query by metaseq and dataseq interface

This commit is contained in:
Ben McClelland
2018-10-03 11:11:19 -07:00
parent 61f8ca8981
commit 145debbdf5
4 changed files with 479 additions and 1 deletions

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@@ -1,6 +1,6 @@
BSD 3-Clause License
Copyright (c) 2018,
Copyright (c) 2018 Versity Software, Inc.
All rights reserved.
Redistribution and use in source and binary forms, with or without

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// Copyright (c) 2018 Versity Software, Inc.
//
// Use of this source code is governed by a BSD-3-Clause license
// that can be found in the LICENSE file in the root of the source
// tree.
package main
import (
"fmt"
"log"
"net/http"
"os"
"time"
scoutfs "github.com/versity/scoutfs-go"
)
const (
max32 = 0xffffffff
max64 = 0xffffffffffffffff
)
type server struct {
update <-chan int
lastcount int
}
func queryPopulation(basedir string, update chan<- int) error {
h, err := scoutfs.NewQuery(basedir,
scoutfs.ByMSeq(scoutfs.InodesEntry{},
scoutfs.InodesEntry{Major: max64, Minor: max32, Ino: max64}))
if err != nil {
return fmt.Errorf("scoutfs new handle: %v", err)
}
defer h.Close()
count := 0
for {
for {
qents, err := h.Next()
if err != nil {
return fmt.Errorf("scoutfs next: %v", err)
}
if len(qents) == 0 {
break
}
for _, qent := range qents {
fmt.Printf("%#v\n", qent)
count++
}
}
update <- count
time.Sleep(500 * time.Millisecond)
}
}
func (s *server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
select {
case x, ok := <-s.update:
if ok {
s.lastcount = x
} else {
fmt.Println("Channel closed!")
os.Exit(1)
}
default:
}
fmt.Fprintf(w, "%s %d", `
<HEAD><meta HTTP-EQUIV="REFRESH" content="1"></HEAD>
<h1>SCOUTFS</h1></p>
Files/Directories updated:`, s.lastcount)
}
func main() {
update := make(chan int, 1)
s := &server{update: update}
go queryPopulation(os.Args[1], update)
log.Fatal(http.ListenAndServe(":8080", s))
}

178
scoutfs.go Normal file
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// Copyright (c) 2018 Versity Software, Inc.
//
// Use of this source code is governed by a BSD-3-Clause license
// that can be found in the LICENSE file in the root of the source
// tree.
package scoutfs
import (
"bytes"
"encoding/binary"
"os"
"syscall"
"unsafe"
)
const (
max64 = 0xffffffffffffffff
max32 = 0xffffffff
)
// Query to keep track of in-process query
type Query struct {
first InodesEntry
last InodesEntry
index uint8
batch uint32
fsfd *os.File
}
// Time represents a time value in seconds and nanoseconds
type Time struct {
Sec uint64
Nsec uint32
}
// NewQuery creates a new scoutfs WalkHandle
// Specify query type with By*() option
// (only 1 allowed, last one wins)
// and specify batching with WithBatchSize()
func NewQuery(path string, opts ...Option) (*Query, error) {
f, err := os.Open(path)
if err != nil {
return nil, err
}
q := &Query{
//default batch size is 128
batch: 128,
fsfd: f,
}
for _, opt := range opts {
opt(q)
}
return q, nil
}
// Option sets various options for NewWalkHandle
type Option func(*Query)
// ByMSeq gets inodes in range of metadata sequence from, to inclusive
func ByMSeq(from, to InodesEntry) Option {
return func(q *Query) {
q.first = from
q.last = to
q.index = QUERYINODESMETASEQ
}
}
// ByDSeq gets inodes in range of data sequence from, to inclusive
func ByDSeq(from, to InodesEntry) Option {
return func(q *Query) {
q.first = from
q.last = to
q.index = QUERYINODESDATASEQ
}
}
// WithBatchSize sets the max number of inodes to be returned at a time
func WithBatchSize(size uint32) Option {
return func(q *Query) {
q.batch = size
}
}
// Next gets the next batch of inodes
func (q *Query) Next() ([]InodesEntry, error) {
buf := make([]byte, int(unsafe.Sizeof(InodesEntry{}))*int(q.batch))
query := queryInodes{
first: q.first,
last: q.last,
entries: uintptr(unsafe.Pointer(&buf[0])),
count: q.batch,
index: q.index,
}
pack, err := query.pack()
if err != nil {
return []InodesEntry{}, err
}
n, err := scoutfsctl(q.fsfd.Fd(), IOCQUERYINODES, uintptr(unsafe.Pointer(&pack)))
if err != nil {
return []InodesEntry{}, err
}
if n == 0 {
return []InodesEntry{}, nil
}
rbuf := bytes.NewReader(buf)
var inodes []InodesEntry
var e InodesEntry
for i := 0; i < n; i++ {
//packed scoutfs_ioctl_walk_inodes_entry requires
//unpacking each member individually
err := binary.Read(rbuf, binary.LittleEndian, &e.Major)
if err != nil {
return []InodesEntry{}, err
}
err = binary.Read(rbuf, binary.LittleEndian, &e.Minor)
if err != nil {
return []InodesEntry{}, err
}
err = binary.Read(rbuf, binary.LittleEndian, &e.Ino)
if err != nil {
return []InodesEntry{}, err
}
inodes = append(inodes, e)
}
q.first = e
q.first.Ino++
q.first.Minor++
if q.first.Ino == 0 {
q.first.Minor++
if q.first.Minor == 0 {
q.first.Major++
}
}
return inodes, nil
}
// Close queryHandle and cleanup
func (q *Query) Close() {
q.fsfd.Close()
}
// StatMore returns scoutfs specific metadata for path
func StatMore(path string) (Stat, error) {
f, err := os.Open(path)
if err != nil {
return Stat{}, err
}
defer f.Close()
var s Stat
_, err = scoutfsctl(f.Fd(), IOCSTATMORE, uintptr(unsafe.Pointer(&s)))
if err != nil {
return Stat{}, err
}
return s, nil
}
func scoutfsctl(fd, cmd, ptr uintptr) (int, error) {
count, _, err := syscall.Syscall(syscall.SYS_IOCTL, fd, cmd, ptr)
if err != 0 {
return 0, err
}
return int(count), nil
}

