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->dn_set.empty()) {
  43     return;
  44   }
  45
  46   Dentry* dn = *(ino->dn_set.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->dn_set.empty()) {
  65       Dentry *dn = *(inode->dn_set.begin());
  66       assert(dn->dir);
  67       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       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   env_to_vec(args);
  88
  89   auto cct = global_init(NULL, args, CEPH_ENTITY_TYPE_CLIENT,
  90                          CODE_ENVIRONMENT_UTILITY,
  91                          CINIT_FLAG_UNPRIVILEGED_DAEMON_DEFAULTS);
  92
  93   common_init_finish(g_ceph_context);
  94
  95   // Expect exactly one positional argument (inode number)
  96   if (args.size() != 1) {
  97     usage();
  98   }
  99   char const *inode_str = args[0];
 100   inodeno_t inode = strtoll(inode_str, NULL, 0);
 101   if (inode <= 0) {
 102     derr << "Invalid inode: " << inode_str << dendl;
 103     return -1;
 104   }
 105
 106   // Initialize filesystem client
 107   struct ceph_mount_info *client;
 108   int r = ceph_create_with_context(&client, g_ceph_context);
 109   if (r) {
 110     derr << "Error initializing libcephfs: " << cpp_strerror(r) << dendl;
 111     return r;
 112   }
 113
 114   r = ceph_mount(client, "/");
 115   if (r) {
 116     derr << "Error mounting: " << cpp_strerror(r) << dendl;
 117     ceph_shutdown(client);
 118     return r;
 119   }
 120
 121
 122   // Populate client cache with inode of interest & ancestors
 123   r = lookup_trace(client, inode);
 124   if (r) {
 125     derr << "Error looking up inode " << std::hex << inode << std::dec <<
 126       ": " << cpp_strerror(r) << dendl;
 127     return -1;
 128   }
 129
 130   // Retrieve inode of interest
 131   struct vinodeno_t vinode;
 132   vinode.ino = inode;
 133   vinode.snapid = CEPH_NOSNAP;
 134   Inode *ino = ceph_ll_get_inode(client, vinode);
 135
 136   // Retrieve dentry trace
 137   std::vector<Dentry*> path;
 138   traverse_dentries(ino, path);
 139
 140   // Print inode and path as a JSON object
 141   JSONFormatter jf(true);
 142   jf.open_object_section("client_debug");
 143   {
 144     jf.open_object_section("inode");
 145     {
 146       ino->dump(&jf);
 147     }
 148     jf.close_section(); // inode
 149     jf.open_array_section("path");
 150     {
 151       for (std::vector<Dentry*>::reverse_iterator p = path.rbegin(); p != path.rend(); ++p) {
 152         jf.open_object_section("dentry");
 153         {
 154           (*p)->dump(&jf);
 155         }
 156         jf.close_section(); // dentry
 157       }
 158     }
 159     jf.close_section(); // path
 160   }
 161   jf.close_section(); // client_debug
 162   jf.flush(std::cout);
 163   std::cout << std::endl;
 164
 165   // Release Inode references
 166   ceph_ll_forget(client, ino, 1);
 167   for (std::vector<Dentry*>::reverse_iterator p = path.rbegin(); p != path.rend(); ++p) {
 168     ceph_ll_forget(client, (*p)->inode.get(), 1);
 169   }
 170   ino = NULL;
 171   path.clear();
 172
 173   // Shut down
 174   r = ceph_unmount(client);
 175   if (r) {
 176     derr << "Error mounting: " << cpp_strerror(r) << dendl;
 177   }
 178   ceph_shutdown(client);
 179
 180   return r;
 181 }