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+// 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.
+
+#ifdef ROCKSDB_LIB_IO_POSIX
+#include "env/io_posix.h"
+#include <errno.h>
+#include <fcntl.h>
+#include <algorithm>
+#if defined(OS_LINUX)
+#include <linux/fs.h>
+#endif
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#ifdef OS_LINUX
+#include <sys/statfs.h>
+#include <sys/syscall.h>
+#include <sys/sysmacros.h>
+#endif
+#include "env/posix_logger.h"
+#include "monitoring/iostats_context_imp.h"
+#include "port/port.h"
+#include "rocksdb/slice.h"
+#include "util/coding.h"
+#include "util/string_util.h"
+#include "util/sync_point.h"
+
+#if defined(OS_LINUX) && !defined(F_SET_RW_HINT)
+#define F_LINUX_SPECIFIC_BASE 1024
+#define F_SET_RW_HINT (F_LINUX_SPECIFIC_BASE + 12)
+#endif
+
+namespace rocksdb {
+
+// A wrapper for fadvise, if the platform doesn't support fadvise,
+// it will simply return 0.
+int Fadvise(int fd, off_t offset, size_t len, int advice) {
+#ifdef OS_LINUX
+ return posix_fadvise(fd, offset, len, advice);
+#else
+ (void)fd;
+ (void)offset;
+ (void)len;
+ (void)advice;
+ return 0; // simply do nothing.
+#endif
+}
+
+namespace {
+size_t GetLogicalBufferSize(int __attribute__((__unused__)) fd) {
+#ifdef OS_LINUX
+ struct stat buf;
+ int result = fstat(fd, &buf);
+ if (result == -1) {
+ return kDefaultPageSize;
+ }
+ if (major(buf.st_dev) == 0) {
+ // Unnamed devices (e.g. non-device mounts), reserved as null device number.
+ // These don't have an entry in /sys/dev/block/. Return a sensible default.
+ return kDefaultPageSize;
+ }
+
+ // Reading queue/logical_block_size does not require special permissions.
+ const int kBufferSize = 100;
+ char path[kBufferSize];
+ char real_path[PATH_MAX + 1];
+ snprintf(path, kBufferSize, "/sys/dev/block/%u:%u", major(buf.st_dev),
+ minor(buf.st_dev));
+ if (realpath(path, real_path) == nullptr) {
+ return kDefaultPageSize;
+ }
+ std::string device_dir(real_path);
+ if (!device_dir.empty() && device_dir.back() == '/') {
+ device_dir.pop_back();
+ }
+ // NOTE: sda3 and nvme0n1p1 do not have a `queue/` subdir, only the parent sda
+ // and nvme0n1 have it.
+ // $ ls -al '/sys/dev/block/8:3'
+ // lrwxrwxrwx. 1 root root 0 Jun 26 01:38 /sys/dev/block/8:3 ->
+ // ../../block/sda/sda3
+ // $ ls -al '/sys/dev/block/259:4'
+ // lrwxrwxrwx 1 root root 0 Jan 31 16:04 /sys/dev/block/259:4 ->
+ // ../../devices/pci0000:17/0000:17:00.0/0000:18:00.0/nvme/nvme0/nvme0n1/nvme0n1p1
+ size_t parent_end = device_dir.rfind('/', device_dir.length() - 1);
+ if (parent_end == std::string::npos) {
+ return kDefaultPageSize;
+ }
+ size_t parent_begin = device_dir.rfind('/', parent_end - 1);
+ if (parent_begin == std::string::npos) {
+ return kDefaultPageSize;
+ }
+ std::string parent =
+ device_dir.substr(parent_begin + 1, parent_end - parent_begin - 1);
+ std::string child = device_dir.substr(parent_end + 1, std::string::npos);
+ if (parent != "block" &&
+ (child.compare(0, 4, "nvme") || child.find('p') != std::string::npos)) {
+ device_dir = device_dir.substr(0, parent_end);
+ }
+ std::string fname = device_dir + "/queue/logical_block_size";
+ FILE* fp;
+ size_t size = 0;
+ fp = fopen(fname.c_str(), "r");
+ if (fp != nullptr) {
+ char* line = nullptr;
+ size_t len = 0;
+ if (getline(&line, &len, fp) != -1) {
+ sscanf(line, "%zu", &size);
+ }
+ free(line);
+ fclose(fp);
+ }
+ if (size != 0 && (size & (size - 1)) == 0) {
+ return size;
+ }
+#endif
+ return kDefaultPageSize;
+}
+} // namespace
+
+/*
+ * DirectIOHelper
+ */
+#ifndef NDEBUG
+namespace {
+
+bool IsSectorAligned(const size_t off, size_t sector_size) {
+ return off % sector_size == 0;
+}
+
+bool IsSectorAligned(const void* ptr, size_t sector_size) {
