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- package vfs
- import (
- "context"
- "errors"
- "fmt"
- "os"
- "path"
- "sync"
- "sync/atomic"
- "time"
- "github.com/rclone/rclone/fs"
- "github.com/rclone/rclone/fs/log"
- "github.com/rclone/rclone/fs/operations"
- "github.com/rclone/rclone/vfs/vfscommon"
- )
- // The File object is tightly coupled to the Dir object. Since they
- // both have locks there is plenty of potential for deadlocks. In
- // order to mitigate this, we use the following conventions
- //
- // File may **only** call these methods from Dir with the File lock
- // held.
- //
- // Dir.Fs
- // Dir.VFS
- //
- // (As these are read only and do not need to take the Dir mutex.)
- //
- // File may **not** call any other Dir methods with the File lock
- // held. This preserves total lock ordering and makes File subordinate
- // to Dir as far as locking is concerned, preventing deadlocks.
- //
- // File may **not** read any members of Dir directly.
- // File represents a file
- type File struct {
- inode uint64 // inode number - read only
- size atomic.Int64 // size of file
- muRW sync.Mutex // synchronize RWFileHandle.openPending(), RWFileHandle.close() and File.Remove
- mu sync.RWMutex // protects the following
- d *Dir // parent directory
- dPath string // path of parent directory. NB dir rename means all Files are flushed
- o fs.Object // NB o may be nil if file is being written
- leaf string // leaf name of the object
- writers []Handle // writers for this file
- virtualModTime *time.Time // modtime for backends with Precision == fs.ModTimeNotSupported
- pendingModTime time.Time // will be applied once o becomes available, i.e. after file was written
- pendingRenameFun func(ctx context.Context) error // will be run/renamed after all writers close
- sys atomic.Value // user defined info to be attached here
- nwriters atomic.Int32 // len(writers)
- appendMode bool // file was opened with O_APPEND
- }
- // newFile creates a new File
- //
- // o may be nil
- func newFile(d *Dir, dPath string, o fs.Object, leaf string) *File {
- f := &File{
- d: d,
- dPath: dPath,
- o: o,
- leaf: leaf,
- inode: newInode(),
- }
- if o != nil {
- f.size.Store(o.Size())
- }
- return f
- }
- // String converts it to printable
- func (f *File) String() string {
- if f == nil {
- return "<nil *File>"
- }
- return f.Path()
- }
- // IsFile returns true for File - satisfies Node interface
- func (f *File) IsFile() bool {
- return true
- }
- // IsDir returns false for File - satisfies Node interface
- func (f *File) IsDir() bool {
- return false
- }
- // Mode bits of the file or directory - satisfies Node interface
- func (f *File) Mode() (mode os.FileMode) {
- f.mu.RLock()
- defer f.mu.RUnlock()
- mode = f.d.vfs.Opt.FilePerms
- if f.appendMode {
- mode |= os.ModeAppend
- }
- return mode
- }
- // Name (base) of the directory - satisfies Node interface
- func (f *File) Name() (name string) {
- f.mu.RLock()
- defer f.mu.RUnlock()
- return f.leaf
- }
- // _path returns the full path of the file
- // use when lock is held
- func (f *File) _path() string {
- return path.Join(f.dPath, f.leaf)
- }
- // Path returns the full path of the file
- func (f *File) Path() string {
- f.mu.RLock()
- dPath, leaf := f.dPath, f.leaf
- f.mu.RUnlock()
- return path.Join(dPath, leaf)
- }
- // Sys returns underlying data source (can be nil) - satisfies Node interface
- func (f *File) Sys() interface{} {
- return f.sys.Load()
- }
- // SetSys sets the underlying data source (can be nil) - satisfies Node interface
- func (f *File) SetSys(x interface{}) {
- f.sys.Store(x)
- }
- // Inode returns the inode number - satisfies Node interface
- func (f *File) Inode() uint64 {
- return f.inode
- }
- // Node returns the Node associated with this - satisfies Noder interface
- func (f *File) Node() Node {
- return f
- }
- // renameDir - call when parent directory has been renamed
- func (f *File) renameDir(dPath string) {
- f.mu.RLock()
- f.dPath = dPath
- f.mu.RUnlock()
- }
- // applyPendingRename runs a previously set rename operation if there are no
- // more remaining writers. Call without lock held.
