diff options
| -rw-r--r-- | src/libstore/build.cc | 44 |
1 files changed, 32 insertions, 12 deletions
diff --git a/src/libstore/build.cc b/src/libstore/build.cc index c5807d32f..cc3588a1e 100644 --- a/src/libstore/build.cc +++ b/src/libstore/build.cc @@ -715,12 +715,15 @@ private: /* Whether we're currently doing a chroot build. */ bool useChroot; - /* A RAII object to delete the chroot directory. */ - boost::shared_ptr<AutoDelete> autoDelChroot; + /* RAII objects to delete the chroot directory and its /tmp + directory. Don't change the order: autoDelChrootTmp has to be + deleted before autoDelChrootRoot. */ + boost::shared_ptr<AutoDelete> autoDelChrootRoot; + boost::shared_ptr<AutoDelete> autoDelChrootTmp; /* In chroot builds, the list of bind mounts currently active. The destructor of BindMount will cause the binds to be - unmounted. */ + unmounted. Keep this *below* autoDelChroot* just to be safe! */ list<boost::shared_ptr<BindMount> > bindMounts; typedef void (DerivationGoal::*GoalState)(); @@ -1692,7 +1695,7 @@ void DerivationGoal::startBuilder() work properly. Purity checking for fixed-output derivations is somewhat pointless anyway. */ useChroot = queryBoolSetting("build-use-chroot", false); - Path tmpRootDir; + Path chrootRootDir; if (fixedOutput) useChroot = false; @@ -1706,22 +1709,39 @@ void DerivationGoal::startBuilder() /tmp/chroot-nix-*" to clean up aborted builds, and if some of the bind-mounts are still active, then "rm -rf" will happily recurse into those mount points (thereby deleting, - say, /nix/store). Ideally, tmpRootDir should be created in + say, /nix/store). Ideally, chrootRootDir should be created in some special location (maybe in /nix/var/nix) where Nix takes care of unmounting / deleting old chroots automatically. */ - tmpRootDir = createTempDir("", "chroot-nix"); + chrootRootDir = createTempDir("", "chroot-nix"); /* Clean up the chroot directory automatically, but don't recurse; that would be very very bad if the unmount of a bind-mount fails. Instead BindMount::unbind() unmounts and deletes exactly those directories that it created to produce the mount point, so that after all the BindMount - destructors have run, tmpRootDir should be empty. */ - autoDelChroot = boost::shared_ptr<AutoDelete>(new AutoDelete(tmpRootDir, false)); + destructors have run, chrootRootDir should be empty. */ + autoDelChrootRoot = boost::shared_ptr<AutoDelete>(new AutoDelete(chrootRootDir, false)); - printMsg(lvlChatty, format("setting up chroot environment in `%1%'") % tmpRootDir); + printMsg(lvlChatty, format("setting up chroot environment in `%1%'") % chrootRootDir); + /* Create a writable /tmp in the chroot. Many builders need + this. (Of course they should really respect $TMPDIR + instead.) */ + Path chrootTmpDir = chrootRootDir + "/tmp"; + createDirs(chrootTmpDir); + + if (chmod(chrootTmpDir.c_str(), 01777) == -1) + throw SysError("creating /tmp in the chroot"); + + /* When deleting this, do recurse (the builder might have left + crap there). As long as nothing important is bind-mounted + under /tmp it's okay (and the bind-mounts are unmounted + before autoDelChrootTmp's destructor runs, anyway). */ + autoDelChrootTmp = boost::shared_ptr<AutoDelete>(new AutoDelete(chrootTmpDir)); + + /* Bind-mount a user-configurable set of directories from the + host file system. */ Paths defaultDirs; defaultDirs.push_back("/dev"); defaultDirs.push_back("/proc"); @@ -1734,7 +1754,7 @@ void DerivationGoal::startBuilder() unmounted in LIFO order. (!!! Does the C++ standard guarantee that list elements are destroyed in order?) */ for (Paths::iterator i = dirsInChroot.begin(); i != dirsInChroot.end(); ++i) - bindMounts.push_front(boost::shared_ptr<BindMount>(new BindMount(*i, tmpRootDir + *i))); + bindMounts.push_front(boost::shared_ptr<BindMount>(new BindMount(*i, chrootRootDir + *i))); #else throw Error("chroot builds are not supported on this platform"); @@ -1773,8 +1793,8 @@ void DerivationGoal::startBuilder() chroot. (Actually the order doesn't matter, since due to the bind mount tmpDir and tmpRootDit/tmpDir are the same directories.) */ - if (useChroot && chroot(tmpRootDir.c_str()) == -1) - throw SysError(format("cannot change root directory to `%1%'") % tmpRootDir); + if (useChroot && chroot(chrootRootDir.c_str()) == -1) + throw SysError(format("cannot change root directory to `%1%'") % chrootRootDir); #endif initChild(); |