+ return uintptr_t(ptr) % sector_size == 0;
+}
+
+}
+#endif
+
+/*
+ * PosixSequentialFile
+ */
+PosixSequentialFile::PosixSequentialFile(const std::string& fname, FILE* file,
+ int fd, const EnvOptions& options)
+ : filename_(fname),
+ file_(file),
+ fd_(fd),
+ use_direct_io_(options.use_direct_reads),
+ logical_sector_size_(GetLogicalBufferSize(fd_)) {
+ assert(!options.use_direct_reads || !options.use_mmap_reads);
+}
+
+PosixSequentialFile::~PosixSequentialFile() {
+ if (!use_direct_io()) {
+ assert(file_);
+ fclose(file_);
+ } else {
+ assert(fd_);
+ close(fd_);
+ }
+}
+
+Status PosixSequentialFile::Read(size_t n, Slice* result, char* scratch) {
+ assert(result != nullptr && !use_direct_io());
+ Status s;
+ size_t r = 0;
+ do {
+ r = fread_unlocked(scratch, 1, n, file_);
+ } while (r == 0 && ferror(file_) && errno == EINTR);
+ *result = Slice(scratch, r);
+ if (r < n) {
+ if (feof(file_)) {
+ // We leave status as ok if we hit the end of the file
+ // We also clear the error so that the reads can continue
+ // if a new data is written to the file
+ clearerr(file_);
+ } else {
+ // A partial read with an error: return a non-ok status
+ s = IOError("While reading file sequentially", filename_, errno);
+ }
+ }
+ return s;
+}
+
+Status PosixSequentialFile::PositionedRead(uint64_t offset, size_t n,
+ Slice* result, char* scratch) {
+ assert(use_direct_io());
+ assert(IsSectorAligned(offset, GetRequiredBufferAlignment()));
+ assert(IsSectorAligned(n, GetRequiredBufferAlignment()));
+ assert(IsSectorAligned(scratch, GetRequiredBufferAlignment()));
+
+ Status s;
+ ssize_t r = -1;
+ size_t left = n;
+ char* ptr = scratch;
+ while (left > 0) {
+ r = pread(fd_, ptr, left, static_cast<off_t>(offset));
+ if (r <= 0) {
+ if (r == -1 && errno == EINTR) {
+ continue;
+ }
+ break;
+ }
+ ptr += r;
+ offset += r;
+ left -= r;
+ if (r % static_cast<ssize_t>(GetRequiredBufferAlignment()) != 0) {
+ // Bytes reads don't fill sectors. Should only happen at the end
+ // of the file.
+ break;
+ }
+ }
+ if (r < 0) {
+ // An error: return a non-ok status
+ s = IOError(
+ "While pread " + ToString(n) + " bytes from offset " + ToString(offset),
+ filename_, errno);
+ }
+ *result = Slice(scratch, (r < 0) ? 0 : n - left);
+ return s;
+}
+
+Status PosixSequentialFile::Skip(uint64_t n) {
+ if (fseek(file_, static_cast<long int>(n), SEEK_CUR)) {
+ return IOError("While fseek to skip " + ToString(n) + " bytes", filename_,
+ errno);
+ }
+ return Status::OK();
+}
+
+Status PosixSequentialFile::InvalidateCache(size_t offset, size_t length) {
+#ifndef OS_LINUX
+ (void)offset;
+ (void)length;
+ return Status::OK();
+#else
+ if (!use_direct_io()) {
+ // free OS pages
+ int ret = Fadvise(fd_, offset, length, POSIX_FADV_DONTNEED);
+ if (ret != 0) {
+ return IOError("While fadvise NotNeeded offset " + ToString(offset) +
+ " len " + ToString(length),
+ filename_, errno);
+ }
+ }
+ return Status::OK();
+#endif
+}
+
+/*
+ * PosixRandomAccessFile
+ */
+#if defined(OS_LINUX)
+size_t PosixHelper::GetUniqueIdFromFile(int fd, char* id, size_t max_size) {
+ if (max_size < kMaxVarint64Length * 3) {
+ return 0;
+ }
+
+ struct stat buf;
+ int result = fstat(fd, &buf);
+ if (result == -1) {
+ return 0;
+ }
+
+ long version = 0;
+ result = ioctl(fd, FS_IOC_GETVERSION, &version);
+ TEST_SYNC_POINT_CALLBACK("GetUniqueIdFromFile:FS_IOC_GETVERSION", &result);
+ if (result == -1) {
+ return 0;
+ }
+ uint64_t uversion = (uint64_t)version;
+
+ char* rid = id;
+ rid = EncodeVarint64(rid, buf.st_dev);
+ rid = EncodeVarint64(rid, buf.st_ino);
+ rid = EncodeVarint64(rid, uversion);
+ assert(rid >= id);
+ return static_cast<size_t>(rid - id);
+}
+#endif
+
+#if defined(OS_MACOSX) || defined(OS_AIX)
+size_t PosixHelper::GetUniqueIdFromFile(int fd, char* id, size_t max_size) {
