1 files changed, 466 insertions, 0 deletions
diff --git a/src/librbd/operation/ResizeRequest.cc b/src/librbd/operation/ResizeRequest.cc
new file mode 100644
index 000000000..1f09ea308
--- /dev/null
+++ b/src/librbd/operation/ResizeRequest.cc
@@ -0,0 +1,466 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#include "librbd/operation/ResizeRequest.h"
+#include "librbd/ExclusiveLock.h"
+#include "librbd/ImageCtx.h"
+#include "librbd/internal.h"
+#include "librbd/ObjectMap.h"
+#include "librbd/Utils.h"
+#include "librbd/io/AioCompletion.h"
+#include "librbd/io/ImageDispatchSpec.h"
+#include "librbd/io/ImageDispatcherInterface.h"
+#include "librbd/io/ObjectDispatcherInterface.h"
+#include "librbd/operation/TrimRequest.h"
+#include "common/dout.h"
+#include "common/errno.h"
+
+#define dout_subsys ceph_subsys_rbd
+#undef dout_prefix
+#define dout_prefix *_dout << "librbd::operation::ResizeRequest: " << this \
+                           << " " << __func__ << ": "
+
+namespace librbd {
+namespace operation {
+
+using util::create_async_context_callback;
+using util::create_context_callback;
+using util::create_rados_callback;
+
+template <typename I>
+ResizeRequest<I>::ResizeRequest(I &image_ctx, Context *on_finish,
+                                uint64_t new_size, bool allow_shrink, ProgressContext &prog_ctx,
+                                uint64_t journal_op_tid, bool disable_journal)
+  : Request<I>(image_ctx, on_finish, journal_op_tid),
+    m_original_size(0), m_new_size(new_size), m_allow_shrink(allow_shrink),
+    m_prog_ctx(prog_ctx), m_new_parent_overlap(0), m_disable_journal(disable_journal),
+    m_xlist_item(this)
+{
+}
+
+template <typename I>
+ResizeRequest<I>::~ResizeRequest() {
+  I &image_ctx = this->m_image_ctx;
+  ResizeRequest *next_req = NULL;
+  {
+    std::unique_lock image_locker{image_ctx.image_lock};
+    ceph_assert(m_xlist_item.remove_myself());
+    if (!image_ctx.resize_reqs.empty()) {
+      next_req = image_ctx.resize_reqs.front();
+    }
+  }
+
+  if (next_req != NULL) {
+    std::shared_lock owner_locker{image_ctx.owner_lock};
+    next_req->send();
+  }
+}
+
+template <typename I>
+void ResizeRequest<I>::send() {
+  I &image_ctx = this->m_image_ctx;
+  ceph_assert(ceph_mutex_is_locked(image_ctx.owner_lock));
+
+  {
+    std::unique_lock image_locker{image_ctx.image_lock};
+    if (!m_xlist_item.is_on_list()) {
+      image_ctx.resize_reqs.push_back(&m_xlist_item);
+      if (image_ctx.resize_reqs.front() != this) {
+        return;
+      }
+    }
+
+    ceph_assert(image_ctx.resize_reqs.front() == this);
+    m_original_size = image_ctx.size;
+    compute_parent_overlap();
+  }
+
+  Request<I>::send();
+}
+
+template <typename I>
+void ResizeRequest<I>::send_op() {
+  [[maybe_unused]] I &image_ctx = this->m_image_ctx;
+  ceph_assert(ceph_mutex_is_locked(image_ctx.owner_lock));
+
+  if (this->is_canceled()) {
+    this->async_complete(-ERESTART);
+  } else {
+    send_pre_block_writes();
+  }
+}
+
+template <typename I>
+void ResizeRequest<I>::send_pre_block_writes() {
+  I &image_ctx = this->m_image_ctx;
+  CephContext *cct = image_ctx.cct;
+  ldout(cct, 5) << dendl;
+
+  image_ctx.io_image_dispatcher->block_writes(create_context_callback<
+    ResizeRequest<I>, &ResizeRequest<I>::handle_pre_block_writes>(this));
+}
+
+template <typename I>
+Context *ResizeRequest<I>::handle_pre_block_writes(int *result) {
+  I &image_ctx = this->m_image_ctx;
+  CephContext *cct = image_ctx.cct;
+  ldout(cct, 5) << "r=" << *result << dendl;
+
+  if (*result < 0) {
+    lderr(cct) << "failed to block writes: " << cpp_strerror(*result) << dendl;
+    image_ctx.io_image_dispatcher->unblock_writes();
+    return this->create_context_finisher(*result);
+  }
+
+  return send_append_op_event();
