<Path> getSelfExe() } -Paths createDirs(const Path & path) -{ - Paths created; - if (path == "/") return created; - - struct stat st; - if (lstat(path.c_str(), &st) == -1) { - created = createDirs(dirOf(path)); - if (mkdir(path.c_str(), 0777) == -1 && errno != EEXIST) - throw SysError("creating directory '%1%'", path); - st = lstat(path); - created.push_back(path); - } - - if (S_ISLNK(st.st_mode) && stat(path.c_str(), &st) == -1) - throw SysError("statting symlink '%1%'", path); - - if (!S_ISDIR(st.st_mode)) throw Error("'%1%' is not a directory", path); - - return created; -} - void readFull(int fd, char * buf, size_t count) { @@ -762,46 +303,6 @@ unsigned int getMaxCPU() ////////////////////////////////////////////////////////////////////// -AutoDelete::AutoDelete() : del{false} {} - -AutoDelete::AutoDelete(const std::string & p, bool recursive) : path(p) -{ - del = true; - this->recursive = recursive; -} - -AutoDelete::~AutoDelete() -{ - try { - if (del) { - if (recursive) - deletePath(path); - else { - if (remove(path.c_str()) == -1) - throw SysError("cannot unlink '%1%'", path); - } - } - } catch (...) { - ignoreException(); - } -} - -void AutoDelete::cancel() -{ - del = false; -} - -void AutoDelete::reset(const Path & p, bool recursive) { - path = p; - this->recursive = recursive; - del = true; -} - - - -////////////////////////////////////////////////////////////////////// - - AutoCloseFD::AutoCloseFD() : fd{-1} {} diff --git a/src/libutil/util.hh b/src/libutil/util.hh index 1ce7e8312..63a4fcb6a 100644 --- a/src/libutil/util.hh +++ b/src/libutil/util.hh @@ -40,135 +40,6 @@ extern const std::string nativeSystem; /** - * @return An absolutized path, resolving paths relative to the - * specified directory, or the current directory otherwise. The path - * is also canonicalised. - */ -Path absPath(Path path, - std::optional<PathView> dir = {}, - bool resolveSymlinks = false); - -/** - * Canonicalise a path by removing all `.` or `..` components and - * double or trailing slashes. Optionally resolves all symlink - * components such that each component of the resulting path is *not* - * a symbolic link. - */ -Path canonPath(PathView path, bool resolveSymlinks = false); - -/** - * Change the permissions of a path - * Not called `chmod` as it shadows and could be confused with - * `int chmod(char *, mode_t)`, which does not handle errors - */ -void chmodPath(const Path & path, mode_t mode); - -/** - * @return The directory part of the given canonical path, i.e., - * everything before the final `/`. If the path is the root or an - * immediate child thereof (e.g., `/foo`), this means `/` - * is returned. - */ -Path dirOf(const PathView path); - -/** - * @return the base name of the given canonical path, i.e., everything - * following the final `/` (trailing slashes are removed). - */ -std::string_view baseNameOf(std::string_view path); - -/** - * Perform tilde expansion on a path. - */ -std::string expandTilde(std::string_view path); - -/** - * Check whether 'path' is a descendant of 'dir'. Both paths must be - * canonicalized. - */ -bool isInDir(std::string_view path, std::string_view dir); - -/** - * Check whether 'path' is equal to 'dir' or a descendant of - * 'dir'. Both paths must be canonicalized. - */ -bool isDirOrInDir(std::string_view path, std::string_view dir); - -/** - * Get status of `path`. - */ -struct stat stat(const Path & path); -struct stat lstat(const Path & path); - -/** - * `lstat` the given path if it exists. - * @return std::nullopt if the path doesn't exist, or an optional containing the result of `lstat` otherwise - */ -std::optional<struct stat> maybeLstat(const Path & path); - -/** - * @return true iff the given path exists. - */ -bool pathExists(const Path & path); - -/** - * A version of pathExists that returns false on a permission error. - * Useful for inferring default paths across directories that might not - * be readable. - * @return true iff the given path can be accessed and exists - */ -bool pathAccessible(const Path & path); - -/** - * Read the contents (target) of a symbolic link. The result is not - * in any way canonicalised. - */ -Path readLink(const Path & path); - -bool isLink(const Path & path); - -/** - * Read the contents of a directory. The entries `.` and `..` are - * removed. - */ -struct DirEntry -{ - std::string name; - ino_t ino; - /** - * one of DT_* - */ - unsigned char type; - DirEntry(std::string name, ino_t ino, unsigned char type) - : name(std::move(name)), ino(ino), type(type) { } -}; - -typedef std::vector<DirEntry> DirEntries; - -DirEntries readDirectory(const Path & path); - -unsigned char getFileType(const Path & path); - -/** - * Read the contents of a file into a string. - */ -std::string readFile(int fd); -std::string readFile(const Path & path); -void readFile(const Path & path, Sink & sink); - -/** - * Write a string to a file. - */ -void writeFile(const Path & path, std::string_view s, mode_t mode = 0666, bool sync = false); - -void writeFile(const Path & path, Source & source, mode_t mode = 0666, bool sync = false); - -/** - * Flush a file's parent directory to disk - */ -void syncParent(const Path & path); - -/** * Read a line from a file descriptor. */ std::string readLine(int fd); @@ -178,14 +49,6 @@ std::string readLine(int fd); */ void writeLine(int fd, std::string s); -/** - * Delete a path; i.e., in the case of a directory, it is deleted - * recursively. It's not an error if the path does not exist. The - * second variant returns the number of bytes and blocks freed. - */ -void deletePath(const Path & path); - -void deletePath(const Path & path, uint64_t & bytesFreed); std::string getUserName(); @@ -238,57 +101,6 @@ Path getStateDir(); */ Path createNixStateDir(); -/** - * Create a directory and all its parents, if necessary. Returns the - * list of created directories, in order of creation. - */ -Paths createDirs(const Path & path); -inline Paths createDirs(PathView path) -{ - return createDirs(Path(path)); -} - -/** - * Create a symlink. - */ -void createSymlink(const Path & target, const Path & link); - -/** - * Atomically create or replace a symlink. - */ -void replaceSymlink(const Path & target, const Path & link); - -void renameFile(const Path & src, const Path & dst); - -/** - * Similar to 'renameFile', but fallback to a copy+remove if `src` and `dst` - * are on a different filesystem. - * - * Beware that this might not be atomic because of the copy that happens behind - * the scenes - */ -void moveFile(const Path & src, const Path & dst); - -struct CopyFileFlags -{ - /** - * Delete the file after copying. - */ - bool deleteAfter = false; - - /** - * Follow symlinks and copy the eventual target. - */ - bool followSymlinks = false; -}; - -/** - * Recursively copy the content of `oldPath` to `newPath`. If `andDelete` is - * `true`, then also remove `oldPath` (making this equivalent to `moveFile`, but - * with the guaranty that the destination will be “fresh”, with no stale inode - * or file descriptor pointing to it). - */ -void copyFile(const Path & oldPath, const Path & newPath, CopyFileFlags flags); /** * Wrappers arount read()/write() that read/write exactly the @@ -313,27 +125,6 @@ void drainFD(int fd, Sink & sink, bool block = true); */ unsigned int getMaxCPU(); -/** - * Automatic cleanup of resources. - */ - - -class AutoDelete -{ - Path path; - bool del; - bool recursive; -public: - AutoDelete(); - AutoDelete(const Path & p, bool recursive = true); - ~AutoDelete(); - void cancel(); - void reset(const Path & p, bool recursive = true); - operator Path() const { return path; } - operator PathView() const { return path; } -}; - - class AutoCloseFD { int fd; @@ -353,19 +144,6 @@ public: void reset() { *this = {}; } }; - -/** - * Create a temporary directory. - */ -Path createTempDir(const Path & tmpRoot = "", const Path & prefix = "nix", - bool includePid = true, bool useGlobalCounter = true, mode_t mode = 0755); - -/** - * Create a temporary file, returning a file handle and its path. - */ -std::pair<AutoCloseFD, Path> createTempFile(const Path & prefix = "nix"); - - class Pipe { public: @@ -375,16 +153,6 @@ public: }; -struct DIRDeleter -{ - void operator()(DIR * dir) const { - closedir(dir); - } -}; - -typedef std::unique_ptr<DIR, DIRDeleter> AutoCloseDir; - - class Pid { pid_t pid = -1; @@ -824,13 +592,6 @@ struct MaintainCount /** - * Used in various places. - */ -typedef std::function<bool(const Path & path)> PathFilter; - -extern PathFilter defaultPathFilter; - -/** * Common initialisation performed in child processes. */ void commonChildInit(); diff --git a/src/nix-collect-garbage/nix-collect-garbage.cc b/src/nix-collect-garbage/nix-collect-garbage.cc index 1cbba0537..54de68232 100644 --- a/src/nix-collect-garbage/nix-collect-garbage.cc +++ b/src/nix-collect-garbage/nix-collect-garbage.cc @@ -1,3 +1,4 @@ +#include "file-system.hh" #include "store-api.hh" #include "store-cast.hh" #include "gc-store.hh" diff --git a/tests/unit/libstore/machines.cc b/tests/unit/libstore/machines.cc index 0277237bb..dc192e5be 100644 --- a/tests/unit/libstore/machines.cc +++ b/tests/unit/libstore/machines.cc @@ -1,3 +1,4 @@ +#include "file-system.hh" #include "machines.hh" #include "globals.hh" #include "tests/test-data.hh" diff --git a/tests/unit/libutil-support/tests/characterization.hh b/tests/unit/libutil-support/tests/characterization.hh index 9de20d02c..472fdba3b 100644 --- a/tests/unit/libutil-support/tests/characterization.hh +++ b/tests/unit/libutil-support/tests/characterization.hh @@ -2,6 +2,8 @@ ///@file #include "environment-variables.hh" +#include "file-system.hh" + #include <gtest/gtest.h> #include <filesystem> diff --git a/tests/unit/libutil/tests.cc b/tests/unit/libutil/tests.cc index 787f79093..c8dc82cb0 100644 --- a/tests/unit/libutil/tests.cc +++ b/tests/unit/libutil/tests.cc @@ -1,3 +1,4 @@ +#include "file-system.hh" #include "util.hh" #include "types.hh" #include "terminal.hh" |