+ if (max_size < kMaxVarint64Length * 3) {
+ return 0;
+ }
+
+ struct stat buf;
+ int result = fstat(fd, &buf);
+ if (result == -1) {
+ return 0;
+ }
+
+ char* rid = id;
+ rid = EncodeVarint64(rid, buf.st_dev);
+ rid = EncodeVarint64(rid, buf.st_ino);
+ rid = EncodeVarint64(rid, buf.st_gen);
+ assert(rid >= id);
+ return static_cast<size_t>(rid - id);
+}
+#endif
+/*
+ * PosixRandomAccessFile
+ *
+ * pread() based random-access
+ */
+PosixRandomAccessFile::PosixRandomAccessFile(const std::string& fname, int fd,
+ const EnvOptions& options)
+ : filename_(fname),
+ fd_(fd),
+ use_direct_io_(options.use_direct_reads),
+ logical_sector_size_(GetLogicalBufferSize(fd_)) {
+ assert(!options.use_direct_reads || !options.use_mmap_reads);
+ assert(!options.use_mmap_reads || sizeof(void*) < 8);
+}
+
+PosixRandomAccessFile::~PosixRandomAccessFile() { close(fd_); }
+
+Status PosixRandomAccessFile::Read(uint64_t offset, size_t n, Slice* result,
+ char* scratch) const {
+ if (use_direct_io()) {
+ assert(IsSectorAligned(offset, GetRequiredBufferAlignment()));
+ assert(IsSectorAligned(n, GetRequiredBufferAlignment()));
+ assert(IsSectorAligned(scratch, GetRequiredBufferAlignment()));
+ }
+ Status s;
+ ssize_t r = -1;
+ size_t left = n;
+ char* ptr = scratch;
+ while (left > 0) {
+ r = pread(fd_, ptr, left, static_cast<off_t>(offset));
+ if (r <= 0) {
+ if (r == -1 && errno == EINTR) {
+ continue;
+ }
+ break;
+ }
+ ptr += r;
+ offset += r;
+ left -= r;
+ if (use_direct_io() &&
+ r % static_cast<ssize_t>(GetRequiredBufferAlignment()) != 0) {
+ // Bytes reads don't fill sectors. Should only happen at the end
+ // of the file.
+ break;
+ }
+ }
+ if (r < 0) {
+ // An error: return a non-ok status
+ s = IOError(
+ "While pread offset " + ToString(offset) + " len " + ToString(n),
+ filename_, errno);
+ }
+ *result = Slice(scratch, (r < 0) ? 0 : n - left);
+ return s;
+}
+
+Status PosixRandomAccessFile::Prefetch(uint64_t offset, size_t n) {
+ Status s;
+ if (!use_direct_io()) {
+ ssize_t r = 0;
+#ifdef OS_LINUX
+ r = readahead(fd_, offset, n);
+#endif
+#ifdef OS_MACOSX
+ radvisory advice;
+ advice.ra_offset = static_cast<off_t>(offset);
+ advice.ra_count = static_cast<int>(n);
+ r = fcntl(fd_, F_RDADVISE, &advice);
+#endif
+ if (r == -1) {
+ s = IOError("While prefetching offset " + ToString(offset) + " len " +
+ ToString(n),
+ filename_, errno);
+ }
+ }
+ return s;
+}
+
+#if defined(OS_LINUX) || defined(OS_MACOSX) || defined(OS_AIX)
+size_t PosixRandomAccessFile::GetUniqueId(char* id, size_t max_size) const {
+ return PosixHelper::GetUniqueIdFromFile(fd_, id, max_size);
+}
+#endif
+
+void PosixRandomAccessFile::Hint(AccessPattern pattern) {
+ if (use_direct_io()) {
+ return;
+ }
+ switch (pattern) {
+ case NORMAL:
+ Fadvise(fd_, 0, 0, POSIX_FADV_NORMAL);
+ break;
+ case RANDOM:
+ Fadvise(fd_, 0, 0, POSIX_FADV_RANDOM);
+ break;
+ case SEQUENTIAL:
+ Fadvise(fd_, 0, 0, POSIX_FADV_SEQUENTIAL);
+ break;
+ case WILLNEED:
+ Fadvise(fd_, 0, 0, POSIX_FADV_WILLNEED);
+ break;
+ case DONTNEED:
+ Fadvise(fd_, 0, 0, POSIX_FADV_DONTNEED);
+ break;
+ default:
+ assert(false);
+ break;
+ }
+}
+
+Status PosixRandomAccessFile::InvalidateCache(size_t offset, size_t length) {
+ if (use_direct_io()) {
+ return Status::OK();
+ }
+#ifndef OS_LINUX
+ (void)offset;
+ (void)length;
+ return Status::OK();
+#else
+ // free OS pages
+ int ret = Fadvise(fd_, offset, length, POSIX_FADV_DONTNEED);
+ if (ret == 0) {
+ return Status::OK();
+ }
+ return IOError("While fadvise NotNeeded offset " + ToString(offset) +
+ " len " + ToString(length),
+ filename_, errno);
+#endif
+}
+
+/*
+ * PosixMmapReadableFile
+ *
+ * mmap() based random-access
+ */
+// base[0,length-1] contains the mmapped contents of the file.
