From 37598a13e877980d4654c632d10921c41c9ad976 Mon Sep 17 00:00:00 2001
From: Ben Radford <benradf@users.noreply.github.com>
Date: Tue, 18 Jul 2023 09:26:48 +0100
Subject: [PATCH 01/16] Revert "Check _NIX_TEST_NO_SANDBOX when setting
 _canUseSandbox."

This reverts commit 7ed0ab2dabececd84578ddf70ecad0e528d67a28.
---
 tests/common/vars-and-functions.sh.in | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/common/vars-and-functions.sh.in b/tests/common/vars-and-functions.sh.in
index ad062387149..dc7ce13ccd0 100644
--- a/tests/common/vars-and-functions.sh.in
+++ b/tests/common/vars-and-functions.sh.in
@@ -141,7 +141,7 @@ restartDaemon() {
     startDaemon
 }
 
-if [[ -z "${_NIX_TEST_NO_SANDBOX:-}" ]] && [[ $(uname) == Linux ]] && [[ -L /proc/self/ns/user ]] && unshare --user true; then
+if [[ $(uname) == Linux ]] && [[ -L /proc/self/ns/user ]] && unshare --user true; then
     _canUseSandbox=1
 fi
 

From f66b65a30ad1f14dd757874c12255eef42368b04 Mon Sep 17 00:00:00 2001
From: Ben Radford <benradf@users.noreply.github.com>
Date: Tue, 18 Jul 2023 09:29:27 +0100
Subject: [PATCH 02/16] Revert "Skip build-remote-trustless unless sandbox is
 supported."

This reverts commit fad0dd4afb66577f9c17b5a315d120ac0f5acd94.
---
 tests/build-remote-trustless-should-fail-0.sh | 1 -
 1 file changed, 1 deletion(-)

diff --git a/tests/build-remote-trustless-should-fail-0.sh b/tests/build-remote-trustless-should-fail-0.sh
index b14101f83a5..fad1def59ff 100644
--- a/tests/build-remote-trustless-should-fail-0.sh
+++ b/tests/build-remote-trustless-should-fail-0.sh
@@ -2,7 +2,6 @@ source common.sh
 
 enableFeatures "daemon-trust-override"
 
-requireSandboxSupport
 restartDaemon
 
 [[ $busybox =~ busybox ]] || skipTest "no busybox"

From a33ee5c84305b85f5bcd0ea1be43b44cf601693f Mon Sep 17 00:00:00 2001
From: Ben Radford <benradf@users.noreply.github.com>
Date: Tue, 18 Jul 2023 10:49:44 +0100
Subject: [PATCH 03/16] Paths added to lower store are accessible via overlay.

---
 tests/overlay-local-store/add-lower-inner.sh  | 31 +++++++++++++++++++
 tests/overlay-local-store/add-lower.sh        |  5 +++
 tests/overlay-local-store/common.sh           | 11 ++++++-
 tests/overlay-local-store/local.mk            |  3 +-
 .../redundant-add-inner.sh                    |  5 +--
 5 files changed, 51 insertions(+), 4 deletions(-)
 create mode 100755 tests/overlay-local-store/add-lower-inner.sh
 create mode 100755 tests/overlay-local-store/add-lower.sh

diff --git a/tests/overlay-local-store/add-lower-inner.sh b/tests/overlay-local-store/add-lower-inner.sh
new file mode 100755
index 00000000000..40a1f397ce7
--- /dev/null
+++ b/tests/overlay-local-store/add-lower-inner.sh
@@ -0,0 +1,31 @@
+#!/usr/bin/env bash
+
+set -eu -o pipefail
+
+set -x
+
+source common.sh
+
+# Avoid store dir being inside sandbox build-dir
+unset NIX_STORE_DIR
+unset NIX_STATE_DIR
+
+storeDirs
+
+initLowerStore
+
+mountOverlayfs
+
+# Add something to the overlay store
+overlayPath=$(addTextToStore "$storeB" "overlay-file" "Add to overlay store")
+stat "$TEST_ROOT/merged-store/$overlayPath"
+
+# Now add something to the lower store
+lowerPath=$(addTextToStore "$storeA" "lower-file" "Add to lower store")
+stat "$TEST_ROOT/store-a/$lowerPath"
+
+# Remount overlayfs to ensure synchronization
+mount -o remount "$TEST_ROOT/merged-store/nix/store"
+
+# Path should be accessible via overlay store
+stat "$TEST_ROOT/merged-store/$lowerPath"
diff --git a/tests/overlay-local-store/add-lower.sh b/tests/overlay-local-store/add-lower.sh
new file mode 100755
index 00000000000..f0ac46a91b5
--- /dev/null
+++ b/tests/overlay-local-store/add-lower.sh
@@ -0,0 +1,5 @@
+source common.sh
+
+requireEnvironment
+setupConfig
+execUnshare ./add-lower-inner.sh
diff --git a/tests/overlay-local-store/common.sh b/tests/overlay-local-store/common.sh
index 14910200043..7850c068bf8 100644
--- a/tests/overlay-local-store/common.sh
+++ b/tests/overlay-local-store/common.sh
@@ -8,7 +8,7 @@ requireEnvironment () {
 }
 
 setupConfig () {
-  echo "drop-supplementary-groups = false" >> "$NIX_CONF_DIR"/nix.conf
+  echo "require-drop-supplementary-groups = false" >> "$NIX_CONF_DIR"/nix.conf
   echo "build-users-group = " >> "$NIX_CONF_DIR"/nix.conf
 }
 
