node: don't mkdir random paths from configuration

Unbreak peapods:
  2023/09/13 18:50:36 open shard S4wpuCnzpWW7SbwhER3U1v: could not open *blobstor.BlobStor: open substorage peapod: open BoltDB instance: open /storage/peapod0.db: is a directory

Call `stat()` gently instead walking up. FS mount point has to exist there in
any event and we should have some access to it.

The real problem is that #2462 (introducing Peapod) was correct on its own.
And #2495 (introducing capacity) was also correct on its own. But they don't
work together.

Refs 7c54307.
Refs c060b16.

util.MkdirAllX will be removed from code in most of the cases.

Signed-off-by: Roman Khimov <roman@nspcc.ru>

CHANGELOG.md

@@ -4,6 +4,7 @@ Changelog for NeoFS Node
 ## [Unreleased]
 
 ### Fixed
+- Inability to start node with peapods configured (#2576)
 
 ### Removed
 

cmd/neofs-node/config.go

@@ -4,9 +4,11 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"io/fs"
 	"net"
 	"os"
 	"os/signal"
+	"path/filepath"
 	"sync"
 	atomicstd "sync/atomic"
 	"syscall"
@@ -931,13 +933,21 @@ func writeSystemAttributes(c *cfg) error {
 	var paths []string
 	for _, sh := range c.applicationConfiguration.EngineCfg.shards {
 		for _, subStorage := range sh.SubStorages {
-			path := subStorage.Path
+			var path = subStorage.Path
+
+			for len(path) > 1 { // Dir returns / or . if nothing else left.
+				fi, err := os.Stat(path)
+				if err == nil && fi.IsDir() {
+					break
+				}
+				if err != nil && !errors.Is(err, fs.ErrNotExist) {
+					return fmt.Errorf("accessing %q: %w", path, err)
+				}
+				path = filepath.Dir(path)
+			}
+
 			paths = append(paths, path)
 
-			err := util.MkdirAllX(path, subStorage.Perm)
-			if err != nil {
-				return fmt.Errorf("can not create (ensure it exists) dir by '%s' path: %w", path, err)
-			}
 		}
 	}