+PosixMmapReadableFile::PosixMmapReadableFile(const int fd,
+ const std::string& fname,
+ void* base, size_t length,
+ const EnvOptions& options)
+ : fd_(fd), filename_(fname), mmapped_region_(base), length_(length) {
+#ifdef NDEBUG
+ (void)options;
+#endif
+ fd_ = fd_ + 0; // suppress the warning for used variables
+ assert(options.use_mmap_reads);
+ assert(!options.use_direct_reads);
+}
+
+PosixMmapReadableFile::~PosixMmapReadableFile() {
+ int ret = munmap(mmapped_region_, length_);
+ if (ret != 0) {
+ fprintf(stdout, "failed to munmap %p length %" ROCKSDB_PRIszt " \n",
+ mmapped_region_, length_);
+ }
+ close(fd_);
+}
+
+Status PosixMmapReadableFile::Read(uint64_t offset, size_t n, Slice* result,
+ char* /*scratch*/) const {
+ Status s;
+ if (offset > length_) {
+ *result = Slice();
+ return IOError("While mmap read offset " + ToString(offset) +
+ " larger than file length " + ToString(length_),
+ filename_, EINVAL);
+ } else if (offset + n > length_) {
+ n = static_cast<size_t>(length_ - offset);
+ }
+ *result = Slice(reinterpret_cast<char*>(mmapped_region_) + offset, n);
+ return s;
+}
+
+Status PosixMmapReadableFile::InvalidateCache(size_t offset, size_t length) {
+#ifndef OS_LINUX
+ (void)offset;
+ (void)length;
+ return Status::OK();
+#else
+ // free OS pages
+ int ret = Fadvise(fd_, offset, length, POSIX_FADV_DONTNEED);
+ if (ret == 0) {
+ return Status::OK();
+ }
+ return IOError("While fadvise not needed. Offset " + ToString(offset) +
+ " len" + ToString(length),
+ filename_, errno);
+#endif
+}
+
+/*
+ * PosixMmapFile
+ *
+ * We preallocate up to an extra megabyte and use memcpy to append new
+ * data to the file. This is safe since we either properly close the
+ * file before reading from it, or for log files, the reading code
+ * knows enough to skip zero suffixes.
+ */
+Status PosixMmapFile::UnmapCurrentRegion() {
+ TEST_KILL_RANDOM("PosixMmapFile::UnmapCurrentRegion:0", rocksdb_kill_odds);
+ if (base_ != nullptr) {
+ int munmap_status = munmap(base_, limit_ - base_);
+ if (munmap_status != 0) {
+ return IOError("While munmap", filename_, munmap_status);
+ }
+ file_offset_ += limit_ - base_;
+ base_ = nullptr;
+ limit_ = nullptr;
+ last_sync_ = nullptr;
+ dst_ = nullptr;
+
+ // Increase the amount we map the next time, but capped at 1MB
+ if (map_size_ < (1 << 20)) {
+ map_size_ *= 2;
+ }
+ }
+ return Status::OK();
+}
+
+Status PosixMmapFile::MapNewRegion() {
+#ifdef ROCKSDB_FALLOCATE_PRESENT
+ assert(base_ == nullptr);
+ TEST_KILL_RANDOM("PosixMmapFile::UnmapCurrentRegion:0", rocksdb_kill_odds);
+ // we can't fallocate with FALLOC_FL_KEEP_SIZE here
+ if (allow_fallocate_) {
+ IOSTATS_TIMER_GUARD(allocate_nanos);
+ int alloc_status = fallocate(fd_, 0, file_offset_, map_size_);
+ if (alloc_status != 0) {
+ // fallback to posix_fallocate
+ alloc_status = posix_fallocate(fd_, file_offset_, map_size_);
+ }
+ if (alloc_status != 0) {
+ return Status::IOError("Error allocating space to file : " + filename_ +
+ "Error : " + strerror(alloc_status));
+ }
+ }
+
+ TEST_KILL_RANDOM("PosixMmapFile::Append:1", rocksdb_kill_odds);
+ void* ptr = mmap(nullptr, map_size_, PROT_READ | PROT_WRITE, MAP_SHARED, fd_,
+ file_offset_);
+ if (ptr == MAP_FAILED) {
+ return Status::IOError("MMap failed on " + filename_);
+ }
+ TEST_KILL_RANDOM("PosixMmapFile::Append:2", rocksdb_kill_odds);
+
+ base_ = reinterpret_cast<char*>(ptr);
+ limit_ = base_ + map_size_;
+ dst_ = base_;
+ last_sync_ = base_;
+ return Status::OK();
+#else
+ return Status::NotSupported("This platform doesn't support fallocate()");
+#endif
+}
+
+Status PosixMmapFile::Msync() {
+ if (dst_ == last_sync_) {
+ return Status::OK();
+ }
+ // Find the beginnings of the pages that contain the first and last
+ // bytes to be synced.
