cmount,vfs: unify Read and Write handles and File and Dir where possible
This commit is contained in:
Nick Craig-Wood
parent
5634659ea3
commit
22ee839d05
2 changed files with 77 additions and 186 deletions
261
cmd/cmount/fs.go
261
cmd/cmount/fs.go
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@ -23,99 +23,72 @@ const fhUnset = ^uint64(0)
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// FS represents the top level filing system
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type FS struct {
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VFS *vfs.VFS
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f fs.Fs
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openDirs *openFiles
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openFilesWr *openFiles
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openFilesRd *openFiles
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ready chan (struct{})
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VFS *vfs.VFS
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f fs.Fs
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ready chan (struct{})
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mu sync.Mutex // to protect the below
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handles []vfs.Handle
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}
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// NewFS makes a new FS
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func NewFS(f fs.Fs) *FS {
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fsys := &FS{
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VFS: vfs.New(f, &vfsflags.Opt),
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f: f,
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openDirs: newOpenFiles(0x01),
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openFilesWr: newOpenFiles(0x02),
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openFilesRd: newOpenFiles(0x03),
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ready: make(chan (struct{})),
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VFS: vfs.New(f, &vfsflags.Opt),
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f: f,
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ready: make(chan (struct{})),
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}
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return fsys
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}
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type openFiles struct {
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mu sync.Mutex
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mark uint8
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nodes []vfs.Noder
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}
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func newOpenFiles(mark uint8) *openFiles {
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return &openFiles{
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mark: mark,
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}
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}
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// Open a node returning a file handle
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func (of *openFiles) Open(node vfs.Noder) (fh uint64) {
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of.mu.Lock()
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defer of.mu.Unlock()
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// Open a handle returning an integer file handle
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func (fsys *FS) openHandle(handle vfs.Handle) (fh uint64) {
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fsys.mu.Lock()
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defer fsys.mu.Unlock()
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var i int
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var oldNode vfs.Noder
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for i, oldNode = range of.nodes {
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if oldNode == nil {
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of.nodes[i] = node
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var oldHandle vfs.Handle
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for i, oldHandle = range fsys.handles {
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if oldHandle == nil {
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fsys.handles[i] = handle
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goto found
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}
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}
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of.nodes = append(of.nodes, node)
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i = len(of.nodes) - 1
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fsys.handles = append(fsys.handles, handle)
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i = len(fsys.handles) - 1
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found:
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return uint64((i << 8) | int(of.mark))
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return uint64(i)
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}
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// InRange to see if this fh could be one of ours
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func (of *openFiles) InRange(fh uint64) bool {
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return uint8(fh) == of.mark
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}
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// get the node for fh, call with the lock held
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func (of *openFiles) get(fh uint64) (i int, node vfs.Noder, errc int) {
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receivedMark := uint8(fh)
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if receivedMark != of.mark {
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fs.Debugf(nil, "Bad file handle: bad mark 0x%X != 0x%X: 0x%X", receivedMark, of.mark, fh)
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return i, nil, -fuse.EBADF
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}
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i64 := fh >> 8
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if i64 > uint64(len(of.nodes)) {
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// get the handle for fh, call with the lock held
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func (fsys *FS) _getHandle(fh uint64) (i int, handle vfs.Handle, errc int) {
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if fh > uint64(len(fsys.handles)) {
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fs.Debugf(nil, "Bad file handle: too big: 0x%X", fh)
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return i, nil, -fuse.EBADF
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}
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i = int(i64)
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node = of.nodes[i]
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if node == nil {
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fs.Debugf(nil, "Bad file handle: nil node: 0x%X", fh)
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i = int(fh)
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handle = fsys.handles[i]
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if handle == nil {