@@ -54,3 +54,12 @@ initLowerStore () {
 execUnshare () {
   exec unshare --mount --map-root-user "$@"
 }
+
+addTextToStore() {
+  storeDir=$1; shift
+  filename=$1; shift
+  content=$1; shift
+  filePath="$TEST_HOME/$filename"
+  echo "$content" > "$filePath"
+  nix-store --store "$storeDir" --add "$filePath"
+}
diff --git a/tests/overlay-local-store/local.mk b/tests/overlay-local-store/local.mk
index b94238a675b..5d14e2561ea 100644
--- a/tests/overlay-local-store/local.mk
+++ b/tests/overlay-local-store/local.mk
@@ -2,6 +2,7 @@ overlay-local-store-tests := \
   $(d)/check-post-init.sh \
   $(d)/redundant-add.sh \
   $(d)/build.sh \
-  $(d)/bad-uris.sh
+  $(d)/bad-uris.sh \
+  $(d)/add-lower.sh
 
 install-tests-groups += overlay-local-store
diff --git a/tests/overlay-local-store/redundant-add-inner.sh b/tests/overlay-local-store/redundant-add-inner.sh
index 97969b40e4f..cfdae68b4c9 100755
--- a/tests/overlay-local-store/redundant-add-inner.sh
+++ b/tests/overlay-local-store/redundant-add-inner.sh
@@ -7,7 +7,7 @@ set -x
 source common.sh
 
 # Avoid store dir being inside sandbox build-dir
-unset NIX_STORE_DIR
+unset NIX_STORE_DIR  # TODO: This causes toRealPath to fail (it expects this var to be set)
 unset NIX_STATE_DIR
 
 storeDirs
@@ -27,4 +27,5 @@ path=$(nix-store --store "$storeB" --add ../dummy)
 stat $(toRealPath "$storeA/nix/store" "$path")
 
 # upper layer should still not have it (no redundant copy)
-expect 1 stat $(toRealPath "$storeB/nix/store" "$path")
+expect 1 stat $(toRealPath "$storeB/nix/store" "$path")  # TODO: Check this is failing for the right reason.
+                                                         # $storeB is a store URI not a directory path

From 0ccf6382af4c34dafacd2a417ba658e62d81adbf Mon Sep 17 00:00:00 2001
From: Ben Radford <benradf@users.noreply.github.com>
Date: Tue, 18 Jul 2023 12:30:33 +0100
Subject: [PATCH 04/16] Add test for verifying overlay store.

---
 tests/overlay-local-store/local.mk        |  3 ++-
 tests/overlay-local-store/verify-inner.sh | 32 +++++++++++++++++++++++
 tests/overlay-local-store/verify.sh       |  5 ++++
 3 files changed, 39 insertions(+), 1 deletion(-)
 create mode 100755 tests/overlay-local-store/verify-inner.sh
 create mode 100755 tests/overlay-local-store/verify.sh

diff --git a/tests/overlay-local-store/local.mk b/tests/overlay-local-store/local.mk
index 5d14e2561ea..5e8c76b4ee6 100644
--- a/tests/overlay-local-store/local.mk
+++ b/tests/overlay-local-store/local.mk
@@ -3,6 +3,7 @@ overlay-local-store-tests := \
   $(d)/redundant-add.sh \
   $(d)/build.sh \
   $(d)/bad-uris.sh \
-  $(d)/add-lower.sh
+  $(d)/add-lower.sh \
+  $(d)/verify.sh
 
 install-tests-groups += overlay-local-store
diff --git a/tests/overlay-local-store/verify-inner.sh b/tests/overlay-local-store/verify-inner.sh
new file mode 100755
index 00000000000..b68800e5c47
--- /dev/null
+++ b/tests/overlay-local-store/verify-inner.sh
@@ -0,0 +1,32 @@
+#!/usr/bin/env bash
+
+set -eu -o pipefail
+
+set -x
+
+source common.sh
+
+# Avoid store dir being inside sandbox build-dir
+unset NIX_STORE_DIR
+unset NIX_STATE_DIR
+
+storeDirs
+
+initLowerStore
+
+mountOverlayfs
+
+#path=$(nix-store --store "$storeB" --add ../dummy)
+
+path=$(nix-build --store $storeB ../hermetic.nix --arg busybox "$busybox" --arg seed 1)
+
+inputDrvPath=$(find "$storeA" -name "*-hermetic-input-1.drv")
+rm -v "$inputDrvPath"
+
+#tree "$TEST_ROOT"
+
+#rm -v "$TEST_ROOT/store-a/$path"
+
+nix-store --store "$storeB" --verify
+
+echo "SUCCESS"
diff --git a/tests/overlay-local-store/verify.sh b/tests/overlay-local-store/verify.sh
new file mode 100755
index 00000000000..8b44603ff83
--- /dev/null
+++ b/tests/overlay-local-store/verify.sh
@@ -0,0 +1,5 @@
+source common.sh
+
+requireEnvironment
+setupConfig
+execUnshare ./verify-inner.sh

From 58085e4eff1e06524f9ad8f6e9f271c19dcbba9e Mon Sep 17 00:00:00 2001
From: Ben Radford <benradf@users.noreply.github.com>
Date: Tue, 18 Jul 2023 13:10:34 +0100
Subject: [PATCH 05/16] Have verify test exercise check-contents too.

---
 tests/overlay-local-store/verify-inner.sh | 25 +++++++++++++++--------
 1 file changed, 16 insertions(+), 9 deletions(-)

diff --git a/tests/overlay-local-store/verify-inner.sh b/tests/overlay-local-store/verify-inner.sh
index b68800e5c47..5f8cbcf0e81 100755
--- a/tests/overlay-local-store/verify-inner.sh
+++ b/tests/overlay-local-store/verify-inner.sh
@@ -16,17 +16,24 @@ initLowerStore
 
 mountOverlayfs
 
-#path=$(nix-store --store "$storeB" --add ../dummy)
+# Realise a derivation from the lower store to propagate paths to overlay DB
+nix-store --store "$storeB" --realise $drvPath
 
-path=$(nix-build --store $storeB ../hermetic.nix --arg busybox "$busybox" --arg seed 1)
+# Also ensure dummy file exists in overlay DB
+dummyPath=$(nix-store --store "$storeB" --add ../dummy)
 
-inputDrvPath=$(find "$storeA" -name "*-hermetic-input-1.drv")
-rm -v "$inputDrvPath"
+# Verify should be successful at this point
+nix-store --store "$storeB" --verify --check-contents
 
