diff options
Diffstat (limited to 'src/libstore/gc.cc')
| -rw-r--r-- | src/libstore/gc.cc | 119 |
1 files changed, 56 insertions, 63 deletions
diff --git a/src/libstore/gc.cc b/src/libstore/gc.cc index b415d5421476..d8a5da0d49e2 100644 --- a/src/libstore/gc.cc +++ b/src/libstore/gc.cc @@ -129,8 +129,8 @@ Path LocalFSStore::addPermRoot(const Path & _storePath, check if the root is in a directory in or linked from the gcroots directory. */ if (settings.checkRootReachability) { - Roots roots = findRoots(); - if (roots.find(gcRoot) == roots.end()) + Roots roots = findRoots(false); + if (roots[storePath].count(gcRoot) == 0) printError( format( "warning: '%1%' is not in a directory where the garbage collector looks for roots; " @@ -197,10 +197,11 @@ void LocalStore::addTempRoot(const Path & path) } -std::set<std::pair<pid_t, Path>> LocalStore::readTempRoots(FDs & fds) -{ - std::set<std::pair<pid_t, Path>> tempRoots; +static std::string censored = "{censored}"; + +void LocalStore::findTempRoots(FDs & fds, Roots & tempRoots, bool censor) +{ /* Read the `temproots' directory for per-process temporary root files. */ for (auto & i : readDirectory(tempRootsDir)) { @@ -250,14 +251,12 @@ std::set<std::pair<pid_t, Path>> LocalStore::readTempRoots(FDs & fds) Path root(contents, pos, end - pos); debug("got temporary root '%s'", root); assertStorePath(root); - tempRoots.emplace(pid, root); + tempRoots[root].emplace(censor ? censored : fmt("{temp:%d}", pid)); pos = end + 1; } fds.push_back(fd); /* keep open */ } - - return tempRoots; } @@ -266,7 +265,7 @@ void LocalStore::findRoots(const Path & path, unsigned char type, Roots & roots) auto foundRoot = [&](const Path & path, const Path & target) { Path storePath = toStorePath(target); if (isStorePath(storePath) && isValidPath(storePath)) - roots[path] = storePath; + roots[storePath].emplace(path); else printInfo(format("skipping invalid root from '%1%' to '%2%'") % path % storePath); }; @@ -306,7 +305,7 @@ void LocalStore::findRoots(const Path & path, unsigned char type, Roots & roots) else if (type == DT_REG) { Path storePath = storeDir + "/" + baseNameOf(path); if (isStorePath(storePath) && isValidPath(storePath)) - roots[path] = storePath; + roots[storePath].emplace(path); } } @@ -321,10 +320,8 @@ void LocalStore::findRoots(const Path & path, unsigned char type, Roots & roots) } -Roots LocalStore::findRootsNoTemp() +void LocalStore::findRootsNoTemp(Roots & roots, bool censor) { - Roots roots; - /* Process direct roots in {gcroots,profiles}. */ findRoots(stateDir + "/" + gcRootsDir, DT_UNKNOWN, roots); findRoots(stateDir + "/profiles", DT_UNKNOWN, roots); @@ -333,32 +330,22 @@ Roots LocalStore::findRootsNoTemp() NIX_ROOT_FINDER environment variable. This is typically used to add running programs to the set of roots (to prevent them from being garbage collected). */ - size_t n = 0; - for (auto & root : findRuntimeRoots()) - roots[fmt("{memory:%d}", n++)] = root; - - return roots; + findRuntimeRoots(roots, censor); } -Roots LocalStore::findRoots() +Roots LocalStore::findRoots(bool censor) { - Roots roots = findRootsNoTemp(); + Roots roots; + findRootsNoTemp(roots, censor); FDs fds; - pid_t prev = -1; - size_t n = 0; - for (auto & root : readTempRoots(fds)) { - if (prev != root.first) n = 0; - prev = root.first; - roots[fmt("{temp:%d:%d}", root.first, n++)] = root.second; - } + findTempRoots(fds, roots, censor); return roots; } - -static void readProcLink(const string & file, StringSet & paths) +static void readProcLink(const string & file, Roots & roots) { /* 64 is the starting buffer size gnu readlink uses... */ auto bufsiz = ssize_t{64}; @@ -377,8 +364,8 @@ try_again: goto try_again; } if (res > 0 && buf[0] == '/') - paths.emplace(static_cast<char *>(buf), res); - return; + roots[std::string(static_cast<char *>(buf), res)] + .emplace(file); } static string quoteRegexChars(const string & raw) @@ -387,20 +374,20 @@ static string quoteRegexChars(const string & raw) return std::regex_replace(raw, specialRegex, R"(\$&)"); } -static void readFileRoots(const char * path, StringSet & paths) +static void readFileRoots(const char * path, Roots & roots) { try { - paths.emplace(readFile(path)); + roots[readFile(path)].emplace(path); } catch (SysError & e) { if (e.errNo != ENOENT && e.errNo != EACCES) throw; } } -PathSet LocalStore::findRuntimeRoots() +void LocalStore::findRuntimeRoots(Roots & roots, bool censor) { - PathSet roots; - StringSet paths; + Roots unchecked; + auto