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// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
// vim: ts=8 sw=2 smarttab
#include "include/int_types.h"
#include "include/types.h"
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include "include/compat.h"
#include "include/linux_fiemap.h"
#include "include/color.h"
#include "include/buffer.h"
#include "include/ceph_assert.h"
#include <iostream>
#include <fstream>
#include <sstream>
#include "common/errno.h"
#include "common/config.h"
#include "common/sync_filesystem.h"
#include "ZFSFileStoreBackend.h"
#define dout_context cct()
#define dout_subsys ceph_subsys_filestore
#undef dout_prefix
#define dout_prefix *_dout << "zfsfilestorebackend(" << get_basedir_path() << ") "
ZFSFileStoreBackend::ZFSFileStoreBackend(FileStore *fs) :
GenericFileStoreBackend(fs), base_zh(NULL), current_zh(NULL),
m_filestore_zfs_snap(cct()->_conf->filestore_zfs_snap)
{
int ret = zfs.init();
if (ret < 0) {
dout(0) << "ZFSFileStoreBackend: failed to init libzfs" << dendl;
return;
}
base_zh = zfs.path_to_zhandle(get_basedir_path().c_str(), ZFS::TYPE_FILESYSTEM);
if (!base_zh) {
dout(0) << "ZFSFileStoreBackend: failed to get zfs handler for basedir" << dendl;
return;
}
update_current_zh();
}
ZFSFileStoreBackend::~ZFSFileStoreBackend()
{
if (base_zh)
zfs.close(base_zh);
if (current_zh)
zfs.close(current_zh);
}
int ZFSFileStoreBackend::update_current_zh()
{
char path[PATH_MAX];
snprintf(path, sizeof(path), "%s/current", zfs.get_name(base_zh));
ZFS::Handle *zh = zfs.open(path, ZFS::TYPE_FILESYSTEM);
if (zh) {
char *mnt;
if (zfs.is_mounted(zh, &mnt)) {
int ret = get_current_path() == mnt;
free(mnt);
if (ret) {
current_zh = zh;
return 0;
}
} else {
int ret = zfs.mount(zh, NULL, 0);
if (ret < 0) {
ret = -errno;
dout(0) << "update_current_zh: zfs_mount '" << zfs.get_name(zh)
<< "' got " << cpp_strerror(ret) << dendl;
return ret;
}
}
zfs.close(zh);
} else {
dout(0) << "update_current_zh: zfs_open '" << path << "' got NULL" << dendl;
return -ENOENT;
}
zh = zfs.path_to_zhandle(get_current_path().c_str(), ZFS::TYPE_FILESYSTEM);
if (zh) {
if (strcmp(zfs.get_name(base_zh), zfs.get_name(zh))) {
current_zh = zh;
return 0;
}
zfs.close(zh);
dout(0) << "update_current_zh: basedir and current/ on the same filesystem" << dendl;
} else {
dout(0) << "update_current_zh: current/ not exist" << dendl;
}
return -ENOENT;
}
int ZFSFileStoreBackend::detect_features()
{
if (!current_zh)
dout(0) << "detect_features: null zfs handle for current/" << dendl;
return 0;
}
bool ZFSFileStoreBackend::can_checkpoint()
{
return m_filestore_zfs_snap && current_zh != NULL;
}
int ZFSFileStoreBackend::create_current()
{
struct stat st;
int ret = ::stat(get_current_path().c_str(), &st);
if (ret == 0) {
// current/ exists
if (!S_ISDIR(st.st_mode)) {
dout(0) << "create_current: current/ exists but is not a directory" << dendl;
return -ENOTDIR;
}
return 0;
} else if (errno != ENOENT) {
ret = -errno;
dout(0) << "create_current: cannot stat current/ " << cpp_strerror(ret) << dendl;
return ret;
}
char path[PATH_MAX];
snprintf(path, sizeof(path), "%s/current", zfs.get_name(base_zh));
ret = zfs.create(path, ZFS::TYPE_FILESYSTEM);
