ntfs: add pathname access for named streams

Add an optional Windows-style pathname interface for named $DATA streams,
enabled with streams_interface=windows. The option defaults to none, and
the named-stream ioctls remain available regardless of this setting.

Support lookup, creation, and removal of named streams for existing regular
files and directories. A stream is opened as a regular file through the
base-name and stream-name form in the final path component. A stream can be
created only for an existing file or directory. The pathname interface
accepts a base file name and stream name only. It rejects paths that also
specify an NTFS attribute type such as $DATA. In windows mode, ordinary
filenames containing a colon are hidden from directory listings and cannot
be accessed through the pathname interface.

Match stream names case-insensitively. Streams and their base objects
report the same inode number. Removing the base object while a stream is
open detaches the stream from the namespace. Since NTFS has no orphan-stream
list, a crash can leave the stream data unreachable on disk.

Expose named streams as regular file descriptors for the file operations
requested by Wine, including read, write, fsync, fdatasync,
sync_file_range, file locking, mmap, futimes, fstat, ftruncate, SEEK_DATA,
SEEK_HOLE, fallocate, and pathname unlink. Stream timestamps are shared
with the base file. fstat reports the base metadata and inode number with
the stream's own size and allocation.

Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>

0 files changed, 0 insertions, 0 deletions