-#tree "$TEST_ROOT"
+# Now delete one of the derivation inputs in the lower store
+inputDrvFullPath=$(find "$storeA" -name "*-hermetic-input-1.drv")
+inputDrvPath=${inputDrvFullPath/*\/nix\/store\///nix/store/}
+rm -v "$inputDrvFullPath"
 
-#rm -v "$TEST_ROOT/store-a/$path"
+# And truncate the contents of dummy file in lower store
+find "$storeA" -name "*-dummy" -exec truncate -s 0 {} \;
 
-nix-store --store "$storeB" --verify
-
-echo "SUCCESS"
+# Verify should fail with the messages about missing input and modified dummy file
+verifyOutput=$(expectStderr 1 nix-store --store "$storeB" --verify --check-contents)
+<<<"$verifyOutput" grepQuiet "path '$inputDrvPath' disappeared, but it still has valid referrers!"
+<<<"$verifyOutput" grepQuiet "path '$dummyPath' was modified! expected hash"

From d5cd74a4012d583d11d491bec9f1fa9a07b11973 Mon Sep 17 00:00:00 2001
From: Ben Radford <benradf@users.noreply.github.com>
Date: Tue, 18 Jul 2023 13:49:13 +0100
Subject: [PATCH 06/16] Override verifyStore to always pass NoRepair for
 LocalOverlayStore.

---
 src/libstore/local-overlay-store.cc       | 7 +++++++
 src/libstore/local-overlay-store.hh       | 2 ++
 tests/overlay-local-store/verify-inner.sh | 3 ++-
 3 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/libstore/local-overlay-store.cc b/src/libstore/local-overlay-store.cc
index ddccb8c5aa9..182955fbe40 100644
--- a/src/libstore/local-overlay-store.cc
+++ b/src/libstore/local-overlay-store.cc
@@ -188,6 +188,13 @@ void LocalOverlayStore::deleteGCPath(const Path & path, uint64_t & bytesFreed)
     }
 }
 
+bool LocalOverlayStore::verifyStore(bool checkContents, RepairFlag repair)
+{
+    if (repair)
+        warn("local-overlay: store does not support --verify --repair");
+    return LocalStore::verifyStore(checkContents, NoRepair);
+}
+
 static RegisterStoreImplementation<LocalOverlayStore, LocalOverlayStoreConfig> regLocalOverlayStore;
 
 }
diff --git a/src/libstore/local-overlay-store.hh b/src/libstore/local-overlay-store.hh
index 6f995ba393c..8fa99ee141f 100644
--- a/src/libstore/local-overlay-store.hh
+++ b/src/libstore/local-overlay-store.hh
@@ -112,6 +112,8 @@ private:
         Callback<std::shared_ptr<const Realisation>> callback) noexcept override;
 
     void deleteGCPath(const Path & path, uint64_t & bytesFreed) override;
+
+    bool verifyStore(bool checkContents, RepairFlag repair) override;
 };
 
 }
diff --git a/tests/overlay-local-store/verify-inner.sh b/tests/overlay-local-store/verify-inner.sh
index 5f8cbcf0e81..8f8839302e0 100755
--- a/tests/overlay-local-store/verify-inner.sh
+++ b/tests/overlay-local-store/verify-inner.sh
@@ -34,6 +34,7 @@ rm -v "$inputDrvFullPath"
 find "$storeA" -name "*-dummy" -exec truncate -s 0 {} \;
 
 # Verify should fail with the messages about missing input and modified dummy file
-verifyOutput=$(expectStderr 1 nix-store --store "$storeB" --verify --check-contents)
+verifyOutput=$(expectStderr 1 nix-store --store "$storeB" --verify --check-contents --repair)
 <<<"$verifyOutput" grepQuiet "path '$inputDrvPath' disappeared, but it still has valid referrers!"
 <<<"$verifyOutput" grepQuiet "path '$dummyPath' was modified! expected hash"
+<<<"$verifyOutput" grepQuiet "store does not support --verify --repair"

From 614efc1240dbfefbdabced808decd8defd33df8e Mon Sep 17 00:00:00 2001
From: Ben Radford <benradf@users.noreply.github.com>
Date: Tue, 18 Jul 2023 13:59:22 +0100
Subject: [PATCH 07/16] Add test for store optimise path deduplication.

---
 src/libstore/local-overlay-store.cc         |  5 +++++
 src/libstore/local-overlay-store.hh         |  2 ++
 tests/overlay-local-store/local.mk          |  3 ++-
 tests/overlay-local-store/optimise-inner.sh | 19 +++++++++++++++++++
 tests/overlay-local-store/optimise.sh       |  5 +++++
 5 files changed, 33 insertions(+), 1 deletion(-)
 create mode 100755 tests/overlay-local-store/optimise-inner.sh
 create mode 100755 tests/overlay-local-store/optimise.sh

diff --git a/src/libstore/local-overlay-store.cc b/src/libstore/local-overlay-store.cc
index 182955fbe40..da0c8e3d57c 100644
--- a/src/libstore/local-overlay-store.cc
+++ b/src/libstore/local-overlay-store.cc
@@ -188,6 +188,11 @@ void LocalOverlayStore::deleteGCPath(const Path & path, uint64_t & bytesFreed)
     }
 }
 
+void LocalOverlayStore::optimiseStore()
+{
+    warn("not implemented");
+}
+
 bool LocalOverlayStore::verifyStore(bool checkContents, RepairFlag repair)
 {
     if (repair)
diff --git a/src/libstore/local-overlay-store.hh b/src/libstore/local-overlay-store.hh
index 8fa99ee141f..ef377b7a6ac 100644
--- a/src/libstore/local-overlay-store.hh
+++ b/src/libstore/local-overlay-store.hh
@@ -113,6 +113,8 @@ private:
 
     void deleteGCPath(const Path & path, uint64_t & bytesFreed) override;
 