- func (f *File) applyPendingRename() {
- f.mu.RLock()
- fun := f.pendingRenameFun
- writing := f._writingInProgress()
- f.mu.RUnlock()
- if fun == nil || writing {
- return
- }
- fs.Debugf(f.Path(), "Running delayed rename now")
- if err := fun(context.TODO()); err != nil {
- fs.Errorf(f.Path(), "delayed File.Rename error: %v", err)
- }
- }
- // rename attempts to immediately rename a file if there are no open writers.
- // Otherwise it will queue the rename operation on the remote until no writers
- // remain.
- func (f *File) rename(ctx context.Context, destDir *Dir, newName string) error {
- f.mu.RLock()
- d := f.d
- oldPendingRenameFun := f.pendingRenameFun
- f.mu.RUnlock()
- if features := d.Fs().Features(); features.Move == nil && features.Copy == nil {
- err := fmt.Errorf("Fs %q can't rename files (no server-side Move or Copy)", d.Fs())
- fs.Errorf(f.Path(), "Dir.Rename error: %v", err)
- return err
- }
- oldPath := f.Path()
- // File.mu is unlocked here to call Dir.Path()
- newPath := path.Join(destDir.Path(), newName)
- renameCall := func(ctx context.Context) (err error) {
- // chain rename calls if any
- if oldPendingRenameFun != nil {
- err := oldPendingRenameFun(ctx)
- if err != nil {
- return err
- }
- }
- f.mu.RLock()
- o := f.o
- d := f.d
- f.mu.RUnlock()
- var newObject fs.Object
- // if o is nil then are writing the file so no need to rename the object
- if o != nil {
- if o.Remote() == newPath {
- return nil // no need to rename
- }
- // do the move of the remote object
- dstOverwritten, _ := d.Fs().NewObject(ctx, newPath)
- newObject, err = operations.Move(ctx, d.Fs(), dstOverwritten, newPath, o)
- if err != nil {
- fs.Errorf(f.Path(), "File.Rename error: %v", err)
- return err
- }
- // newObject can be nil here for example if --dry-run
- if newObject == nil {
- err = errors.New("rename failed: nil object returned")
- fs.Errorf(f.Path(), "File.Rename %v", err)
- return err
- }
- }
- // Rename in the cache
- if d.vfs.cache != nil && d.vfs.cache.Exists(oldPath) {
- if err := d.vfs.cache.Rename(oldPath, newPath, newObject); err != nil {
- fs.Infof(f.Path(), "File.Rename failed in Cache: %v", err)
- }
- }
- // Update the node with the new details
- fs.Debugf(f.Path(), "Updating file with %v %p", newObject, f)
- // f.rename(destDir, newObject)
- f.mu.Lock()
- if newObject != nil {
- f.o = newObject
- }
- f.pendingRenameFun = nil
- f.mu.Unlock()
- return nil
- }
- // rename the file object
- dPath := destDir.Path()
- f.mu.Lock()
- f.d = destDir
- f.dPath = dPath
- f.leaf = newName
- writing := f._writingInProgress()
- f.mu.Unlock()
- // Delay the rename if not using RW caching. For the minimal case we
- // need to look in the cache to see if caching is in use.
- CacheMode := d.vfs.Opt.CacheMode
- if writing &&
- (CacheMode < vfscommon.CacheModeMinimal ||
- (CacheMode == vfscommon.CacheModeMinimal && !destDir.vfs.cache.Exists(oldPath))) {
- fs.Debugf(oldPath, "File is currently open, delaying rename %p", f)
- f.mu.Lock()
- f.pendingRenameFun = renameCall
- f.mu.Unlock()
- return nil
- }
- return renameCall(ctx)
- }
- // addWriter adds a write handle to the file
- func (f *File) addWriter(h Handle) {
- f.mu.Lock()
- f.writers = append(f.writers, h)
- f.nwriters.Add(1)
- f.mu.Unlock()
- }
- // delWriter removes a write handle from the file
- func (f *File) delWriter(h Handle) {
- f.mu.Lock()
- defer f.applyPendingRename()
- defer f.mu.Unlock()
- var found = -1
- for i := range f.writers {
- if f.writers[i] == h {
- found = i
- break
- }
- }
- if found >= 0 {
- f.writers = append(f.writers[:found], f.writers[found+1:]...)