+ size_t p1 = TruncateToPageBoundary(last_sync_ - base_);
+ size_t p2 = TruncateToPageBoundary(dst_ - base_ - 1);
+ last_sync_ = dst_;
+ TEST_KILL_RANDOM("PosixMmapFile::Msync:0", rocksdb_kill_odds);
+ if (msync(base_ + p1, p2 - p1 + page_size_, MS_SYNC) < 0) {
+ return IOError("While msync", filename_, errno);
+ }
+ return Status::OK();
+}
+
+PosixMmapFile::PosixMmapFile(const std::string& fname, int fd, size_t page_size,
+ const EnvOptions& options)
+ : filename_(fname),
+ fd_(fd),
+ page_size_(page_size),
+ map_size_(Roundup(65536, page_size)),
+ base_(nullptr),
+ limit_(nullptr),
+ dst_(nullptr),
+ last_sync_(nullptr),
+ file_offset_(0) {
+#ifdef ROCKSDB_FALLOCATE_PRESENT
+ allow_fallocate_ = options.allow_fallocate;
+ fallocate_with_keep_size_ = options.fallocate_with_keep_size;
+#else
+ (void)options;
+#endif
+ assert((page_size & (page_size - 1)) == 0);
+ assert(options.use_mmap_writes);
+ assert(!options.use_direct_writes);
+}
+
+PosixMmapFile::~PosixMmapFile() {
+ if (fd_ >= 0) {
+ PosixMmapFile::Close();
+ }
+}
+
+Status PosixMmapFile::Append(const Slice& data) {
+ const char* src = data.data();
+ size_t left = data.size();
+ while (left > 0) {
+ assert(base_ <= dst_);
+ assert(dst_ <= limit_);
+ size_t avail = limit_ - dst_;
+ if (avail == 0) {
+ Status s = UnmapCurrentRegion();
+ if (!s.ok()) {
+ return s;
+ }
+ s = MapNewRegion();
+ if (!s.ok()) {
+ return s;
+ }
+ TEST_KILL_RANDOM("PosixMmapFile::Append:0", rocksdb_kill_odds);
+ }
+
+ size_t n = (left <= avail) ? left : avail;
+ assert(dst_);
+ memcpy(dst_, src, n);
+ dst_ += n;
+ src += n;
+ left -= n;
+ }
+ return Status::OK();
+}
+
+Status PosixMmapFile::Close() {
+ Status s;
+ size_t unused = limit_ - dst_;
+
+ s = UnmapCurrentRegion();
+ if (!s.ok()) {
+ s = IOError("While closing mmapped file", filename_, errno);
+ } else if (unused > 0) {
+ // Trim the extra space at the end of the file
+ if (ftruncate(fd_, file_offset_ - unused) < 0) {
+ s = IOError("While ftruncating mmaped file", filename_, errno);
+ }
+ }
+
+ if (close(fd_) < 0) {
+ if (s.ok()) {
+ s = IOError("While closing mmapped file", filename_, errno);
+ }
+ }
+
+ fd_ = -1;
+ base_ = nullptr;
+ limit_ = nullptr;
+ return s;
+}
+
+Status PosixMmapFile::Flush() { return Status::OK(); }
+
+Status PosixMmapFile::Sync() {
+ if (fdatasync(fd_) < 0) {
+ return IOError("While fdatasync mmapped file", filename_, errno);
+ }
+
+ return Msync();
+}
+
+/**
+ * Flush data as well as metadata to stable storage.
