ceph/src/rgw/rgw_gc.cc

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab
   3
   4 #include "rgw_gc.h"
   5 #include "include/rados/librados.hpp"
   6 #include "cls/rgw/cls_rgw_client.h"
   7 #include "cls/refcount/cls_refcount_client.h"
   8 #include "cls/lock/cls_lock_client.h"
   9 #include "auth/Crypto.h"
  10
  11 #include <list>
  12
  13 #define dout_context g_ceph_context
  14 #define dout_subsys ceph_subsys_rgw
  15
  16 using namespace std;
  17 using namespace librados;
  18
  19 static string gc_oid_prefix = "gc";
  20 static string gc_index_lock_name = "gc_process";
  21
  22
  23 #define HASH_PRIME 7877
  24
  25 void RGWGC::initialize(CephContext *_cct, RGWRados *_store) {
  26   cct = _cct;
  27   store = _store;
  28
  29   max_objs = cct->_conf->rgw_gc_max_objs;
  30   if (max_objs > HASH_PRIME)
  31     max_objs = HASH_PRIME;
  32
  33   obj_names = new string[max_objs];
  34
  35   for (int i = 0; i < max_objs; i++) {
  36     obj_names[i] = gc_oid_prefix;
  37     char buf[32];
  38     snprintf(buf, 32, ".%d", i);
  39     obj_names[i].append(buf);
  40   }
  41 }
  42
  43 void RGWGC::finalize()
  44 {
  45   delete[] obj_names;
  46 }
  47
  48 int RGWGC::tag_index(const string& tag)
  49 {
  50   return ceph_str_hash_linux(tag.c_str(), tag.size()) % HASH_PRIME % max_objs;
  51 }
  52
  53 void RGWGC::add_chain(ObjectWriteOperation& op, cls_rgw_obj_chain& chain, const string& tag)
  54 {
  55   cls_rgw_gc_obj_info info;
  56   info.chain = chain;
  57   info.tag = tag;
  58
  59   cls_rgw_gc_set_entry(op, cct->_conf->rgw_gc_obj_min_wait, info);
  60 }
  61
  62 int RGWGC::send_chain(cls_rgw_obj_chain& chain, const string& tag, bool sync)
  63 {
  64   ObjectWriteOperation op;
  65   add_chain(op, chain, tag);
  66
  67   int i = tag_index(tag);
  68
  69   if (sync)
  70     return store->gc_operate(obj_names[i], &op);
  71
  72   return store->gc_aio_operate(obj_names[i], &op);
  73 }
  74
  75 int RGWGC::defer_chain(const string& tag, bool sync)
  76 {
  77   ObjectWriteOperation op;
  78   cls_rgw_gc_defer_entry(op, cct->_conf->rgw_gc_obj_min_wait, tag);
  79
  80   int i = tag_index(tag);
  81
  82   if (sync)
  83     return store->gc_operate(obj_names[i], &op);
  84
  85   return store->gc_aio_operate(obj_names[i], &op);
  86 }
  87
  88 int RGWGC::remove(int index, const std::list<string>& tags)
  89 {
  90   ObjectWriteOperation op;
  91   cls_rgw_gc_remove(op, tags);
  92   return store->gc_operate(obj_names[index], &op);
  93 }
  94
  95 int RGWGC::list(int *index, string& marker, uint32_t max, bool expired_only, std::list<cls_rgw_gc_obj_info>& result, bool *truncated)
  96 {
  97   result.clear();
  98
  99   for (; *index < max_objs && result.size() < max; (*index)++, marker.clear()) {
 100     std::list<cls_rgw_gc_obj_info> entries;
 101     int ret = cls_rgw_gc_list(store->gc_pool_ctx, obj_names[*index], marker, max - result.size(), expired_only, entries, truncated);
 102     if (ret == -ENOENT)
 103       continue;
 104     if (ret < 0)
 105       return ret;
 106
 107     std::list<cls_rgw_gc_obj_info>::iterator iter;
 108     for (iter = entries.begin(); iter != entries.end(); ++iter) {
 109       result.push_back(*iter);
 110     }
 111
 112     if (*index == max_objs - 1) {
 113       /* we cut short here, truncated will hold the correct value */
 114       return 0;
 115     }
 116
 117     if (result.size() == max) {
 118       /* close approximation, it might be that the next of the objects don't hold
 119        * anything, in this case truncated should have been false, but we can find
 120        * that out on the next iteration
 121        */
 122       *truncated = true;
 123       return 0;
 124     }
 125
 126   }
 127   *truncated = false;
 128
 129   return 0;
 130 }
 131
 132 int RGWGC::process(int index, int max_secs)
 133 {
 134   rados::cls::lock::Lock l(gc_index_lock_name);
 135   utime_t end = ceph_clock_now();
 136   std::list<string> remove_tags;
 137
 138   /* max_secs should be greater than zero. We don't want a zero max_secs
 139    * to be translated as no timeout, since we'd then need to break the
 140    * lock and that would require a manual intervention. In this case
 141    * we can just wait it out. */
 142   if (max_secs <= 0)
 143     return -EAGAIN;
 144
 145   end += max_secs;
 146   utime_t time(max_secs, 0);
 147   l.set_duration(time);
 148
 149   int ret = l.lock_exclusive(&store->gc_pool_ctx, obj_names[index]);
 150   if (ret == -EBUSY) { /* already locked by another gc processor */
