From: Casey Bodley <cbodley@redhat.com>
Date: Mon, 23 Nov 2020 23:06:26 +0000 (-0500)
Subject: rgw: temporarily disable calls to defer_gc() in RGWGetObj
X-Git-Tag: v17.0.0~524^2
X-Git-Url: http://git.apps.os.sepia.ceph.com/?a=commitdiff_plain;h=94df9cd37a1ca457130f90803281b166a5fa7eef;p=ceph.git

rgw: temporarily disable calls to defer_gc() in RGWGetObj

cls_rgw_gc_queue_update_entry() is known to cause data loss when called
on objects that have not actually been scheduled for garbage collection

RGWGetObj is the only caller, and uses defer_gc() when reads are taking
a long time compared to rgw_gc_obj_min_wait. if an object has since been
deleted and submitted for garbage collection, this allows RGWGetObj to
defer that gc until the entire read completes

by disabling these calls to defer_gc(), very long reads (longer than 1hr,
with default configuration) may fail if the object gets deleted, and a
retry will result in a 404 Not Found error as expected

Fixes: https://tracker.ceph.com/issues/47866

Signed-off-by: Casey Bodley <cbodley@redhat.com>
---

diff --git a/src/rgw/rgw_op.cc b/src/rgw/rgw_op.cc
index 67c0d3227aad2..1cfc906b78c73 100644
--- a/src/rgw/rgw_op.cc
+++ b/src/rgw/rgw_op.cc
@@ -2017,16 +2017,8 @@ int RGWGetObj::handle_slo_manifest(bufferlist& bl, optional_yield y)
 
 int RGWGetObj::get_data_cb(bufferlist& bl, off_t bl_ofs, off_t bl_len)
 {
-  /* garbage collection related handling */
-  utime_t start_time = ceph_clock_now();
-  if (start_time > gc_invalidate_time) {
-    int r = store->defer_gc(s->obj_ctx, s->bucket.get(), s->object.get(), s->yield);
-    if (r < 0) {
-      ldpp_dout(this, 0) << "WARNING: could not defer gc entry for obj" << dendl;
-    }
-    gc_invalidate_time = start_time;
-    gc_invalidate_time += (s->cct->_conf->rgw_gc_obj_min_wait / 2);
-  }
+  /* garbage collection related handling:
+   * defer_gc disabled for https://tracker.ceph.com/issues/47866 */
   return send_response_data(bl, bl_ofs, bl_len);
 }