github.com/rclone/rclone@v1.66.1-0.20240517100346-7b89735ae726/cmd/mount/file.go (about)

     1  //go:build linux
     2  
     3  package mount
     4  
     5  import (
     6  	"context"
     7  	"syscall"
     8  	"time"
     9  
    10  	"bazil.org/fuse"
    11  	fusefs "bazil.org/fuse/fs"
    12  	"github.com/rclone/rclone/fs/log"
    13  	"github.com/rclone/rclone/vfs"
    14  )
    15  
    16  // File represents a file
    17  type File struct {
    18  	*vfs.File
    19  	fsys *FS
    20  }
    21  
    22  // Check interface satisfied
    23  var _ fusefs.Node = (*File)(nil)
    24  
    25  // Attr fills out the attributes for the file
    26  func (f *File) Attr(ctx context.Context, a *fuse.Attr) (err error) {
    27  	defer log.Trace(f, "")("a=%+v, err=%v", a, &err)
    28  	a.Valid = f.fsys.opt.AttrTimeout
    29  	modTime := f.File.ModTime()
    30  	Size := uint64(f.File.Size())
    31  	Blocks := (Size + 511) / 512
    32  	a.Gid = f.VFS().Opt.GID
    33  	a.Uid = f.VFS().Opt.UID
    34  	a.Mode = f.VFS().Opt.FilePerms
    35  	a.Size = Size
    36  	a.Atime = modTime
    37  	a.Mtime = modTime
    38  	a.Ctime = modTime
    39  	a.Blocks = Blocks
    40  	return nil
    41  }
    42  
    43  // Check interface satisfied
    44  var _ fusefs.NodeSetattrer = (*File)(nil)
    45  
    46  // Setattr handles attribute changes from FUSE. Currently supports ModTime and Size only
    47  func (f *File) Setattr(ctx context.Context, req *fuse.SetattrRequest, resp *fuse.SetattrResponse) (err error) {
    48  	defer log.Trace(f, "a=%+v", req)("err=%v", &err)
    49  	if !f.VFS().Opt.NoModTime {
    50  		if req.Valid.Mtime() {
    51  			err = f.File.SetModTime(req.Mtime)
    52  		} else if req.Valid.MtimeNow() {
    53  			err = f.File.SetModTime(time.Now())
    54  		}
    55  	}
    56  	if req.Valid.Size() {
    57  		err = f.File.Truncate(int64(req.Size))
    58  	}
    59  	return translateError(err)
    60  }
    61  
    62  // Check interface satisfied
    63  var _ fusefs.NodeOpener = (*File)(nil)
    64  
    65  // Open the file for read or write
    66  func (f *File) Open(ctx context.Context, req *fuse.OpenRequest, resp *fuse.OpenResponse) (fh fusefs.Handle, err error) {
    67  	defer log.Trace(f, "flags=%v", req.Flags)("fh=%v, err=%v", &fh, &err)
    68  
    69  	// fuse flags are based off syscall flags as are os flags, so
    70  	// should be compatible
    71  	handle, err := f.File.Open(int(req.Flags))
    72  	if err != nil {
    73  		return nil, translateError(err)
    74  	}
    75  
    76  	// If size unknown then use direct io to read
    77  	if entry := handle.Node().DirEntry(); entry != nil && entry.Size() < 0 {
    78  		resp.Flags |= fuse.OpenDirectIO
    79  	}
    80  	if f.fsys.opt.DirectIO {
    81  		resp.Flags |= fuse.OpenDirectIO
    82  	}
    83  
    84  	return &FileHandle{handle}, nil
    85  }
    86  
    87  // Check interface satisfied
    88  var _ fusefs.NodeFsyncer = (*File)(nil)
    89  
    90  // Fsync the file
    91  //
    92  // Note that we don't do anything except return OK
    93  func (f *File) Fsync(ctx context.Context, req *fuse.FsyncRequest) (err error) {
    94  	defer log.Trace(f, "")("err=%v", &err)
    95  	return nil
    96  }
    97  
    98  // Getxattr gets an extended attribute by the given name from the
    99  // node.
   100  //
   101  // If there is no xattr by that name, returns fuse.ErrNoXattr.
   102  func (f *File) Getxattr(ctx context.Context, req *fuse.GetxattrRequest, resp *fuse.GetxattrResponse) error {
   103  	return syscall.ENOSYS // we never implement this
   104  }
   105  
   106  var _ fusefs.NodeGetxattrer = (*File)(nil)
   107  
   108  // Listxattr lists the extended attributes recorded for the node.
   109  func (f *File) Listxattr(ctx context.Context, req *fuse.ListxattrRequest, resp *fuse.ListxattrResponse) error {
   110  	return syscall.ENOSYS // we never implement this
   111  }
   112  
   113  var _ fusefs.NodeListxattrer = (*File)(nil)
   114  
   115  // Setxattr sets an extended attribute with the given name and
   116  // value for the node.
   117  func (f *File) Setxattr(ctx context.Context, req *fuse.SetxattrRequest) error {
   118  	return syscall.ENOSYS // we never implement this
   119  }
   120  
   121  var _ fusefs.NodeSetxattrer = (*File)(nil)
   122  
   123  // Removexattr removes an extended attribute for the name.
   124  //
   125  // If there is no xattr by that name, returns fuse.ErrNoXattr.
   126  func (f *File) Removexattr(ctx context.Context, req *fuse.RemovexattrRequest) error {
   127  	return syscall.ENOSYS // we never implement this
   128  }
   129  
   130  var _ fusefs.NodeRemovexattrer = (*File)(nil)