+    void optimiseStore() override;
+
     bool verifyStore(bool checkContents, RepairFlag repair) override;
 };
 
diff --git a/tests/overlay-local-store/local.mk b/tests/overlay-local-store/local.mk
index 5e8c76b4ee6..3a6d00bc1e8 100644
--- a/tests/overlay-local-store/local.mk
+++ b/tests/overlay-local-store/local.mk
@@ -4,6 +4,7 @@ overlay-local-store-tests := \
   $(d)/build.sh \
   $(d)/bad-uris.sh \
   $(d)/add-lower.sh \
-  $(d)/verify.sh
+  $(d)/verify.sh \
+  $(d)/optimise.sh
 
 install-tests-groups += overlay-local-store
diff --git a/tests/overlay-local-store/optimise-inner.sh b/tests/overlay-local-store/optimise-inner.sh
new file mode 100755
index 00000000000..76c5a0cb6f9
--- /dev/null
+++ b/tests/overlay-local-store/optimise-inner.sh
@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+
+set -eu -o pipefail
+
+set -x
+
+source common.sh
+
+# Avoid store dir being inside sandbox build-dir
+unset NIX_STORE_DIR
+unset NIX_STATE_DIR
+
+storeDirs
+
+initLowerStore
+
+mountOverlayfs
+
+nix-store --store "$storeB" --optimise
diff --git a/tests/overlay-local-store/optimise.sh b/tests/overlay-local-store/optimise.sh
new file mode 100755
index 00000000000..569afa248a9
--- /dev/null
+++ b/tests/overlay-local-store/optimise.sh
@@ -0,0 +1,5 @@
+source common.sh
+
+requireEnvironment
+setupConfig
+execUnshare ./optimise-inner.sh

From a9510f950228957cde98001b67e123aa2d4d62c9 Mon Sep 17 00:00:00 2001
From: Ben Radford <benradf@users.noreply.github.com>
Date: Wed, 19 Jul 2023 11:23:54 +0100
Subject: [PATCH 08/16] Implement test for store path deduplication.

---
 tests/overlay-local-store/common.sh         | 16 ++++------
 tests/overlay-local-store/optimise-inner.sh | 33 +++++++++++++++++++++
 2 files changed, 39 insertions(+), 10 deletions(-)

diff --git a/tests/overlay-local-store/common.sh b/tests/overlay-local-store/common.sh
index 7850c068bf8..5a678c947fc 100644
--- a/tests/overlay-local-store/common.sh
+++ b/tests/overlay-local-store/common.sh
@@ -22,11 +22,12 @@ storeDirs () {
 
 # Mounting Overlay Store
 mountOverlayfs () {
+  mergedStorePath="$TEST_ROOT/merged-store/nix/store"
   mount -t overlay overlay \
     -o lowerdir="$storeA/nix/store" \
     -o upperdir="$storeBTop" \
     -o workdir="$TEST_ROOT/workdir" \
-    "$TEST_ROOT/merged-store/nix/store" \
+    "$mergedStorePath" \
     || skipTest "overlayfs is not supported"
 
   cleanupOverlay () {
@@ -36,6 +37,10 @@ mountOverlayfs () {
   trap cleanupOverlay EXIT
 }
 
+remountOverlayfs () {
+  mount -o remount "$mergedStorePath"
+}
+
 toRealPath () {
   storeDir=$1; shift
   storePath=$1; shift
@@ -54,12 +59,3 @@ initLowerStore () {
 execUnshare () {
   exec unshare --mount --map-root-user "$@"
 }
-
-addTextToStore() {
-  storeDir=$1; shift
-  filename=$1; shift
-  content=$1; shift
-  filePath="$TEST_HOME/$filename"
-  echo "$content" > "$filePath"
-  nix-store --store "$storeDir" --add "$filePath"
-}
diff --git a/tests/overlay-local-store/optimise-inner.sh b/tests/overlay-local-store/optimise-inner.sh
index 76c5a0cb6f9..c60c742a2c2 100755
--- a/tests/overlay-local-store/optimise-inner.sh
+++ b/tests/overlay-local-store/optimise-inner.sh
@@ -16,4 +16,37 @@ initLowerStore
 
 mountOverlayfs
 
+# Create a file to add to store
+dupFilePath="$TEST_ROOT/dup-file"
+echo Duplicate > "$dupFilePath"
+
+# Add it to the overlay store (it will be written to the upper layer)
+dupFileStorePath=$(nix-store --store "$storeB" --add "$dupFilePath")
+
+# Now add it to the lower store so the store path is duplicated
+nix-store --store "$storeA" --add "$dupFilePath"
+
+# Ensure overlayfs and layers and synchronised
+remountOverlayfs
+
+dupFilename="${dupFileStorePath#/nix/store}"
+lowerPath="$storeA/$dupFileStorePath"
+upperPath="$storeBTop/$dupFilename"
+overlayPath="$mergedStorePath/$dupFilename"
+
+# Check store path exists in both layers and overlay
+lowerInode=$(stat -c %i "$lowerPath")
+upperInode=$(stat -c %i "$upperPath")
+overlayInode=$(stat -c %i "$overlayPath")
+[[ $upperInode == $overlayInode ]]
+[[ $upperInode != $lowerInode ]]
+
+# Run optimise to deduplicate store paths
 nix-store --store "$storeB" --optimise
+remountOverlayfs
+
+stat "$lowerPath"
+stat "$overlayPath"
+expect 1 stat "$upperPath"
+
+#expect 1 stat $(toRealPath "$storeA/nix/store" "$path")

From 8ddbcb736a17d08ce899de345548064eebf673c9 Mon Sep 17 00:00:00 2001
From: Ben Radford <benradf@users.noreply.github.com>
Date: Wed, 19 Jul 2023 12:32:32 +0100
Subject: [PATCH 09/16] Implement overlay store deduplication.

