aboutsummaryrefslogtreecommitdiff
path: root/src/nix/run.cc
diff options
context:
space:
mode:
Diffstat (limited to 'src/nix/run.cc')
-rw-r--r--src/nix/run.cc41
1 files changed, 39 insertions, 2 deletions
diff --git a/src/nix/run.cc b/src/nix/run.cc
index ed1c2650c..00af5bb18 100644
--- a/src/nix/run.cc
+++ b/src/nix/run.cc
@@ -5,6 +5,7 @@
#include "store-api.hh"
#include "derivations.hh"
#include "local-store.hh"
+#include "finally.hh"
#if __linux__
#include <sys/mount.h>
@@ -52,8 +53,44 @@ struct CmdRun : StoreCommand, MixInstallables
if (unshare(CLONE_NEWUSER | CLONE_NEWNS) == -1)
throw SysError("setting up a private mount namespace");
- if (mount(store2->realStoreDir.c_str(), store->storeDir.c_str(), "", MS_BIND, 0) == -1)
- throw SysError(format("mounting ‘%s’ on ‘%s’") % store2->realStoreDir % store->storeDir);
+ /* Bind-mount realStoreDir on /nix/store. If the latter
+ mount point doesn't already exists, we have to create a
+ chroot environment containing the mount point and bind
+ mounts for the children of /. Would be nice if we could
+ use overlayfs here, but that doesn't work in a user
+ namespace yet (Ubuntu has a patch for this:
+ https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1478578). */
+ if (!pathExists(store->storeDir)) {
+ // FIXME: Use overlayfs?
+
+ Path tmpDir = createTempDir();
+
+ createDirs(tmpDir + store->storeDir);
+
+ if (mount(store2->realStoreDir.c_str(), (tmpDir + store->storeDir).c_str(), "", MS_BIND, 0) == -1)
+ throw SysError(format("mounting ‘%s’ on ‘%s’") % store2->realStoreDir % store->storeDir);
+
+ for (auto entry : readDirectory("/")) {
+ Path dst = tmpDir + "/" + entry.name;
+ if (pathExists(dst)) continue;
+ if (mkdir(dst.c_str(), 0700) == -1)
+ throw SysError(format("creating directory ‘%s’") % dst);
+ if (mount(("/" + entry.name).c_str(), dst.c_str(), "", MS_BIND | MS_REC, 0) == -1)
+ throw SysError(format("mounting ‘%s’ on ‘%s’") % ("/" + entry.name) % dst);
+ }
+
+ char * cwd = getcwd(0, 0);
+ if (!cwd) throw SysError("getting current directory");
+ Finally freeCwd([&]() { free(cwd); });
+
+ if (chroot(tmpDir.c_str()) == -1)
+ throw SysError(format("chrooting into ‘%s’") % tmpDir);
+
+ if (chdir(cwd) == -1)
+ throw SysError(format("chdir to ‘%s’ in chroot") % cwd);
+ } else
+ if (mount(store2->realStoreDir.c_str(), store->storeDir.c_str(), "", MS_BIND, 0) == -1)
+ throw SysError(format("mounting ‘%s’ on ‘%s’") % store2->realStoreDir % store->storeDir);
#else
throw Error(format("mounting the Nix store on ‘%s’ is not supported on this platform") % store->storeDir);
#endif