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rocksdb/utilities/flashcache/flashcache.cc

145 lines
4.5 KiB

// Copyright (c) 2014, Facebook, Inc. All rights reserved.
// This source code is licensed under the BSD-style license found in the
// LICENSE file in the root directory of this source tree. An additional grant
// of patent rights can be found in the PATENTS file in the same directory.
#include "rocksdb/utilities/flashcache.h"
#include "utilities/flashcache/flashcache.h"
#ifdef OS_LINUX
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <unistd.h>
#include "third-party/flashcache/flashcache_ioctl.h"
#endif
namespace rocksdb {
#if !defined(ROCKSDB_LITE) && defined(OS_LINUX)
// Most of the code that handles flashcache is copied from websql's branch of
// mysql-5.6
class FlashcacheAwareEnv : public EnvWrapper {
public:
FlashcacheAwareEnv(Env* base, int cachedev_fd)
: EnvWrapper(base), cachedev_fd_(cachedev_fd) {
pid_t pid = getpid();
/* cleanup previous whitelistings */
if (ioctl(cachedev_fd_, FLASHCACHEDELALLWHITELIST, &pid) < 0) {
close(cachedev_fd_);
cachedev_fd_ = -1;
fprintf(stderr, "ioctl del-all-whitelist for flashcache failed\n");
return;
}
if (ioctl(cachedev_fd_, FLASHCACHEADDWHITELIST, &pid) < 0) {
fprintf(stderr, "ioctl add-whitelist for flashcache failed\n");
}
}
~FlashcacheAwareEnv() {
// cachedev_fd_ is -1 if it's unitialized
if (cachedev_fd_ != -1) {
pid_t pid = getpid();
if (ioctl(cachedev_fd_, FLASHCACHEDELWHITELIST, &pid) < 0) {
fprintf(stderr, "ioctl del-whitelist for flashcache failed\n");
}
close(cachedev_fd_);
}
}
static int BlacklistCurrentThread(int cachedev_fd) {
pid_t pid = static_cast<pid_t>(syscall(SYS_gettid));
return ioctl(cachedev_fd, FLASHCACHEADDNCPID, &pid);
}
static int WhitelistCurrentThread(int cachedev_fd) {
pid_t pid = static_cast<pid_t>(syscall(SYS_gettid));
return ioctl(cachedev_fd, FLASHCACHEDELNCPID, &pid);
}
int GetFlashCacheFileDescriptor() { return cachedev_fd_; }
struct Arg {
Arg(void (*f)(void* arg), void* a, int _cachedev_fd)
: original_function_(f), original_arg_(a), cachedev_fd(_cachedev_fd) {}
void (*original_function_)(void* arg);
void* original_arg_;
int cachedev_fd;
};
static void BgThreadWrapper(void* a) {
Arg* arg = reinterpret_cast<Arg*>(a);
if (arg->cachedev_fd != -1) {
if (BlacklistCurrentThread(arg->cachedev_fd) < 0) {
fprintf(stderr, "ioctl add-nc-pid for flashcache failed\n");
}
}
arg->original_function_(arg->original_arg_);
if (arg->cachedev_fd != -1) {
if (WhitelistCurrentThread(arg->cachedev_fd) < 0) {
fprintf(stderr, "ioctl del-nc-pid for flashcache failed\n");
}
}
delete arg;
}
int UnSchedule(void* arg, Priority pri) override {
// no unschedule for you
return 0;
}
void Schedule(void (*f)(void* arg), void* a, Priority pri,
void* tag = nullptr) override {
EnvWrapper::Schedule(&BgThreadWrapper, new Arg(f, a, cachedev_fd_), pri,
tag);
}
private:
int cachedev_fd_;
};
std::unique_ptr<Env> NewFlashcacheAwareEnv(Env* base,
const std::string& flashcache_dev) {
// Cachedev should remain open or ioctl will be lost
int cachedev_fd = open(flashcache_dev.c_str(), O_RDONLY);
if (cachedev_fd < 0) {
fprintf(stderr, "Open flash device failed\n");
return nullptr;
}
std::unique_ptr<Env> ret(new FlashcacheAwareEnv(base, cachedev_fd));
return std::move(ret);
}
int FlashcacheBlacklistCurrentThread(Env* flashcache_aware_env) {
int fd = dynamic_cast<FlashcacheAwareEnv*>(flashcache_aware_env)
->GetFlashCacheFileDescriptor();
if (fd == -1) {
return -1;
}
return FlashcacheAwareEnv::BlacklistCurrentThread(fd);
}
int FlashcacheWhitelistCurrentThread(Env* flashcache_aware_env) {
int fd = dynamic_cast<FlashcacheAwareEnv*>(flashcache_aware_env)
->GetFlashCacheFileDescriptor();
if (fd == -1) {
return -1;
}
return FlashcacheAwareEnv::WhitelistCurrentThread(fd);
}
#else // !defined(ROCKSDB_LITE) && defined(OS_LINUX)
std::unique_ptr<Env> NewFlashcacheAwareEnv(Env* base,
const std::string& flashcache_dev) {
return nullptr;
}
int FlashcacheBlacklistCurrentThread(Env* flashcache_aware_env) { return -1; }
int FlashcacheWhitelistCurrentThread(Env* flashcache_aware_env) { return -1; }
#endif // !defined(ROCKSDB_LITE) && defined(OS_LINUX)
} // namespace rocksdb