---
 src/libstore/local-overlay-store.cc         | 18 +++++++++++++++++-
 tests/overlay-local-store/optimise-inner.sh |  3 +--
 2 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/src/libstore/local-overlay-store.cc b/src/libstore/local-overlay-store.cc
index da0c8e3d57c..9e530ed9b81 100644
--- a/src/libstore/local-overlay-store.cc
+++ b/src/libstore/local-overlay-store.cc
@@ -190,7 +190,23 @@ void LocalOverlayStore::deleteGCPath(const Path & path, uint64_t & bytesFreed)
 
 void LocalOverlayStore::optimiseStore()
 {
-    warn("not implemented");
+    Activity act(*logger, actOptimiseStore);
+
+    // Note for LocalOverlayStore, queryAllValidPaths only returns paths in upper layer
+    auto paths = queryAllValidPaths();
+
+    act.progress(0, paths.size());
+
+    uint64_t done = 0;
+
+    for (auto & path : paths) {
+        if (lowerStore->isValidPath(path)) {
+            // Deduplicate store path
+            deletePath(toUpperPath(path));
+        }
+        done++;
+        act.progress(done, paths.size());
+    }
 }
 
 bool LocalOverlayStore::verifyStore(bool checkContents, RepairFlag repair)
diff --git a/tests/overlay-local-store/optimise-inner.sh b/tests/overlay-local-store/optimise-inner.sh
index c60c742a2c2..2b778b311c8 100755
--- a/tests/overlay-local-store/optimise-inner.sh
+++ b/tests/overlay-local-store/optimise-inner.sh
@@ -45,8 +45,7 @@ overlayInode=$(stat -c %i "$overlayPath")
 nix-store --store "$storeB" --optimise
 remountOverlayfs
 
+# Check path only exists in lower store
 stat "$lowerPath"
 stat "$overlayPath"
 expect 1 stat "$upperPath"
-
-#expect 1 stat $(toRealPath "$storeA/nix/store" "$path")

From d1c77b201a1b0e6c14470b69c134652a8858fc18 Mon Sep 17 00:00:00 2001
From: Ben Radford <benradf@users.noreply.github.com>
Date: Wed, 19 Jul 2023 13:25:37 +0100
Subject: [PATCH 10/16] Explicitly exec shell to fix ENOENT errors.

---
 tests/overlay-local-store/common.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/overlay-local-store/common.sh b/tests/overlay-local-store/common.sh
index 5a678c947fc..0e98e931fc1 100644
--- a/tests/overlay-local-store/common.sh
+++ b/tests/overlay-local-store/common.sh
@@ -57,5 +57,5 @@ initLowerStore () {
 }
 
 execUnshare () {
-  exec unshare --mount --map-root-user "$@"
+  exec unshare --mount --map-root-user "$SHELL" "$@"
 }

From 44f855d14ee40dfeaf52c4f01e2de124fe0f18fc Mon Sep 17 00:00:00 2001
From: Ben Radford <benradf@users.noreply.github.com>
Date: Wed, 19 Jul 2023 15:09:58 +0100
Subject: [PATCH 11/16] Missing addTextToStore function.

---
 tests/overlay-local-store/common.sh | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/tests/overlay-local-store/common.sh b/tests/overlay-local-store/common.sh
index 0e98e931fc1..2fba2e7f60d 100644
--- a/tests/overlay-local-store/common.sh
+++ b/tests/overlay-local-store/common.sh
@@ -59,3 +59,12 @@ initLowerStore () {
 execUnshare () {
   exec unshare --mount --map-root-user "$SHELL" "$@"
 }
+
+addTextToStore() {
+  storeDir=$1; shift
+  filename=$1; shift
+  content=$1; shift
+  filePath="$TEST_HOME/$filename"
+  echo "$content" > "$filePath"
+  nix-store --store "$storeDir" --add "$filePath"
+}

From 7fda19e2f139a7e41cb53cdbdd692dbc98755d91 Mon Sep 17 00:00:00 2001
From: Ben Radford <benradf@users.noreply.github.com>
Date: Wed, 19 Jul 2023 16:46:51 +0100
Subject: [PATCH 12/16] Mount tmpfs first to ensure overlayfs works
 consistently.

---
 tests/overlay-local-store/common.sh         | 19 +++++++++++--------
 tests/overlay-local-store/optimise-inner.sh |  2 +-
 2 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/tests/overlay-local-store/common.sh b/tests/overlay-local-store/common.sh
index 2fba2e7f60d..6aec96ba17b 100644
--- a/tests/overlay-local-store/common.sh
+++ b/tests/overlay-local-store/common.sh
@@ -13,26 +13,29 @@ setupConfig () {
 }
 
 storeDirs () {
-  storeA="$TEST_ROOT/store-a"
-  storeBTop="$TEST_ROOT/store-b"
-  storeB="local-overlay?root=$TEST_ROOT/merged-store&lower-store=$storeA&upper-layer=$storeBTop"
+  storesRoot="$TEST_ROOT/stores"
+  mkdir -p "$storesRoot"
+  mount -t tmpfs tmpfs "$storesRoot"
+  storeA="$storesRoot/store-a"
+  storeBTop="$storesRoot/store-b"
+  storeB="local-overlay?root=$storesRoot/merged-store&lower-store=$storeA&upper-layer=$storeBTop"
   # Creating testing directories
-  mkdir -p "$TEST_ROOT"/{store-a/nix/store,store-b,merged-store/nix/store,workdir}
+  mkdir -p "$storesRoot"/{store-a/nix/store,store-b,merged-store/nix/store,workdir}
 }
 
 # Mounting Overlay Store
 mountOverlayfs () {
-  mergedStorePath="$TEST_ROOT/merged-store/nix/store"
+  mergedStorePath="$storesRoot/merged-store/nix/store"
   mount -t overlay overlay \
     -o lowerdir="$storeA/nix/store" \
     -o upperdir="$storeBTop" \
-    -o workdir="$TEST_ROOT/workdir" \
+    -o workdir="$storesRoot/workdir" \
     "$mergedStorePath" \
     || skipTest "overlayfs is not supported"
 
   cleanupOverlay () {
-    umount "$TEST_ROOT/merged-store/nix/store"
-    rm -r $TEST_ROOT/workdir
+    umount "$storesRoot/merged-store/nix/store"
+    rm -r $storesRoot/workdir
   }
   trap cleanupOverlay EXIT
 }
diff --git a/tests/overlay-local-store/optimise-inner.sh b/tests/overlay-local-store/optimise-inner.sh
index 2b778b311c8..079e2232687 100755
--- a/tests/overlay-local-store/optimise-inner.sh
+++ b/tests/overlay-local-store/optimise-inner.sh
@@ -17,7 +17,7 @@ initLowerStore
 mountOverlayfs
 
