Adding upstream version 18.2.2.upstream/18.2.2

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 471 insertions, 0 deletions

diff --git a/src/os/bluestore/BtreeAllocator.cc b/src/os/bluestore/BtreeAllocator.cc
new file mode 100644
index 000000000..2455ec111
--- /dev/null
+++ b/src/os/bluestore/BtreeAllocator.cc
@@ -0,0 +1,471 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:nil -*-
+// vim: ts=8 sw=2 smarttab
+
+#include "BtreeAllocator.h"
+
+#include <bit>
+#include <limits>
+
+#include "common/config_proxy.h"
+#include "common/debug.h"
+
+#define dout_context cct
+#define dout_subsys ceph_subsys_bluestore
+#undef  dout_prefix
+#define dout_prefix *_dout << "BtreeAllocator "
+
+/*
+ * This is a helper function that can be used by the allocator to find
+ * a suitable block to allocate. This will search the specified B-tree
+ * looking for a block that matches the specified criteria.
+ */
+uint64_t BtreeAllocator::_pick_block_after(uint64_t *cursor,
+					   uint64_t size,
+					   uint64_t align)
+{
+  auto rs_start = range_tree.lower_bound(*cursor);
+  for (auto rs = rs_start; rs != range_tree.end(); ++rs) {
+    uint64_t offset = rs->first;
+    if (offset + size <= rs->second) {
+      *cursor = offset + size;
+      return offset;
+    }
+  }
+  if (*cursor == 0) {
+    // If we already started from beginning, don't bother with searching from beginning
+    return -1ULL;
+  }
+  // If we reached end, start from beginning till cursor.
+  for (auto rs = range_tree.begin(); rs != rs_start; ++rs) {
+    uint64_t offset = rs->first;
+    if (offset + size <= rs->second) {
+      *cursor = offset + size;
+      return offset;
+    }
+  }
+  return -1ULL;
+}
+
+uint64_t BtreeAllocator::_pick_block_fits(uint64_t size,
+                                        uint64_t align)
+{
+  // instead of searching from cursor, just pick the smallest range which fits
+  // the needs
+  auto rs_start = range_size_tree.lower_bound(range_value_t{0,size});
+  for (auto rs = rs_start; rs != range_size_tree.end(); ++rs) {
+    uint64_t offset = rs->start;
+    if (offset + size <= rs->start + rs->size) {
+      return offset;
+    }
+  }
+  return -1ULL;
+}
+
+void BtreeAllocator::_add_to_tree(uint64_t start, uint64_t size)
+{
+  ceph_assert(size != 0);
+
+  uint64_t end = start + size;
+
+  auto rs_after = range_tree.upper_bound(start);
+
+  /* Make sure we don't overlap with either of our neighbors */
+  auto rs_before = range_tree.end();
+  if (rs_after != range_tree.begin()) {
+    rs_before = std::prev(rs_after);
+  }
+
+  bool merge_before = (rs_before != range_tree.end() && rs_before->second == start);
+  bool merge_after = (rs_after != range_tree.end() && rs_after->first == end);
+
+  if (merge_before && merge_after) {
+    // | before   |//////| after |
+    // | before >>>>>>>>>>>>>>>  |
+    range_seg_t seg_before{rs_before->first, rs_before->second};
+    range_seg_t seg_after{rs_after->first, rs_after->second};
+    // expand the head seg before rs_{before,after} are invalidated
+    rs_before->second = seg_after.end;
+    // remove the tail seg from offset tree
+    range_tree.erase(rs_after);
+    // remove the head and tail seg from size tree
+    range_size_tree.erase(seg_before);
+    range_size_tree.erase(seg_after);
+    // insert the merged seg into size tree
+    range_size_tree.emplace(seg_before.start, seg_after.end);
+  } else if (merge_before) {
+    // | before   |//////|
+    // | before >>>>>>>> |
+    // remove the head seg from the size tree
+    range_seg_t seg_before{rs_before->first, rs_before->second};
+    range_size_tree.erase(seg_before);
+    // expand the head seg in the offset tree
+    rs_before->second = end;