- f.nwriters.Add(-1)
- } else {
- fs.Debugf(f._path(), "File.delWriter couldn't find handle")
- }
- }
- // activeWriters returns the number of writers on the file
- //
- // Note that we don't take the mutex here. If we do then we can get a
- // deadlock.
- func (f *File) activeWriters() int {
- return int(f.nwriters.Load())
- }
- // _roundModTime rounds the time passed in to the Precision of the
- // underlying Fs
- //
- // It should be called with the lock held
- func (f *File) _roundModTime(modTime time.Time) time.Time {
- precision := f.d.f.Precision()
- if precision == fs.ModTimeNotSupported {
- return modTime
- }
- return modTime.Truncate(precision)
- }
- // ModTime returns the modified time of the file
- //
- // if NoModTime is set then it returns the mod time of the directory
- func (f *File) ModTime() (modTime time.Time) {
- f.mu.RLock()
- d, o, pendingModTime, virtualModTime := f.d, f.o, f.pendingModTime, f.virtualModTime
- f.mu.RUnlock()
- // Set the virtual modtime up for backends which don't support setting modtime
- //
- // Note that we only cache modtime values that we have returned to the OS
- // if we haven't returned a value to the OS then we can change it
- defer func() {
- if f.d.f.Precision() == fs.ModTimeNotSupported && (virtualModTime == nil || !virtualModTime.Equal(modTime)) {
- f.virtualModTime = &modTime
- fs.Debugf(f._path(), "Set virtual modtime to %v", f.virtualModTime)
- }
- }()
- if d.vfs.Opt.NoModTime {
- return d.ModTime()
- }
- // Read the modtime from a dirty item if it exists
- if f.d.vfs.Opt.CacheMode >= vfscommon.CacheModeMinimal {
- if item := f.d.vfs.cache.DirtyItem(f._path()); item != nil {
- modTime, err := item.GetModTime()
- if err != nil {
- fs.Errorf(f._path(), "ModTime: Item GetModTime failed: %v", err)
- } else {
- return f._roundModTime(modTime)
- }
- }
- }
- if !pendingModTime.IsZero() {
- return f._roundModTime(pendingModTime)
- }
- if virtualModTime != nil && !virtualModTime.IsZero() {
- fs.Debugf(f._path(), "Returning virtual modtime %v", f.virtualModTime)
- return f._roundModTime(*virtualModTime)
- }
- if o == nil {
- return time.Now()
- }
- return o.ModTime(context.TODO())
- }
- // nonNegative returns 0 if i is -ve, i otherwise
- func nonNegative(i int64) int64 {
- if i >= 0 {
- return i
- }
- return 0
- }
- // Size of the file
- func (f *File) Size() int64 {
- f.mu.RLock()
- defer f.mu.RUnlock()
- // Read the size from a dirty item if it exists
- if f.d.vfs.Opt.CacheMode >= vfscommon.CacheModeMinimal {
- if item := f.d.vfs.cache.DirtyItem(f._path()); item != nil {
- size, err := item.GetSize()
- if err != nil {
- fs.Errorf(f._path(), "Size: Item GetSize failed: %v", err)
- } else {
- return size
- }
- }
- }
- // if o is nil it isn't valid yet or there are writers, so return the size so far
- if f._writingInProgress() {
- return f.size.Load()
- }
- return nonNegative(f.o.Size())
- }
- // SetModTime sets the modtime for the file
- //
- // if NoModTime is set then it does nothing
- func (f *File) SetModTime(modTime time.Time) error {
- f.mu.Lock()
- defer f.mu.Unlock()
- if f.d.vfs.Opt.NoModTime {
- return nil
- }
- if f.d.vfs.Opt.ReadOnly {
- return EROFS
- }
- f.pendingModTime = modTime
- // set the time of the file in the cache
- if f.d.vfs.cache != nil && f.d.vfs.cache.Exists(f._path()) {
- f.d.vfs.cache.SetModTime(f._path(), f.pendingModTime)
- }
- // Only update the ModTime when there are no writers, setObject will do it
- if !f._writingInProgress() {
- return f._applyPendingModTime()
- }
- // queue up for later, hoping f.o becomes available
- return nil
- }
- // Apply a pending mod time
- // Call with the mutex held
- func (f *File) _applyPendingModTime() error {
- if f.pendingModTime.IsZero() {
- return nil
- }
