rgw:lc: using midnight time to check obj expiration

Amazon S3 calculates the expiration time by adding the number of days specified in the rule to the object creation time and rounding the resulting time to the next day midnight.
So rgw should using the rounding down midnight time to compare with the object creation time to check obj expiration.

Fixes: http://tracker.ceph.com/issues/21533

Signed-off-by: Shasha Lu <lu.shasha@eisoo.com>

src/include/utime.h

@@ -171,6 +171,17 @@ class utime_t {
     return utime_t(tt, 0);
   }
 
+  utime_t round_to_day() {
+    struct tm bdt;
+    time_t tt = sec();
+    localtime_r(&tt, &bdt);
+    bdt.tm_sec = 0;
+    bdt.tm_min = 0;
+    bdt.tm_hour = 0;
+    tt = mktime(&bdt);
+    return utime_t(tt, 0);
+  }
+
   // cast to double
   operator double() const {
     return (double)sec() + ((double)nsec() / 1000000000.0L);

src/rgw/rgw_lc.cc

@@ -244,16 +244,20 @@ int RGWLC::bucket_lc_prepare(int index)
   return 0;
 }
 
-bool RGWLC::obj_has_expired(double timediff, int days)
+bool RGWLC::obj_has_expired(ceph::real_time mtime, int days)
 {
-  double cmp;
+  double timediff, cmp;
+  utime_t base_time;
   if (cct->_conf->rgw_lc_debug_interval <= 0) {
     /* Normal case, run properly */
     cmp = days*24*60*60;
+    base_time = ceph_clock_now().round_to_day();
   } else {
     /* We're in debug mode; Treat each rgw_lc_debug_interval seconds as a day */
     cmp = days*cct->_conf->rgw_lc_debug_interval;
+    base_time = ceph_clock_now();
   }
+  timediff = base_time - ceph::real_clock::to_time_t(m_time);
 
   return (timediff >= cmp);
 }
@@ -298,9 +302,8 @@ int RGWLC::handle_multipart_expiration(RGWRados::Bucket *target, const map<strin
           return ret;
       }
 
-      utime_t now = ceph_clock_now();
       for (auto obj_iter = objs.begin(); obj_iter != objs.end(); ++obj_iter) {
-        if (obj_has_expired(now - ceph::real_clock::to_time_t(obj_iter->meta.mtime), prefix_iter->second.mp_expiration)) {
+        if (obj_has_expired(obj_iter->meta.mtime, prefix_iter->second.mp_expiration)) {
           rgw_obj_key key(obj_iter->key);
           if (!mp_obj.from_meta(key.name)) {
             continue;
@@ -384,7 +387,6 @@ int RGWLC::bucket_lc_process(string& shard_id)
           return ret;
         }
 
-        utime_t now = ceph_clock_now();
         bool is_expired;
         for (auto obj_iter = objs.begin(); obj_iter != objs.end(); ++obj_iter) {
           rgw_obj_key key(obj_iter->key);
@@ -396,7 +398,7 @@ int RGWLC::bucket_lc_process(string& shard_id)
             //we have checked it before
             is_expired = true;
           } else {
-            is_expired = obj_has_expired(now - ceph::real_clock::to_time_t(obj_iter->meta.mtime), prefix_iter->second.expiration);
+            is_expired = obj_has_expired(obj_iter->meta.mtime, prefix_iter->second.expiration);
           }
           if (is_expired) {
             RGWObjectCtx rctx(store);
@@ -450,7 +452,6 @@ int RGWLC::bucket_lc_process(string& shard_id)
           return ret;
         }
 
-        utime_t now = ceph_clock_now();
         ceph::real_time mtime;
         bool remove_indeed = true;
         int expiration;
@@ -485,9 +486,9 @@ int RGWLC::bucket_lc_process(string& shard_id)
               continue;
             } else if (!skip_expiration) {
               if (expiration > 0) {
-                is_expired = obj_has_expired(now - ceph::real_clock::to_time_t(mtime), expiration);
+                is_expired = obj_has_expired(mtime, expiration);
               } else {
-                is_expired = now >= ceph::real_clock::to_time_t(*prefix_iter->second.expiration_date);
+                is_expired = ceph_clock_now() >= ceph::real_clock::to_time_t(*prefix_iter->second.expiration_date);
               }
             }
           } else {
@@ -497,7 +498,7 @@ int RGWLC::bucket_lc_process(string& shard_id)
             remove_indeed = true;
             mtime = (obj_iter == objs.begin())?pre_obj.meta.mtime:(obj_iter - 1)->meta.mtime;
             expiration = prefix_iter->second.noncur_expiration;
-            is_expired = obj_has_expired(now - ceph::real_clock::to_time_t(mtime), expiration);
+            is_expired = obj_has_expired(mtime, expiration);
           }
           if (skip_expiration || is_expired) {
             if (obj_iter->is_visible()) {