This series applies on top of Ted's fscrypt tree[0] addresses the review
comments from Eric.
Changes since v1:
- Never allocate fscrypt_ctx in "own pages" mode
- Fix code comments
- Fix issues reported by checkpatch.pl
[0] git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.git fscrypt
David Gstir (6):
fscrypt: Use correct index in decrypt path.
fscrypt: Never allocate fscrypt_ctx on in-place encryption
fscrypt: Cleanup fscrypt_{decrypt,encrypt}_page()
fscrypt: Cleanup page locking requirements for
fscrypt_{decrypt,encrypt}_page()
fscrypt: Delay bounce page pool allocation until needed
fscrypt: Rename FS_WRITE_PATH_FL to FS_CTX_HAS_BOUNCE_BUFFER_FL
fs/crypto/crypto.c | 135 ++++++++++++++++++++++++++++-------------------
fs/crypto/keyinfo.c | 2 +-
fs/ext4/inode.c | 1 -
fs/f2fs/data.c | 1 -
include/linux/fscrypto.h | 14 ++---
5 files changed, 90 insertions(+), 63 deletions(-)
--
2.10.1
Actually use the fs-provided index instead of always using page->index
which is only set for page-cache pages.
Fixes: 9c4bb8a3a9b4 ("fscrypt: Let fs select encryption index/tweak")
Signed-off-by: David Gstir <[email protected]>
---
fs/crypto/crypto.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/crypto/crypto.c b/fs/crypto/crypto.c
index b6029785714c..3c1124beae28 100644
--- a/fs/crypto/crypto.c
+++ b/fs/crypto/crypto.c
@@ -296,7 +296,7 @@ EXPORT_SYMBOL(fscrypt_encrypt_page);
int fscrypt_decrypt_page(const struct inode *inode, struct page *page,
unsigned int len, unsigned int offs, pgoff_t index)
{
- return do_page_crypto(inode, FS_DECRYPT, page->index, page, page, len, offs,
+ return do_page_crypto(inode, FS_DECRYPT, index, page, page, len, offs,
GFP_NOFS);
}
EXPORT_SYMBOL(fscrypt_decrypt_page);
--
2.10.1
... to better explain its purpose after introducing in-place encryption
without bounce buffer.
Signed-off-by: David Gstir <[email protected]>
---
fs/crypto/crypto.c | 6 +++---
include/linux/fscrypto.h | 2 +-
2 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/fs/crypto/crypto.c b/fs/crypto/crypto.c
index c1e4316045e9..20dd4402af42 100644
--- a/fs/crypto/crypto.c
+++ b/fs/crypto/crypto.c
@@ -63,7 +63,7 @@ void fscrypt_release_ctx(struct fscrypt_ctx *ctx)
{
unsigned long flags;
- if (ctx->flags & FS_WRITE_PATH_FL && ctx->w.bounce_page) {
+ if (ctx->flags & FS_CTX_HAS_BOUNCE_BUFFER_FL && ctx->w.bounce_page) {
mempool_free(ctx->w.bounce_page, fscrypt_bounce_page_pool);
ctx->w.bounce_page = NULL;
}
@@ -121,7 +121,7 @@ struct fscrypt_ctx *fscrypt_get_ctx(const struct inode *inode, gfp_t gfp_flags)
} else {
ctx->flags &= ~FS_CTX_REQUIRES_FREE_ENCRYPT_FL;
}
- ctx->flags &= ~FS_WRITE_PATH_FL;
+ ctx->flags &= ~FS_CTX_HAS_BOUNCE_BUFFER_FL;
return ctx;
}
EXPORT_SYMBOL(fscrypt_get_ctx);
@@ -210,7 +210,7 @@ static struct page *alloc_bounce_page(struct fscrypt_ctx *ctx, gfp_t gfp_flags)
ctx->w.bounce_page = mempool_alloc(fscrypt_bounce_page_pool, gfp_flags);
if (ctx->w.bounce_page == NULL)
return ERR_PTR(-ENOMEM);
- ctx->flags |= FS_WRITE_PATH_FL;
+ ctx->flags |= FS_CTX_HAS_BOUNCE_BUFFER_FL;
return ctx->w.bounce_page;
}
diff --git a/include/linux/fscrypto.h b/include/linux/fscrypto.h
index 6039c86ff849..00aa834bf2d9 100644
--- a/include/linux/fscrypto.h
+++ b/include/linux/fscrypto.h
@@ -84,7 +84,7 @@ struct fscrypt_info {
};
#define FS_CTX_REQUIRES_FREE_ENCRYPT_FL 0x00000001
-#define FS_WRITE_PATH_FL 0x00000002
+#define FS_CTX_HAS_BOUNCE_BUFFER_FL 0x00000002
struct fscrypt_ctx {
union {
--
2.10.1
Since fscrypt users can now indicated if fscrypt_encrypt_page() should
use a bounce page, we can delay the bounce page pool initialization util
it is really needed. That is until fscrypt_operations has no
FS_CFLG_OWN_PAGES flag set.
