Revision 0d4a2b733070a1bd52f981313f9e17f126701407 authored by Yi Wu on 04 August 2017, 20:09:56 UTC, committed by Facebook Github Bot on 04 August 2017, 20:12:07 UTC
Summary: The FsyncFiles background job call Fsync() periodically for blob files. However it can access WritableFileWriter concurrently with a Put() or Write(). And WritableFileWriter does not support concurrent access. It will lead to WritableFileWriter buffer being flush with same content twice, and blob file end up corrupted. Fixing by simply let FsyncFiles hold write_mutex_. Closes https://github.com/facebook/rocksdb/pull/2685 Differential Revision: D5561908 Pulled By: yiwu-arbug fbshipit-source-id: f0bb5bcab0e05694e053b8c49eab43640721e872
1 parent 627c9f1
aligned_buffer.h
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
//
// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors.
#pragma once
#include <algorithm>
#include "port/port.h"
namespace rocksdb {
inline size_t TruncateToPageBoundary(size_t page_size, size_t s) {
s -= (s & (page_size - 1));
assert((s % page_size) == 0);
return s;
}
inline size_t Roundup(size_t x, size_t y) {
return ((x + y - 1) / y) * y;
}
// This class is to manage an aligned user
// allocated buffer for direct I/O purposes
// though can be used for any purpose.
class AlignedBuffer {
size_t alignment_;
std::unique_ptr<char[]> buf_;
size_t capacity_;
size_t cursize_;
char* bufstart_;
public:
AlignedBuffer()
: alignment_(),
capacity_(0),
cursize_(0),
bufstart_(nullptr) {
}
AlignedBuffer(AlignedBuffer&& o) ROCKSDB_NOEXCEPT {
*this = std::move(o);
}
AlignedBuffer& operator=(AlignedBuffer&& o) ROCKSDB_NOEXCEPT {
alignment_ = std::move(o.alignment_);
buf_ = std::move(o.buf_);
capacity_ = std::move(o.capacity_);
cursize_ = std::move(o.cursize_);
bufstart_ = std::move(o.bufstart_);
return *this;
}
AlignedBuffer(const AlignedBuffer&) = delete;
AlignedBuffer& operator=(const AlignedBuffer&) = delete;
static bool isAligned(const void* ptr, size_t alignment) {
return reinterpret_cast<uintptr_t>(ptr) % alignment == 0;
}
static bool isAligned(size_t n, size_t alignment) {
return n % alignment == 0;
}
size_t Alignment() const {
return alignment_;
}
size_t Capacity() const {
return capacity_;
}
size_t CurrentSize() const {
return cursize_;
}
const char* BufferStart() const {
return bufstart_;
}
char* BufferStart() { return bufstart_; }
void Clear() {
cursize_ = 0;
}
void Alignment(size_t alignment) {
assert(alignment > 0);
assert((alignment & (alignment - 1)) == 0);
alignment_ = alignment;
}
// Allocates a new buffer and sets bufstart_ to the aligned first byte
void AllocateNewBuffer(size_t requested_capacity, bool copy_data = false) {
assert(alignment_ > 0);
assert((alignment_ & (alignment_ - 1)) == 0);
if (copy_data && requested_capacity < cursize_) {
// If we are downsizing to a capacity that is smaller than the current
// data in the buffer. Ignore the request.
return;
}
size_t new_capacity = Roundup(requested_capacity, alignment_);
char* new_buf = new char[new_capacity + alignment_];
char* new_bufstart = reinterpret_cast<char*>(
(reinterpret_cast<uintptr_t>(new_buf) + (alignment_ - 1)) &
~static_cast<uintptr_t>(alignment_ - 1));
if (copy_data) {
memcpy(new_bufstart, bufstart_, cursize_);
} else {
cursize_ = 0;
}
bufstart_ = new_bufstart;
capacity_ = new_capacity;
buf_.reset(new_buf);
}
// Used for write
// Returns the number of bytes appended
size_t Append(const char* src, size_t append_size) {
size_t buffer_remaining = capacity_ - cursize_;
size_t to_copy = std::min(append_size, buffer_remaining);
if (to_copy > 0) {
memcpy(bufstart_ + cursize_, src, to_copy);
cursize_ += to_copy;
}
return to_copy;
}
size_t Read(char* dest, size_t offset, size_t read_size) const {
assert(offset < cursize_);
size_t to_read = 0;
if(offset < cursize_) {
to_read = std::min(cursize_ - offset, read_size);
}
if (to_read > 0) {
memcpy(dest, bufstart_ + offset, to_read);
}
return to_read;
}
/// Pad to alignment
void PadToAlignmentWith(int padding) {
size_t total_size = Roundup(cursize_, alignment_);
size_t pad_size = total_size - cursize_;
if (pad_size > 0) {
assert((pad_size + cursize_) <= capacity_);
memset(bufstart_ + cursize_, padding, pad_size);
cursize_ += pad_size;
}
}
// After a partial flush move the tail to the beginning of the buffer
void RefitTail(size_t tail_offset, size_t tail_size) {
if (tail_size > 0) {
memmove(bufstart_, bufstart_ + tail_offset, tail_size);
}
cursize_ = tail_size;
}
// Returns place to start writing
char* Destination() {
return bufstart_ + cursize_;
}
void Size(size_t cursize) {
cursize_ = cursize;
}
};
}
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