218
scoutfsdefs.go Normal file
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// Copyright (c) 2018 Versity Software, Inc.
//
// Use of this source code is governed by a BSD-3-Clause license
// that can be found in the LICENSE file in the root of the source
// tree.
package scoutfs
import (
"bytes"
"encoding/binary"
"fmt"
)
const (
//IOCQUERYINODES scoutfs ioctl
IOCQUERYINODES = 0x40357301
//IOCINOPATH scoutfs ioctl
IOCINOPATH = 0x401c7302
//IOCDATAVERSION scoutfs ioctl
IOCDATAVERSION = 0x40087304
//IOCRELEASE scoutfs ioctl
IOCRELEASE = 0x40187305
//IOCSTAGE scoutfs ioctl
IOCSTAGE = 0x401c7306
//IOCSTATMORE scoutfs ioctl
IOCSTATMORE = 0x40207307
//QUERYINODESMETASEQ find inodes by metadata sequence
QUERYINODESMETASEQ = '\u0000'
//QUERYINODESDATASEQ find inodes by data sequence
QUERYINODESDATASEQ = '\u0001'
)
/* pahole for scoutfs_ioctl_walk_inodes_entry
struct scoutfs_ioctl_walk_inodes_entry {
__u64 major; // 0 8
__u32 minor; // 8 4
__u64 ino; // 12 8
// size: 20, cachelines: 1, members: 3
// last cacheline: 20 bytes
};
*/
//InodesEntry is scoutfs entry for inode iteration
type InodesEntry struct {
Major uint64
Minor uint32
Ino uint64
}
/* pahole for scoutfs_ioctl_walk_inodes
struct scoutfs_ioctl_walk_inodes {
struct scoutfs_ioctl_walk_inodes_entry first; // 0 20
struct scoutfs_ioctl_walk_inodes_entry last; // 20 20
__u64 entries_ptr; // 40 8
__u32 nr_entries; // 48 4
__u8 index; // 52 1
// size: 53, cachelines: 1, members: 5
// last cacheline: 53 bytes
};
*/
//queryInodes is scoutfs request structure for IOCQUERYINODES
type queryInodes struct {
first InodesEntry
last InodesEntry
entries uintptr
count uint32
index uint8
}
//packed scoutfs_ioctl_walk_inodes requires packing queryInodes byhand
//the 53 size comes from pahole output above
func (q queryInodes) pack() ([53]byte, error) {
var pack [53]byte
var pbuf = bytes.NewBuffer(make([]byte, 0, len(pack)))
if err := binary.Write(pbuf, binary.LittleEndian, q.first.Major); err != nil {
return [53]byte{}, fmt.Errorf("pack first.Major: %v", err)
}
if err := binary.Write(pbuf, binary.LittleEndian, q.first.Minor); err != nil {
return [53]byte{}, fmt.Errorf("pack first.Minor: %v", err)
}
if err := binary.Write(pbuf, binary.LittleEndian, q.first.Ino); err != nil {
return [53]byte{}, fmt.Errorf("pack first.Ino: %v", err)
}
if err := binary.Write(pbuf, binary.LittleEndian, q.last.Major); err != nil {
return [53]byte{}, fmt.Errorf("pack last.Major: %v", err)
}
if err := binary.Write(pbuf, binary.LittleEndian, q.last.Minor); err != nil {
return [53]byte{}, fmt.Errorf("pack last.Minor: %v", err)