Signed-off-by: David Gstir <[email protected]>
---
fs/crypto/crypto.c | 9 +++++++--
fs/crypto/keyinfo.c | 2 +-
include/linux/fscrypto.h | 2 +-
3 files changed, 9 insertions(+), 4 deletions(-)
diff --git a/fs/crypto/crypto.c b/fs/crypto/crypto.c
index 6f5c3a8df70b..c1e4316045e9 100644
--- a/fs/crypto/crypto.c
+++ b/fs/crypto/crypto.c
@@ -525,17 +525,22 @@ static void fscrypt_destroy(void)
/**
* fscrypt_initialize() - allocate major buffers for fs encryption.
+ * @cop_flags: fscrypt operations flags
*
* We only call this when we start accessing encrypted files, since it
* results in memory getting allocated that wouldn't otherwise be used.
*
* Return: Zero on success, non-zero otherwise.
*/
-int fscrypt_initialize(void)
+int fscrypt_initialize(unsigned int cop_flags)
{
int i, res = -ENOMEM;
- if (fscrypt_bounce_page_pool)
+ /*
+ * No need to allocate a bounce page pool if there already is one or
+ * this FS won't use it.
+ */
+ if (cop_flags & FS_CFLG_OWN_PAGES || fscrypt_bounce_page_pool)
return 0;
mutex_lock(&fscrypt_init_mutex);
diff --git a/fs/crypto/keyinfo.c b/fs/crypto/keyinfo.c
index 67fb6d8876d0..5951f4ebf2a9 100644
--- a/fs/crypto/keyinfo.c
+++ b/fs/crypto/keyinfo.c
@@ -188,7 +188,7 @@ int get_crypt_info(struct inode *inode)
u8 *raw_key = NULL;
int res;
- res = fscrypt_initialize();
+ res = fscrypt_initialize(inode->i_sb->s_cop->flags);
if (res)
return res;
diff --git a/include/linux/fscrypto.h b/include/linux/fscrypto.h
index 65be74f3afb6..6039c86ff849 100644
--- a/include/linux/fscrypto.h
+++ b/include/linux/fscrypto.h
@@ -244,7 +244,7 @@ static inline void fscrypt_set_d_op(struct dentry *dentry)
#if IS_ENABLED(CONFIG_FS_ENCRYPTION)
/* crypto.c */
extern struct kmem_cache *fscrypt_info_cachep;
-int fscrypt_initialize(void);
+int fscrypt_initialize(unsigned int cop_flags);
extern struct fscrypt_ctx *fscrypt_get_ctx(const struct inode *, gfp_t);
extern void fscrypt_release_ctx(struct fscrypt_ctx *);
--
2.10.1
- Improve documentation
- Add BUG_ON(len == 0) to avoid accidental switch of offs and len
parameters
- Improve variable names for readability
Signed-off-by: David Gstir <[email protected]>
---
fs/crypto/crypto.c | 93 +++++++++++++++++++++++++++---------------------
include/linux/fscrypto.h | 8 ++---
2 files changed, 56 insertions(+), 45 deletions(-)
diff --git a/fs/crypto/crypto.c b/fs/crypto/crypto.c
index 8536ac0b50d3..8805ec5d7de2 100644
--- a/fs/crypto/crypto.c
+++ b/fs/crypto/crypto.c
@@ -147,9 +147,9 @@ typedef enum {
} fscrypt_direction_t;
static int do_page_crypto(const struct inode *inode,
- fscrypt_direction_t rw, pgoff_t index,
+ fscrypt_direction_t rw, u64 lblk_num,
struct page *src_page, struct page *dest_page,
- unsigned int src_len, unsigned int src_offset,
+ unsigned int len, unsigned int offs,
gfp_t gfp_flags)
{
struct {
@@ -163,6 +163,8 @@ static int do_page_crypto(const struct inode *inode,
struct crypto_skcipher *tfm = ci->ci_ctfm;
int res = 0;
+ BUG_ON(len == 0);
+
req = skcipher_request_alloc(tfm, gfp_flags);
if (!req) {
printk_ratelimited(KERN_ERR