+}
+
+template <typename I>
+Context *ResizeRequest<I>::send_append_op_event() {
+  I &image_ctx = this->m_image_ctx;
+  CephContext *cct = image_ctx.cct;
+
+  if (m_new_size < m_original_size && !m_allow_shrink) {
+    ldout(cct, 1) << "shrinking the image is not permitted" << dendl;
+    image_ctx.io_image_dispatcher->unblock_writes();
+    this->async_complete(-EINVAL);
+    return nullptr;
+  }
+
+  if (m_disable_journal || !this->template append_op_event<
+        ResizeRequest<I>, &ResizeRequest<I>::handle_append_op_event>(this)) {
+    return send_grow_object_map();
+  }
+
+  ldout(cct, 5) << dendl;
+  return nullptr;
+}
+
+template <typename I>
+Context *ResizeRequest<I>::handle_append_op_event(int *result) {
+  I &image_ctx = this->m_image_ctx;
+  CephContext *cct = image_ctx.cct;
+  ldout(cct, 5) << "r=" << *result << dendl;
+
+  if (*result < 0) {
+    lderr(cct) << "failed to commit journal entry: " << cpp_strerror(*result)
+               << dendl;
+    image_ctx.io_image_dispatcher->unblock_writes();
+    return this->create_context_finisher(*result);
+  }
+
+  return send_grow_object_map();
+}
+
+template <typename I>
+void ResizeRequest<I>::send_trim_image() {
+  I &image_ctx = this->m_image_ctx;
+  CephContext *cct = image_ctx.cct;
+  ldout(cct, 5) << dendl;
+
+  std::shared_lock owner_locker{image_ctx.owner_lock};
+  TrimRequest<I> *req = TrimRequest<I>::create(
+    image_ctx, create_context_callback<
+      ResizeRequest<I>, &ResizeRequest<I>::handle_trim_image>(this),
+    m_original_size, m_new_size, m_prog_ctx);
+  req->send();
+}
+
+template <typename I>
+Context *ResizeRequest<I>::handle_trim_image(int *result) {
+  I &image_ctx = this->m_image_ctx;
+  CephContext *cct = image_ctx.cct;
+  ldout(cct, 5) << "r=" << *result << dendl;
+
+  if (*result == -ERESTART) {
+    ldout(cct, 5) << "resize operation interrupted" << dendl;
+    return this->create_context_finisher(*result);
+  } else if (*result < 0) {
+    lderr(cct) << "failed to trim image: " << cpp_strerror(*result) << dendl;
+    return this->create_context_finisher(*result);
+  }
+
+  send_post_block_writes();
+  return nullptr;
+}
+
+template <typename I>
+void ResizeRequest<I>::send_flush_cache() {
+  I &image_ctx = this->m_image_ctx;
+
+  CephContext *cct = image_ctx.cct;
+  ldout(cct, 5) << dendl;
+
+  std::shared_lock owner_locker{image_ctx.owner_lock};
+  auto ctx = create_context_callback<
+    ResizeRequest<I>, &ResizeRequest<I>::handle_flush_cache>(this);
+  auto aio_comp = io::AioCompletion::create_and_start(
+    ctx, util::get_image_ctx(&image_ctx), io::AIO_TYPE_FLUSH);
+  auto req = io::ImageDispatchSpec::create_flush(
+    image_ctx, io::IMAGE_DISPATCH_LAYER_INTERNAL_START, aio_comp,
+    io::FLUSH_SOURCE_INTERNAL, {});
+  req->send();
+}
+
+template <typename I>
+Context *ResizeRequest<I>::handle_flush_cache(int *result) {
+  I &image_ctx = this->m_image_ctx;
+  CephContext *cct = image_ctx.cct;
+  ldout(cct, 5) << "r=" << *result << dendl;
+
+  if (*result < 0) {
+    lderr(cct) << "failed to flush cache: " << cpp_strerror(*result) << dendl;
+    return this->create_context_finisher(*result);
+  }
+
+  send_invalidate_cache();
+  return nullptr;
+}
+
+template <typename I>
+void ResizeRequest<I>::send_invalidate_cache() {
+  I &image_ctx = this->m_image_ctx;
+  CephContext *cct = image_ctx.cct;
+  ldout(cct, 5) << dendl;
+
+  // need to invalidate since we're deleting objects, and
+  // ObjectCacher doesn't track non-existent objects
+  image_ctx.io_image_dispatcher->invalidate_cache(create_context_callback<
+    ResizeRequest<I>, &ResizeRequest<I>::handle_invalidate_cache>(this));
+}
+
+template <typename I>
+Context *ResizeRequest<I>::handle_invalidate_cache(int *result) {