}
if err := binary.Write(pbuf, binary.LittleEndian, q.last.Ino); err != nil {
return [53]byte{}, fmt.Errorf("pack last.Ino: %v", err)
}
if err := binary.Write(pbuf, binary.LittleEndian, uint64(q.entries)); err != nil {
return [53]byte{}, fmt.Errorf("pack entries: %v", err)
}
if err := binary.Write(pbuf, binary.LittleEndian, q.count); err != nil {
return [53]byte{}, fmt.Errorf("pack count: %v", err)
}
if err := binary.Write(pbuf, binary.LittleEndian, q.index); err != nil {
return [53]byte{}, fmt.Errorf("pack index: %v", err)
}
if err := binary.Read(pbuf, binary.LittleEndian, &pack); err != nil {
return [53]byte{}, fmt.Errorf("read packed: %v", err)
}
return pack, nil
}
/* pahole for scoutfs_ioctl_ino_path
struct scoutfs_ioctl_ino_path {
__u64 ino; // 0 8
__u64 dir_ino; // 8 8
__u64 dir_pos; // 16 8
__u64 result_ptr; // 24 8
__u16 result_bytes; // 32 2
// size: 34, cachelines: 1, members: 5
// last cacheline: 34 bytes
};
*/
// InoPath ioctl struct
type InoPath struct {
Ino uint64
DirIno uint64
DirPos uint64
ResultPtr uint64
ResultBytes uint64
}
/* pahole for scoutfs_ioctl_ino_path_result
struct scoutfs_ioctl_ino_path_result {
__u64 dir_ino; // 0 8
__u64 dir_pos; // 8 8
__u16 path_bytes; // 16 2
__u8 path[0]; // 18 0
// size: 18, cachelines: 1, members: 4
// last cacheline: 18 bytes
};
*/
// InoPathResult ioctl struct
type InoPathResult struct {
DirIno uint64
DirPos uint64
PathBytes uint16
ResultBytes uint64
}
/* pahole for scoutfs_ioctl_release
struct scoutfs_ioctl_release {
__u64 block; // 0 8
__u64 count; // 8 8
__u64 data_version; // 16 8
// size: 24, cachelines: 1, members: 3
// last cacheline: 24 bytes
};
*/
// IocRelease ioctl struct
type IocRelease struct {
Block uint64
Count uint64
DataVersion uint64
}
/* pahole for scoutfs_ioctl_stage
struct scoutfs_ioctl_stage {
__u64 data_version; // 0 8
__u64 buf_ptr; // 8 8
__u64 offset; // 16 8
__s32 count; // 24 4
// size: 28, cachelines: 1, members: 4
// last cacheline: 28 bytes
};
*/
// IocStage ioctl struct
type IocStage struct {
DataVersion uint64
BufPtr uint64
Offset uint64
count int32
}
/* pahole for scoutfs_ioctl_stat_more
struct scoutfs_ioctl_stat_more {
__u64 valid_bytes; // 0 8
__u64 meta_seq; // 8 8
__u64 data_seq; // 16 8
__u64 data_version; // 24 8
__u64 online_blocks; // 32 8
__u64 offline_blocks; // 40 8
// size: 48, cachelines: 1, members: 6
// last cacheline: 48 bytes
};
*/
//Stat holds scoutfs specific per file metadata
type Stat struct {
ValidBytes uint64
MetaSeq uint64
DataSeq uint64
DataVersion uint64
OnlineBlocks uint64
OfflineBlocks uint64
}