xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

fscrypt: Cleanup page locking requirements for fscrypt_{decrypt,encrypt}_page()

Browse Source 
Rename the FS_CFLG_INPLACE_ENCRYPTION flag to FS_CFLG_OWN_PAGES which,
when set, indicates that the fs uses pages under its own control as
opposed to writeback pages which require locking and a bounce buffer for
encryption.

Signed-off-by: David Gstir <david@sigma-star.at>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This commit is contained in:
David Gstir
2016-12-06 23:53:56 +01:00
committed by Theodore Ts'o
parent 1400451f04
commit bd7b829038
4 changed files with 9 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files

11
fs/crypto/crypto.c
View File

@@ -238,7 +238,7 @@ static struct page *alloc_bounce_page(struct fscrypt_ctx *ctx, gfp_t gfp_flags)
* fscrypt_restore_control_page() on the returned ciphertext page to
* release the bounce buffer and the encryption context.
*
* In-place encryption is used by setting the FS_CFLG_INPLACE_ENCRYPTION flag in
* In-place encryption is used by setting the FS_CFLG_OWN_PAGES flag in
* fscrypt_operations. Here, the input-page is returned with its content
* encrypted.
*
@@ -258,7 +258,7 @@ struct page *fscrypt_encrypt_page(const struct inode *inode,
BUG_ON(len % FS_CRYPTO_BLOCK_SIZE != 0);
if (inode->i_sb->s_cop->flags & FS_CFLG_INPLACE_ENCRYPTION) {
if (inode->i_sb->s_cop->flags & FS_CFLG_OWN_PAGES) {
/* with inplace-encryption we just encrypt the page */
err = do_page_crypto(inode, FS_ENCRYPT, lblk_num,
page, ciphertext_page,
@@ -269,6 +269,8 @@ struct page *fscrypt_encrypt_page(const struct inode *inode,
return ciphertext_page;
}
BUG_ON(!PageLocked(page));
ctx = fscrypt_get_ctx(inode, gfp_flags);
if (IS_ERR(ctx))
return (struct page *)ctx;
@@ -301,7 +303,7 @@ EXPORT_SYMBOL(fscrypt_encrypt_page);
* fscrypt_decrypt_page() - Decrypts a page in-place
* @inode: The corresponding inode for the page to decrypt.
* @page: The page to decrypt. Must be locked in case
* it is a writeback page.
* it is a writeback page (FS_CFLG_OWN_PAGES unset).
* @len: Number of bytes in @page to be decrypted.
* @offs: Start of data in @page.
* @lblk_num: Logical block number.
@@ -315,6 +317,9 @@ EXPORT_SYMBOL(fscrypt_encrypt_page);
int fscrypt_decrypt_page(const struct inode *inode, struct page *page,
unsigned int len, unsigned int offs, u64 lblk_num)
{
if (!(inode->i_sb->s_cop->flags & FS_CFLG_OWN_PAGES))
BUG_ON(!PageLocked(page));
return do_page_crypto(inode, FS_DECRYPT, lblk_num, page, page, len,
offs, GFP_NOFS);
}