From 996137cdfdff9ec6fbb5c93e21d75b21052e01ae Mon Sep 17 00:00:00 2001
From: Luke Shumaker <lukeshu@lukeshu.com>
Date: Tue, 28 Feb 2023 08:05:47 -0700
Subject: rebuildnodes: Fix a data race
Calling FreeNodeRef while an item from that node is still in use is a BAD
TIME.
---
lib/btrfsprogs/btrfsinspect/rebuildnodes/keyio/keyio.go | 6 +++++-
lib/btrfsprogs/btrfsinspect/rebuildnodes/rebuild.go | 1 +
lib/btrfsprogs/btrfsinspect/rebuildnodes/rebuild_treecb.go | 8 ++++++--
3 files changed, 12 insertions(+), 3 deletions(-)
(limited to 'lib/btrfsprogs/btrfsinspect')
diff --git a/lib/btrfsprogs/btrfsinspect/rebuildnodes/keyio/keyio.go b/lib/btrfsprogs/btrfsinspect/rebuildnodes/keyio/keyio.go
index 9e3b144..04df2b6 100644
--- a/lib/btrfsprogs/btrfsinspect/rebuildnodes/keyio/keyio.go
+++ b/lib/btrfsprogs/btrfsinspect/rebuildnodes/keyio/keyio.go
@@ -7,6 +7,7 @@ package keyio
import (
"context"
"fmt"
+ "sync"
"github.com/datawire/dlib/dlog"
@@ -48,6 +49,7 @@ type Handle struct {
Names map[ItemPtr][]byte // DIR_INDEX
Sizes map[ItemPtr]SizeAndErr // EXTENT_CSUM and EXTENT_DATA
+ mu sync.Mutex
cache containers.ARCache[btrfsvol.LogicalAddr, *diskio.Ref[btrfsvol.LogicalAddr, btrfstree.Node]]
}
@@ -153,6 +155,8 @@ func (o *Handle) readNode(ctx context.Context, laddr btrfsvol.LogicalAddr) *disk
}
func (o *Handle) ReadItem(ctx context.Context, ptr ItemPtr) btrfsitem.Item {
+ o.mu.Lock()
+ defer o.mu.Unlock()
if o.graph.Nodes[ptr.Node].Level != 0 {
panic(fmt.Errorf("should not happen: keyio.Handle.ReadItem called for non-leaf node@%v", ptr.Node))
}
@@ -164,5 +168,5 @@ func (o *Handle) ReadItem(ctx context.Context, ptr ItemPtr) btrfsitem.Item {
panic(fmt.Errorf("should not happen: keyio.Handle.ReadItem called for out-of-bounds item index: index=%v len=%v",
ptr.Idx, len(items)))
}
- return items[ptr.Idx].Body
+ return items[ptr.Idx].Body.CloneItem()
}
diff --git a/lib/btrfsprogs/btrfsinspect/rebuildnodes/rebuild.go b/lib/btrfsprogs/btrfsinspect/rebuildnodes/rebuild.go
index 643fbe7..bc36485 100644
--- a/lib/btrfsprogs/btrfsinspect/rebuildnodes/rebuild.go
+++ b/lib/btrfsprogs/btrfsinspect/rebuildnodes/rebuild.go
@@ -288,6 +288,7 @@ func (o *rebuilder) processSettledItemQueue(ctx context.Context) error {
Key: item.Key,
Body: item.Body,
})
+ item.Body.Free()
if item.ItemType == btrfsitem.ROOT_ITEM_KEY {
o.treeQueue.Insert(item.ObjectID)
}
diff --git a/lib/btrfsprogs/btrfsinspect/rebuildnodes/rebuild_treecb.go b/lib/btrfsprogs/btrfsinspect/rebuildnodes/rebuild_treecb.go
index d1d354a..492436b 100644
--- a/lib/btrfsprogs/btrfsinspect/rebuildnodes/rebuild_treecb.go
+++ b/lib/btrfsprogs/btrfsinspect/rebuildnodes/rebuild_treecb.go
@@ -44,7 +44,9 @@ func (o *rebuilder) LookupRoot(ctx context.Context, tree btrfsprim.ObjID) (offse
o.enqueueRetry(btrfsprim.ROOT_TREE_OBJECTID)
return 0, btrfsitem.Root{}, false
}
- switch itemBody := o.rebuilt.Tree(ctx, wantKey.TreeID).ReadItem(ctx, foundKey).(type) {
+ itemBody := o.rebuilt.Tree(ctx, wantKey.TreeID).ReadItem(ctx, foundKey)
+ defer itemBody.Free()
+ switch itemBody := itemBody.(type) {
case *btrfsitem.Root:
return btrfsprim.Generation(foundKey.Offset), *itemBody, true
case *btrfsitem.Error:
@@ -68,7 +70,9 @@ func (o *rebuilder) LookupUUID(ctx context.Context, uuid btrfsprim.UUID) (id btr
o.enqueueRetry(btrfsprim.UUID_TREE_OBJECTID)
return 0, false
}
- switch itemBody := o.rebuilt.Tree(ctx, wantKey.TreeID).ReadItem(ctx, wantKey.Key.Key()).(type) {
+ itemBody := o.rebuilt.Tree(ctx, wantKey.TreeID).ReadItem(ctx, wantKey.Key.Key())
+ defer itemBody.Free()
+ switch itemBody := itemBody.(type) {
case *btrfsitem.UUIDMap:
return itemBody.ObjID, true
case *btrfsitem.Error:
--
cgit v1.2.3-2-g168b