[autofile/group] do not panic when checking size

It's OK if the head will grow a little bit bigger, but we'll avoid
panic.

Refs #2703

CHANGELOG_PENDING.md

@@ -29,3 +29,4 @@ Friendly reminder, we have a [bug bounty program](https://hackerone.com/tendermi
 - [crypto/merkle] [\#2756](https://github.com/tendermint/tendermint/issues/2756) Fix crypto/merkle ProofOperators.Verify to check bounds on keypath parts.
 - [mempool] fix a bug where we create a WAL despite `wal_dir` being empty
 - [p2p] \#2771 Fix `peer-id` label name in prometheus metrics
+- [autofile] [\#2703] do not panic when checking Head size

libs/autofile/group.go

@@ -230,7 +230,8 @@ func (g *Group) checkHeadSizeLimit() {
 	}
 	size, err := g.Head.Size()
 	if err != nil {
-		panic(err)
+		g.Logger.Error("Group's head may grow without bound", "head", g.Head.Path, "err", err)
+		return
 	}
 	if size >= limit {
 		g.RotateFile()
@@ -252,11 +253,11 @@ func (g *Group) checkTotalSizeLimit() {
 		}
 		if index == gInfo.MaxIndex {
 			// Special degenerate case, just do nothing.
-			g.Logger.Info("Group's head may grow without bound", "head", g.Head.Path)
+			g.Logger.Error("Group's head may grow without bound", "head", g.Head.Path)
 			return
 		}
 		pathToRemove := filePathForIndex(g.Head.Path, index, gInfo.MaxIndex)
-		fileInfo, err := os.Stat(pathToRemove)
+		fInfo, err := os.Stat(pathToRemove)
 		if err != nil {
 			g.Logger.Error("Failed to fetch info for file", "file", pathToRemove)
 			continue
@@ -266,7 +267,7 @@ func (g *Group) checkTotalSizeLimit() {
 			g.Logger.Error("Failed to remove path", "path", pathToRemove)
 			return
 		}
-		totalSize -= fileInfo.Size()
+		totalSize -= fInfo.Size()
 	}
 }