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fs.Debugf(nil, "Bad file handle: nil handle: 0x%X", fh)
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return i, nil, -fuse.EBADF
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}
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return i, node, 0
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return i, handle, 0
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}
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// Get the node for the file handle
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func (of *openFiles) Get(fh uint64) (node vfs.Noder, errc int) {
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of.mu.Lock()
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_, node, errc = of.get(fh)
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of.mu.Unlock()
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// Get the handle for the file handle
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func (fsys *FS) getHandle(fh uint64) (handle vfs.Handle, errc int) {
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fsys.mu.Lock()
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_, handle, errc = fsys._getHandle(fh)
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fsys.mu.Unlock()
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return
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}
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// Close the node
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func (of *openFiles) Close(fh uint64) (errc int) {
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of.mu.Lock()
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i, _, errc := of.get(fh)
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// Close the handle
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func (fsys *FS) closeHandle(fh uint64) (errc int) {
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fsys.mu.Lock()
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i, _, errc := fsys._getHandle(fh)
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if errc == 0 {
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of.nodes[i] = nil
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fsys.handles[i] = nil
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}
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of.mu.Unlock()
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fsys.mu.Unlock()
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return
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}
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@ -158,35 +131,13 @@ func (fsys *FS) lookupFile(path string) (file *vfs.File, errc int) {
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return file, 0
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}
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// Get the underlying openFile handle from the file handle
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func (fsys *FS) getOpenFilesFromFh(fh uint64) (of *openFiles, errc int) {
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switch {
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case fsys.openFilesRd.InRange(fh):
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return fsys.openFilesRd, 0
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case fsys.openFilesWr.InRange(fh):
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return fsys.openFilesWr, 0
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case fsys.openDirs.InRange(fh):
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return fsys.openDirs, 0
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}
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return nil, -fuse.EBADF
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}
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// Get the underlying handle from the file handle
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func (fsys *FS) getHandleFromFh(fh uint64) (handle vfs.Noder, errc int) {
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of, errc := fsys.getOpenFilesFromFh(fh)
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if errc != 0 {
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return nil, errc
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}
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return of.Get(fh)
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}
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// get a node from the path or from the fh if not fhUnset
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func (fsys *FS) getNode(path string, fh uint64) (node vfs.Node, errc int) {
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if fh == fhUnset {
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node, errc = fsys.lookupNode(path)
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} else {
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var n vfs.Noder
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n, errc = fsys.getHandleFromFh(fh)
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var n vfs.Handle
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n, errc = fsys.getHandle(fh)
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if errc == 0 {
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node = n.Node()
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}
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@ -196,19 +147,14 @@ func (fsys *FS) getNode(path string, fh uint64) (node vfs.Node, errc int) {
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// stat fills up the stat block for Node
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func (fsys *FS) stat(node vfs.Node, stat *fuse.Stat_t) (errc int) {
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var Size uint64
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var Blocks uint64
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var modTime time.Time
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var Mode os.FileMode
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switch x := node.(type) {
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case *vfs.Dir:
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modTime = x.ModTime()
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Mode = fsys.VFS.Opt.DirPerms | fuse.S_IFDIR
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case *vfs.File:
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modTime = x.ModTime()
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Size = uint64(x.Size())
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Blocks = (Size + 511) / 512
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Mode = fsys.VFS.Opt.FilePerms | fuse.S_IFREG
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Size := uint64(node.Size())
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Blocks := (Size + 511) / 512
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modTime := node.ModTime()
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Mode := node.Mode().Perm()
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if node.IsDir() {
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Mode |= fuse.S_IFDIR
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} else {
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Mode |= fuse.S_IFREG
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}
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//stat.Dev = 1
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stat.Ino = node.Inode() // FIXME do we need to set the inode number?
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@ -255,13 +201,11 @@ func (fsys *FS) Getattr(path string, stat *fuse.Stat_t, fh uint64) (errc int) {
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// Opendir opens path as a directory
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func (fsys *FS) Opendir(path string) (errc int, fh uint64) {
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defer fs.Trace(path, "")("errc=%d, fh=0x%X", &errc, &fh)
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dir, errc := fsys.lookupDir(path)
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if errc == 0 {
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fh = fsys.openDirs.Open(dir)
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} else {
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fh = fhUnset
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handle, err := fsys.VFS.OpenFile(path, os.O_RDONLY, 0777)
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if errc != 0 {
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return translateError(err), fhUnset
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}
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return
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return 0, fsys.openHandle(handle)
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}
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// Readdir reads the directory at dirPath
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@ -272,17 +216,12 @@ func (fsys *FS) Readdir(dirPath string,
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itemsRead := -1
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defer fs.Trace(dirPath, "ofst=%d, fh=0x%X", ofst, fh)("items=%d, errc=%d", &itemsRead, &errc)
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node, errc := fsys.openDirs.Get(fh)
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node, errc := fsys.getHandle(fh)
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if errc != 0 {
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return errc
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}
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dir, ok := node.(*vfs.Dir)
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if !ok {
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return -fuse.ENOTDIR
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}
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items, err := dir.ReadDirAll()
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items, err := node.Readdir(-1)
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if err != nil {
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return translateError(err)
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}
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@ -303,8 +242,11 @@ func (fsys *FS) Readdir(dirPath string,
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fill(".", nil, 0)
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fill("..", nil, 0)
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for _, item := range items {
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name := path.Base(item.DirEntry().Remote())
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fill(name, nil, 0)
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node, ok := item.(vfs.Node)
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if ok {
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name := path.Base(node.DirEntry().Remote())
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fill(name, nil, 0)
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}
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}
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itemsRead = len(items)
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return 0
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@ -313,7 +255,7 @@ func (fsys *FS) Readdir(dirPath string,
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// Releasedir finished reading the directory
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func (fsys *FS) Releasedir(path string, fh uint64) (errc int) {
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defer fs.Trace(path, "fh=0x%X", fh)("errc=%d", &errc)
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return fsys.openDirs.Close(fh)
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return fsys.closeHandle(fh)
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}
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// Statfs reads overall stats on the filessystem
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@ -346,14 +288,7 @@ func (fsys *FS) Open(path string, flags int) (errc int, fh uint64) {
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return translateError(err), fhUnset
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}
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switch fh := handle.(type) {
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case *vfs.WriteFileHandle:
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return 0, fsys.openFilesWr.Open(fh)
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case *vfs.ReadFileHandle:
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return 0, fsys.openFilesRd.Open(fh)
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}
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return -fuse.EPERM, fhUnset
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return 0, fsys.openHandle(handle)
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}
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// Create creates and opens a file.
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@ -367,7 +302,7 @@ func (fsys *FS) Create(filePath string, flags int, mode uint32) (errc int, fh ui
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if err != nil {
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return translateError(err), fhUnset
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}
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return 0, fsys.openFilesWr.Open(handle)
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return 0, fsys.openHandle(handle)
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}
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// Truncate truncates a file to size
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@ -377,12 +312,8 @@ func (fsys *FS) Truncate(path string, size int64, fh uint64) (errc int) {
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if errc != 0 {
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return errc
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}
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file, ok := node.(*vfs.File)
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if !ok {
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return -fuse.EIO
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}
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// Read the size so far
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currentSize := file.Size()
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currentSize := node.Size()
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fs.Debugf(path, "truncate to %d, currentSize %d", size, currentSize)
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if int64(currentSize) != size {
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fs.Errorf(path, "Can't truncate files")
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@ -391,10 +322,10 @@ func (fsys *FS) Truncate(path string, size int64, fh uint64) (errc int) {
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return 0
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}
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// Read data from file handle
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func (fsys *FS) Read(path string, buff []byte, ofst int64, fh uint64) (n int) {
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defer fs.Trace(path, "ofst=%d, fh=0x%X", ofst, fh)("n=%d", &n)
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// FIXME detect seek
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handle, errc := fsys.openFilesRd.Get(fh)
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handle, errc := fsys.getHandle(fh)
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if errc != 0 {
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return errc
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}
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@ -407,19 +338,14 @@ func (fsys *FS) Read(path string, buff []byte, ofst int64, fh uint64) (n int) {
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return n
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}
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// Write data to file handle
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func (fsys *FS) Write(path string, buff []byte, ofst int64, fh uint64) (n int) {
