Spin-off syscall-related file operations (#78)

* [file_utils] spin-off syscall-related file operations

1. Eliminate the potential circular dependency between
   persistent-data/block.h and persistent-data/file_utils.h,
   if the former one wants to include the latter.
2. Avoid namespace pollution by removing the "using namespace std"
   declaration in block.tcc.
3. Correct the header hierarchy: base/xml_utils.h now no longer
   depends on the higher-level persistent-data/file_utils.h

* [file_utils] support block files in get_file_length()
This commit is contained in:
Ming-Hung Tsai 2017-04-30 01:51:52 +08:00 committed by Joe Thornber
parent 8f25e1b234
commit b7d418131d
20 changed files with 210 additions and 191 deletions

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@ -33,6 +33,7 @@ SOURCE=\
base/error_state.cc \
base/error_string.cc \
base/grid_layout.cc \
base/file_utils.cc \
base/progress_monitor.cc \
base/rolling_hash.cc \
base/xml_utils.cc \

143
base/file_utils.cc Normal file
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@ -0,0 +1,143 @@
#include "base/file_utils.h"
#include "base/error_string.h"
#include <sstream>
#include <stdexcept>
#include <linux/fs.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
//----------------------------------------------------------------
// FIXME: give this namespace a name
namespace {
using namespace std;
int const DEFAULT_MODE = 0666;
int const OPEN_FLAGS = O_DIRECT;
// FIXME: introduce a new exception for this, or at least lift this
// to exception.h
void syscall_failed(char const *call) {
ostringstream out;
out << "syscall '" << call << "' failed: " << base::error_string(errno);
throw runtime_error(out.str());
}
void syscall_failed(string const &call, string const &message)
{
ostringstream out;
out << "syscall '" << call << "' failed: " << base::error_string(errno) << "\n"
<< message;
throw runtime_error(out.str());
}
}
//----------------------------------------------------------------
int
file_utils::open_file(string const &path, int flags) {
int fd = ::open(path.c_str(), OPEN_FLAGS | flags, DEFAULT_MODE);
if (fd < 0)
syscall_failed("open",
"Note: you cannot run this tool with these options on live metadata.");
return fd;
}
bool
file_utils::file_exists(string const &path) {
struct ::stat info;
int r = ::stat(path.c_str(), &info);
if (r) {
if (errno == ENOENT)
return false;
syscall_failed("stat");
return false; // never get here
} else
return S_ISREG(info.st_mode) || S_ISBLK(info.st_mode);
}
void
file_utils::check_file_exists(string const &file) {
struct stat info;
int r = ::stat(file.c_str(), &info);
if (r)
throw runtime_error("Couldn't stat file");
if (!S_ISREG(info.st_mode))
throw runtime_error("Not a regular file");
}
int
file_utils::create_block_file(string const &path, off_t file_size) {
if (file_exists(path)) {
ostringstream out;
out << __FUNCTION__ << ": file '" << path << "' already exists";
throw runtime_error(out.str());
}
int fd = open_file(path, O_CREAT | O_EXCL | O_RDWR);
int r = ::ftruncate(fd, file_size);
if (r < 0)
syscall_failed("ftruncate");
return fd;
}
int
file_utils::open_block_file(string const &path, off_t min_size, bool writeable, bool excl) {
if (!file_exists(path)) {
ostringstream out;
out << __FUNCTION__ << ": file '" << path << "' doesn't exist";
throw runtime_error(out.str());
}
int flags = writeable ? O_RDWR : O_RDONLY;
if (excl)
flags |= O_EXCL;
return open_file(path, flags);
}
uint64_t
file_utils::get_file_length(string const &file) {
struct stat info;
uint64_t nr_bytes;
int r = ::stat(file.c_str(), &info);
if (r)
throw runtime_error("Couldn't stat path");
if (S_ISREG(info.st_mode))
// It's okay to cast st_size to a uint64_t value.
// If LFS is enabled, st_size should not be negative for regular files.
nr_bytes = static_cast<uint64_t>(info.st_size);
else if (S_ISBLK(info.st_mode)) {
// To get the size of a block device we need to
// open it, and then make an ioctl call.
int fd = ::open(file.c_str(), O_RDONLY);
if (fd < 0)
throw runtime_error("couldn't open block device to ascertain size");
r = ::ioctl(fd, BLKGETSIZE64, &nr_bytes);
if (r) {
::close(fd);
throw runtime_error("ioctl BLKGETSIZE64 failed");
}
::close(fd);
} else
// FIXME: needs a better message
throw runtime_error("bad path");
return nr_bytes;
}
//----------------------------------------------------------------

