After rewriting a path, make it read-only

This commit is contained in:
Eelco Dolstra 2020-09-23 19:10:16 +02:00
parent 31ab4c3816
commit 688bd4fb50

View file

@ -3735,15 +3735,12 @@ void DerivationGoal::runChild()
} }
static void moveCheckToStore(const Path & src, const Path & dst) /* Move/rename path 'src' to 'dst'. Temporarily make 'src' writable if
{ it's a directory and we're not root (to be able to update the
/* For the rename of directory to succeed, we must be running as root or
the directory must be made temporarily writable (to update the
directory's parent link ".."). */ directory's parent link ".."). */
struct stat st; static void movePath(const Path & src, const Path & dst)
if (lstat(src.c_str(), &st) == -1) { {
throw SysError("getting attributes of path '%1%'", src); auto st = lstat(src);
}
bool changePerm = (geteuid() && S_ISDIR(st.st_mode) && !(st.st_mode & S_IWUSR)); bool changePerm = (geteuid() && S_ISDIR(st.st_mode) && !(st.st_mode & S_IWUSR));
@ -3942,6 +3939,10 @@ void DerivationGoal::registerOutputs()
sink.s = make_ref<std::string>(rewriteStrings(*sink.s, outputRewrites)); sink.s = make_ref<std::string>(rewriteStrings(*sink.s, outputRewrites));
StringSource source(*sink.s); StringSource source(*sink.s);
restorePath(actualPath, source); restorePath(actualPath, source);
/* FIXME: set proper permissions in restorePath() so
we don't have to do another traversal. */
canonicalisePathMetaData(actualPath, -1, inodesSeen);
} }
}; };
@ -4024,7 +4025,7 @@ void DerivationGoal::registerOutputs()
[&](DerivationOutputInputAddressed output) { [&](DerivationOutputInputAddressed output) {
/* input-addressed case */ /* input-addressed case */
auto requiredFinalPath = output.path; auto requiredFinalPath = output.path;
/* Preemtively add rewrite rule for final hash, as that is /* Preemptively add rewrite rule for final hash, as that is
what the NAR hash will use rather than normalized-self references */ what the NAR hash will use rather than normalized-self references */
if (scratchPath != requiredFinalPath) if (scratchPath != requiredFinalPath)
outputRewrites.insert_or_assign( outputRewrites.insert_or_assign(
@ -4098,27 +4099,9 @@ void DerivationGoal::registerOutputs()
else. No moving needed. */ else. No moving needed. */
assert(newInfo.ca); assert(newInfo.ca);
} else { } else {
/* Temporarily add write perm so we can move, will be fixed auto destPath = worker.store.toRealPath(finalDestPath);
later. */ movePath(actualPath, destPath);
{ actualPath = destPath;
struct stat st;
auto & mode = st.st_mode;
if (lstat(actualPath.c_str(), &st))
throw SysError("getting attributes of path '%1%'", actualPath);
mode |= 0200;
/* Try to change the perms, but only if the file isn't a
symlink as symlinks permissions are mostly ignored and
calling `chmod` on it will just forward the call to the
target of the link. */
if (!S_ISLNK(st.st_mode))
if (chmod(actualPath.c_str(), mode) == -1)
throw SysError("changing mode of '%1%' to %2$o", actualPath, mode);
}
if (rename(
actualPath.c_str(),
worker.store.toRealPath(finalDestPath).c_str()) == -1)
throw SysError("moving build output '%1%' from it's temporary location to the Nix store", finalDestPath);
actualPath = worker.store.toRealPath(finalDestPath);
} }
} }
@ -4128,9 +4111,9 @@ void DerivationGoal::registerOutputs()
if (newInfo.narHash != oldInfo.narHash) { if (newInfo.narHash != oldInfo.narHash) {
worker.checkMismatch = true; worker.checkMismatch = true;
if (settings.runDiffHook || settings.keepFailed) { if (settings.runDiffHook || settings.keepFailed) {
Path dst = worker.store.toRealPath(finalDestPath + checkSuffix); auto dst = worker.store.toRealPath(finalDestPath + checkSuffix);
deletePath(dst); deletePath(dst);
moveCheckToStore(actualPath, dst); movePath(actualPath, dst);
handleDiffHook( handleDiffHook(
buildUser ? buildUser->getUID() : getuid(), buildUser ? buildUser->getUID() : getuid(),