From 65ee7f5da4db9fd0c4a519dd681a49ceb8b99f4c Mon Sep 17 00:00:00 2001
From: eldritch horrors <pennae@lix.systems>
Date: Tue, 11 Feb 2025 01:06:15 +0100
Subject: [PATCH] libstore: use non-blocking locks in createTempDirInStore

gc tryLocks first, then deletes. we can use the same order since there's
no sequence of operations that would let us lock our new directory *and*
have the gc delete it (except outright bugs). the worst possible outcome
is that we create a few directories that'll be deleted by a later gc run

Change-Id: I6d3524f4990f8deee10804e6fbb0d0a26f3d57fe
---
 lix/libstore/local-store.cc | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/lix/libstore/local-store.cc b/lix/libstore/local-store.cc
index 3ce6c237d..66be6dc99 100644
--- a/lix/libstore/local-store.cc
+++ b/lix/libstore/local-store.cc
@@ -1493,8 +1493,7 @@ std::pair<Path, AutoCloseFD> LocalStore::createTempDirInStore()
         if (tmpDirFd.get() < 0) {
             continue;
         }
-        lockFile(tmpDirFd.get(), ltWrite);
-        lockedByUs = true;
+        lockedByUs = tryLockFile(tmpDirFd.get(), ltWrite);
     } while (!pathExists(tmpDirFn) || !lockedByUs);
     return {tmpDirFn, std::move(tmpDirFd)};
 }