+    // insert the merged seg into size tree
+    range_size_tree.emplace(seg_before.start, end);
+  } else if (merge_after) {
+    // |//////| after |
+    // | merge after  |
+    // remove the tail seg from size tree
+    range_seg_t seg_after{rs_after->first, rs_after->second};
+    range_size_tree.erase(seg_after);
+    // remove the tail seg from offset tree
+    range_tree.erase(rs_after);
+    // insert the merged seg
+    range_tree.emplace(start, seg_after.end);
+    range_size_tree.emplace(start, seg_after.end);
+  } else {
+    // no neighbours
+    range_tree.emplace_hint(rs_after, start, end);
+    range_size_tree.emplace(start, end);
+  }
+  num_free += size;
+}
+
+void BtreeAllocator::_process_range_removal(uint64_t start, uint64_t end,
+  BtreeAllocator::range_tree_t::iterator& rs)
+{
+  bool left_over = (rs->first != start);
+  bool right_over = (rs->second != end);
+
+  range_seg_t seg_whole{rs->first, rs->second};
+  range_size_tree.erase(seg_whole);
+
+  // | left <|////|  right |
+  if (left_over && right_over) {
+    // add the spin-off right seg
+    range_seg_t seg_after{end, seg_whole.end};
+    range_tree.emplace_hint(rs, seg_after.start, seg_after.end);
+    range_size_tree.emplace(seg_after);
+    // shink the left seg in offset tree
+    rs->second = start;
+    // insert the shrinked left seg back into size tree
+    range_size_tree.emplace(seg_whole.start, start);
+  } else if (left_over) {
+    // | left <|///////////|
+    // shrink the left seg in the offset tree
+    rs->second = start;
+    // insert the shrinked left seg back into size tree
+    range_size_tree.emplace(seg_whole.start, start);
+  } else if (right_over) {
+    // |//////////| right |
+    // remove the whole seg from offset tree
+    range_tree.erase(rs);
+    // add the spin-off right seg
+    range_seg_t seg_after{end, seg_whole.end};
+    range_tree.emplace(seg_after.start, seg_after.end);
+    range_size_tree.emplace(seg_after);
+  } else {
+    range_tree.erase(rs);
+  }
+  num_free -= (end - start);
+}
+
+void BtreeAllocator::_remove_from_tree(uint64_t start, uint64_t size)
+{
+  uint64_t end = start + size;
+
+  ceph_assert(size != 0);
+  ceph_assert(size <= num_free);
+
+  auto rs = range_tree.find(start);
+  /* Make sure we completely overlap with someone */
+  ceph_assert(rs != range_tree.end());
+  ceph_assert(rs->first <= start);
+  ceph_assert(rs->second >= end);
+
+  _process_range_removal(start, end, rs);
+}
+
+void BtreeAllocator::_try_remove_from_tree(uint64_t start, uint64_t size,
+  std::function<void(uint64_t, uint64_t, bool)> cb)
+{
+  uint64_t end = start + size;
+
+  ceph_assert(size != 0);
+
+  auto rs = range_tree.find(start);
+
+  if (rs == range_tree.end() || rs->first >= end) {
+    cb(start, size, false);
+    return;
+  }
+
+  do {
+
+    auto next_rs = rs;
+    ++next_rs;
+
+    if (start < rs->first) {
+      cb(start, rs->first - start, false);
+      start = rs->first;
+    }
+    auto range_end = std::min(rs->second, end);
+    _process_range_removal(start, range_end, rs);
+    cb(start, range_end - start, true);
+    start = range_end;
+
+    rs = next_rs;
+  } while (rs != range_tree.end() && rs->first < end && start < end);
+  if (start < end) {
+    cb(start, end - start, false);
+  }
+}
+
+int64_t BtreeAllocator::_allocate(
+  uint64_t want,
+  uint64_t unit,
+  uint64_t max_alloc_size,
+  int64_t  hint, // unused, for now!
+  PExtentVector* extents)
+{
+  uint64_t allocated = 0;
+  while (allocated < want) {
+    uint64_t offset, length;
+    int r = _allocate(std::min(max_alloc_size, want - allocated),
+                      unit, &offset, &length);
+    if (r < 0) {
+      // Allocation failed.
