ntfs: do not read ahead encrypted files

ntfs_read_folio() refuses EFS-encrypted files with -EOPNOTSUPP because
decryption is not implemented.  ntfs_readahead() has no NInoEncrypted()
test and passes them to iomap_readahead(), which maps the runlist and
fills the folios with the raw on-disk ciphertext.  The folios are
marked uptodate, so the read that follows never reaches ->read_folio
and returns ciphertext instead of -EOPNOTSUPP.

ntfs_read_locked_inode() sets NInoEncrypted() and NInoNonResident() for
a non-resident encrypted $DATA attribute and rejects the
encrypted-and-compressed combination, so none of the three existing
conditions fires.  read(), mmap(), splice() and fadvise() all populate
the page cache through readahead.

Skipping readahead leaves the folio unpopulated, so the read falls back
to ntfs_read_folio() and gets the intended error.

Fixes: b041ca562526 ("ntfs: update iomap and address space operations")
Signed-off-by: Zhan Xusheng <zhanxusheng@xiaomi.com>
Reviewed-by: Baolin Liu <liubaolin@kylinos.cn>
Reviewed-by: Hyunchul Lee <hyc.lee@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>

0 files changed, 0 insertions, 0 deletions