- defer func() { f.pendingModTime = time.Time{} }()
- if f.o == nil {
- return errors.New("cannot apply ModTime, file object is not available")
- }
- dt := f.pendingModTime.Sub(f.o.ModTime(context.Background()))
- modifyWindow := f.o.Fs().Precision()
- if dt < modifyWindow && dt > -modifyWindow {
- fs.Debugf(f.o, "Not setting pending mod time %v as it is already set", f.pendingModTime)
- return nil
- }
- // set the time of the object
- err := f.o.SetModTime(context.TODO(), f.pendingModTime)
- switch err {
- case nil:
- fs.Debugf(f.o, "Applied pending mod time %v OK", f.pendingModTime)
- case fs.ErrorCantSetModTime, fs.ErrorCantSetModTimeWithoutDelete:
- // do nothing, in order to not break "touch somefile" if it exists already
- default:
- fs.Errorf(f.o, "Failed to apply pending mod time %v: %v", f.pendingModTime, err)
- return err
- }
- return nil
- }
- // Apply a pending mod time
- func (f *File) applyPendingModTime() error {
- f.mu.Lock()
- defer f.mu.Unlock()
- return f._applyPendingModTime()
- }
- // _writingInProgress returns true of there are any open writers
- // Call with read lock held
- func (f *File) _writingInProgress() bool {
- return f.o == nil || len(f.writers) != 0
- }
- // writingInProgress returns true of there are any open writers
- func (f *File) writingInProgress() bool {
- f.mu.RLock()
- defer f.mu.RUnlock()
- return f.o == nil || len(f.writers) != 0
- }
- // Update the size while writing
- func (f *File) setSize(n int64) {
- f.size.Store(n)
- }
- // Update the object when written and add it to the directory
- func (f *File) setObject(o fs.Object) {
- f.mu.Lock()
- f.o = o
- _ = f._applyPendingModTime()
- d := f.d
- f.mu.Unlock()
- // Release File.mu before calling Dir method
- d.addObject(f)
- }
- // Update the object but don't update the directory cache - for use by
- // the directory cache
- func (f *File) setObjectNoUpdate(o fs.Object) {
- f.mu.Lock()
- f.o = o
- f.virtualModTime = nil
- fs.Debugf(f._path(), "Reset virtual modtime")
- f.mu.Unlock()
- }
- // Get the current fs.Object - may be nil
- func (f *File) getObject() fs.Object {
- f.mu.RLock()
- defer f.mu.RUnlock()
- return f.o
- }
- // exists returns whether the file exists already
- func (f *File) exists() bool {
- f.mu.RLock()
- defer f.mu.RUnlock()
- return f.o != nil
- }
- // Wait for f.o to become non nil for a short time returning it or an
- // error. Use when opening a read handle.
- //
- // Call without the mutex held
- func (f *File) waitForValidObject() (o fs.Object, err error) {
- for i := 0; i < 50; i++ {
- f.mu.RLock()
- o = f.o
- nwriters := len(f.writers)
- f.mu.RUnlock()
- if o != nil {
- return o, nil
- }
- if nwriters == 0 {
- return nil, errors.New("can't open file - writer failed")
- }
- time.Sleep(100 * time.Millisecond)
- }
- return nil, ENOENT
- }
- // openRead open the file for read
- func (f *File) openRead() (fh *ReadFileHandle, err error) {
- // if o is nil it isn't valid yet
- _, err = f.waitForValidObject()
- if err != nil {
- return nil, err
- }
- // fs.Debugf(f.Path(), "File.openRead")
- fh, err = newReadFileHandle(f)
- if err != nil {
- fs.Debugf(f.Path(), "File.openRead failed: %v", err)
- return nil, err
- }
- return fh, nil
- }
- // openWrite open the file for write
- func (f *File) openWrite(flags int) (fh *WriteFileHandle, err error) {
- f.mu.RLock()
- d := f.d
- f.mu.RUnlock()
- if d.vfs.Opt.ReadOnly {
- return nil, EROFS
- }
- // fs.Debugf(f.Path(), "File.openWrite")
- fh, err = newWriteFileHandle(d, f, f.Path(), flags)
- if err != nil {
- fs.Debugf(f.Path(), "File.openWrite failed: %v", err)
- return nil, err
- }
- return fh, nil
- }
- // openRW open the file for read and write using a temporary file
- //
- // It uses the open flags passed in.
