From ac7caa8f3b354fba7622d9da29a1171b5b709734 Mon Sep 17 00:00:00 2001
From: Justin Chadwell <me@jedevc.com>
Date: Wed, 25 Sep 2024 10:49:50 +0100
Subject: [PATCH] chore: use a better root for computing free disk space

We shouldn't use the cachemount root, we should actually properly
use the worker's specified root which is propagated from the config.

Signed-off-by: Justin Chadwell <me@jedevc.com>
---
 cache/manager.go                      | 7 +++++--
 cache/manager_test.go                 | 1 +
 solver/llbsolver/mounts/mount_test.go | 1 +
 source/git/source_test.go             | 1 +
 source/http/source_test.go            | 1 +
 worker/base/worker.go                 | 2 ++
 worker/containerd/containerd.go       | 1 +
 worker/runc/runc.go                   | 1 +
 8 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/cache/manager.go b/cache/manager.go
index 266b4eddd753..c4e2e84f12fc 100644
--- a/cache/manager.go
+++ b/cache/manager.go
@@ -49,6 +49,7 @@ type ManagerOpt struct {
 	Applier         diff.Applier
 	Differ          diff.Comparer
 	MetadataStore   *metadata.Store
+	Root            string
 	MountPoolRoot   string
 }
 
@@ -94,6 +95,8 @@ type cacheManager struct {
 	Differ          diff.Comparer
 	MetadataStore   *metadata.Store
 
+	root string
+
 	mountPool sharableMountPool
 
 	muPrune sync.Mutex // make sure parallel prune is not allowed so there will not be inconsistent results
@@ -110,6 +113,7 @@ func NewManager(opt ManagerOpt) (Manager, error) {
 		Applier:         opt.Applier,
 		Differ:          opt.Differ,
 		MetadataStore:   opt.MetadataStore,
+		root:            opt.Root,
 		records:         make(map[string]*cacheRecord),
 	}
 
@@ -1054,8 +1058,7 @@ func (cm *cacheManager) pruneOnce(ctx context.Context, ch chan client.UsageInfo,
 		}
 	}
 
-	// TODO: pick a better path here
-	dstat, err := disk.GetDiskStat(cm.mountPool.tmpdirRoot)
+	dstat, err := disk.GetDiskStat(cm.root)
 	if err != nil {
 		if opt.Free != 0 {
 			// if we are pruning based on disk space, failing to get info on it
diff --git a/cache/manager_test.go b/cache/manager_test.go
index 2a9ee9877935..1aef32987104 100644
--- a/cache/manager_test.go
+++ b/cache/manager_test.go
@@ -152,6 +152,7 @@ func newCacheManager(ctx context.Context, t *testing.T, opt cmOpt) (co *cmOut, c
 		GarbageCollect: mdb.GarbageCollect,
 		Applier:        applier,
 		Differ:         differ,
+		Root:           tmpdir,
 		MountPoolRoot:  filepath.Join(tmpdir, "cachemounts"),
 	})
 	if err != nil {
diff --git a/solver/llbsolver/mounts/mount_test.go b/solver/llbsolver/mounts/mount_test.go
index 44536d795dc2..180f40607b75 100644
--- a/solver/llbsolver/mounts/mount_test.go
+++ b/solver/llbsolver/mounts/mount_test.go
@@ -109,6 +109,7 @@ func newCacheManager(ctx context.Context, t *testing.T, opt cmOpt) (co *cmOut, e
 		Differ:         differ,
 		LeaseManager:   lm,
 		GarbageCollect: mdb.GarbageCollect,
+		Root:           tmpdir,
 		MountPoolRoot:  filepath.Join(tmpdir, "cachemounts"),
 	})
 	if err != nil {
diff --git a/source/git/source_test.go b/source/git/source_test.go
index 104263934a7c..59a0fdd83e4f 100644
--- a/source/git/source_test.go
+++ b/source/git/source_test.go
@@ -649,6 +649,7 @@ func setupGitSource(t *testing.T, tmpdir string) source.Source {
 		Applier:        applier,
 		Differ:         differ,
 		GarbageCollect: mdb.GarbageCollect,
+		Root:           tmpdir,
 		MountPoolRoot:  filepath.Join(tmpdir, "cachemounts"),
 	})
 	require.NoError(t, err)
diff --git a/source/http/source_test.go b/source/http/source_test.go
index 980ec2117b2e..8f091dd7008c 100644
--- a/source/http/source_test.go
+++ b/source/http/source_test.go
@@ -355,6 +355,7 @@ func newHTTPSource(t *testing.T) (source.Source, error) {
 		Applier:        applier,
 		Differ:         differ,
 		GarbageCollect: mdb.GarbageCollect,
+		Root:           tmpdir,
 		MountPoolRoot:  filepath.Join(tmpdir, "cachemounts"),
 	})
 	if err != nil {
diff --git a/worker/base/worker.go b/worker/base/worker.go
index d57cf457618f..0a1743929a91 100644
--- a/worker/base/worker.go
+++ b/worker/base/worker.go
@@ -62,6 +62,7 @@ const labelCreatedAt = "buildkit/createdat"
 // See also CommonOpt.
 type WorkerOpt struct {
 	ID               string
+	Root             string
 	Labels           map[string]string
 	Platforms        []ocispecs.Platform
 	GCPolicy         []client.PruneInfo
@@ -110,6 +111,7 @@ func NewWorker(ctx context.Context, opt WorkerOpt) (*Worker, error) {
 		ContentStore:    opt.ContentStore,
 		Differ:          opt.Differ,
 		MetadataStore:   opt.MetadataStore,
+		Root:            opt.Root,
 		MountPoolRoot:   opt.MountPoolRoot,
 	})
 	if err != nil {
diff --git a/worker/containerd/containerd.go b/worker/containerd/containerd.go
index d3ec2e4d632b..c00b951bb3f7 100644
--- a/worker/containerd/containerd.go
+++ b/worker/containerd/containerd.go
@@ -184,6 +184,7 @@ func newContainerd(client *containerd.Client, workerOpts WorkerOptions) (base.Wo
 
 	opt := base.WorkerOpt{
 		ID:               id,
+		Root:             root,
 		Labels:           xlabels,
 		MetadataStore:    md,
 		NetworkProviders: np,
diff --git a/worker/runc/runc.go b/worker/runc/runc.go
index 937e96017b56..ce756ce3754e 100644
--- a/worker/runc/runc.go
+++ b/worker/runc/runc.go
@@ -150,6 +150,7 @@ func NewWorkerOpt(root string, snFactory SnapshotterFactory, rootless bool, proc
 
 	opt = base.WorkerOpt{
 		ID:               id,
+		Root:             root,
 		Labels:           xlabels,
 		MetadataStore:    md,
 		NetworkProviders: np,