21
base/file_utils.h Normal file
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@ -0,0 +1,21 @@
#ifndef BASE_FILE_UTILS_H
#define BASE_FILE_UTILS_H
#include <string>
#include <sys/types.h>
#include <stdint.h>
//----------------------------------------------------------------
namespace file_utils {
int open_file(std::string const &path, int flags);
bool file_exists(std::string const &path);
void check_file_exists(std::string const &file);
int create_block_file(std::string const &path, off_t file_size);
int open_block_file(std::string const &path, off_t min_size, bool writeable, bool excl = true);
uint64_t get_file_length(std::string const &file);
}
//----------------------------------------------------------------
#endif

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@ -1,8 +1,9 @@
#include "xml_utils.h"
#include "persistent-data/file_utils.h"
#include "base/file_utils.h"
#include <fstream>
#include <iostream>
#include <sys/stat.h>
using namespace xml_utils;
@ -11,13 +12,13 @@ using namespace xml_utils;
void
xml_parser::parse(std::string const &backup_file, bool quiet)
{
persistent_data::check_file_exists(backup_file);
file_utils::check_file_exists(backup_file);
ifstream in(backup_file.c_str(), ifstream::in);
std::unique_ptr<base::progress_monitor> monitor = create_monitor(quiet);
size_t total = 0;
size_t input_length = get_file_length(backup_file);
size_t input_length = file_utils::get_file_length(backup_file);
XML_Error error_code = XML_ERROR_NONE;
while (!in.eof() && error_code == XML_ERROR_NONE) {
@ -43,19 +44,6 @@ xml_parser::parse(std::string const &backup_file, bool quiet)
}
}
size_t
xml_parser::get_file_length(string const &file) const
{
struct stat info;
int r;
r = ::stat(file.c_str(), &info);
if (r)
throw runtime_error("Couldn't stat backup path");
return info.st_size;
}
unique_ptr<base::progress_monitor>
xml_parser::create_monitor(bool quiet)
{

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@ -36,7 +36,6 @@ namespace xml_utils {
void parse(std::string const &backup_file, bool quiet);
private:
size_t get_file_length(string const &file) const;
unique_ptr<base::progress_monitor> create_monitor(bool quiet);
XML_Parser parser_;

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@ -1,5 +1,6 @@
#include "version.h"
#include "base/file_utils.h"
#include "base/output_file_requirements.h"
#include "caching/commands.h"
#include "caching/metadata.h"
@ -17,22 +18,12 @@
using namespace boost;
using namespace caching;
using namespace persistent_data;
using namespace file_utils;
using namespace std;
//----------------------------------------------------------------
namespace {
size_t get_file_length(string const &file) {
struct stat info;
int r;
r = ::stat(file.c_str(), &info);
if (r)
throw runtime_error("Couldn't stat backup path");
return info.st_size;
}
unique_ptr<progress_monitor> create_monitor(bool quiet) {
if (!quiet && isatty(fileno(stdout)))
return create_progress_bar("Restoring");

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@ -3,10 +3,13 @@
#include "persistent-data/checksum.h"
#include "persistent-data/errors.h"
#include <sstream>
using namespace base;
using namespace era;
using namespace superblock_damage;
using namespace persistent_data;
using namespace std;
//----------------------------------------------------------------