+  I &image_ctx = this->m_image_ctx;
+  CephContext *cct = image_ctx.cct;
+  ldout(cct, 5) << "r=" << *result << dendl;
+
+  // ignore busy error -- writeback was successfully flushed so we might be
+  // wasting some cache space for trimmed objects, but they will get purged
+  // eventually. Most likely cause of the issue was a in-flight cache read
+  if (*result < 0 && *result != -EBUSY) {
+    lderr(cct) << "failed to invalidate cache: " << cpp_strerror(*result)
+               << dendl;
+    return this->create_context_finisher(*result);
+  }
+
+  send_trim_image();
+  return nullptr;
+}
+
+template <typename I>
+Context *ResizeRequest<I>::send_grow_object_map() {
+  I &image_ctx = this->m_image_ctx;
+
+  {
+    std::unique_lock image_locker{image_ctx.image_lock};
+    m_shrink_size_visible = true;
+  }
+
+  if (m_original_size == m_new_size) {
+    image_ctx.io_image_dispatcher->unblock_writes();
+    return this->create_context_finisher(0);
+  } else if (m_new_size < m_original_size) {
+    image_ctx.io_image_dispatcher->unblock_writes();
+    send_flush_cache();
+    return nullptr;
+  }
+
+  image_ctx.owner_lock.lock_shared();
+  image_ctx.image_lock.lock_shared();
+  if (image_ctx.object_map == nullptr) {
+    image_ctx.image_lock.unlock_shared();
+    image_ctx.owner_lock.unlock_shared();
+
+    // IO is still blocked
+    send_update_header();
+    return nullptr;
+  }
+
+  CephContext *cct = image_ctx.cct;
+  ldout(cct, 5) << dendl;
+
+  // should have been canceled prior to releasing lock
+  ceph_assert(image_ctx.exclusive_lock == nullptr ||
+              image_ctx.exclusive_lock->is_lock_owner());
+
+  image_ctx.object_map->aio_resize(
+    m_new_size, OBJECT_NONEXISTENT, create_context_callback<
+      ResizeRequest<I>, &ResizeRequest<I>::handle_grow_object_map>(this));
+  image_ctx.image_lock.unlock_shared();
+  image_ctx.owner_lock.unlock_shared();
+  return nullptr;
+}
+
+template <typename I>
+Context *ResizeRequest<I>::handle_grow_object_map(int *result) {
+  I &image_ctx = this->m_image_ctx;
+  CephContext *cct = image_ctx.cct;
+  ldout(cct, 5) << "r=" << *result << dendl;
+
+  if (*result < 0) {
+    lderr(cct) << "failed to resize object map: "
+               << cpp_strerror(*result) << dendl;
+    image_ctx.io_image_dispatcher->unblock_writes();
+    return this->create_context_finisher(*result);
+  }
+
+  // IO is still blocked
+  send_update_header();
+  return nullptr;
+}
+
+template <typename I>
+Context *ResizeRequest<I>::send_shrink_object_map() {
+  I &image_ctx = this->m_image_ctx;
+
+  image_ctx.owner_lock.lock_shared();
+  image_ctx.image_lock.lock_shared();
+  if (image_ctx.object_map == nullptr || m_new_size > m_original_size) {
+    image_ctx.image_lock.unlock_shared();
+    image_ctx.owner_lock.unlock_shared();
+
+    update_size_and_overlap();
+    return this->create_context_finisher(0);
+  }
+
+  CephContext *cct = image_ctx.cct;
+  ldout(cct, 5) << "original_size=" << m_original_size << ", "
+                << "new_size=" << m_new_size << dendl;
+
+  // should have been canceled prior to releasing lock
+  ceph_assert(image_ctx.exclusive_lock == nullptr ||
+              image_ctx.exclusive_lock->is_lock_owner());
+
+  image_ctx.object_map->aio_resize(
+    m_new_size, OBJECT_NONEXISTENT, create_context_callback<
+      ResizeRequest<I>, &ResizeRequest<I>::handle_shrink_object_map>(this));
+  image_ctx.image_lock.unlock_shared();
+  image_ctx.owner_lock.unlock_shared();
+  return nullptr;
+}
+
+template <typename I>
+Context *ResizeRequest<I>::handle_shrink_object_map(int *result) {
+  I &image_ctx = this->m_image_ctx;
+  CephContext *cct = image_ctx.cct;
+  ldout(cct, 5) << "r=" << *result << dendl;
+
+  if (*result < 0) {
+    lderr(cct) << "failed to resize object map: "
