ntfs3: serve as alias for the legacy ntfs driver

Johan Hovold reported that removing the legacy ntfs driver broke boot
for him since his fstab uses the legacy ntfs driver to access firmware
from the original Windows partition.

Use ntfs3 as an alias for legacy ntfs if CONFIG_NTFS_FS is selected.
This is similar to how ext3 is treated.

Link: https://lore.kernel.org/r/Zf2zPf5TO5oYt3I3@hovoldconsulting.com
Link: https://lore.kernel.org/r/20240325-hinkriegen-zuziehen-d7e2c490427a@brauner
Fixes: 7ffa8f3d3023 ("fs: Remove NTFS classic")
Tested-by: Johan Hovold <johan+linaro@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Johan Hovold <johan@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

fs: add CONFIG_BUFFER_HEAD

Add a new config option that controls building the buffer_head code, and
select it from all file systems and stacking drivers that need it.

For the block device nodes and alternative iomap based buffered I/O path
is provided when buffer_head support is not enabled, and iomap needs a
a small tweak to define the IOMAP_F_BUFFER_HEAD flag to 0 to not call
into the buffer_head code when it doesn't exist.

Otherwise this is just Kconfig and ifdef changes.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20230801172201.1923299-7-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs: build the legacy direct I/O code conditionally

Add a new LEGACY_DIRECT_IO config symbol that is only selected by the
file systems that still use the legacy blockdev_direct_IO code, so that
kernels without support for those file systems don't need to build the
code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20230125065839.191256-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs/ntfs3: Add Kconfig, Makefile and doc

This adds Kconfig, Makefile and doc

Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>