diff options
Diffstat (limited to 'src/libstore')
| -rw-r--r-- | src/libstore/build.cc | 43 | ||||
| -rw-r--r-- | src/libstore/gc.cc | 32 | ||||
| -rw-r--r-- | src/libstore/local-store.hh | 5 | ||||
| -rw-r--r-- | src/libstore/optimise-store.cc | 74 | ||||
| -rw-r--r-- | src/libstore/remote-store.cc | 2 | ||||
| -rw-r--r-- | src/libstore/store-api.cc | 4 | ||||
| -rw-r--r-- | src/libstore/store-api.hh | 7 |
7 files changed, 103 insertions, 64 deletions
diff --git a/src/libstore/build.cc b/src/libstore/build.cc index 0972d6e19364..1840fb7b21bc 100644 --- a/src/libstore/build.cc +++ b/src/libstore/build.cc @@ -45,7 +45,7 @@ #include <sched.h> #endif -#define CHROOT_ENABLED HAVE_CHROOT && HAVE_UNSHARE && HAVE_SYS_MOUNT_H && defined(MS_BIND) && defined(CLONE_NEWNS) +#define CHROOT_ENABLED HAVE_CHROOT && HAVE_UNSHARE && HAVE_SYS_MOUNT_H && defined(MS_BIND) && defined(MS_PRIVATE) && defined(CLONE_NEWNS) #if CHROOT_ENABLED #include <sys/socket.h> @@ -604,18 +604,17 @@ void getOwnership(const Path & path) } -void deletePathWrapped(const Path & path, - unsigned long long & bytesFreed, unsigned long long & blocksFreed) +void deletePathWrapped(const Path & path, unsigned long long & bytesFreed) { try { /* First try to delete it ourselves. */ - deletePath(path, bytesFreed, blocksFreed); + deletePath(path, bytesFreed); } catch (SysError & e) { /* If this failed due to a permission error, then try it with the setuid helper. */ if (settings.buildUsersGroup != "" && !amPrivileged()) { getOwnership(path); - deletePath(path, bytesFreed, blocksFreed); + deletePath(path, bytesFreed); } else throw; } @@ -624,8 +623,8 @@ void deletePathWrapped(const Path & path, void deletePathWrapped(const Path & path) { - unsigned long long dummy1, dummy2; - deletePathWrapped(path, dummy1, dummy2); + unsigned long long dummy1; + deletePathWrapped(path, dummy1); } @@ -1470,9 +1469,9 @@ HookReply DerivationGoal::tryBuildHook() } -void chmod(const Path & path, mode_t mode) +void chmod_(const Path & path, mode_t mode) { - if (::chmod(path.c_str(), 01777) == -1) + if (chmod(path.c_str(), mode) == -1) throw SysError(format("setting permissions on `%1%'") % path); } @@ -1674,7 +1673,7 @@ void DerivationGoal::startBuilder() instead.) */ Path chrootTmpDir = chrootRootDir + "/tmp"; createDirs(chrootTmpDir); - chmod(chrootTmpDir, 01777); + chmod_(chrootTmpDir, 01777); /* Create a /etc/passwd with entries for the build user and the nobody account. The latter is kind of a hack to support @@ -1710,7 +1709,7 @@ void DerivationGoal::startBuilder() precaution, make the fake Nix store only writable by the build user. */ createDirs(chrootRootDir + settings.nixStore); - chmod(chrootRootDir + settings.nixStore, 01777); + chmod_(chrootRootDir + settings.nixStore, 01777); foreach (PathSet::iterator, i, inputPaths) { struct stat st; @@ -1844,22 +1843,40 @@ void DerivationGoal::initChild() char domainname[] = "(none)"; // kernel default setdomainname(domainname, sizeof(domainname)); + /* Make all filesystems private. This is necessary + because subtrees may have been mounted as "shared" + (MS_SHARED). (Systemd does this, for instance.) Even + though we have a private mount namespace, mounting + filesystems on top of a shared subtree still propagates + outside of the namespace. Making a subtree private is + local to the namespace, though, so setting MS_PRIVATE + does not affect the outside world. */ + Strings mounts = tokenizeString(readFile("/proc/self/mountinfo", true), "\n"); + foreach (Strings::iterator, i, mounts) { + Strings