 # Create a file to add to store
-dupFilePath="$TEST_ROOT/dup-file"
+dupFilePath="$storesRoot/dup-file"
 echo Duplicate > "$dupFilePath"
 
 # Add it to the overlay store (it will be written to the upper layer)

From 9769a0ae7d840f1df7db3de4524180016830e57e Mon Sep 17 00:00:00 2001
From: Ben Radford <benradf@users.noreply.github.com>
Date: Thu, 20 Jul 2023 10:27:11 +0100
Subject: [PATCH 13/16] Ensure all overlay tests use new tmpfs store paths.

---
 tests/overlay-local-store/add-lower-inner.sh  |  8 +++---
 tests/overlay-local-store/bad-uris.sh         |  4 +--
 .../check-post-init-inner.sh                  |  2 +-
 tests/overlay-local-store/common.sh           | 28 +++++++++++--------
 tests/overlay-local-store/optimise-inner.sh   |  2 +-
 5 files changed, 25 insertions(+), 19 deletions(-)

diff --git a/tests/overlay-local-store/add-lower-inner.sh b/tests/overlay-local-store/add-lower-inner.sh
index 40a1f397ce7..8c71f078066 100755
--- a/tests/overlay-local-store/add-lower-inner.sh
+++ b/tests/overlay-local-store/add-lower-inner.sh
@@ -18,14 +18,14 @@ mountOverlayfs
 
 # Add something to the overlay store
 overlayPath=$(addTextToStore "$storeB" "overlay-file" "Add to overlay store")
-stat "$TEST_ROOT/merged-store/$overlayPath"
+stat "$storeVolume/merged-store/$overlayPath"
 
 # Now add something to the lower store
 lowerPath=$(addTextToStore "$storeA" "lower-file" "Add to lower store")
-stat "$TEST_ROOT/store-a/$lowerPath"
+stat "$storeVolume/store-a/$lowerPath"
 
 # Remount overlayfs to ensure synchronization
-mount -o remount "$TEST_ROOT/merged-store/nix/store"
+mount -o remount "$storeVolume/merged-store/nix/store"
 
 # Path should be accessible via overlay store
-stat "$TEST_ROOT/merged-store/$lowerPath"
+stat "$storeVolume/merged-store/$lowerPath"
diff --git a/tests/overlay-local-store/bad-uris.sh b/tests/overlay-local-store/bad-uris.sh
index d4261bd97db..c5926473507 100644
--- a/tests/overlay-local-store/bad-uris.sh
+++ b/tests/overlay-local-store/bad-uris.sh
@@ -7,8 +7,8 @@ storeDirs
 mkdir -p $TEST_ROOT/bad_test
 badTestRoot=$TEST_ROOT/bad_test
 storeBadRoot="local-overlay?root=$badTestRoot&lower-store=$storeA&upper-layer=$storeBTop"
-storeBadLower="local-overlay?root=$TEST_ROOT/merged-store&lower-store=$badTestRoot&upper-layer=$storeBTop"
-storeBadUpper="local-overlay?root=$TEST_ROOT/merged-store&lower-store=$storeA&upper-layer=$badTestRoot"
+storeBadLower="local-overlay?root=$storeVolume/merged-store&lower-store=$badTestRoot&upper-layer=$storeBTop"
+storeBadUpper="local-overlay?root=$storeVolume/merged-store&lower-store=$storeA&upper-layer=$badTestRoot"
 
 declare -a storesBad=(
     "$storeBadRoot" "$storeBadLower" "$storeBadUpper"
diff --git a/tests/overlay-local-store/check-post-init-inner.sh b/tests/overlay-local-store/check-post-init-inner.sh
index 37ed8c113f9..c7d1c70d445 100755
--- a/tests/overlay-local-store/check-post-init-inner.sh
+++ b/tests/overlay-local-store/check-post-init-inner.sh
@@ -25,7 +25,7 @@ stat $(toRealPath "$storeA/nix/store" "$path")
 expect 1 stat $(toRealPath "$storeBTop" "$path")
 
 # Checking for path in overlay store matching lower layer
-diff $(toRealPath "$storeA/nix/store" "$path") $(toRealPath "$TEST_ROOT/merged-store/nix/store" "$path")
+diff $(toRealPath "$storeA/nix/store" "$path") $(toRealPath "$storeVolume/merged-store/nix/store" "$path")
 
 # Checking requisites query agreement
 [[ \
diff --git a/tests/overlay-local-store/common.sh b/tests/overlay-local-store/common.sh
index 6aec96ba17b..686523e9c98 100644
--- a/tests/overlay-local-store/common.sh
+++ b/tests/overlay-local-store/common.sh
@@ -12,30 +12,36 @@ setupConfig () {
   echo "build-users-group = " >> "$NIX_CONF_DIR"/nix.conf
 }
 
