zrepl/internal/endpoint/endpoint_zfs_abstraction_replication_cursor.go
2024-10-18 19:21:17 +02:00

268 lines
8.6 KiB
Go

package endpoint
import (
"context"
"encoding/json"
"fmt"
"sort"
"github.com/pkg/errors"
"github.com/zrepl/zrepl/internal/zfs"
)
const replicationCursorBookmarkNamePrefix = "zrepl_CURSOR"
func ReplicationCursorBookmarkName(fs string, guid uint64, id JobID) (string, error) {
return replicationCursorBookmarkNameImpl(fs, guid, id.String())
}
func replicationCursorBookmarkNameImpl(fs string, guid uint64, jobid string) (string, error) {
return makeJobAndGuidBookmarkName(replicationCursorBookmarkNamePrefix, fs, guid, jobid)
}
var ErrV1ReplicationCursor = fmt.Errorf("bookmark name is a v1-replication cursor")
// err != nil always means that the bookmark is not a valid replication bookmark
//
// Returns ErrV1ReplicationCursor as error if the bookmark is a v1 replication cursor
func ParseReplicationCursorBookmarkName(fullname string) (uint64, JobID, error) {
// check for legacy cursors
{
if err := zfs.EntityNamecheck(fullname, zfs.EntityTypeBookmark); err != nil {
return 0, JobID{}, errors.Wrap(err, "parse replication cursor bookmark name")
}
_, _, name, err := zfs.DecomposeVersionString(fullname)
if err != nil {
return 0, JobID{}, errors.Wrap(err, "parse replication cursor bookmark name: decompose version string")
}
const V1ReplicationCursorBookmarkName = "zrepl_replication_cursor"
if name == V1ReplicationCursorBookmarkName {
return 0, JobID{}, ErrV1ReplicationCursor
}
// fallthrough to main parser
}
guid, jobID, err := parseJobAndGuidBookmarkName(fullname, replicationCursorBookmarkNamePrefix)
if err != nil {
err = errors.Wrap(err, "parse replication cursor bookmark name") // no shadow
}
return guid, jobID, err
}
const tentativeReplicationCursorBookmarkNamePrefix = "zrepl_CURSORTENTATIVE_"
// v must be validated by caller
func TentativeReplicationCursorBookmarkName(fs string, guid uint64, id JobID) (string, error) {
return tentativeReplicationCursorBookmarkNameImpl(fs, guid, id.String())
}
func tentativeReplicationCursorBookmarkNameImpl(fs string, guid uint64, jobid string) (string, error) {
return makeJobAndGuidBookmarkName(tentativeReplicationCursorBookmarkNamePrefix, fs, guid, jobid)
}
// name is the full bookmark name, including dataset path
//
// err != nil always means that the bookmark is not a step bookmark
func ParseTentativeReplicationCursorBookmarkName(fullname string) (guid uint64, jobID JobID, err error) {
guid, jobID, err = parseJobAndGuidBookmarkName(fullname, tentativeReplicationCursorBookmarkNamePrefix)
if err != nil {
err = errors.Wrap(err, "parse step bookmark name") // no shadow!
}
return guid, jobID, err
}
// may return nil for both values, indicating there is no cursor
func GetMostRecentReplicationCursorOfJob(ctx context.Context, fs string, jobID JobID) (*zfs.FilesystemVersion, error) {
fsp, err := zfs.NewDatasetPath(fs)
if err != nil {
return nil, err
}
candidates, err := GetReplicationCursors(ctx, fsp, jobID)
if err != nil || len(candidates) == 0 {
return nil, err
}
sort.Slice(candidates, func(i, j int) bool {
return candidates[i].CreateTXG < candidates[j].CreateTXG
})
mostRecent := candidates[len(candidates)-1]
return &mostRecent, nil
}
func GetReplicationCursors(ctx context.Context, dp *zfs.DatasetPath, jobID JobID) ([]zfs.FilesystemVersion, error) {
fs := dp.ToString()
q := ListZFSHoldsAndBookmarksQuery{
FS: ListZFSHoldsAndBookmarksQueryFilesystemFilter{FS: &fs},
What: map[AbstractionType]bool{
AbstractionReplicationCursorBookmarkV1: true,
AbstractionReplicationCursorBookmarkV2: true,
},
JobID: &jobID,
CreateTXG: CreateTXGRange{},
Concurrency: 1,
}
abs, absErr, err := ListAbstractions(ctx, q)
if err != nil {
return nil, errors.Wrap(err, "get replication cursor: list bookmarks and holds")
}
if len(absErr) > 0 {
return nil, ListAbstractionsErrors(absErr)
}
var v1, v2 []Abstraction
for _, a := range abs {
switch a.GetType() {
case AbstractionReplicationCursorBookmarkV1:
v1 = append(v1, a)
case AbstractionReplicationCursorBookmarkV2:
v2 = append(v2, a)
default:
panic("unexpected abstraction: " + a.GetType())
}
}
if len(v1) > 0 {
getLogger(ctx).WithField("bookmark", v1).