fields = tokenizeString(*i, " "); + assert(fields.size() >= 5); + Strings::iterator j = fields.begin(); + std::advance(j, 4); + if (mount(0, j->c_str(), 0, MS_PRIVATE, 0) == -1) + throw SysError(format("unable to make filesystem `%1%' private") % *j); + } + /* Bind-mount all the directories from the "host" filesystem that we want in the chroot environment. */ foreach (PathSet::iterator, i, dirsInChroot) { Path source = *i; Path target = chrootRootDir + source; + if (source == "/proc") continue; // backwards compatibility debug(format("bind mounting `%1%' to `%2%'") % source % target); - createDirs(target); - if (mount(source.c_str(), target.c_str(), "", MS_BIND, 0) == -1) throw SysError(format("bind mount from `%1%' to `%2%' failed") % source % target); } /* Bind a new instance of procfs on /proc to reflect our private PID namespace. */ + createDirs(chrootRootDir + "/proc"); if (mount("none", (chrootRootDir + "/proc").c_str(), "proc", 0, 0) == -1) throw SysError("mounting /proc"); diff --git a/src/libstore/gc.cc b/src/libstore/gc.cc index 1355702f8701..88b7bec32677 100644 --- a/src/libstore/gc.cc +++ b/src/libstore/gc.cc @@ -425,10 +425,9 @@ bool LocalStore::isActiveTempFile(const GCState & state, void LocalStore::deleteGarbage(GCState & state, const Path & path) { printMsg(lvlInfo, format("deleting `%1%'") % path); - unsigned long long bytesFreed, blocksFreed; - deletePathWrapped(path, bytesFreed, blocksFreed); + unsigned long long bytesFreed; + deletePathWrapped(path, bytesFreed); state.results.bytesFreed += bytesFreed; - state.results.blocksFreed += blocksFreed; } @@ -550,7 +549,7 @@ bool LocalStore::tryToDelete(GCState & state, const Path & path) } else deleteGarbage(state, path); - if (state.options.maxFreed && state.results.bytesFreed + state.bytesInvalidated > state.options.maxFreed) { + if (state.results.bytesFreed + state.bytesInvalidated > state.options.maxFreed) { printMsg(lvlInfo, format("deleted or invalidated more than %1% bytes; stopping") % state.options.maxFreed); throw GCLimitReached(); } @@ -576,11 +575,13 @@ bool LocalStore::tryToDelete(GCState & state, const Path & path) safely deleted. FIXME: race condition with optimisePath(): we might see a link count of 1 just before optimisePath() increases the link count. */ -void LocalStore::removeUnusedLinks() +void LocalStore::removeUnusedLinks(const GCState & state) { AutoCloseDir dir = opendir(linksDir.c_str()); if (!dir) throw SysError(format("opening directory `%1%'") % linksDir); + long long actualSize = 0, unsharedSize = 0; + struct dirent * dirent; while (errno = 0, dirent = readdir(dir)) { checkInterrupt(); @@ -592,13 +593,28 @@ void LocalStore::removeUnusedLinks() if (lstat(path.c_str(), &st) == -1) throw SysError(format("statting `%1%'") % path); - if (st.st_nlink != 1) continue; + if (st.st_nlink != 1) { + unsigned long long size = st.st_blocks * 512ULL; + actualSize += size; + unsharedSize += (st.st_nlink - 1) * size; + continue; + } printMsg(lvlTalkative, format("deleting unused link `%1%'") % path); if (unlink(path.c_str()) == -1) throw SysError(format("deleting `%1%'") % path); + + state.results.bytesFreed += st.st_blocks * 512; } + + struct stat st; + if (stat(linksDir.c_str(), &st) == -1) + throw SysError(format("statting `%1%'") % linksDir); + long long overhead = st.st_blocks * 512ULL; + + printMsg(lvlInfo, format("note: currently hard linking saves %.2f MiB") + % ((unsharedSize - actualSize - overhead) / (1024.0 * 1024.0))); } @@ -660,7 +676,7 @@ void