+               << cpp_strerror(*result) << dendl;
+    image_ctx.io_image_dispatcher->unblock_writes();
+    return this->create_context_finisher(*result);
+  }
+
+  update_size_and_overlap();
+  return this->create_context_finisher(0);
+}
+
+template <typename I>
+void ResizeRequest<I>::send_post_block_writes() {
+  I &image_ctx = this->m_image_ctx;
+  CephContext *cct = image_ctx.cct;
+  ldout(cct, 5) << dendl;
+
+  std::shared_lock owner_locker{image_ctx.owner_lock};
+  image_ctx.io_image_dispatcher->block_writes(create_context_callback<
+    ResizeRequest<I>, &ResizeRequest<I>::handle_post_block_writes>(this));
+}
+
+template <typename I>
+Context *ResizeRequest<I>::handle_post_block_writes(int *result) {
+  I &image_ctx = this->m_image_ctx;
+  CephContext *cct = image_ctx.cct;
+  ldout(cct, 5) << "r=" << *result << dendl;
+
+  if (*result < 0) {
+    image_ctx.io_image_dispatcher->unblock_writes();
+    lderr(cct) << "failed to block writes prior to header update: "
+               << cpp_strerror(*result) << dendl;
+    return this->create_context_finisher(*result);
+  }
+
+  send_update_header();
+  return nullptr;
+}
+
+template <typename I>
+void ResizeRequest<I>::send_update_header() {
+  I &image_ctx = this->m_image_ctx;
+  CephContext *cct = image_ctx.cct;
+  ldout(cct, 5) << "original_size=" << m_original_size << ", "
+                << "new_size=" << m_new_size << dendl;;
+
+  // should have been canceled prior to releasing lock
+  std::shared_lock owner_locker{image_ctx.owner_lock};
+  ceph_assert(image_ctx.exclusive_lock == nullptr ||
+              image_ctx.exclusive_lock->is_lock_owner());
+
+  librados::ObjectWriteOperation op;
+  if (image_ctx.old_format) {
+    // rewrite only the size field of the header
+    ceph_le64 new_size(m_new_size);
+    bufferlist bl;
+    bl.append(reinterpret_cast<const char*>(&new_size), sizeof(new_size));
+    op.write(offsetof(rbd_obj_header_ondisk, image_size), bl);
+  } else {
+    cls_client::set_size(&op, m_new_size);
+  }
+
+  librados::AioCompletion *rados_completion = create_rados_callback<
+    ResizeRequest<I>, &ResizeRequest<I>::handle_update_header>(this);
+  int r = image_ctx.md_ctx.aio_operate(image_ctx.header_oid,
+    				       rados_completion, &op);
+  ceph_assert(r == 0);
+  rados_completion->release();
+}
+
+template <typename I>
+Context *ResizeRequest<I>::handle_update_header(int *result) {
+  I &image_ctx = this->m_image_ctx;
+  CephContext *cct = image_ctx.cct;
+  ldout(cct, 5) << "r=" << *result << dendl;
+
+  if (*result < 0) {
+    lderr(cct) << "failed to update image header: " << cpp_strerror(*result)
+               << dendl;
+    image_ctx.io_image_dispatcher->unblock_writes();
+    return this->create_context_finisher(*result);
+  }
+
+  return send_shrink_object_map();
+}
+
+template <typename I>
+void ResizeRequest<I>::compute_parent_overlap() {
+  I &image_ctx = this->m_image_ctx;
+  ceph_assert(ceph_mutex_is_locked(image_ctx.image_lock));
+
+  if (image_ctx.parent == NULL) {
+    m_new_parent_overlap = 0;
+  } else {
+    m_new_parent_overlap = std::min(m_new_size, image_ctx.parent_md.overlap);
+  }
+}
+
+template <typename I>
+void ResizeRequest<I>::update_size_and_overlap() {
+  I &image_ctx = this->m_image_ctx;
+  {
+    std::unique_lock image_locker{image_ctx.image_lock};
+    image_ctx.size = m_new_size;
+
+    if (image_ctx.parent != NULL && m_new_size < m_original_size) {
+      image_ctx.parent_md.overlap = m_new_parent_overlap;
+    }
+  }
+
+  // blocked by PRE_BLOCK_WRITES (grow) or POST_BLOCK_WRITES (shrink) state
+  image_ctx.io_image_dispatcher->unblock_writes();
+}
+
+} // namespace operation
+} // namespace librbd
+
+template class librbd::operation::ResizeRequest<librbd::ImageCtx>;