+ */
+Status PosixMmapFile::Fsync() {
+ if (fsync(fd_) < 0) {
+ return IOError("While fsync mmaped file", filename_, errno);
+ }
+
+ return Msync();
+}
+
+/**
+ * Get the size of valid data in the file. This will not match the
+ * size that is returned from the filesystem because we use mmap
+ * to extend file by map_size every time.
+ */
+uint64_t PosixMmapFile::GetFileSize() {
+ size_t used = dst_ - base_;
+ return file_offset_ + used;
+}
+
+Status PosixMmapFile::InvalidateCache(size_t offset, size_t length) {
+#ifndef OS_LINUX
+ (void)offset;
+ (void)length;
+ return Status::OK();
+#else
+ // free OS pages
+ int ret = Fadvise(fd_, offset, length, POSIX_FADV_DONTNEED);
+ if (ret == 0) {
+ return Status::OK();
+ }
+ return IOError("While fadvise NotNeeded mmapped file", filename_, errno);
+#endif
+}
+
+#ifdef ROCKSDB_FALLOCATE_PRESENT
+Status PosixMmapFile::Allocate(uint64_t offset, uint64_t len) {
+ assert(offset <= std::numeric_limits<off_t>::max());
+ assert(len <= std::numeric_limits<off_t>::max());
+ TEST_KILL_RANDOM("PosixMmapFile::Allocate:0", rocksdb_kill_odds);
+ int alloc_status = 0;
+ if (allow_fallocate_) {
+ alloc_status = fallocate(
+ fd_, fallocate_with_keep_size_ ? FALLOC_FL_KEEP_SIZE : 0,
+ static_cast<off_t>(offset), static_cast<off_t>(len));
+ }
+ if (alloc_status == 0) {
+ return Status::OK();
+ } else {
+ return IOError(
+ "While fallocate offset " + ToString(offset) + " len " + ToString(len),
+ filename_, errno);
+ }
+}
+#endif
+
+/*
+ * PosixWritableFile
+ *
+ * Use posix write to write data to a file.
+ */
+PosixWritableFile::PosixWritableFile(const std::string& fname, int fd,
+ const EnvOptions& options)
+ : filename_(fname),
+ use_direct_io_(options.use_direct_writes),
+ fd_(fd),
+ filesize_(0),
+ logical_sector_size_(GetLogicalBufferSize(fd_)) {
+#ifdef ROCKSDB_FALLOCATE_PRESENT
+ allow_fallocate_ = options.allow_fallocate;
+ fallocate_with_keep_size_ = options.fallocate_with_keep_size;
+#endif
+ assert(!options.use_mmap_writes);
+}
+
+PosixWritableFile::~PosixWritableFile() {
+ if (fd_ >= 0) {
+ PosixWritableFile::Close();
+ }
+}
+
+Status PosixWritableFile::Append(const Slice& data) {
+ if (use_direct_io()) {
+ assert(IsSectorAligned(data.size(), GetRequiredBufferAlignment()));
+ assert(IsSectorAligned(data.data(), GetRequiredBufferAlignment()));
+ }
+ const char* src = data.data();
+ size_t left = data.size();
+ while (left != 0) {
+ ssize_t done = write(fd_, src, left);
+ if (done < 0) {
+ if (errno == EINTR) {
+ continue;
+ }
+ return IOError("While appending to file", filename_, errno);
+ }
+ left -= done;
+ src += done;
+ }
+ filesize_ += data.size();
+ return Status::OK();
+}
+
+Status PosixWritableFile::PositionedAppend(const Slice& data, uint64_t offset) {
+ if (use_direct_io()) {
+ assert(IsSectorAligned(offset, GetRequiredBufferAlignment()));
+ assert(IsSectorAligned(data.size(), GetRequiredBufferAlignment()));
+ assert(IsSectorAligned(data.data(), GetRequiredBufferAlignment()));
+ }
+ assert(offset <= std::numeric_limits<off_t>::max());
+ const char* src = data.data();
+ size_t left = data.size();
+ while (left != 0) {
+ ssize_t done = pwrite(fd_, src, left, static_cast<off_t>(offset));
+ if (done < 0) {
+ if (errno == EINTR) {
+ continue;
+ }
+ return IOError("While pwrite to file at offset " + ToString(offset),
+ filename_, errno);
+ }
+ left -= done;
+ offset += done;
+ src += done;
+ }
+ filesize_ = offset;
+ return Status::OK();
+}
+
+Status PosixWritableFile::Truncate(uint64_t size) {
+ Status s;
+ int r = ftruncate(fd_, size);
+ if (r < 0) {
+ s = IOError("While ftruncate file to size " + ToString(size), filename_,
+ errno);
+ } else {
+ filesize_ = size;
+ }
+ return s;
+}
+
+Status PosixWritableFile::Close() {
+ Status s;
+
+ size_t block_size;
+ size_t last_allocated_block;
+ GetPreallocationStatus(&block_size, &last_allocated_block);
+ if (last_allocated_block > 0) {
+ // trim the extra space preallocated at the end of the file
+ // NOTE(ljin): we probably don't want to surface failure as an IOError,
+ // but it will be nice to log these errors.
