ceph/src/tools/ceph-client-debug.cc

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab
   3 /*
   4  * Ceph - scalable distributed file system
   5  *
   6  * Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
   7  *
   8  * This is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License version 2.1, as published by the Free Software
  11  * Foundation.  See file COPYING.
  12  *
  13  */
  14
  15
  16 #include "common/ceph_argparse.h"
  17 #include "global/global_init.h"
  18 #include "common/Formatter.h"
  19 #include "common/debug.h"
  20 #include "common/errno.h"
  21 #include "client/Inode.h"
  22 #include "client/Dentry.h"
  23 #include "client/Dir.h"
  24 #include "include/cephfs/libcephfs.h"
  25
  26 #define dout_context g_ceph_context
  27 #define dout_subsys ceph_subsys_client
  28
  29 void usage()
  30 {
  31   std::cout << "Usage: ceph-client-debug [options] <inode number>" << std::endl;
  32   generic_client_usage();
  33 }
  34
  35
  36 /**
  37  * Given an inode, look up the path from the Client cache: assumes
  38  * client cache is fully populated.
  39  */
  40 void traverse_dentries(Inode *ino, std::vector<Dentry*> &parts)
  41 {
  42   if (ino->dentries.empty()) {
  43     return;
  44   }
  45
  46   Dentry* dn = *(ino->dentries.begin());
  47   parts.push_back(dn);
  48   traverse_dentries(dn->dir->parent_inode, parts);
  49 }
  50
  51
  52 /**
  53  * Given an inode, send lookup requests to the MDS for
  54  * all its ancestors, such that the full trace will be
  55  * populated in client cache.
  56  */
  57 int lookup_trace(ceph_mount_info *client, inodeno_t const ino)
  58 {
  59   Inode *inode;
  60   int r = ceph_ll_lookup_inode(client, ino, &inode);
  61   if (r != 0) {
  62     return r;
  63   } else {
  64     if (!inode->dentries.empty()) {
  65       Dentry *dn = *(inode->dentries.begin());
  66       ceph_assert(dn->dir);
  67       ceph_assert(dn->dir->parent_inode);
  68       r = lookup_trace(client, dn->dir->parent_inode->ino);
  69       if (r) {
  70         return r;
  71       }
  72     } else {
  73       // We reached the root of the tree
  74       ceph_assert(inode->ino == CEPH_INO_ROOT);
  75     }
  76   }
  77
  78   return r;
  79 }
  80
  81
  82 int main(int argc, const char **argv)
  83 {
  84   // Argument handling
  85   vector<const char*> args;
  86   argv_to_vec(argc, argv, args);
  87   if (args.empty()) {
  88     cerr << argv[0] << ": -h or --help for usage" << std::endl;
  89     exit(1);
  90   }
  91   if (ceph_argparse_need_usage(args)) {
  92     usage();
  93     exit(0);
  94   }
  95
  96   auto cct = global_init(NULL, args, CEPH_ENTITY_TYPE_CLIENT,
  97                          CODE_ENVIRONMENT_UTILITY,
  98                          CINIT_FLAG_UNPRIVILEGED_DAEMON_DEFAULTS|
  99                          CINIT_FLAG_NO_DEFAULT_CONFIG_FILE);
 100
 101   common_init_finish(g_ceph_context);
 102
 103   // Expect exactly one positional argument (inode number)
 104   if (args.size() != 1) {
 105     cerr << "missing position argument (inode number)" << std::endl;
 106     exit(1);
 107   }
 108   char const *inode_str = args[0];
 109   inodeno_t inode = strtoll(inode_str, NULL, 0);
 110   if (inode <= 0) {
 111     derr << "Invalid inode: " << inode_str << dendl;
 112     return -1;
 113   }
 114
 115   // Initialize filesystem client
 116   struct ceph_mount_info *client;
 117   int r = ceph_create_with_context(&client, g_ceph_context);
 118   if (r) {
 119     derr << "Error initializing libcephfs: " << cpp_strerror(r) << dendl;
 120     return r;
 121   }
 122
 123   r = ceph_mount(client, "/");
 124   if (r) {
 125     derr << "Error mounting: " << cpp_strerror(r) << dendl;
 126     ceph_shutdown(client);
 127     return r;
 128   }
 129
 130
 131   // Populate client cache with inode of interest & ancestors
 132   r = lookup_trace(client, inode);
 133   if (r) {
 134     derr << "Error looking up inode " << std::hex << inode << std::dec <<
 135       ": " << cpp_strerror(r) << dendl;
 136     return -1;
 137   }
 138
 139   // Retrieve inode of interest
 140   struct vinodeno_t vinode;
 141   vinode.ino = inode;
 142   vinode.snapid = CEPH_NOSNAP;
 143   Inode *ino = ceph_ll_get_inode(client, vinode);
 144
 145   // Retrieve dentry trace
 146   std::vector<Dentry*> path;
 147   traverse_dentries(ino, path);
 148
 149   // Print inode and path as a JSON object
 150   JSONFormatter jf(true);
 151   jf.open_object_section("client_debug");
 152   {
 153     jf.open_object_section("inode");
 154     {
 155       ino->dump(&jf);
 156     }
 157     jf.close_section(); // inode
 158     jf.open_array_section("path");
 159     {
 160       for (std::vector<Dentry*>::reverse_iterator p = path.rbegin(); p != path.rend(); ++p) {
 161         jf.open_object_section("dentry");
 162         {
 163           (*p)->dump(&jf);
 164         }
 165         jf.close_section(); // dentry
 166       }
 167     }
 168     jf.close_section(); // path
 169   }
 170   jf.close_section(); // client_debug
 171   jf.flush(std::cout);
 172   std::cout << std::endl;
 173
 174   // Release Inode references
 175   ceph_ll_forget(client, ino, 1);
 176   for (std::vector<Dentry*>::reverse_iterator p = path.rbegin(); p != path.rend(); ++p) {
 177     ceph_ll_forget(client, (*p)->inode.get(), 1);
 178   }
 179   ino = NULL;
 180   path.clear();
 181
 182   // Shut down
 183   r = ceph_unmount(client);
 184   if (r) {
 185     derr << "Error mounting: " << cpp_strerror(r) << dendl;
 186   }
 187   ceph_shutdown(client);
 188
 189   return r;
 190 }