Warn("found v1-replication cursor bookmarks, consider running migration 'replication-cursor:v1-v2' after successful replication with this zrepl version")
}
candidates := make([]zfs.FilesystemVersion, 0)
for _, v := range v2 {
candidates = append(candidates, v.GetFilesystemVersion())
}
return candidates, nil
}
// idempotently create a replication cursor targeting `target`
//
// returns ErrBookmarkCloningNotSupported if version is a bookmark and bookmarking bookmarks is not supported by ZFS
func CreateReplicationCursor(ctx context.Context, fs string, target zfs.FilesystemVersion, jobID JobID) (a Abstraction, err error) {
return createBookmarkAbstraction(ctx, AbstractionReplicationCursorBookmarkV2, fs, target, jobID)
}
func CreateTentativeReplicationCursor(ctx context.Context, fs string, target zfs.FilesystemVersion, jobID JobID) (a Abstraction, err error) {
return createBookmarkAbstraction(ctx, AbstractionTentativeReplicationCursorBookmark, fs, target, jobID)
}
func createBookmarkAbstraction(ctx context.Context, abstractionType AbstractionType, fs string, target zfs.FilesystemVersion, jobID JobID) (a Abstraction, err error) {
bookmarkNamer := abstractionType.BookmarkNamer()
if bookmarkNamer == nil {
panic(abstractionType)
}
bookmarkname, err := bookmarkNamer(fs, target.GetGuid(), jobID)
if err != nil {
return nil, errors.Wrapf(err, "determine %s name", abstractionType)
}
// idempotently create bookmark (guid is encoded in it)
cursorBookmark, err := zfs.ZFSBookmark(ctx, fs, target, bookmarkname)
if err != nil {
if err == zfs.ErrBookmarkCloningNotSupported {
return nil, err // TODO go1.13 use wrapping
}
return nil, errors.Wrapf(err, "cannot create bookmark")
}
return &bookmarkBasedAbstraction{
Type: abstractionType,
FS: fs,
FilesystemVersion: cursorBookmark,
JobID: jobID,
}, nil
}
func ReplicationCursorV2Extractor(fs *zfs.DatasetPath, v zfs.FilesystemVersion) (_ Abstraction) {
if v.Type != zfs.Bookmark {
panic("impl error")
}
fullname := v.ToAbsPath(fs)
guid, jobid, err := ParseReplicationCursorBookmarkName(fullname)
if err == nil {
if guid != v.Guid {
// TODO log this possibly tinkered-with bookmark
return nil
}
return &bookmarkBasedAbstraction{
Type: AbstractionReplicationCursorBookmarkV2,
FS: fs.ToString(),
FilesystemVersion: v,
JobID: jobid,
}
}
return nil
}
func ReplicationCursorV1Extractor(fs *zfs.DatasetPath, v zfs.FilesystemVersion) (_ Abstraction) {
if v.Type != zfs.Bookmark {
panic("impl error")
}
fullname := v.ToAbsPath(fs)
_, _, err := ParseReplicationCursorBookmarkName(fullname)
if err == ErrV1ReplicationCursor {
return &ReplicationCursorV1{
Type: AbstractionReplicationCursorBookmarkV1,
FS: fs.ToString(),
FilesystemVersion: v,
}
}
return nil
}
var _ BookmarkExtractor = TentativeReplicationCursorExtractor
func TentativeReplicationCursorExtractor(fs *zfs.DatasetPath, v zfs.FilesystemVersion) (_ Abstraction) {
if v.Type != zfs.Bookmark {
panic("impl error")
}
fullname := v.ToAbsPath(fs)
guid, jobid, err := ParseTentativeReplicationCursorBookmarkName(fullname)
if guid != v.Guid {
// TODO log this possibly tinkered-with bookmark
return nil
}
if err == nil {
bm := &bookmarkBasedAbstraction{
Type: AbstractionTentativeReplicationCursorBookmark,
FS: fs.ToString(),
FilesystemVersion: v,
JobID: jobid,
}
return bm
}
return nil
}
type ReplicationCursorV1 struct {
Type AbstractionType
FS string
zfs.FilesystemVersion
}
func (c ReplicationCursorV1) GetType() AbstractionType { return c.Type }
func (c ReplicationCursorV1) GetFS() string { return c.FS }
func (c ReplicationCursorV1) GetFullPath() string { return fmt.Sprintf("%s#%s", c.FS, c.GetName()) }
func (c ReplicationCursorV1) GetJobID() *JobID { return nil }
func (c ReplicationCursorV1) GetFilesystemVersion() zfs.FilesystemVersion { return c.FilesystemVersion }
func (c ReplicationCursorV1) MarshalJSON() ([]byte, error) {
return json.Marshal(AbstractionJSON{c})
}
func (c ReplicationCursorV1) String() string {
return fmt.Sprintf("%s %s", c.Type, c.GetFullPath())
}
func (c ReplicationCursorV1) Destroy(ctx context.Context) error {
if err := zfs.ZFSDestroyIdempotent(ctx, c.GetFullPath()); err != nil {
return errors.Wrapf(err, "destroy %s %s: zfs", c.Type, c.GetFullPath())
}
return nil
}