+ int dummy __attribute__((__unused__));
+ dummy = ftruncate(fd_, filesize_);
+#if defined(ROCKSDB_FALLOCATE_PRESENT) && defined(FALLOC_FL_PUNCH_HOLE) && \
+ !defined(TRAVIS)
+ // in some file systems, ftruncate only trims trailing space if the
+ // new file size is smaller than the current size. Calling fallocate
+ // with FALLOC_FL_PUNCH_HOLE flag to explicitly release these unused
+ // blocks. FALLOC_FL_PUNCH_HOLE is supported on at least the following
+ // filesystems:
+ // XFS (since Linux 2.6.38)
+ // ext4 (since Linux 3.0)
+ // Btrfs (since Linux 3.7)
+ // tmpfs (since Linux 3.5)
+ // We ignore error since failure of this operation does not affect
+ // correctness.
+ // TRAVIS - this code does not work on TRAVIS filesystems.
+ // the FALLOC_FL_KEEP_SIZE option is expected to not change the size
+ // of the file, but it does. Simple strace report will show that.
+ // While we work with Travis-CI team to figure out if this is a
+ // quirk of Docker/AUFS, we will comment this out.
+ struct stat file_stats;
+ int result = fstat(fd_, &file_stats);
+ // After ftruncate, we check whether ftruncate has the correct behavior.
+ // If not, we should hack it with FALLOC_FL_PUNCH_HOLE
+ if (result == 0 &&
+ (file_stats.st_size + file_stats.st_blksize - 1) /
+ file_stats.st_blksize !=
+ file_stats.st_blocks / (file_stats.st_blksize / 512)) {
+ IOSTATS_TIMER_GUARD(allocate_nanos);
+ if (allow_fallocate_) {
+ fallocate(fd_, FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE, filesize_,
+ block_size * last_allocated_block - filesize_);
+ }
+ }
+#endif
+ }
+
+ if (close(fd_) < 0) {
+ s = IOError("While closing file after writing", filename_, errno);
+ }
+ fd_ = -1;
+ return s;
+}
+
+// write out the cached data to the OS cache
+Status PosixWritableFile::Flush() { return Status::OK(); }
+
+Status PosixWritableFile::Sync() {
+ if (fdatasync(fd_) < 0) {
+ return IOError("While fdatasync", filename_, errno);
+ }
+ return Status::OK();
+}
+
+Status PosixWritableFile::Fsync() {
+ if (fsync(fd_) < 0) {
+ return IOError("While fsync", filename_, errno);
+ }
+ return Status::OK();
+}
+
+bool PosixWritableFile::IsSyncThreadSafe() const { return true; }
+
+uint64_t PosixWritableFile::GetFileSize() { return filesize_; }
+
+void PosixWritableFile::SetWriteLifeTimeHint(Env::WriteLifeTimeHint hint) {
+#ifdef OS_LINUX
+// Suppress Valgrind "Unimplemented functionality" error.