procDir = AutoCloseDir{opendir("/proc")}; if (procDir) { struct dirent * ent; @@ -410,10 +397,10 @@ PathSet LocalStore::findRuntimeRoots() while (errno = 0, ent = readdir(procDir.get())) { checkInterrupt(); if (std::regex_match(ent->d_name, digitsRegex)) { - readProcLink((format("/proc/%1%/exe") % ent->d_name).str(), paths); - readProcLink((format("/proc/%1%/cwd") % ent->d_name).str(), paths); + readProcLink(fmt("/proc/%s/exe" ,ent->d_name), unchecked); + readProcLink(fmt("/proc/%s/cwd", ent->d_name), unchecked); - auto fdStr = (format("/proc/%1%/fd") % ent->d_name).str(); + auto fdStr = fmt("/proc/%s/fd", ent->d_name); auto fdDir = AutoCloseDir(opendir(fdStr.c_str())); if (!fdDir) { if (errno == ENOENT || errno == EACCES) @@ -422,9 +409,8 @@ PathSet LocalStore::findRuntimeRoots() } struct dirent * fd_ent; while (errno = 0, fd_ent = readdir(fdDir.get())) { - if (fd_ent->d_name[0] != '.') { - readProcLink((format("%1%/%2%") % fdStr % fd_ent->d_name).str(), paths); - } + if (fd_ent->d_name[0] != '.') + readProcLink(fmt("%s/%s", fdStr, fd_ent->d_name), unchecked); } if (errno) { if (errno == ESRCH) @@ -434,18 +420,19 @@ PathSet LocalStore::findRuntimeRoots() fdDir.reset(); try { - auto mapLines = - tokenizeString<std::vector<string>>(readFile((format("/proc/%1%/maps") % ent->d_name).str(), true), "\n"); - for (const auto& line : mapLines) { + auto mapFile = fmt("/proc/%s/maps", ent->d_name); + auto mapLines = tokenizeString<std::vector<string>>(readFile(mapFile, true), "\n"); + for (const auto & line : mapLines) { auto match = std::smatch{}; if (std::regex_match(line, match, mapRegex)) - paths.emplace(match[1]); + unchecked[match[1]].emplace(mapFile); } - auto envString = readFile((format("/proc/%1%/environ") % ent->d_name).str(), true); + auto envFile = fmt("/proc/%s/environ", ent->d_name); + auto envString = readFile(envFile, true); auto env_end = std::sregex_iterator{}; for (auto i = std::sregex_iterator{envString.begin(), envString.end(), storePathRegex}; i != env_end; ++i) - paths.emplace(i->str()); + unchecked[i->str()].emplace(envFile); } catch (SysError & e) { if (errno == ENOENT || errno == EACCES || errno == ESRCH) continue; @@ -465,7 +452,7 @@ PathSet LocalStore::findRuntimeRoots() for (const auto & line : lsofLines) { std::smatch match; if (std::regex_match(line, match, lsofRegex)) - paths.emplace(match[1]); + unchecked[match[1]].emplace("{lsof}"); } } catch (ExecError & e) { /* lsof not installed, lsof failed */ @@ -473,21 +460,23 @@ PathSet LocalStore::findRuntimeRoots() #endif #if defined(__linux__) - readFileRoots("/proc/sys/kernel/modprobe", paths); - readFileRoots("/proc/sys/kernel/fbsplash", paths); - readFileRoots("/proc/sys/kernel/poweroff_cmd", paths); + readFileRoots("/proc/sys/kernel/modprobe", unchecked); + readFileRoots("/proc/sys/kernel/fbsplash", unchecked); + readFileRoots("/proc/sys/kernel/poweroff_cmd", unchecked); #endif - for (auto & i : paths) - if (isInStore(i)) { - Path path = toStorePath(i); - if (roots.find(path) == roots.end() && isStorePath(path) && isValidPath(path)) { + for (auto & [target, links] : unchecked) { + if (isInStore(target)) { + Path path = toStorePath(target); + if (isStorePath(path) && isValidPath(path)) { debug(format("got additional root '%1%'") % path); - roots.insert(path); + if (censor) + roots[path].insert(censored); + else + roots[path].insert(links.begin(), links.end()); } } - - return roots; + } } @@ -754,16 +743,20 @@ void LocalStore::collectGarbage(const GCOptions & options, GCResults & results) /* Find the roots. Since we've grabbed the GC lock, the set of permanent roots cannot increase now. */ printError(format("finding garbage collector roots...")); - Roots rootMap = options.ignoreLiveness ? Roots() : findRootsNoTemp(); + Roots rootMap; + if (!options.ignoreLiveness) + findRootsNoTemp(rootMap, true); - for (auto & i : rootMap) state.roots.insert(i.second); + for (auto & i : rootMap) state.roots.insert(i.first); /* Read the temporary roots. This acquires read locks on all per-process temporary root files. So after this point no paths can be added to the set of temporary roots. */ FDs fds; - for (auto & root : readTempRoots(fds)) - state.tempRoots.insert(root.second); + Roots tempRoots; + findTempRoots(fds, tempRoots, true); + for (auto & root : tempRoots) + state.tempRoots.insert(root.first); state.roots.insert(state.tempRoots.begin(), state.tempRoots.end()); /* After this point the set of roots or temporary roots cannot |