perkeep/pkg/fs/rover.go

511 lines
13 KiB
Go

// +build linux darwin
/*
Copyright 2014 The Perkeep Authors
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package fs
import (
"context"
"errors"
"log"
"os"
"path/filepath"
"strings"
"sync"
"time"
"bazil.org/fuse"
"bazil.org/fuse/fs"
"perkeep.org/pkg/blob"
"perkeep.org/pkg/schema"
"perkeep.org/pkg/search"
)
// roVersionsDir is a fuse directory that represents
// the current state of a permanode directory.
// Unlike roDir, a file within roVersionsDir
// is presented as a directory (roFileVersionsDir) containing
// the different versions of the file (roFileVersion).
// It is read-only.
// Its permanode is the permanode with camliPath:entname attributes.
// TODO: There might be a way to reuse roDir
type roVersionsDir struct {
fs *CamliFileSystem
permanode blob.Ref
parent *roVersionsDir // or nil, if the parent is versionsDir
name string // ent name (base name within parent)
mu sync.Mutex
children map[string]roFileOrDir
xattrs map[string][]byte
}
func newROVersionsDir(fs *CamliFileSystem, permanode blob.Ref, name string) *roVersionsDir {
return &roVersionsDir{
fs: fs,
permanode: permanode,
name: name,
}
}
// for debugging
func (n *roVersionsDir) fullPath() string {
if n == nil {
return ""
}
return filepath.Join(n.parent.fullPath(), n.name)
}
func (n *roVersionsDir) Attr(ctx context.Context, a *fuse.Attr) error {
a.Mode = os.ModeDir | 0500
a.Uid = uint32(os.Getuid())
a.Gid = uint32(os.Getgid())
a.Inode = n.permanode.Sum64()
return nil
}
// populate hits the blobstore to populate map of child nodes.
func (n *roVersionsDir) populate(ctx context.Context) error {
n.mu.Lock()
defer n.mu.Unlock()
// Things never change here, so if we've ever populated, we're
// populated.
if n.children != nil {
return nil
}
log.Printf("roVersionsDir.populate(%q)", n.fullPath())
res, err := n.fs.client.Describe(ctx, &search.DescribeRequest{
BlobRef: n.permanode,
Depth: 3,
})
if err != nil {
log.Println("roVersionsDir.paths:", err)
return nil
}
db := res.Meta[n.permanode.String()]
if db == nil {
return errors.New("dir blobref not described")
}
// Find all child permanodes and stick them in n.children
n.children = make(map[string]roFileOrDir)
for k, v := range db.Permanode.Attr {
const p = "camliPath:"
if !strings.HasPrefix(k, p) || len(v) < 1 {
continue
}
name := k[len(p):]
childRef := v[0]
child := res.Meta[childRef]
if child == nil {
log.Printf("child not described: %v", childRef)
continue
}
if child.Permanode == nil {
log.Printf("child Permanode is nil: %v", childRef)
continue
}
if target := child.Permanode.Attr.Get("camliSymlinkTarget"); target != "" {
// This is a symlink.
n.children[name] = &roFileVersionsDir{
fs: n.fs,
permanode: blob.ParseOrZero(childRef),
parent: n,
name: name,
symLink: true,
target: target,
}
} else if isDir(child.Permanode) {
// This is a directory.
n.children[name] = &roVersionsDir{
fs: n.fs,
permanode: blob.ParseOrZero(childRef),
parent: n,
name: name,
}
} else if contentRef := child.Permanode.Attr.Get("camliContent"); contentRef != "" {
// This is a file.
content := res.Meta[contentRef]
if content == nil {
log.Printf("child content not described: %v", childRef)
continue
}
if content.CamliType != "file" {
log.Printf("child not a file: %v", childRef)
continue
}
n.children[name] = &roFileVersionsDir{
fs: n.fs,
permanode: blob.ParseOrZero(childRef),
parent: n,
name: name,
}
} else {
// unknown type
continue
}
n.children[name].xattr().load(child.Permanode)
}
return nil
}
func (n *roVersionsDir) ReadDir(ctx context.Context) ([]fuse.Dirent, error) {
if err := n.populate(ctx); err != nil {
log.Println("populate:", err)
return nil, fuse.EIO
}
n.mu.Lock()
defer n.mu.Unlock()
var ents []fuse.Dirent
for name, childNode := range n.children {
var ino uint64
switch v := childNode.(type) {
case *roVersionsDir:
ino = v.permanode.Sum64()
case *roFileVersion:
ino = v.permanode.Sum64()
default:
log.Printf("roVersionsDir.ReadDir: unknown child type %T", childNode)
}
// TODO: figure out what Dirent.Type means.