+#ifndef ROCKSDB_VALGRIND_RUN
+ if (hint == write_hint_) {
+ return;
+ }
+ if (fcntl(fd_, F_SET_RW_HINT, &hint) == 0) {
+ write_hint_ = hint;
+ }
+#else
+ (void)hint;
+#endif // ROCKSDB_VALGRIND_RUN
+#else
+ (void)hint;
+#endif // OS_LINUX
+}
+
+Status PosixWritableFile::InvalidateCache(size_t offset, size_t length) {
+ if (use_direct_io()) {
+ return Status::OK();
+ }
+#ifndef OS_LINUX
+ (void)offset;
+ (void)length;
+ return Status::OK();
+#else
+ // free OS pages
+ int ret = Fadvise(fd_, offset, length, POSIX_FADV_DONTNEED);
+ if (ret == 0) {
+ return Status::OK();
+ }
+ return IOError("While fadvise NotNeeded", filename_, errno);
+#endif
+}
+
+#ifdef ROCKSDB_FALLOCATE_PRESENT
+Status PosixWritableFile::Allocate(uint64_t offset, uint64_t len) {
+ assert(offset <= std::numeric_limits<off_t>::max());
+ assert(len <= std::numeric_limits<off_t>::max());
+ TEST_KILL_RANDOM("PosixWritableFile::Allocate:0", rocksdb_kill_odds);
+ IOSTATS_TIMER_GUARD(allocate_nanos);
+ int alloc_status = 0;
+ if (allow_fallocate_) {
+ alloc_status = fallocate(
+ fd_, fallocate_with_keep_size_ ? FALLOC_FL_KEEP_SIZE : 0,
+ static_cast<off_t>(offset), static_cast<off_t>(len));
+ }
+ if (alloc_status == 0) {
+ return Status::OK();
+ } else {
+ return IOError(
+ "While fallocate offset " + ToString(offset) + " len " + ToString(len),
+ filename_, errno);
+ }
+}
+#endif
+
+#ifdef ROCKSDB_RANGESYNC_PRESENT
+Status PosixWritableFile::RangeSync(uint64_t offset, uint64_t nbytes) {
+ assert(offset <= std::numeric_limits<off_t>::max());
+ assert(nbytes <= std::numeric_limits<off_t>::max());
+ if (sync_file_range(fd_, static_cast<off_t>(offset),
+ static_cast<off_t>(nbytes), SYNC_FILE_RANGE_WRITE) == 0) {
+ return Status::OK();
+ } else {
+ return IOError("While sync_file_range offset " + ToString(offset) +
+ " bytes " + ToString(nbytes),
+ filename_, errno);
+ }
+}
+#endif
+
+#ifdef OS_LINUX
+size_t PosixWritableFile::GetUniqueId(char* id, size_t max_size) const {
+ return PosixHelper::GetUniqueIdFromFile(fd_, id, max_size);
+}
+#endif
+
+/*
+ * PosixRandomRWFile
+ */
+
+PosixRandomRWFile::PosixRandomRWFile(const std::string& fname, int fd,
+ const EnvOptions& /*options*/)
+ : filename_(fname), fd_(fd) {}
+
+PosixRandomRWFile::~PosixRandomRWFile() {
+ if (fd_ >= 0) {
+ Close();
+ }
+}
+
+Status PosixRandomRWFile::Write(uint64_t offset, const Slice& data) {
+ const char* src = data.data();
+ size_t left = data.size();
+ while (left != 0) {
+ ssize_t done = pwrite(fd_, src, left, offset);
+ if (done < 0) {
+ // error while writing to file
+ if (errno == EINTR) {
+ // write was interrupted, try again.
+ continue;
+ }
+ return IOError(
+ "While write random read/write file at offset " + ToString(offset),
+ filename_, errno);
+ }
+
+ // Wrote `done` bytes
+ left -= done;
+ offset += done;
+ src += done;
+ }
+
+ return Status::OK();
+}
+
+Status PosixRandomRWFile::Read(uint64_t offset, size_t n, Slice* result,
+ char* scratch) const {
+ size_t left = n;
+ char* ptr = scratch;
+ while (left > 0) {
+ ssize_t done = pread(fd_, ptr, left, offset);
+ if (done < 0) {
+ // error while reading from file
+ if (errno == EINTR) {
+ // read was interrupted, try again.
+ continue;
+ }
+ return IOError("While reading random read/write file offset " +
+ ToString(offset) + " len " + ToString(n),
+ filename_, errno);
+ } else if (done == 0) {
+ // Nothing more to read
+ break;
+ }
+
+ // Read `done` bytes
+ ptr += done;
+ offset += done;
+ left -= done;
+ }
+
+ *result = Slice(scratch, n - left);
+ return Status::OK();
+}
+
+Status PosixRandomRWFile::Flush() { return Status::OK(); }
+
+Status PosixRandomRWFile::Sync() {
+ if (fdatasync(fd_) < 0) {
+ return IOError("While fdatasync random read/write file", filename_, errno);
+ }
+ return Status::OK();
+}
+
+Status PosixRandomRWFile::Fsync() {
+ if (fsync(fd_) < 0) {
+ return IOError("While fsync random read/write file", filename_, errno);
+ }
+ return Status::OK();
+}
+
+Status PosixRandomRWFile::Close() {
+ if (close(fd_) < 0) {
+ return IOError("While close random read/write file", filename_, errno);
+ }
+ fd_ = -1;
+ return Status::OK();
+}
+
+PosixMemoryMappedFileBuffer::~PosixMemoryMappedFileBuffer() {
+ // TODO should have error handling though not much we can do...
+ munmap(this->base_, length_);
+}
+
+/*
+ * PosixDirectory
+ */
+
+PosixDirectory::~PosixDirectory() { close(fd_); }
+
+Status PosixDirectory::Fsync() {
+#ifndef OS_AIX
+ if (fsync(fd_) == -1) {
+ return IOError("While fsync", "a directory", errno);
+ }
+#endif
+ return Status::OK();
+}
+} // namespace rocksdb
+#endif
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-30 12:24:12 +0000