+
+
 storeDirs () {
-  storesRoot="$TEST_ROOT/stores"
-  mkdir -p "$storesRoot"
-  mount -t tmpfs tmpfs "$storesRoot"
-  storeA="$storesRoot/store-a"
-  storeBTop="$storesRoot/store-b"
-  storeB="local-overlay?root=$storesRoot/merged-store&lower-store=$storeA&upper-layer=$storeBTop"
+  # Attempt to create store dirs on tmpfs volume.
+  # This ensures lowerdir, upperdir and workdir will be on
+  # a consistent filesystem that fully supports OverlayFS.
+  storeVolume="$TEST_ROOT/stores"
+  mkdir -p "$storeVolume"
+  mount -t tmpfs tmpfs "$storeVolume" || true  # But continue anyway if that fails.
+
+  storeA="$storeVolume/store-a"
+  storeBTop="$storeVolume/store-b"
+  storeB="local-overlay?root=$storeVolume/merged-store&lower-store=$storeA&upper-layer=$storeBTop"
   # Creating testing directories
-  mkdir -p "$storesRoot"/{store-a/nix/store,store-b,merged-store/nix/store,workdir}
+  mkdir -p "$storeVolume"/{store-a/nix/store,store-b,merged-store/nix/store,workdir}
 }
 
 # Mounting Overlay Store
 mountOverlayfs () {
-  mergedStorePath="$storesRoot/merged-store/nix/store"
+  mergedStorePath="$storeVolume/merged-store/nix/store"
   mount -t overlay overlay \
     -o lowerdir="$storeA/nix/store" \
     -o upperdir="$storeBTop" \
-    -o workdir="$storesRoot/workdir" \
+    -o workdir="$storeVolume/workdir" \
     "$mergedStorePath" \
     || skipTest "overlayfs is not supported"
 
   cleanupOverlay () {
-    umount "$storesRoot/merged-store/nix/store"
-    rm -r $storesRoot/workdir
+    umount "$storeVolume/merged-store/nix/store"
+    rm -r $storeVolume/workdir
   }
   trap cleanupOverlay EXIT
 }
diff --git a/tests/overlay-local-store/optimise-inner.sh b/tests/overlay-local-store/optimise-inner.sh
index 079e2232687..2b778b311c8 100755
--- a/tests/overlay-local-store/optimise-inner.sh
+++ b/tests/overlay-local-store/optimise-inner.sh
@@ -17,7 +17,7 @@ initLowerStore
 mountOverlayfs
 
 # Create a file to add to store
-dupFilePath="$storesRoot/dup-file"
+dupFilePath="$TEST_ROOT/dup-file"
 echo Duplicate > "$dupFilePath"
 
 # Add it to the overlay store (it will be written to the upper layer)

From 878c84d5ee88f2e6c56abb42211a729c4d342e14 Mon Sep 17 00:00:00 2001
From: Ben Radford <benradf@users.noreply.github.com>
Date: Thu, 20 Jul 2023 10:27:35 +0100
Subject: [PATCH 14/16] Fix errors about NIX_STORE_DIR being unset.

---
 tests/overlay-local-store/check-post-init-inner.sh | 2 +-
 tests/overlay-local-store/common.sh                | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/tests/overlay-local-store/check-post-init-inner.sh b/tests/overlay-local-store/check-post-init-inner.sh
index c7d1c70d445..2e7db2adc41 100755
--- a/tests/overlay-local-store/check-post-init-inner.sh
+++ b/tests/overlay-local-store/check-post-init-inner.sh
@@ -62,7 +62,7 @@ nix-store --verify-path --store "$storeA" "$path"
 # Verifying path in merged-store
 nix-store --verify-path --store "$storeB" "$path"
 
-hashPart=$(echo $path | sed "s^$NIX_STORE_DIR/^^" | sed 's/-.*//')
+hashPart=$(echo $path | sed "s^${NIX_STORE_DIR:-/nix/store}/^^" | sed 's/-.*//')
 
 # Lower store can find from hash part
 [[ $(nix store --store $storeA path-from-hash-part $hashPart) == $path ]]
diff --git a/tests/overlay-local-store/common.sh b/tests/overlay-local-store/common.sh
index 686523e9c98..ac4a59cd8ed 100644
--- a/tests/overlay-local-store/common.sh
+++ b/tests/overlay-local-store/common.sh
@@ -53,7 +53,7 @@ remountOverlayfs () {
 toRealPath () {
   storeDir=$1; shift
   storePath=$1; shift
-  echo $storeDir$(echo $storePath | sed "s^$NIX_STORE_DIR^^")
+  echo $storeDir$(echo $storePath | sed "s^${NIX_STORE_DIR:-/nix/store}^^")
 }
 
 initLowerStore () {

From 2c66a093e05bc466d00c9365bc43567fd9d5c334 Mon Sep 17 00:00:00 2001
From: Ben Radford <benradf@users.noreply.github.com>
Date: Thu, 20 Jul 2023 11:03:14 +0100
Subject: [PATCH 15/16] Define storeBRoot variable distinct from storeB URI.

---
 tests/overlay-local-store/add-lower-inner.sh       |  6 +++---
 tests/overlay-local-store/bad-uris.sh              |  4 ++--
 tests/overlay-local-store/check-post-init-inner.sh |  2 +-
 tests/overlay-local-store/common.sh                | 10 +++++-----
 tests/overlay-local-store/redundant-add-inner.sh   |  5 ++---
 5 files changed, 13 insertions(+), 14 deletions(-)

diff --git a/tests/overlay-local-store/add-lower-inner.sh b/tests/overlay-local-store/add-lower-inner.sh
index 8c71f078066..ca7db7ab6ce 100755
--- a/tests/overlay-local-store/add-lower-inner.sh
+++ b/tests/overlay-local-store/add-lower-inner.sh
@@ -18,14 +18,14 @@ mountOverlayfs
 
 # Add something to the overlay store
 overlayPath=$(addTextToStore "$storeB" "overlay-file" "Add to overlay store")
-stat "$storeVolume/merged-store/$overlayPath"
+stat "$storeBRoot/$overlayPath"
 
 # Now add something to the lower store
 lowerPath=$(addTextToStore "$storeA" "lower-file" "Add to lower store")
 stat "$storeVolume/store-a/$lowerPath"
 
