From 624b86d06571f69adbf930e15effb69b940c5369 Mon Sep 17 00:00:00 2001
From: Aliaksandr Valialkin <valyala@victoriametrics.com>
Date: Thu, 13 Apr 2023 22:48:05 -0700
Subject: [PATCH] lib/fs: rename HardLinkFiles to MustHardLinkFiles

Callers of this function log the returned error and then exit.
Let's log the error with the call stack inside the function itself.
This simplifies the code at callers' side, while leaving the same
level of debuggability in case of errors.
---
 lib/fs/fs.go             | 9 ++++-----
 lib/mergeset/table.go    | 4 +---
 lib/storage/partition.go | 4 +---
 3 files changed, 6 insertions(+), 11 deletions(-)

diff --git a/lib/fs/fs.go b/lib/fs/fs.go
index c86eef2335..726a123de7 100644
--- a/lib/fs/fs.go
+++ b/lib/fs/fs.go
@@ -259,13 +259,13 @@ func MustRemoveTemporaryDirs(dir string) {
 	MustSyncPath(dir)
 }
 
-// HardLinkFiles makes hard links for all the files from srcDir in dstDir.
-func HardLinkFiles(srcDir, dstDir string) error {
+// MustHardLinkFiles makes hard links for all the files from srcDir in dstDir.
+func MustHardLinkFiles(srcDir, dstDir string) {
 	mustMkdirSync(dstDir)
 
 	des, err := os.ReadDir(srcDir)
 	if err != nil {
-		return fmt.Errorf("cannot read files in scrDir: %w", err)
+		logger.Panicf("FATAL: cannot read files in scrDir: %s", err)
 	}
 	for _, de := range des {
 		if IsDirOrSymlink(de) {
@@ -276,12 +276,11 @@ func HardLinkFiles(srcDir, dstDir string) error {
 		srcPath := filepath.Join(srcDir, fn)
 		dstPath := filepath.Join(dstDir, fn)
 		if err := os.Link(srcPath, dstPath); err != nil {
-			return err
+			logger.Panicf("FATAL: cannot link files: %s", err)
 		}
 	}
 
 	MustSyncPath(dstDir)
-	return nil
 }
 
 // IsDirOrSymlink returns true if de is directory or symlink.
diff --git a/lib/mergeset/table.go b/lib/mergeset/table.go
index 2c57add628..96a02ce7f5 100644
--- a/lib/mergeset/table.go
+++ b/lib/mergeset/table.go
@@ -1477,9 +1477,7 @@ func (tb *Table) CreateSnapshotAt(dstDir string, deadline uint64) error {
 		}
 		srcPartPath := pw.p.path
 		dstPartPath := filepath.Join(dstDir, filepath.Base(srcPartPath))
-		if err := fs.HardLinkFiles(srcPartPath, dstPartPath); err != nil {
-			return fmt.Errorf("cannot create hard links from %q to %q: %w", srcPartPath, dstPartPath, err)
-		}
+		fs.MustHardLinkFiles(srcPartPath, dstPartPath)
 	}
 
 	fs.MustSyncPath(dstDir)
diff --git a/lib/storage/partition.go b/lib/storage/partition.go
index 096eeb5934..5761a54731 100644
--- a/lib/storage/partition.go
+++ b/lib/storage/partition.go
@@ -1897,9 +1897,7 @@ func (pt *partition) createSnapshot(srcDir, dstDir string, pws []*partWrapper) e
 	for _, pw := range pws {
 		srcPartPath := pw.p.path
 		dstPartPath := filepath.Join(dstDir, filepath.Base(srcPartPath))
-		if err := fs.HardLinkFiles(srcPartPath, dstPartPath); err != nil {
-			return fmt.Errorf("cannot create hard links from %q to %q: %w", srcPartPath, dstPartPath, err)
-		}
+		fs.MustHardLinkFiles(srcPartPath, dstPartPath)
 	}
 
 	// Copy the appliedRetentionFilename to dstDir.