Add subcommand getpath to eden debug

Summary: Add a command to lookup the path for an inode given the inode number and eden mount path.

Reviewed By: bolinfest

Differential Revision: D5627411

fbshipit-source-id: 25928f506d3f48d8a6784fe81fb17fa0500d6bc9

eden/cli/debug.py

@@ -302,6 +302,18 @@ def do_overlay(args: argparse.Namespace):
         _display_overlay(args, overlay_dir, 1, '/')
 
 
+def do_getpath(args: argparse.Namespace):
+    config = cmd_util.create_config(args)
+
+    mount, _ = get_mount_path(args.mount)
+
+    with config.get_thrift_client() as client:
+        inodePathInfo = client.debugGetInodePath(mount, args.number)
+        print('%s %s' %
+              ('loaded' if inodePathInfo.loaded else 'unloaded',
+               os.path.normpath(os.path.join(mount, inodePathInfo.path))))
+
+
 def get_loaded_inode_count(inode_info):
     count = 0
     for tree in inode_info:
@@ -388,6 +400,17 @@ def setup_argparse(parser: argparse.ArgumentParser):
         help='The path to the eden mount point.')
     parser.set_defaults(func=do_overlay)
 
+    parser = subparsers.add_parser(
+        'getpath', help='Get the eden path that corresponds to an inode number')
+    parser.add_argument(
+        'mount',
+        help='The path to the eden mount point.')
+    parser.add_argument(
+        'number',
+        type=int,
+        help='Display information for the specified inode number.')
+    parser.set_defaults(func=do_getpath)
+
     parser = subparsers.add_parser(
         'unload', help='Unload unused inodes')
     parser.add_argument(

eden/fs/service/EdenServiceHandler.cpp

@@ -25,6 +25,7 @@
 #include "eden/fs/inodes/EdenMount.h"
 #include "eden/fs/inodes/FileInode.h"
 #include "eden/fs/inodes/InodeError.h"
+#include "eden/fs/inodes/InodeMap.h"
 #include "eden/fs/inodes/Overlay.h"
 #include "eden/fs/inodes/TreeInode.h"
 #include "eden/fs/model/Blob.h"
@@ -592,6 +593,36 @@ void EdenServiceHandler::debugInodeStatus(
 
   inode->getDebugStatus(inodeInfo);
 }
+
+void EdenServiceHandler::debugGetInodePath(
+    InodePathDebugInfo& info,
+    std::unique_ptr<std::string> mountPoint,
+    int64_t inodeNumber) {
+  auto inodeNum = static_cast<fuse_ino_t>(inodeNumber);
+  auto edenMount = server_->getMount(*mountPoint);
+  auto inodeMap = edenMount->getInodeMap();
+
+  // Check if the inode is loaded
+  auto loadedData = inodeMap->lookupLoadedInode(inodeNum);
+  if (loadedData == nullptr) {
+    XLOG(INFO) << "looking up unloaded inode " << inodeNum;
+    // If it's not, check if it's unloaded. If the inodeNum is invalid, this
+    // lookup will throw
+    auto unloadedData = inodeMap->lookupUnloadedInode(inodeNum);
+    info.path = unloadedData.name.stringPiece().str();
+    info.loaded = false;
+  } else {
+    // If the inode is loaded, return its path
+    auto path = loadedData->getPath();
+    if (path) {
+      info.path = path->stringPiece().str();
+      info.loaded = true;
+    } else {
+      throw newEdenError("missing path for loaded inode {}", inodeNum);
+    }
+  }
+}
+
 void EdenServiceHandler::unloadInodeForPath(
     unique_ptr<string> mountPoint,
     std::unique_ptr<std::string> path) {

eden/fs/service/EdenServiceHandler.h

@@ -145,6 +145,11 @@ class EdenServiceHandler : virtual public StreamingEdenServiceSvIf,
       std::unique_ptr<std::string> mountPoint,
       std::unique_ptr<std::string> path) override;
 
+  void debugGetInodePath(
+      InodePathDebugInfo& inodePath,
+      std::unique_ptr<std::string> mountPoint,
+      int64_t inodeNumber) override;
+
   void unloadInodeForPath(
       std::unique_ptr<std::string> mountPoint,
       std::unique_ptr<std::string> path) override;

eden/fs/service/eden.thrift

@@ -211,6 +211,11 @@ struct TreeInodeDebugInfo {
   6: i64 refcount
 }
 
+struct InodePathDebugInfo {
+  1: string path
+  2: bool loaded
+}
+
 service EdenService extends fb303.FacebookService {
   list<MountInfo> listMounts() throws (1: EdenError ex)
   void mount(1: MountInfo info) throws (1: EdenError ex)
@@ -432,6 +437,17 @@ service EdenService extends fb303.FacebookService {
     2: string path,
   ) throws (1: EdenError ex)
 
+  /**
+   * Get the InodePathDebugInfo for the inode that corresponds to the given
+   * inode number. This provides the path for the inode and also indicates
+   * whether the inode is currently loaded or not. Requires that the Eden
+   * mountPoint be specified.
+   */
+  InodePathDebugInfo debugGetInodePath(
+    1: string mountPoint,
+    2: i64 inodeNumber,
+  ) throws (1: EdenError ex)
+
   /**
   * Unloads unused Inodes of a tree Node
   */

eden/integration/debug_getpath_test.py

@@ -0,0 +1,63 @@
+#!/usr/bin/env python3
+#
+# Copyright (c) 2016-present, Facebook, Inc.
+# All rights reserved.
+#
+# This source code is licensed under the BSD-style license found in the
+# LICENSE file in the root directory of this source tree. An additional grant
+# of patent rights can be found in the PATENTS file in the same directory.
+
+from .lib import testcase, edenclient
+import os
+
+# This is the name of the default repository created by EdenRepoTestBase.
+repo_name = 'main'
+
+
+@testcase.eden_repo_test
+class DebugGetPathTest:
+    def populate_repo(self):
+        self.repo.write_file('hello', 'hola\n')
+        self.repo.write_file(os.path.join('dir', 'file'), 'blah\n')
+        self.repo.commit('Initial commit.')
+
+    def test_getpath_root_inode(self):
+        '''
+        Test that calling `eden debug getname 1` returns the path to the eden
+        mount, and indicates that the inode is loaded.
+        '''
+        output = self.eden.run_cmd(
+            'debug',
+            'getpath',
+            self.mount,
+            '1')
+
+        self.assertEqual('loaded ' + self.mount + '\n', output)
+
+    def test_getpath_dot_eden_inode(self):
+        '''
+        Test that calling `eden debug getname 2` returns the path to the .eden
+        directory, and indicates that the inode is loaded.
+        '''
+        output = self.eden.run_cmd(
+            'debug',
+            'getpath',
+            self.mount,
+            '2')
+
+        self.assertEqual(
+            'loaded ' + os.path.join(self.mount, ".eden") + '\n',
+            output)
+
+    def test_getpath_invalid_inode(self):
+        '''
+        Test that calling `eden debug getname 1234` raises an error since
+        1234 is not a valid inode number
+        '''
+        with self.assertRaises(edenclient.EdenCommandError) as context:
+            self.eden.run_cmd(
+                'debug',
+                'getpath',
+                self.mount,
+                '1234')
+            self.assertIn('unknown inode number 1234', str(context.exception))