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defer fs.Trace(path, "ofst=%d, fh=0x%X", ofst, fh)("n=%d", &n)
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// FIXME detect seek
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handle, errc := fsys.openFilesWr.Get(fh)
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handle, errc := fsys.getHandle(fh)
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if errc != 0 {
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return errc
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}
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wfh, ok := handle.(*vfs.WriteFileHandle)
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if !ok {
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// Can only write to write file handle
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return -fuse.EIO
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}
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n, err := wfh.WriteAt(buff, ofst)
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n, err := handle.WriteAt(buff, ofst)
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if err != nil {
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return translateError(err)
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}
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@ -429,44 +355,22 @@ func (fsys *FS) Write(path string, buff []byte, ofst int64, fh uint64) (n int) {
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// Flush flushes an open file descriptor or path
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func (fsys *FS) Flush(path string, fh uint64) (errc int) {
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defer fs.Trace(path, "fh=0x%X", fh)("errc=%d", &errc)
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handle, errc := fsys.getHandleFromFh(fh)
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handle, errc := fsys.getHandle(fh)
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if errc != 0 {
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return errc
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}
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var err error
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switch x := handle.(type) {
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case *vfs.ReadFileHandle:
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err = x.Flush()
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case *vfs.WriteFileHandle:
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err = x.Flush()
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default:
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return -fuse.EIO
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}
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return translateError(err)
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return translateError(handle.Flush())
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}
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// Release closes the file if still open
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func (fsys *FS) Release(path string, fh uint64) (errc int) {
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defer fs.Trace(path, "fh=0x%X", fh)("errc=%d", &errc)
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of, errc := fsys.getOpenFilesFromFh(fh)
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handle, errc := fsys.getHandle(fh)
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if errc != 0 {
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return errc
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}
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handle, errc := of.Get(fh)
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if errc != 0 {
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return errc
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}
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_ = of.Close(fh)
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var err error
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switch x := handle.(type) {
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case *vfs.ReadFileHandle:
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err = x.Release()
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case *vfs.WriteFileHandle:
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err = x.Release()
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default:
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return -fuse.EIO
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}
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return translateError(err)
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_ = fsys.closeHandle(fh)
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return translateError(handle.Release())
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}
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// Unlink removes a file.
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@ -503,15 +407,7 @@ func (fsys *FS) Rmdir(dirPath string) (errc int) {
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// Rename renames a file.
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func (fsys *FS) Rename(oldPath string, newPath string) (errc int) {
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defer fs.Trace(oldPath, "newPath=%q", newPath)("errc=%d", &errc)
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oldLeaf, oldParentDir, errc := fsys.lookupParentDir(oldPath)
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if errc != 0 {
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return errc
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}
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newLeaf, newParentDir, errc := fsys.lookupParentDir(newPath)
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if errc != 0 {
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return errc
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}
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return translateError(oldParentDir.Rename(oldLeaf, newLeaf, newParentDir))
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return translateError(fsys.VFS.Rename(oldPath, newPath))
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}
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// Utimens changes the access and modification times of a file.
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@ -527,14 +423,7 @@ func (fsys *FS) Utimens(path string, tmsp []fuse.Timespec) (errc int) {
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} else {
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t = tmsp[1].Time()
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}
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var err error
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switch x := node.(type) {
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case *vfs.Dir:
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err = x.SetModTime(t)
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case *vfs.File:
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err = x.SetModTime(t)
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}
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return translateError(err)
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return translateError(node.SetModTime(t))
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}
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// Mknod creates a file node.
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@ -105,6 +105,7 @@ type Handle interface {
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// Additional methods useful for FUSE filesystems
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Flush() error
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Release() error
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Node() Node
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}
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// baseHandle implements all the missing methods
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@ -129,6 +130,7 @@ func (h baseHandle) WriteAt(b []byte, off int64) (n int, err error) { retu
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func (h baseHandle) WriteString(s string) (n int, err error) { return 0, ENOSYS }
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func (h baseHandle) Flush() (err error) { return ENOSYS }
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func (h baseHandle) Release() (err error) { return ENOSYS }
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func (h baseHandle) Node() Node { return nil }
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// Check interfaces
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||||
var (
|
||||
|
|
|
|||
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Reference in a new issue