8a2c77bc2a
Encrypted files traditionally haven't supported DIO, due to the need to encrypt/decrypt the data. However, when the encryption is implemented using inline encryption (blk-crypto) instead of the traditional filesystem-layer encryption, it is straightforward to support DIO. Therefore, make f2fs support DIO on files that are using inline encryption. Since f2fs uses iomap for DIO, and fscrypt support was already added to iomap DIO, this just requires two small changes: - Let DIO proceed when supported, by checking fscrypt_dio_supported() instead of assuming that encrypted files never support DIO. - In f2fs_iomap_begin(), use fscrypt_limit_io_blocks() to limit the length of the mapping in the rare case where a DUN discontiguity occurs in the middle of an extent. The iomap DIO implementation requires this, since it assumes that it can submit a bio covering (up to) the whole mapping, without checking fscrypt constraints itself. Co-developed-by: Satya Tangirala <satyat@google.com> Signed-off-by: Satya Tangirala <satyat@google.com> Acked-by: Jaegeuk Kim <jaegeuk@kernel.org> Link: https://lore.kernel.org/r/20220128233940.79464-5-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.