// fuse.go says "Type uint32 // ?"
dirent := fuse.Dirent{
Name: name,
Inode: ino,
}
log.Printf("roVersionsDir(%q) appending inode %x, %+v", n.fullPath(), dirent.Inode, dirent)
ents = append(ents, dirent)
}
return ents, nil
}
func (n *roVersionsDir) Lookup(ctx context.Context, name string) (ret fs.Node, err error) {
defer func() {
log.Printf("roVersionsDir(%q).Lookup(%q) = %#v, %v", n.fullPath(), name, ret, err)
}()
if err := n.populate(ctx); err != nil {
log.Println("populate:", err)
return nil, fuse.EIO
}
n.mu.Lock()
defer n.mu.Unlock()
if n2 := n.children[name]; n2 != nil {
return n2, nil
}
return nil, fuse.ENOENT
}
// roFileVersionsDir is a fuse directory that represents
// a permandode file. It contains the different versions
// of the file (roFileVersion).
// It is read-only.
type roFileVersionsDir struct {
fs *CamliFileSystem
permanode blob.Ref
parent *roVersionsDir
name string // ent name (base name within parent)
symLink bool // if true, is a symlink
target string // if a symlink
mu sync.Mutex
children map[string]roFileOrDir
xattrs map[string][]byte
}
func newROFileVersionsDir(fs *CamliFileSystem, permanode blob.Ref, name string) *roFileVersionsDir {
return &roFileVersionsDir{
fs: fs,
permanode: permanode,
name: name,
}
}
// for debugging
func (n *roFileVersionsDir) fullPath() string {
if n == nil {
return ""
}
return filepath.Join(n.parent.fullPath(), n.name)
}
func (n *roFileVersionsDir) Attr(ctx context.Context, a *fuse.Attr) error {
a.Inode = n.permanode.Sum64()
a.Mode = os.ModeDir | 0500
a.Uid = uint32(os.Getuid())
a.Gid = uint32(os.Getgid())
return nil
}
// populate hits the blobstore to populate map of child nodes.
func (n *roFileVersionsDir) populate(ctx context.Context) error {
n.mu.Lock()
defer n.mu.Unlock()
// Things never change here, so if we've ever populated, we're
// populated.
if n.children != nil {
return nil
}
log.Printf("roFileVersionsDir.populate(%q)", n.fullPath())
res, err := n.fs.client.GetClaims(ctx, &search.ClaimsRequest{n.permanode, "camliContent"})
if err != nil {
return errors.New("error while getting claims")
}
n.children = make(map[string]roFileOrDir)
for _, cl := range res.Claims {
pn, ok := blob.Parse(cl.Value)
if !ok {
return errors.New("invalid blobref")
}
res, err := n.fs.client.Describe(ctx, &search.DescribeRequest{
BlobRef: pn, // this is camliContent
Depth: 1,
At: cl.Date,
})
if err != nil {
return errors.New("blobref not described")
}
db := res.Meta[cl.Value]
if db == nil {
return errors.New("blobref not described")
}
name := cl.Date.String()
n.children[name] = &roFileVersion{
fs: n.fs,
permanode: n.permanode,
parent: n,
name: name,
content: db.BlobRef,
size: db.File.Size,
mtime: cl.Date.Time(),
}
}
return nil
}
func (n *roFileVersionsDir) ReadDir(ctx context.Context) ([]fuse.Dirent, error) {
if err := n.populate(ctx); err != nil {
log.Println("populate:", err)
return nil, fuse.EIO
}
n.mu.Lock()
defer n.mu.Unlock()
var ents []fuse.Dirent
for name, childNode := range n.children {
var ino uint64
switch v := childNode.(type) {
case *roDir:
ino = v.permanode.Sum64()
case *roFile:
ino = v.permanode.Sum64()
default:
log.Printf("roFileVersionsDir.ReadDir: unknown child type %T", childNode)
}
// TODO: figure out what Dirent.Type means.
// fuse.go says "Type uint32 // ?"
dirent := fuse.Dirent{
Name: name,
Inode: ino,
}
log.Printf("roFileVersionsDir(%q) appending inode %x, %+v", n.fullPath(), dirent.Inode, dirent)
ents = append(ents, dirent)
}
return ents, nil
}
func (n *roFileVersionsDir) Lookup(ctx context.Context, name string) (ret fs.Node, err error) {
defer func() {
log.Printf("roFileVersionsDir(%q).Lookup(%q) = %#v, %v", n.fullPath(), name, ret, err)
}()
if err := n.populate(ctx); err != nil {
log.Println("populate:", err)
return nil, fuse.EIO
}
n.mu.Lock()
defer n.mu.Unlock()
if n2 := n.children[name]; n2 != nil {
return n2, nil
}
return nil, fuse.ENOENT
}
// roFileVersion is a fuse file that represents
// a permanode file at a specific point in time.
