ntfs: wait for sync mft writes to complete

ntfs: wait for sync mft writes to complete

ntfs_sync_mft_mirror() and write_mft_record_nolock() with @sync set
are both documented as synchronous, but neither actually waits for
the bio they submit nor inspects bi_status.  write_inode() can
return success while dirty mft record bytes are still in flight, and
bio errors are silently dropped: the volume is not marked with
errors and the inode is not redirtied.  This breaks fsync()/sync
metadata durability.

Switch ntfs_sync_mft_mirror() and the @sync path of
write_mft_record_nolock() to submit_bio_wait() and propagate the
returned error to the caller.  Capture ntfs_sync_mft_mirror()'s
return value at its call sites in write_mft_record_nolock() so a
mirror write failure surfaces too.

The @sync parameter only controls the main MFT bio.  The !@sync main
submission is therefore unchanged and still uses ntfs_bio_end_io() to
drop the folio reference taken before submission.  The mirror call
has always been documented as performing synchronous I/O regardless
of @sync, so making it actually block restores the originally
intended contract for both @sync and !@sync callers.

Note this only fixes the synchronous mirror/main paths reachable
from write_mft_record_nolock().  The main MFT write submitted from
ntfs_write_mft_block() (the .writepages path) still does not wait
for completion or check bi_status; that requires a larger
restructuring and is left to a follow-up patch.

Fixes: 115380f9a2f9 ("ntfs: update mft operations")
Signed-off-by: DaeMyung Kang <charsyam@gmail.com>
Reviewed-by: Hyunchul Lee <hyc.lee@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>