- func (f *File) openRW(flags int) (fh *RWFileHandle, err error) {
- f.mu.RLock()
- d := f.d
- f.mu.RUnlock()
- // FIXME chunked
- if flags&accessModeMask != os.O_RDONLY && d.vfs.Opt.ReadOnly {
- return nil, EROFS
- }
- // fs.Debugf(f.Path(), "File.openRW")
- fh, err = newRWFileHandle(d, f, flags)
- if err != nil {
- fs.Debugf(f.Path(), "File.openRW failed: %v", err)
- return nil, err
- }
- return fh, nil
- }
- // Sync the file
- //
- // Note that we don't do anything except return OK
- func (f *File) Sync() error {
- return nil
- }
- // Remove the file
- func (f *File) Remove() (err error) {
- defer log.Trace(f.Path(), "")("err=%v", &err)
- f.mu.RLock()
- d := f.d
- f.mu.RUnlock()
- if d.vfs.Opt.ReadOnly {
- return EROFS
- }
- // Remove the object from the cache
- wasWriting := false
- if d.vfs.cache != nil && d.vfs.cache.Exists(f.Path()) {
- wasWriting = d.vfs.cache.Remove(f.Path())
- }
- f.muRW.Lock() // muRW must be locked before mu to avoid
- f.mu.Lock() // deadlock in RWFileHandle.openPending and .close
- if f.o != nil {
- err = f.o.Remove(context.TODO())
- }
- f.mu.Unlock()
- f.muRW.Unlock()
- if err != nil {
- if wasWriting {
- // Ignore error deleting file if was writing it as it may not be uploaded yet
- err = nil
- fs.Debugf(f._path(), "Ignoring File.Remove file error as uploading: %v", err)
- } else {
- fs.Debugf(f._path(), "File.Remove file error: %v", err)
- }
- }
- // Remove the item from the directory listing
- // called with File.mu released when there is no error removing the underlying file
- if err == nil {
- d.delObject(f.Name())
- }
- return err
- }
- // RemoveAll the file - same as remove for files
- func (f *File) RemoveAll() error {
- return f.Remove()
- }
- // DirEntry returns the underlying fs.DirEntry - may be nil
- func (f *File) DirEntry() (entry fs.DirEntry) {
- f.mu.RLock()
- defer f.mu.RUnlock()
- return f.o
- }
- // Dir returns the directory this file is in
- func (f *File) Dir() *Dir {
- f.mu.RLock()
- defer f.mu.RUnlock()
- return f.d
- }
- // VFS returns the instance of the VFS
- func (f *File) VFS() *VFS {
- f.mu.RLock()
- defer f.mu.RUnlock()
- return f.d.vfs
- }
- // Fs returns the underlying Fs for the file
- func (f *File) Fs() fs.Fs {
- f.mu.RLock()
- defer f.mu.RUnlock()
- return f.d.Fs()
- }
- // Open a file according to the flags provided
- //
- // O_RDONLY open the file read-only.
- // O_WRONLY open the file write-only.
- // O_RDWR open the file read-write.
- //
- // O_APPEND append data to the file when writing.
- // O_CREATE create a new file if none exists.
- // O_EXCL used with O_CREATE, file must not exist
- // O_SYNC open for synchronous I/O.