if (ret < 0 && errno != EEXIST) {
ret = -errno;
dout(0) << "create_current: zfs_create '" << path << "' got " << cpp_strerror(ret) << dendl;
return ret;
}
ret = update_current_zh();
return ret;
}
static int list_checkpoints_callback(ZFS::Handle *zh, void *data)
{
list<string> *ls = static_cast<list<string> *>(data);
string str = ZFS::get_name(zh);
size_t pos = str.find('@');
ceph_assert(pos != string::npos && pos + 1 != str.length());
ls->push_back(str.substr(pos + 1));
return 0;
}
int ZFSFileStoreBackend::list_checkpoints(list<string>& ls)
{
dout(10) << "list_checkpoints:" << dendl;
if (!current_zh)
return -EINVAL;
list<string> snaps;
int ret = zfs.iter_snapshots_sorted(current_zh, list_checkpoints_callback, &snaps);
if (ret < 0) {
ret = -errno;
dout(0) << "list_checkpoints: zfs_iter_snapshots_sorted got" << cpp_strerror(ret) << dendl;
return ret;
}
ls.swap(snaps);
return 0;
}
int ZFSFileStoreBackend::create_checkpoint(const string& name, uint64_t *cid)
{
dout(10) << "create_checkpoint: '" << name << "'" << dendl;
if (!current_zh)
return -EINVAL;
// looks like zfsonlinux doesn't flush dirty data when taking snapshot
int ret = sync_filesystem(get_current_fd());
if (ret < 0) {
ret = -errno;
dout(0) << "create_checkpoint: sync_filesystem got" << cpp_strerror(ret) << dendl;
return ret;
}
char path[PATH_MAX];
snprintf(path, sizeof(path), "%s@%s", zfs.get_name(current_zh), name.c_str());
ret = zfs.snapshot(path, false);
if (ret < 0) {
ret = -errno;
dout(0) << "create_checkpoint: zfs_snapshot '" << path << "' got" << cpp_strerror(ret) << dendl;
return ret;
}
if (cid)
*cid = 0;
return 0;
}
int ZFSFileStoreBackend::rollback_to(const string& name)
{
dout(10) << "rollback_to: '" << name << "'" << dendl;
if (!current_zh)
return -EINVAL;
// umount current to avoid triggering online rollback deadlock
int ret;
if (zfs.is_mounted(current_zh, NULL)) {
ret = zfs.umount(current_zh, NULL, 0);
if (ret < 0) {
ret = -errno;
dout(0) << "rollback_to: zfs_umount '" << zfs.get_name(current_zh) << "' got" << cpp_strerror(ret) << dendl;
}
}
char path[PATH_MAX];
snprintf(path, sizeof(path), "%s@%s", zfs.get_name(current_zh), name.c_str());
ZFS::Handle *snap_zh = zfs.open(path, ZFS::TYPE_SNAPSHOT);
if (!snap_zh) {
dout(0) << "rollback_to: zfs_open '" << path << "' got NULL" << dendl;
return -ENOENT;
}
ret = zfs.rollback(current_zh, snap_zh, false);
if (ret < 0) {
ret = -errno;
dout(0) << "rollback_to: zfs_rollback '" << zfs.get_name(snap_zh) << "' got" << cpp_strerror(ret) << dendl;
}
if (!zfs.is_mounted(current_zh, NULL)) {
int ret = zfs.mount(current_zh, NULL, 0);
if (ret < 0) {
ret = -errno;
dout(0) << "update_current_zh: zfs_mount '" << zfs.get_name(current_zh) << "' got " << cpp_strerror(ret) << dendl;
return ret;
}
}
zfs.close(snap_zh);
return ret;
}
int ZFSFileStoreBackend::destroy_checkpoint(const string& name)
{
dout(10) << "destroy_checkpoint: '" << name << "'" << dendl;
if (!current_zh)
return -EINVAL;
int ret = zfs.destroy_snaps(current_zh, name.c_str(), true);
if (ret < 0) {
ret = -errno;
dout(0) << "destroy_checkpoint: zfs_destroy_snaps '" << name << "' got" << cpp_strerror(ret) << dendl;
}
return ret;
}
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