// It is read-only.
type roFileVersion struct {
fs *CamliFileSystem
permanode blob.Ref
parent *roFileVersionsDir
name string // ent name (base name within parent)
mu sync.Mutex // protects all following fields
symLink bool // if true, is a symlink
target string // if a symlink
content blob.Ref // if a regular file
size int64
mtime, atime time.Time // if zero, use serverStart
xattrs map[string][]byte
}
func (n *roFileVersion) Open(ctx context.Context, req *fuse.OpenRequest, res *fuse.OpenResponse) (fs.Handle, error) {
roFileOpen.Incr()
if isWriteFlags(req.Flags) {
return nil, fuse.EPERM
}
log.Printf("roFile.Open: %v: content: %v dir=%v flags=%v", n.permanode, n.content, req.Dir, req.Flags)
r, err := schema.NewFileReader(ctx, n.fs.fetcher, n.content)
if err != nil {
roFileOpenError.Incr()
log.Printf("roFile.Open: %v", err)
return nil, fuse.EIO
}
// Turn off the OpenDirectIO bit (on by default in rsc fuse server.go),
// else append operations don't work for some reason.
res.Flags &= ^fuse.OpenDirectIO
// Read-only.
nod := &node{
fs: n.fs,
blobref: n.content,
}
return &nodeReader{n: nod, fr: r}, nil
}
func (n *roVersionsDir) Getxattr(ctx context.Context, req *fuse.GetxattrRequest, res *fuse.GetxattrResponse) error {
return n.xattr().get(req, res)
}
func (n *roVersionsDir) Listxattr(ctx context.Context, req *fuse.ListxattrRequest, res *fuse.ListxattrResponse) error {
return n.xattr().list(req, res)
}
func (n *roFileVersion) Getxattr(ctx context.Context, req *fuse.GetxattrRequest, res *fuse.GetxattrResponse) error {
return n.xattr().get(req, res)
}
func (n *roFileVersion) Listxattr(ctx context.Context, req *fuse.ListxattrRequest, res *fuse.ListxattrResponse) error {
return n.xattr().list(req, res)
}
func (n *roFileVersion) Removexattr(ctx context.Context, req *fuse.RemovexattrRequest) error {
return fuse.EPERM
}
func (n *roFileVersion) Setxattr(ctx context.Context, req *fuse.SetxattrRequest) error {
return fuse.EPERM
}
// for debugging
func (n *roFileVersion) fullPath() string {
if n == nil {
return ""
}
return filepath.Join(n.parent.fullPath(), n.name)
}
func (n *roFileVersion) Attr(ctx context.Context, a *fuse.Attr) error {
// TODO: don't grab n.mu three+ times in here.
var mode os.FileMode = 0400 // read-only
n.mu.Lock()
size := n.size
var blocks uint64
if size > 0 {
blocks = uint64(size)/512 + 1
}
inode := n.permanode.Sum64()
if n.symLink {
mode |= os.ModeSymlink
}
n.mu.Unlock()
*a = fuse.Attr{
Inode: inode,
Mode: mode,
Uid: uint32(os.Getuid()),
Gid: uint32(os.Getgid()),
Size: uint64(size),
Blocks: blocks,
Mtime: n.modTime(),
Atime: n.accessTime(),
Ctime: serverStart,
Crtime: serverStart,
}
return nil
}
func (n *roFileVersion) accessTime() time.Time {
n.mu.Lock()
if !n.atime.IsZero() {
defer n.mu.Unlock()
return n.atime
}
n.mu.Unlock()
return n.modTime()
}
func (n *roFileVersion) modTime() time.Time {
n.mu.Lock()
defer n.mu.Unlock()
if !n.mtime.IsZero() {
return n.mtime
}
return serverStart
}
func (n *roFileVersion) Fsync(ctx context.Context, r *fuse.FsyncRequest) error {
// noop
return nil
}
func (n *roFileVersion) permanodeString() string {
return n.permanode.String()
}
func (n *roFileVersionsDir) permanodeString() string {
return n.permanode.String()
}
func (n *roVersionsDir) permanodeString() string {
return n.permanode.String()
}
func (n *roFileVersion) xattr() *xattr {
return &xattr{"roFileVersion", n.fs, n.permanode, &n.mu, &n.xattrs}
}
func (n *roFileVersionsDir) xattr() *xattr {
return &xattr{"roFileVersionsDir", n.fs, n.permanode, &n.mu, &n.xattrs}
}
func (n *roVersionsDir) xattr() *xattr {
return &xattr{"roVersionsDir", n.fs, n.permanode, &n.mu, &n.xattrs}
}