 151     dout(0) << "RGWGC::process() failed to acquire lock on " << obj_names[index] << dendl;
 152     return 0;
 153   }
 154   if (ret < 0)
 155     return ret;
 156
 157   string marker;
 158   bool truncated;
 159   IoCtx *ctx = new IoCtx;
 160   do {
 161     int max = 100;
 162     std::list<cls_rgw_gc_obj_info> entries;
 163     ret = cls_rgw_gc_list(store->gc_pool_ctx, obj_names[index], marker, max, true, entries, &truncated);
 164     if (ret == -ENOENT) {
 165       ret = 0;
 166       goto done;
 167     }
 168     if (ret < 0)
 169       goto done;
 170
 171     string last_pool;
 172     std::list<cls_rgw_gc_obj_info>::iterator iter;
 173     for (iter = entries.begin(); iter != entries.end(); ++iter) {
 174       bool remove_tag;
 175       cls_rgw_gc_obj_info& info = *iter;
 176       std::list<cls_rgw_obj>::iterator liter;
 177       cls_rgw_obj_chain& chain = info.chain;
 178
 179       utime_t now = ceph_clock_now();
 180       if (now >= end)
 181         goto done;
 182
 183       remove_tag = true;
 184       for (liter = chain.objs.begin(); liter != chain.objs.end(); ++liter) {
 185         cls_rgw_obj& obj = *liter;
 186
 187         if (obj.pool != last_pool) {
 188           delete ctx;
 189           ctx = new IoCtx;
 190           ret = rgw_init_ioctx(store->get_rados_handle(), obj.pool, *ctx);
 191           if (ret < 0) {
 192             dout(0) << "ERROR: failed to create ioctx pool=" << obj.pool << dendl;
 193             continue;
 194           }
 195           last_pool = obj.pool;
 196         }
 197
 198         ctx->locator_set_key(obj.loc);
 199
 200         const string& oid = obj.key.name; /* just stored raw oid there */
 201
 202         dout(0) << "gc::process: removing " << obj.pool << ":" << obj.key.name << dendl;
 203         ObjectWriteOperation op;
 204         cls_refcount_put(op, info.tag, true);
 205         ret = ctx->operate(oid, &op);
 206         if (ret == -ENOENT)
 207           ret = 0;
 208         if (ret < 0) {
 209           remove_tag = false;
 210           dout(0) << "failed to remove " << obj.pool << ":" << oid << "@" << obj.loc << dendl;
 211         }
 212
 213         if (going_down()) // leave early, even if tag isn't removed, it's ok
 214           goto done;
 215       }
 216       if (remove_tag) {
 217         remove_tags.push_back(info.tag);
 218 #define MAX_REMOVE_CHUNK 16
 219         if (remove_tags.size() > MAX_REMOVE_CHUNK) {
 220           RGWGC::remove(index, remove_tags);
 221           remove_tags.clear();
 222         }
 223       }
 224     }
 225   } while (truncated);
 226
 227 done:
 228   if (!remove_tags.empty())
 229     RGWGC::remove(index, remove_tags);
 230   l.unlock(&store->gc_pool_ctx, obj_names[index]);
 231   delete ctx;
 232   return 0;
 233 }
 234
 235 int RGWGC::process()
 236 {
 237   int max_secs = cct->_conf->rgw_gc_processor_max_time;
 238
 239   unsigned start;
 240   int ret = get_random_bytes((char *)&start, sizeof(start));
 241   if (ret < 0)
 242     return ret;
 243
 244   for (int i = 0; i < max_objs; i++) {
 245     int index = (i + start) % max_objs;
 246     ret = process(index, max_secs);
 247     if (ret < 0)
 248       return ret;
 249   }
 250
 251   return 0;
 252 }
 253
 254 bool RGWGC::going_down()
 255 {
 256   return down_flag;
 257 }
 258
 259 void RGWGC::start_processor()
 260 {
 261   worker = new GCWorker(cct, this);
 262   worker->create("rgw_gc");
 263 }
 264
 265 void RGWGC::stop_processor()
 266 {
 267   down_flag = true;
 268   if (worker) {
 269     worker->stop();
 270     worker->join();
 271   }
 272   delete worker;
 273   worker = NULL;
 274 }
 275
 276 void *RGWGC::GCWorker::entry() {
 277   do {
 278     utime_t start = ceph_clock_now();
 279     dout(2) << "garbage collection: start" << dendl;
 280     int r = gc->process();
 281     if (r < 0) {
 282       dout(0) << "ERROR: garbage collection process() returned error r=" << r << dendl;
 283     }
 284     dout(2) << "garbage collection: stop" << dendl;
 285
 286     if (gc->going_down())
 287       break;
 288
 289     utime_t end = ceph_clock_now();
 290     end -= start;
 291     int secs = cct->_conf->rgw_gc_processor_period;
 292
 293     if (secs <= end.sec())
 294       continue; // next round
 295
 296     secs -= end.sec();
 297
 298     lock.Lock();
 299     cond.WaitInterval(lock, utime_t(secs, 0));
 300     lock.Unlock();
 301   } while (!gc->going_down());
 302
 303   return NULL;
 304 }
 305
 306 void RGWGC::GCWorker::stop()
 307 {
 308   Mutex::Locker l(lock);
 309   cond.Signal();
 310 }
 311