+      break;
+    }
+    extents->emplace_back(offset, length);
+    allocated += length;
+  }
+  assert(range_size_tree.size() == range_tree.size());
+  return allocated ? allocated : -ENOSPC;
+}
+
+int BtreeAllocator::_allocate(
+  uint64_t size,
+  uint64_t unit,
+  uint64_t *offset,
+  uint64_t *length)
+{
+  uint64_t max_size = 0;
+  if (auto p = range_size_tree.rbegin(); p != range_size_tree.rend()) {
+    max_size = p->size;
+  }
+
+  bool force_range_size_alloc = false;
+  if (max_size < size) {
+    if (max_size < unit) {
+      return -ENOSPC;
+    }
+    size = p2align(max_size, unit);
+    ceph_assert(size > 0);
+    force_range_size_alloc = true;
+  }
+
+  const int free_pct = num_free * 100 / device_size;
+  uint64_t start = 0;
+  /*
+   * If we're running low on space switch to using the size
+   * sorted B-tree (best-fit).
+   */
+  if (force_range_size_alloc ||
+      max_size < range_size_alloc_threshold ||
+      free_pct < range_size_alloc_free_pct) {
+    do {
+      start = _pick_block_fits(size, unit);
+      dout(20) << __func__ << " best fit=" << start << " size=" << size << dendl;
+      if (start != uint64_t(-1ULL)) {
+        break;
+      }
+      // try to collect smaller extents as we could fail to retrieve
+      // that large block due to misaligned extents
+      size = p2align(size >> 1, unit);
+    } while (size >= unit);
+  } else {
+    do {
+      /*
+       * Find the largest power of 2 block size that evenly divides the
+       * requested size. This is used to try to allocate blocks with similar
+       * alignment from the same area (i.e. same cursor bucket) but it does
+       * not guarantee that other allocations sizes may exist in the same
+       * region.
+       */
+      uint64_t* cursor = &lbas[cbits(size) - 1];
+      start = _pick_block_after(cursor, size, unit);
+      dout(20) << __func__ << " first fit=" << start << " size=" << size << dendl;
+      if (start != uint64_t(-1ULL)) {
+        break;
+      }
+      // try to collect smaller extents as we could fail to retrieve
+      // that large block due to misaligned extents
+      size = p2align(size >> 1, unit);
+    } while (size >= unit);
+  }
+  if (start == -1ULL) {
+    return -ENOSPC;
+  }
+
+  _remove_from_tree(start, size);
+
+  *offset = start;
+  *length = size;
+  return 0;
+}
+
+void BtreeAllocator::_release(const interval_set<uint64_t>& release_set)
+{
+  for (auto p = release_set.begin(); p != release_set.end(); ++p) {
+    const auto offset = p.get_start();
+    const auto length = p.get_len();
+    ceph_assert(offset + length <= uint64_t(device_size));
+    ldout(cct, 10) << __func__ << std::hex
+      << " offset 0x" << offset
+      << " length 0x" << length
+      << std::dec << dendl;
+    _add_to_tree(offset, length);
+  }
+}
+
+void BtreeAllocator::_release(const PExtentVector& release_set) {
+  for (auto& e : release_set) {
+    ldout(cct, 10) << __func__ << std::hex
+      << " offset 0x" << e.offset
+      << " length 0x" << e.length
+      << std::dec << dendl;
+    _add_to_tree(e.offset, e.length);
+  }
+}
+
+void BtreeAllocator::_shutdown()
+{
+  range_size_tree.clear();
+  range_tree.clear();
+}
+
+BtreeAllocator::BtreeAllocator(CephContext* cct,
+			       int64_t device_size,
+			       int64_t block_size,
+			       uint64_t max_mem,
+			       std::string_view name) :
+  Allocator(name, device_size, block_size),
+  range_size_alloc_threshold(
+    cct->_conf.get_val<uint64_t>("bluestore_avl_alloc_bf_threshold")),
+  range_size_alloc_free_pct(
+    cct->_conf.get_val<uint64_t>("bluestore_avl_alloc_bf_free_pct")),
+  range_count_cap(max_mem / sizeof(range_seg_t)),
+  cct(cct)
+{}
+
+BtreeAllocator::BtreeAllocator(CephContext* cct,
+			       int64_t device_size,
+			       int64_t block_size,
+			       std::string_view name) :
+  BtreeAllocator(cct, device_size, block_size, 0 /* max_mem */, name)
+{}
+
+BtreeAllocator::~BtreeAllocator()
+{
+  shutdown();
+}
+
+int64_t BtreeAllocator::allocate(
+  uint64_t want,
+  uint64_t unit,
+  uint64_t max_alloc_size,
+  int64_t  hint, // unused, for now!