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@ -19,99 +19,14 @@
#include "block.h"
#include "base/error_string.h"
#include "base/file_utils.h"
#include "block-cache/io_engine.h"
#include <errno.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <fcntl.h>
#include <boost/bind.hpp>
#include <stdexcept>
#include <sstream>
//----------------------------------------------------------------
// FIXME: give this namesace a name
namespace {
using namespace std;
int const DEFAULT_MODE = 0666;
int const OPEN_FLAGS = O_DIRECT;
// FIXME: introduce a new exception for this, or at least lift this
// to exception.h
void syscall_failed(char const *call) {
ostringstream out;
out << "syscall '" << call << "' failed: " << base::error_string(errno);
throw runtime_error(out.str());
}
void syscall_failed(string const &call, string const &message)
{
ostringstream out;
out << "syscall '" << call << "' failed: " << base::error_string(errno) << "\n"
<< message;
throw runtime_error(out.str());
}
int open_file(string const &path, int flags) {
int fd = ::open(path.c_str(), OPEN_FLAGS | flags, DEFAULT_MODE);
if (fd < 0)
syscall_failed("open",
"Note: you cannot run this tool with these options on live metadata.");
return fd;
}
bool file_exists(string const &path) {
struct ::stat info;
int r = ::stat(path.c_str(), &info);
if (r) {
if (errno == ENOENT)
return false;
syscall_failed("stat");
return false; // never get here
} else
return S_ISREG(info.st_mode) || S_ISBLK(info.st_mode);
}
int create_block_file(string const &path, off_t file_size) {
if (file_exists(path)) {
ostringstream out;
out << __FUNCTION__ << ": file '" << path << "' already exists";
throw runtime_error(out.str());
}
int fd = open_file(path, O_CREAT | O_EXCL | O_RDWR);
int r = ::ftruncate(fd, file_size);
if (r < 0)
syscall_failed("ftruncate");
return fd;
}
int open_block_file(string const &path, off_t min_size, bool writeable, bool excl = true) {
if (!file_exists(path)) {
ostringstream out;
out << __FUNCTION__ << ": file '" << path << "' doesn't exist";
throw runtime_error(out.str());
}
int flags = writeable ? O_RDWR : O_RDONLY;
if (excl)
flags |= O_EXCL;
return open_file(path, flags);
}
};
namespace persistent_data {
template <uint32_t BlockSize>
block_manager<BlockSize>::read_ref::read_ref(block_cache::block &b)
@ -233,17 +148,17 @@ namespace persistent_data {
template <uint32_t BlockSize>
int
block_manager<BlockSize>::open_or_create_block_file(string const &path, off_t file_size, mode m, bool excl)
block_manager<BlockSize>::open_or_create_block_file(std::string const &path, off_t file_size, mode m, bool excl)
{
switch (m) {
case READ_ONLY:
return open_block_file(path, file_size, false, excl);
return file_utils::open_block_file(path, file_size, false, excl);
case READ_WRITE:
return open_block_file(path, file_size, true, excl);
return file_utils::open_block_file(path, file_size, true, excl);
case CREATE:
return create_block_file(path, file_size);
return file_utils::create_block_file(path, file_size);
default:
throw std::runtime_error("unsupported mode");

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@ -38,7 +38,7 @@ namespace persistent_data {
virtual void inc(block_address b) {
count_map::iterator it = counts_.find(b);
if (it == counts_.end())
counts_.insert(make_pair(b, 1));
counts_.insert(std::make_pair(b, 1));
else
it->second++;
}

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@ -3,6 +3,7 @@
#include <stdexcept>
using namespace persistent_data;
using namespace std;
//----------------------------------------------------------------
@ -91,7 +92,7 @@ bloom_filter::flush()
}
void
bloom_filter::fill_probes(block_address b, vector<unsigned> &probes) const
bloom_filter::fill_probes(block_address b, std::vector<unsigned> &probes) const
{
uint32_t h1 = hash1(b) & mask_;
uint32_t h2 = hash2(b) & mask_;
@ -105,7 +106,7 @@ bloom_filter::fill_probes(block_address b, vector<unsigned> &probes) const
}
void
bloom_filter::print_debug(ostream &out)
bloom_filter::print_debug(std::ostream &out)
{
print_residency(out);
@ -133,7 +134,7 @@ bloom_filter::print_debug(ostream &out)
}
void
bloom_filter::print_residency(ostream &out)
bloom_filter::print_residency(std::ostream &out)
{
unsigned count = 0;
for (unsigned i = 0; i < bits_.get_nr_bits(); i++)

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@ -26,12 +26,12 @@ namespace persistent_data {
void set(uint64_t b);
void flush();
void print_debug(ostream &out);
void print_debug(std::ostream &out);
private:
void print_residency(ostream &out);
void print_residency(std::ostream &out);
void fill_probes(block_address b, vector<unsigned> &probes) const;
void fill_probes(block_address b, std::vector<unsigned> &probes) const;
transaction_manager &tm_;
persistent_data::bitset bits_;

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@ -24,6 +24,7 @@
#include "persistent-data/validators.h"
#include <iostream>
#include <sstream>
//----------------------------------------------------------------