- // O_TRUNC if possible, truncate file when opened
- //
- // We ignore O_SYNC and O_EXCL
- func (f *File) Open(flags int) (fd Handle, err error) {
- defer log.Trace(f.Path(), "flags=%s", decodeOpenFlags(flags))("fd=%v, err=%v", &fd, &err)
- var (
- write bool // if set need write support
- read bool // if set need read support
- rdwrMode = flags & accessModeMask
- )
- // http://pubs.opengroup.org/onlinepubs/7908799/xsh/open.html
- // The result of using O_TRUNC with O_RDONLY is undefined.
- // Linux seems to truncate the file, but we prefer to return EINVAL
- if rdwrMode == os.O_RDONLY && flags&os.O_TRUNC != 0 {
- return nil, EINVAL
- }
- // Figure out the read/write intents
- switch {
- case rdwrMode == os.O_RDONLY:
- read = true
- case rdwrMode == os.O_WRONLY:
- write = true
- case rdwrMode == os.O_RDWR:
- read = true
- write = true
- default:
- fs.Debugf(f.Path(), "Can't figure out how to open with flags: 0x%X", flags)
- return nil, EPERM
- }
- // If append is set then set read to force openRW
- if flags&os.O_APPEND != 0 {
- read = true
- f.mu.Lock()
- f.appendMode = true
- f.mu.Unlock()
- }
- // If truncate is set then set write to force openRW
- if flags&os.O_TRUNC != 0 {
- write = true
- }
- // If create is set then set write to force openRW
- if flags&os.O_CREATE != 0 {
- write = true
- }
- // Open the correct sort of handle
- f.mu.RLock()
- d := f.d
- f.mu.RUnlock()
- CacheMode := d.vfs.Opt.CacheMode
- if CacheMode >= vfscommon.CacheModeMinimal && (d.vfs.cache.InUse(f.Path()) || d.vfs.cache.Exists(f.Path())) {
- fd, err = f.openRW(flags)
- } else if read && write {
- if CacheMode >= vfscommon.CacheModeMinimal {
- fd, err = f.openRW(flags)
- } else {
- // Open write only and hope the user doesn't
- // want to read. If they do they will get an
- // EPERM plus an Error log.
- fd, err = f.openWrite(flags)
- }
- } else if write {
- if CacheMode >= vfscommon.CacheModeWrites {
- fd, err = f.openRW(flags)
- } else {
- fd, err = f.openWrite(flags)
- }
- } else if read {
- if CacheMode >= vfscommon.CacheModeFull {
- fd, err = f.openRW(flags)
- } else {
- fd, err = f.openRead()
- }
- } else {
- fs.Debugf(f.Path(), "Can't figure out how to open with flags: 0x%X", flags)
- return nil, EPERM
- }
- // if creating a file, add the file to the directory
- if err == nil && flags&os.O_CREATE != 0 {
- // called without File.mu held
- d.addObject(f)
- }
- return fd, err
- }
- // Truncate changes the size of the named file.
- func (f *File) Truncate(size int64) (err error) {
- // make a copy of fh.writers with the lock held then unlock so
- // we can call other file methods.
- f.mu.Lock()
- writers := make([]Handle, len(f.writers))
- copy(writers, f.writers)
- f.mu.Unlock()
- // If have writers then call truncate for each writer
- if len(writers) != 0 {
- var openWriters = len(writers)
- fs.Debugf(f.Path(), "Truncating %d file handles", len(writers))
- for _, h := range writers {
- truncateErr := h.Truncate(size)
- if truncateErr == ECLOSED {
- // Ignore ECLOSED since file handle can get closed while this is running
- openWriters--
- } else if truncateErr != nil {
- err = truncateErr
- }
- }
- // If at least one open writer return here
- if openWriters > 0 {
- return err
- }
- }
- // if o is nil it isn't valid yet
- o, err := f.waitForValidObject()
- if err != nil {
- return err
- }
- // If no writers, and size is already correct then all done
- if o.Size() == size {
- return nil
- }
- fs.Debugf(f.Path(), "Truncating file")
- // Otherwise if no writers then truncate the file by opening
- // the file and truncating it.
- flags := os.O_WRONLY
- if size == 0 {
- flags |= os.O_TRUNC
- }
- fh, err := f.Open(flags)
- if err != nil {
- return err
- }
- defer fs.CheckClose(fh, &err)
- if size != 0 {
- return fh.Truncate(size)
- }
- return nil
- }
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