 # Remount overlayfs to ensure synchronization
-mount -o remount "$storeVolume/merged-store/nix/store"
+remountOverlayfs
 
 # Path should be accessible via overlay store
-stat "$storeVolume/merged-store/$lowerPath"
+stat "$storeBRoot/$lowerPath"
diff --git a/tests/overlay-local-store/bad-uris.sh b/tests/overlay-local-store/bad-uris.sh
index c5926473507..462bf27ebcb 100644
--- a/tests/overlay-local-store/bad-uris.sh
+++ b/tests/overlay-local-store/bad-uris.sh
@@ -7,8 +7,8 @@ storeDirs
 mkdir -p $TEST_ROOT/bad_test
 badTestRoot=$TEST_ROOT/bad_test
 storeBadRoot="local-overlay?root=$badTestRoot&lower-store=$storeA&upper-layer=$storeBTop"
-storeBadLower="local-overlay?root=$storeVolume/merged-store&lower-store=$badTestRoot&upper-layer=$storeBTop"
-storeBadUpper="local-overlay?root=$storeVolume/merged-store&lower-store=$storeA&upper-layer=$badTestRoot"
+storeBadLower="local-overlay?root=$storeBRoot&lower-store=$badTestRoot&upper-layer=$storeBTop"
+storeBadUpper="local-overlay?root=$storeBRoot&lower-store=$storeA&upper-layer=$badTestRoot"
 
 declare -a storesBad=(
     "$storeBadRoot" "$storeBadLower" "$storeBadUpper"
diff --git a/tests/overlay-local-store/check-post-init-inner.sh b/tests/overlay-local-store/check-post-init-inner.sh
index 2e7db2adc41..0f4654cc21a 100755
--- a/tests/overlay-local-store/check-post-init-inner.sh
+++ b/tests/overlay-local-store/check-post-init-inner.sh
@@ -25,7 +25,7 @@ stat $(toRealPath "$storeA/nix/store" "$path")
 expect 1 stat $(toRealPath "$storeBTop" "$path")
 
 # Checking for path in overlay store matching lower layer
-diff $(toRealPath "$storeA/nix/store" "$path") $(toRealPath "$storeVolume/merged-store/nix/store" "$path")
+diff $(toRealPath "$storeA/nix/store" "$path") $(toRealPath "$storeBRoot/nix/store" "$path")
 
 # Checking requisites query agreement
 [[ \
diff --git a/tests/overlay-local-store/common.sh b/tests/overlay-local-store/common.sh
index ac4a59cd8ed..2b23352ab59 100644
--- a/tests/overlay-local-store/common.sh
+++ b/tests/overlay-local-store/common.sh
@@ -24,30 +24,30 @@ storeDirs () {
 
   storeA="$storeVolume/store-a"
   storeBTop="$storeVolume/store-b"
-  storeB="local-overlay?root=$storeVolume/merged-store&lower-store=$storeA&upper-layer=$storeBTop"
+  storeBRoot="$storeVolume/merged-store"
+  storeB="local-overlay?root=$storeBRoot&lower-store=$storeA&upper-layer=$storeBTop"
   # Creating testing directories
   mkdir -p "$storeVolume"/{store-a/nix/store,store-b,merged-store/nix/store,workdir}
 }
 
 # Mounting Overlay Store
 mountOverlayfs () {
-  mergedStorePath="$storeVolume/merged-store/nix/store"
   mount -t overlay overlay \
     -o lowerdir="$storeA/nix/store" \
     -o upperdir="$storeBTop" \
     -o workdir="$storeVolume/workdir" \
-    "$mergedStorePath" \
+    "$storeBRoot/nix/store" \
     || skipTest "overlayfs is not supported"
 
   cleanupOverlay () {
-    umount "$storeVolume/merged-store/nix/store"
+    umount "$storeBRoot/nix/store"
     rm -r $storeVolume/workdir
   }
   trap cleanupOverlay EXIT
 }
 
 remountOverlayfs () {
-  mount -o remount "$mergedStorePath"
+  mount -o remount "$storeBRoot/nix/store"
 }
 
 toRealPath () {
diff --git a/tests/overlay-local-store/redundant-add-inner.sh b/tests/overlay-local-store/redundant-add-inner.sh
index cfdae68b4c9..34b841e38dc 100755
--- a/tests/overlay-local-store/redundant-add-inner.sh
+++ b/tests/overlay-local-store/redundant-add-inner.sh
@@ -7,7 +7,7 @@ set -x
 source common.sh
 
 # Avoid store dir being inside sandbox build-dir
-unset NIX_STORE_DIR  # TODO: This causes toRealPath to fail (it expects this var to be set)
+unset NIX_STORE_DIR
 unset NIX_STATE_DIR
 
 storeDirs
@@ -27,5 +27,4 @@ path=$(nix-store --store "$storeB" --add ../dummy)
 stat $(toRealPath "$storeA/nix/store" "$path")
 
 # upper layer should still not have it (no redundant copy)
-expect 1 stat $(toRealPath "$storeB/nix/store" "$path")  # TODO: Check this is failing for the right reason.
-                                                         # $storeB is a store URI not a directory path
+expect 1 stat $(toRealPath "$storeBTop" "$path")

From 2fc00ec19f8eb7ec2285135a180763d632102762 Mon Sep 17 00:00:00 2001
From: Ben Radford <benradf@users.noreply.github.com>
Date: Thu, 20 Jul 2023 11:27:28 +0100
Subject: [PATCH 16/16] Fix unbound variable error in optimise test.

---
 tests/overlay-local-store/optimise-inner.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/overlay-local-store/optimise-inner.sh b/tests/overlay-local-store/optimise-inner.sh
index 2b778b311c8..b7994054cc5 100755
--- a/tests/overlay-local-store/optimise-inner.sh
+++ b/tests/overlay-local-store/optimise-inner.sh
@@ -32,7 +32,7 @@ remountOverlayfs
 dupFilename="${dupFileStorePath#/nix/store}"
 lowerPath="$storeA/$dupFileStorePath"
 upperPath="$storeBTop/$dupFilename"
-overlayPath="$mergedStorePath/$dupFilename"
+overlayPath="$storeBRoot/nix/store/$dupFilename"
 
 # Check store path exists in both layers and overlay
 lowerInode=$(stat -c %i "$lowerPath")