+  PExtentVector* extents)
+{
+  ldout(cct, 10) << __func__ << std::hex
+                 << " want 0x" << want
+                 << " unit 0x" << unit
+                 << " max_alloc_size 0x" << max_alloc_size
+                 << " hint 0x" << hint
+                 << std::dec << dendl;
+  ceph_assert(std::has_single_bit(unit));
+  ceph_assert(want % unit == 0);
+
+  if (max_alloc_size == 0) {
+    max_alloc_size = want;
+  }
+  if (constexpr auto cap = std::numeric_limits<decltype(bluestore_pextent_t::length)>::max();
+      max_alloc_size >= cap) {
+    max_alloc_size = p2align(uint64_t(cap), (uint64_t)block_size);
+  }
+  std::lock_guard l(lock);
+  return _allocate(want, unit, max_alloc_size, hint, extents);
+}
+
+void BtreeAllocator::release(const interval_set<uint64_t>& release_set) {
+  std::lock_guard l(lock);
+  _release(release_set);
+}
+
+uint64_t BtreeAllocator::get_free()
+{
+  std::lock_guard l(lock);
+  return num_free;
+}
+
+double BtreeAllocator::get_fragmentation()
+{
+  std::lock_guard l(lock);
+  return _get_fragmentation();
+}
+
+void BtreeAllocator::dump()
+{
+  std::lock_guard l(lock);
+  _dump();
+}
+
+void BtreeAllocator::_dump() const
+{
+  ldout(cct, 0) << __func__ << " range_tree: " << dendl;
+  for (auto& rs : range_tree) {
+    ldout(cct, 0) << std::hex
+      << "0x" << rs.first << "~" << rs.second
+      << std::dec
+      << dendl;
+  }
+
+  ldout(cct, 0) << __func__ << " range_size_tree: " << dendl;
+  for (auto& rs : range_size_tree) {
+    ldout(cct, 0) << std::hex
+      << "0x" << rs.size << "@" << rs.start
+      << std::dec
+      << dendl;
+  }
+}
+
+void BtreeAllocator::foreach(std::function<void(uint64_t offset, uint64_t length)> notify)
+{
+  std::lock_guard l(lock);
+  for (auto& rs : range_tree) {
+    notify(rs.first, rs.second - rs.first);
+  }
+}
+
+void BtreeAllocator::init_add_free(uint64_t offset, uint64_t length)
+{
+  if (!length)
+    return;
+  std::lock_guard l(lock);
+  ceph_assert(offset + length <= uint64_t(device_size));
+  ldout(cct, 10) << __func__ << std::hex
+                 << " offset 0x" << offset
+                 << " length 0x" << length
+                 << std::dec << dendl;
+  _add_to_tree(offset, length);
+}
+
+void BtreeAllocator::init_rm_free(uint64_t offset, uint64_t length)
+{
+  if (!length)
+    return;
+  std::lock_guard l(lock);
+  ceph_assert(offset + length <= uint64_t(device_size));
+  ldout(cct, 10) << __func__ << std::hex
+                 << " offset 0x" << offset
+                 << " length 0x" << length
+                 << std::dec << dendl;
+  _remove_from_tree(offset, length);
+}
+
+void BtreeAllocator::shutdown()
+{
+  std::lock_guard l(lock);
+  _shutdown();
+}