tree 41926790732b2cfaaf7d3b34858826d9fb2e0e1f
parent 930d453995bdf4a0000bd162dfd4b70c6d7329f8
author Eric Biggers <ebiggers@google.com> 1558369786 -0700
committer Eric Biggers <ebiggers@google.com> 1559064473 -0700

fscrypt: introduce fscrypt_decrypt_block_inplace()

Currently fscrypt_decrypt_page() does one of two logically distinct
things depending on whether FS_CFLG_OWN_PAGES is set in the filesystem's
fscrypt_operations: decrypt a pagecache page in-place, or decrypt a
filesystem block in-place in any page.  Currently these happen to share
the same implementation, but this conflates the notion of blocks and
pages.  It also makes it so that all callers have to provide inode and
lblk_num, when fscrypt could determine these itself for pagecache pages.

Therefore, move the FS_CFLG_OWN_PAGES behavior into a new function
fscrypt_decrypt_block_inplace().  This mirrors
fscrypt_encrypt_block_inplace().

This is in preparation for allowing encryption on ext4 filesystems with
blocksize != PAGE_SIZE.

Reviewed-by: Chandan Rajendra <chandan@linux.ibm.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>