ceph/src/librbd/watcher/RewatchRequest.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 "librbd/watcher/RewatchRequest.h"
   5 #include "common/RWLock.h"
   6 #include "common/errno.h"
   7 #include "librbd/Utils.h"
   8
   9 #define dout_subsys ceph_subsys_rbd
  10 #undef dout_prefix
  11 #define dout_prefix *_dout << "librbd::watcher::RewatchRequest: " \
  12                            << this << " " << __func__ << " "
  13
  14 namespace librbd {
  15
  16 using util::create_context_callback;
  17 using util::create_rados_callback;
  18
  19 namespace watcher {
  20
  21 using std::string;
  22
  23 RewatchRequest::RewatchRequest(librados::IoCtx& ioctx, const string& oid,
  24                                RWLock &watch_lock,
  25                                librados::WatchCtx2 *watch_ctx,
  26                                uint64_t *watch_handle, Context *on_finish)
  27   : m_ioctx(ioctx), m_oid(oid), m_watch_lock(watch_lock),
  28     m_watch_ctx(watch_ctx), m_watch_handle(watch_handle),
  29     m_on_finish(on_finish) {
  30 }
  31
  32 void RewatchRequest::send() {
  33   unwatch();
  34 }
  35
  36 void RewatchRequest::unwatch() {
  37   assert(m_watch_lock.is_wlocked());
  38   ceph_assert(m_watch_lock.is_wlocked());
  39   if (*m_watch_handle == 0) {
  40     rewatch();
  41     return;
  42   }
  43
  44   CephContext *cct = reinterpret_cast<CephContext *>(m_ioctx.cct());
  45   ldout(cct, 10) << dendl;
  46
  47   uint64_t watch_handle = 0;
  48   std::swap(*m_watch_handle, watch_handle);
  49
  50   librados::AioCompletion *aio_comp = create_rados_callback<
  51                         RewatchRequest, &RewatchRequest::handle_unwatch>(this);
  52   int r = m_ioctx.aio_unwatch(watch_handle, aio_comp);
  53   assert(r == 0);
  54   aio_comp->release();
  55 }
  56
  57 void RewatchRequest::handle_unwatch(int r) {
  58   CephContext *cct = reinterpret_cast<CephContext *>(m_ioctx.cct());
  59   ldout(cct, 10) << "r=" << r << dendl;
  60
  61   if (r == -EBLACKLISTED) {
  62     lderr(cct) << "client blacklisted" << dendl;
  63     finish(r);
  64     return;
  65   } else if (r < 0) {
  66     lderr(cct) << "failed to unwatch: " << cpp_strerror(r) << dendl;
  67   }
  68   rewatch();
  69 }
  70
  71 void RewatchRequest::rewatch() {
  72   CephContext *cct = reinterpret_cast<CephContext *>(m_ioctx.cct());
  73   ldout(cct, 10) << dendl;
  74
  75   librados::AioCompletion *aio_comp = create_rados_callback<
  76                         RewatchRequest, &RewatchRequest::handle_rewatch>(this);
  77   int r = m_ioctx.aio_watch(m_oid, aio_comp, &m_rewatch_handle, m_watch_ctx);
  78   assert(r == 0);
  79   aio_comp->release();
  80 }
  81
  82 void RewatchRequest::handle_rewatch(int r) {
  83   CephContext *cct = reinterpret_cast<CephContext *>(m_ioctx.cct());
  84   ldout(cct, 10) << "r=" << r << dendl;
  85   if (r < 0) {
  86     lderr(cct) << "failed to watch object: " << cpp_strerror(r)
  87                << dendl;
  88     m_rewatch_handle = 0;
  89   }
  90
  91   {
  92     RWLock::WLocker watch_locker(m_watch_lock);
  93     *m_watch_handle = m_rewatch_handle;
  94   }
  95
  96   finish(r);
  97 }
  98
  99 void RewatchRequest::finish(int r) {
 100   CephContext *cct = reinterpret_cast<CephContext *>(m_ioctx.cct());
 101   ldout(cct, 10) << "r=" << r << dendl;
 102
 103   m_on_finish->complete(r);
 104   delete this;
 105 }
 106
 107 } // namespace watcher
 108 } // namespace librbd
 109