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@ -5,56 +5,26 @@
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sstream>
#include <unistd.h>
using namespace base;
using namespace bcache;
using namespace persistent_data;
using namespace std;
//----------------------------------------------------------------
persistent_data::block_address
persistent_data::get_nr_blocks(string const &path, sector_t block_size)
persistent_data::get_nr_blocks(std::string const &path, sector_t block_size)
{
using namespace persistent_data;
struct stat info;
block_address nr_blocks;
int r = ::stat(path.c_str(), &info);
if (r) {
ostringstream out;
out << "Couldn't stat dev path '" << path << "': "
<< strerror(errno);
throw runtime_error(out.str());
}
if (S_ISREG(info.st_mode) && info.st_size)
nr_blocks = div_down<block_address>(info.st_size, block_size);
else if (S_ISBLK(info.st_mode)) {
// To get the size of a block device we need to
// open it, and then make an ioctl call.
int fd = ::open(path.c_str(), O_RDONLY);
if (fd < 0)
throw runtime_error("couldn't open block device to ascertain size");
r = ::ioctl(fd, BLKGETSIZE64, &nr_blocks);
if (r) {
::close(fd);
throw runtime_error("ioctl BLKGETSIZE64 failed");
}
::close(fd);
nr_blocks = div_down<block_address>(nr_blocks, block_size);
} else
// FIXME: needs a better message
throw runtime_error("bad path");
return nr_blocks;
return div_down<block_address>(file_utils::get_file_length(path),
block_size);
}
block_address
persistent_data::get_nr_metadata_blocks(string const &path)
persistent_data::get_nr_metadata_blocks(std::string const &path)
{
return get_nr_blocks(path, MD_BLOCK_SIZE);
}
@ -66,15 +36,4 @@ persistent_data::open_bm(std::string const &dev_path, block_manager<>::mode m, b
return block_manager<>::ptr(new block_manager<>(dev_path, nr_blocks, 1, m, excl));
}
void
persistent_data::check_file_exists(string const &file) {
struct stat info;
int r = ::stat(file.c_str(), &info);
if (r)
throw runtime_error("Couldn't stat file");
if (!S_ISREG(info.st_mode))
throw runtime_error("Not a regular file");
}
//----------------------------------------------------------------

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@ -9,13 +9,11 @@
// FIXME: move to a different unit
namespace persistent_data {
persistent_data::block_address get_nr_blocks(string const &path, sector_t block_size = MD_BLOCK_SIZE);
block_address get_nr_metadata_blocks(string const &path);
persistent_data::block_address get_nr_blocks(std::string const &path, sector_t block_size = MD_BLOCK_SIZE);
block_address get_nr_metadata_blocks(std::string const &path);
block_manager<>::ptr open_bm(std::string const &dev_path,
block_manager<>::mode m, bool excl = true);
void check_file_exists(std::string const &file);
}
//----------------------------------------------------------------

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@ -21,6 +21,8 @@
#include <boost/shared_ptr.hpp>
using namespace std;
//----------------------------------------------------------------
namespace {

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@ -22,6 +22,7 @@
#include <list>
using namespace persistent_data;
using namespace std;
//----------------------------------------------------------------

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@ -4,6 +4,8 @@
#include "persistent-data/errors.h"
#include "persistent-data/validators.h"
#include <sstream>
using namespace bcache;
using namespace persistent_data;

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@ -2,25 +2,14 @@
#include "thin-provisioning/cache_stream.h"
#include "persistent-data/file_utils.h"
#include <fcntl.h>
using namespace thin_provisioning;
using namespace std;
using namespace persistent_data;
//----------------------------------------------------------------
namespace {
int open_file(string const &path) {
int fd = ::open(path.c_str(), O_RDONLY | O_DIRECT | O_EXCL, 0666);
if (fd < 0)
syscall_failed("open",
"Note: you cannot run this tool with these options on live metadata.");
return fd;
}
}
//----------------------------------------------------------------
cache_stream::cache_stream(string const &path,
block_address block_size,
size_t cache_mem)
@ -29,7 +18,7 @@ cache_stream::cache_stream(string const &path,
// hack because cache uses LRU rather than MRU
cache_blocks_((cache_mem / block_size) / 2u),
fd_(open_file(path)),
fd_(file_utils::open_file(path, O_RDONLY | O_EXCL)),
v_(new bcache::noop_validator()),
cache_(new block_cache(fd_, block_size / 512, nr_blocks_, cache_mem)),
current_index_(0) {

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@ -3,8 +3,11 @@
#include "thin-provisioning/superblock.h"
#include "persistent-data/file_utils.h"
#include <sstream>
using namespace thin_provisioning;
using namespace superblock_detail;
using namespace std;
//----------------------------------------------------------------

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@ -1,8 +1,10 @@
#include <iostream>
#include <getopt.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <linux/fs.h>
#include <libgen.h>
#include <fcntl.h>
#undef BLOCK_SIZE