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 void RGWGC::initialize(CephContext *_cct, RGWRados *_store) {
  24   cct = _cct;
  25   store = _store;
  26
  27   max_objs = min(cct->_conf->rgw_gc_max_objs, rgw_shards_max());
  28
  29   obj_names = new string[max_objs];
  30
  31   for (int i = 0; i < max_objs; i++) {
  32     obj_names[i] = gc_oid_prefix;
  33     char buf[32];
  34     snprintf(buf, 32, ".%d", i);
  35     obj_names[i].append(buf);
  36   }
  37 }
  38
  39 void RGWGC::finalize()
  40 {
  41   delete[] obj_names;
  42 }
  43
  44 int RGWGC::tag_index(const string& tag)
  45 {
  46   return rgw_shards_hash(tag, max_objs);
  47 }
  48
  49 void RGWGC::add_chain(ObjectWriteOperation& op, cls_rgw_obj_chain& chain, const string& tag)
  50 {
  51   cls_rgw_gc_obj_info info;
  52   info.chain = chain;
  53   info.tag = tag;
  54
  55   cls_rgw_gc_set_entry(op, cct->_conf->rgw_gc_obj_min_wait, info);
  56 }
  57
  58 int RGWGC::send_chain(cls_rgw_obj_chain& chain, const string& tag, bool sync)
  59 {
  60   ObjectWriteOperation op;
  61   add_chain(op, chain, tag);
  62
  63   int i = tag_index(tag);
  64
  65   if (sync)
  66     return store->gc_operate(obj_names[i], &op);
  67
  68   return store->gc_aio_operate(obj_names[i], &op);
  69 }
  70
  71 int RGWGC::defer_chain(const string& tag, bool sync)
  72 {
  73   ObjectWriteOperation op;
  74   cls_rgw_gc_defer_entry(op, cct->_conf->rgw_gc_obj_min_wait, tag);
  75
  76   int i = tag_index(tag);
  77
  78   if (sync)
  79     return store->gc_operate(obj_names[i], &op);
  80
  81   return store->gc_aio_operate(obj_names[i], &op);
  82 }
  83
  84 int RGWGC::remove(int index, const std::list<string>& tags)
  85 {
  86   ObjectWriteOperation op;
  87   cls_rgw_gc_remove(op, tags);
  88   return store->gc_operate(obj_names[index], &op);
  89 }
  90
  91 int RGWGC::list(int *index, string& marker, uint32_t max, bool expired_only, std::list<cls_rgw_gc_obj_info>& result, bool *truncated)
  92 {
  93   result.clear();
  94   string next_marker;
  95
  96   for (; *index < max_objs && result.size() < max; (*index)++, marker.clear()) {
  97     std::list<cls_rgw_gc_obj_info> entries;
  98     int ret = cls_rgw_gc_list(store->gc_pool_ctx, obj_names[*index], marker, max - result.size(), expired_only, entries, truncated, next_marker);
  99     if (ret == -ENOENT)
 100       continue;
 101     if (ret < 0)
 102       return ret;
 103
 104     std::list<cls_rgw_gc_obj_info>::iterator iter;
 105     for (iter = entries.begin(); iter != entries.end(); ++iter) {
 106       result.push_back(*iter);
 107     }
 108
 109     marker = next_marker;
 110
 111     if (*index == max_objs - 1) {
 112       /* we cut short here, truncated will hold the correct value */
 113       return 0;
 114     }
 115
 116     if (result.size() == max) {
 117       /* close approximation, it might be that the next of the objects don't hold
 118        * anything, in this case truncated should have been false, but we can find
 119        * that out on the next iteration
 120        */
 121       *truncated = true;
 122       return 0;
 123     }
 124
 125   }
 126   *truncated = false;
 127
 128   return 0;
 129 }
 130
 131 int RGWGC::process(int index, int max_secs)
 132 {
 133   rados::cls::lock::Lock l(gc_index_lock_name);
 134   utime_t end = ceph_clock_now();
 135   std::list<string> remove_tags;
 136
 137   /* max_secs should be greater than zero. We don't want a zero max_secs
 138    * to be translated as no timeout, since we'd then need to break the
 139    * lock and that would require a manual intervention. In this case
 140    * we can just wait it out. */
 141   if (max_secs <= 0)
 142     return -EAGAIN;
 143
 144   end += max_secs;
 145   utime_t time(max_secs, 0);
 146   l.set_duration(time);
 147
 148   int ret = l.lock_exclusive(&store->gc_pool_ctx, obj_names[index]);
 149   if (ret == -EBUSY) { /* already locked by another gc processor */
 150     dout(10) << "RGWGC::process() failed to acquire lock on " << obj_names[index] << dendl;
 151     return 0;
 152   }
 153   if (ret < 0)
 154     return ret;
 155
 156   string marker;
 157   string next_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, next_marker);
 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(5) << "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     if (!remove_tags.empty()) {
 226       RGWGC::remove(index, remove_tags);
 227       remove_tags.clear();
 228     }
 229   } while (truncated);
 230
 231 done:
 232   if (!remove_tags.empty())
 233     RGWGC::remove(index, remove_tags);
 234   l.unlock(&store->gc_pool_ctx, obj_names[index]);
 235   delete ctx;
 236   return 0;
 237 }
 238
 239 int RGWGC::process()
 240 {
 241   int max_secs = cct->_conf->rgw_gc_processor_max_time;
 242
 243   unsigned start;
 244   int ret = get_random_bytes((char *)&start, sizeof(start));
 245   if (ret < 0)
 246     return ret;
 247
 248   for (int i = 0; i < max_objs; i++) {
 249     int index = (i + start) % max_objs;
 250     ret = process(index, max_secs);
 251     if (ret < 0)
 252       return ret;
 253   }
 254
 255   return 0;
 256 }
 257
 258 bool RGWGC::going_down()
 259 {
 260   return down_flag;
 261 }
 262
 263 void RGWGC::start_processor()
 264 {
 265   worker = new GCWorker(cct, this);
 266   worker->create("rgw_gc");
 267 }
 268
 269 void RGWGC::stop_processor()
 270 {
 271   down_flag = true;
 272   if (worker) {
 273     worker->stop();
 274     worker->join();
 275   }
 276   delete worker;
 277   worker = NULL;
 278 }
 279
 280 void *RGWGC::GCWorker::entry() {
 281   do {
 282     utime_t start = ceph_clock_now();
 283     dout(2) << "garbage collection: start" << dendl;
 284     int r = gc->process();
 285     if (r < 0) {
 286       dout(0) << "ERROR: garbage collection process() returned error r=" << r << dendl;
 287     }
 288     dout(2) << "garbage collection: stop" << dendl;
 289
 290     if (gc->going_down())
 291       break;
 292
 293     utime_t end = ceph_clock_now();
 294     end -= start;
 295     int secs = cct->_conf->rgw_gc_processor_period;
 296
 297     if (secs <= end.sec())
 298       continue; // next round
 299
 300     secs -= end.sec();
 301
 302     lock.Lock();
 303     cond.WaitInterval(lock, utime_t(secs, 0));
 304     lock.Unlock();
 305   } while (!gc->going_down());
 306
 307   return NULL;
 308 }
 309
 310 void RGWGC::GCWorker::stop()
 311 {
 312   Mutex::Locker l(lock);
 313   cond.Signal();
 314 }
 315