LocalStore::collectGarbage(const GCOptions & options, GCResults & results) throw Error(format("cannot delete path `%1%' since it is still alive") % *i); } - } else { + } else if (options.maxFreed > 0) { if (shouldDelete(state.options.action)) printMsg(lvlError, format("deleting garbage...")); @@ -718,7 +734,7 @@ void LocalStore::collectGarbage(const GCOptions & options, GCResults & results) /* Clean up the links directory. */ printMsg(lvlError, format("deleting unused links...")); - removeUnusedLinks(); + removeUnusedLinks(state); } diff --git a/src/libstore/local-store.hh b/src/libstore/local-store.hh index 3cb016e9cafd..ba0582922121 100644 --- a/src/libstore/local-store.hh +++ b/src/libstore/local-store.hh @@ -261,7 +261,7 @@ private: int openGCLock(LockType lockType); - void removeUnusedLinks(); + void removeUnusedLinks(const GCState & state); void startSubstituter(const Path & substituter, RunningSubstituter & runningSubstituter); @@ -298,8 +298,7 @@ void getOwnership(const Path & path); /* Like deletePath(), but changes the ownership of `path' using the setuid wrapper if necessary (and possible). */ -void deletePathWrapped(const Path & path, - unsigned long long & bytesFreed, unsigned long long & blocksFreed); +void deletePathWrapped(const Path & path, unsigned long long & bytesFreed); void deletePathWrapped(const Path & path); diff --git a/src/libstore/optimise-store.cc b/src/libstore/optimise-store.cc index 334f4f355f43..9d0242bbc857 100644 --- a/src/libstore/optimise-store.cc +++ b/src/libstore/optimise-store.cc @@ -102,11 +102,11 @@ void LocalStore::optimisePath_(OptimiseStats & stats, const Path & path) /* Nope, create a hard link in the links directory. */ makeMutable(path); MakeImmutable mk1(path); - - if (link(path.c_str(), linkPath.c_str()) == -1) + if (link(path.c_str(), linkPath.c_str()) == 0) return; + if (errno != EEXIST) throw SysError(format("cannot link `%1%' to `%2%'") % linkPath % path); - - return; + /* Fall through if another process created ‘linkPath’ before + we did. */ } /* Yes! We've seen a file with the same contents. Replace the @@ -123,9 +123,6 @@ void LocalStore::optimisePath_(OptimiseStats & stats, const Path & path) printMsg(lvlTalkative, format("linking `%1%' to `%2%'") % path % linkPath); - Path tempLink = (format("%1%/.tmp-link-%2%-%3%") - % settings.nixStore % getpid() % rand()).str(); - /* Make the containing directory writable, but only if it's not the store itself (we don't want or need to mess with its permissions). */ @@ -140,40 +137,55 @@ void LocalStore::optimisePath_(OptimiseStats & stats, const Path & path) so make it mutable first (and make it immutable again when we're done). We also have to make ‘path’ mutable, otherwise rename() will fail to delete it. */ - makeMutable(linkPath); - MakeImmutable mk1(linkPath); - makeMutable(path); MakeImmutable mk2(path); - if (link(linkPath.c_str(), tempLink.c_str()) == -1) { - if (errno == EMLINK) { - /* Too many links to the same file (>= 32000 on most file - systems). This is likely to happen with empty files. - Just shrug and ignore. */ - printMsg(lvlInfo, format("`%1%' has maximum number of links") % linkPath); - return; + /* Another process might be doing the same thing (creating a new + link to ‘linkPath’) and make ‘linkPath’ immutable before we're + done. In that case, just retry. */ + unsigned int retries = 1024; + while (--retries > 0) { + makeMutable(linkPath); + MakeImmutable mk1(linkPath); + + Path tempLink = (format("%1%/.tmp-link-%2%-%3%") + % settings.nixStore % getpid() % rand()).str(); + + if (link(linkPath.c_str(), tempLink.c_str()) == -1) { + if (errno == EMLINK) { + /* Too many links to the same file (>= 32000 on most + file systems). This is likely to happen with empty + files. Just shrug and ignore. */ + if (st.st_size) + printMsg(lvlInfo, format("`%1%' has maximum number of links") % linkPath); + return; + } + if (errno == EPERM) continue; + throw SysError(format("cannot link `%1%' to `%2%'") % tempLink % linkPath); } - throw SysError(format("cannot link `%1%' to `%2%'") % tempLink % linkPath); - } - - /* Atomically replace the old file with the new hard link. */ - if (rename(tempLink.c_str(), path.c_str()) == -1) { - if (errno == EMLINK) { - /* Some filesystems generate too many links on the rename, - rather than on the original link. (Probably it - temporarily increases the st_nlink field before - decreasing it again.) */ - printMsg(lvlInfo, format("`%1%' has maximum number of links") % linkPath); - /* Unlink the temp link. */ + /* Atomically replace the old file with the new hard link. */ + if (rename(tempLink.c_str(), path.c_str()) == -1) { if (unlink(tempLink.c_str()) == -1) printMsg(lvlError, format("unable to unlink `%1%'") % tempLink); - return; + if (errno == EMLINK) { + /* Some filesystems generate too many links on the + rename, rather than on the original link. + (Probably it temporarily increases the st_nlink + field before decreasing it again.) */ + if (st.st_size) + printMsg(lvlInfo, format("`%1%' has maximum number of links") % linkPath); + return; + } + if (errno == EPERM) continue; + throw SysError(format("cannot rename `%1%' to `%2%'") % tempLink % path); } - throw SysError(format("cannot rename `%1%' to `%2%'") % tempLink % path); + + break; } + if (retries == 0) throw Error(format("cannot link `%1%' to `%2%'") % path % linkPath); + stats.filesLinked++; stats.bytesFreed += st.st_size; stats.blocksFreed += st.st_blocks; diff --git a/src/libstore/remote-store.cc b/src/libstore/remote-store.cc index 56396541adec..d3c05f0df4b1 100644 --- a/src/libstore/remote-store.cc +++ b/src/libstore/remote-store.cc @@ -558,7 +558,7 @@ void RemoteStore::collectGarbage(const GCOptions & options, GCResults & results) results.paths = readStrings<PathSet>(from); results.bytesFreed = readLongLong(from); - results.blocksFreed = readLongLong(from); + readLongLong(from); // obsolete } diff --git a/src/libstore/store-api.cc b/src/libstore/store-api.cc index 6f81a9aab072..32aaca6be0ea 100644 --- a/src/libstore/store-api.cc +++ b/src/libstore/store-api.cc @@ -2,7 +2,7 @@ #include "globals.hh" #include "util.hh" -#include <limits.h> +#include <climits> namespace nix { @@ -12,7 +12,7 @@ GCOptions::GCOptions() { action = gcDeleteDead; ignoreLiveness = false; - maxFreed = 0; + maxFreed = ULLONG_MAX; } diff --git a/src/libstore/store-api.hh b/src/libstore/store-api.hh index 324d802dc450..a562360ce34c 100644 --- a/src/libstore/store-api.hh +++ b/src/libstore/store-api.hh @@ -48,8 +48,7 @@ struct GCOptions /* For `gcDeleteSpecific', the paths to delete. */ PathSet pathsToDelete; - /* Stop after at least `maxFreed' bytes have been freed. 0 means - no limit. */ + /* Stop after at least `maxFreed' bytes have been freed. */ unsigned long long maxFreed; GCOptions(); @@ -66,13 +65,9 @@ struct GCResults number of bytes that would be or was freed. */ unsigned long long bytesFreed; - /* The number of file system blocks that would be or was freed. */ - unsigned long long blocksFreed; - GCResults() { bytesFreed = 0; - blocksFreed = 0; } }; |