ext4 crypto: implement the ext4 encryption write path

Pulls block_write_begin() into fs/ext4/inode.c because it might need
to do a low-level read of the existing data, in which case we need to
decrypt it.

Signed-off-by: Michael Halcrow <mhalcrow@google.com>
Signed-off-by: Ildar Muslukhov <ildarm@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This commit is contained in:
Michael Halcrow
2015-04-12 00:55:10 -04:00
committed by Theodore Ts'o
parent dde680cefc
commit 2058f83a72
4 changed files with 173 additions and 6 deletions

View File

@@ -3122,6 +3122,9 @@ static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex)
ee_len = ext4_ext_get_actual_len(ex);
ee_pblock = ext4_ext_pblock(ex);
if (ext4_encrypted_inode(inode))
return ext4_encrypted_zeroout(inode, ex);
ret = sb_issue_zeroout(inode->i_sb, ee_pblock, ee_len, GFP_NOFS);
if (ret > 0)
ret = 0;
@@ -4898,6 +4901,20 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
ext4_lblk_t lblk;
unsigned int blkbits = inode->i_blkbits;
/*
* Encrypted inodes can't handle collapse range or insert
* range since we would need to re-encrypt blocks with a
* different IV or XTS tweak (which are based on the logical
* block number).
*
* XXX It's not clear why zero range isn't working, but we'll
* leave it disabled for encrypted inodes for now. This is a
* bug we should fix....
*/
if (ext4_encrypted_inode(inode) &&
(mode & (FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE)))
return -EOPNOTSUPP;
/* Return error if mode is not supported */
if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |
FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE))