Commit b50f7b26 authored by David Gstir's avatar David Gstir Committed by Theodore Ts'o
Browse files

fscrypt: Allow fscrypt_decrypt_page() to function with non-writeback pages 



Some filesystem might pass pages which do not have page->mapping->host
set to the encrypted inode. We want the caller to explicitly pass the
corresponding inode.

Signed-off-by: default avatarDavid Gstir <david@sigma-star.at>
Signed-off-by: default avatarRichard Weinberger <richard@nod.at>
Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent 1c7dcf69

fs/crypto/crypto.c

+6 −5
Original line number Diff line number Diff line
@@ -271,6 +271,7 @@ EXPORT_SYMBOL(fscrypt_encrypt_page); 


/**

 * f2crypt_decrypt_page() - Decrypts a page in-place

 * @inode: The encrypted inode to decrypt.

 * @page:  The page to decrypt. Must be locked.

 *

 * Decrypts page in-place using the ctx encryption context.
@@ -279,12 +280,12 @@ EXPORT_SYMBOL(fscrypt_encrypt_page); 
 *

 * Return: Zero on success, non-zero otherwise.

 */

int fscrypt_decrypt_page(struct page *page)

int fscrypt_decrypt_page(struct inode *inode, struct page *page)

{

	BUG_ON(!PageLocked(page));



	return do_page_crypto(page->mapping->host,

			FS_DECRYPT, page->index, page, page, GFP_NOFS);

	return do_page_crypto(inode, FS_DECRYPT, page->index, page, page,

			GFP_NOFS);

}

EXPORT_SYMBOL(fscrypt_decrypt_page);
@@ -419,7 +420,7 @@ static void completion_pages(struct work_struct *work) 


	bio_for_each_segment_all(bv, bio, i) {

		struct page *page = bv->bv_page;

		int ret = fscrypt_decrypt_page(page);

		int ret = fscrypt_decrypt_page(page->mapping->host, page);



		if (ret) {

			WARN_ON_ONCE(1);

fs/ext4/inode.c

+3 −2
Original line number Diff line number Diff line
@@ -1166,7 +1166,7 @@ static int ext4_block_write_begin(struct page *page, loff_t pos, unsigned len, 
	if (unlikely(err))

		page_zero_new_buffers(page, from, to);

	else if (decrypt)

		err = fscrypt_decrypt_page(page);

		err = fscrypt_decrypt_page(page->mapping->host, page);

	return err;

}

#endif
@@ -3743,7 +3743,8 @@ static int __ext4_block_zero_page_range(handle_t *handle, 
			/* We expect the key to be set. */

			BUG_ON(!fscrypt_has_encryption_key(inode));

			BUG_ON(blocksize != PAGE_SIZE);

			WARN_ON_ONCE(fscrypt_decrypt_page(page));

			WARN_ON_ONCE(fscrypt_decrypt_page(page->mapping->host,

						page));

		}

	}

	if (ext4_should_journal_data(inode)) {

include/linux/fscrypto.h

+3 −2
Original line number Diff line number Diff line
@@ -249,7 +249,7 @@ int fscrypt_initialize(void); 
extern struct fscrypt_ctx *fscrypt_get_ctx(struct inode *, gfp_t);

extern void fscrypt_release_ctx(struct fscrypt_ctx *);

extern struct page *fscrypt_encrypt_page(struct inode *, struct page *, gfp_t);

extern int fscrypt_decrypt_page(struct page *);

extern int fscrypt_decrypt_page(struct inode *, struct page *);

extern void fscrypt_decrypt_bio_pages(struct fscrypt_ctx *, struct bio *);

extern void fscrypt_pullback_bio_page(struct page **, bool);

extern void fscrypt_restore_control_page(struct page *);
@@ -298,7 +298,8 @@ static inline struct page *fscrypt_notsupp_encrypt_page(struct inode *i, 
	return ERR_PTR(-EOPNOTSUPP);

}



static inline int fscrypt_notsupp_decrypt_page(struct page *p)

static inline int fscrypt_notsupp_decrypt_page(struct inode *i,

						struct page *p)

{

	return -EOPNOTSUPP;

}

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