@@ -176,14 +178,14 @@ static int do_page_crypto(const struct inode *inode,
page_crypt_complete, &ecr);
BUILD_BUG_ON(sizeof(xts_tweak) != FS_XTS_TWEAK_SIZE);
- xts_tweak.index = cpu_to_le64(index);
+ xts_tweak.index = cpu_to_le64(lblk_num);
memset(xts_tweak.padding, 0, sizeof(xts_tweak.padding));
sg_init_table(&dst, 1);
- sg_set_page(&dst, dest_page, src_len, src_offset);
+ sg_set_page(&dst, dest_page, len, offs);
sg_init_table(&src, 1);
- sg_set_page(&src, src_page, src_len, src_offset);
- skcipher_request_set_crypt(req, &src, &dst, src_len, &xts_tweak);
+ sg_set_page(&src, src_page, len, offs);
+ skcipher_request_set_crypt(req, &src, &dst, len, &xts_tweak);
if (rw == FS_DECRYPT)
res = crypto_skcipher_decrypt(req);
else
@@ -214,44 +216,53 @@ static struct page *alloc_bounce_page(struct fscrypt_ctx *ctx, gfp_t gfp_flags)
/**
* fscypt_encrypt_page() - Encrypts a page
- * @inode: The inode for which the encryption should take place
- * @plaintext_page: The page to encrypt. Must be locked.
- * @plaintext_len: Length of plaintext within page
- * @plaintext_offset: Offset of plaintext within page
- * @index: Index for encryption. This is mainly the page index, but
- * but might be different for multiple calls on same page.
- * @gfp_flags: The gfp flag for memory allocation
+ * @inode: The inode for which the encryption should take place
+ * @page: The page to encrypt. Must be locked for bounce-page
+ * encryption.
+ * @len: Length of data to encrypt in @page and encrypted
+ * data in returned page.
+ * @offs: Offset of data within @page and returned
+ * page holding encrypted data.
+ * @lblk_num: Logical block number. This must be unique for multiple
+ * calls with same inode, except when overwriting
+ * previously written data.
+ * @gfp_flags: The gfp flag for memory allocation
*
- * Encrypts plaintext_page using the ctx encryption context. If
- * the filesystem supports it, encryption is performed in-place, otherwise a
- * new ciphertext_page is allocated and returned.
+ * Encrypts @page using the ctx encryption context. Performs encryption
+ * either in-place or into a newly allocated bounce page.
+ * Called on the page write path.
*
- * Called on the page write path. The caller must call
+ * Bounce page allocation is the default.
+ * In this case, the contents of @page are encrypted and stored in an
+ * allocated bounce page. @page has to be locked and the caller must call
* fscrypt_restore_control_page() on the returned ciphertext page to
* release the bounce buffer and the encryption context.
*
- * Return: An allocated page with the encrypted content on success. Else, an
+ * In-place encryption is used by setting the FS_CFLG_INPLACE_ENCRYPTION flag in
+ * fscrypt_operations. Here, the input-page is returned with its content
+ * encrypted.
+ *
+ * Return: A page with the encrypted content on success. Else, an
* error value or NULL.
*/
struct page *fscrypt_encrypt_page(const struct inode *inode,
- struct page *plaintext_page,
- unsigned int plaintext_len,
- unsigned int plaintext_offset,
- pgoff_t index, gfp_t gfp_flags)
+ struct page *page,
+ unsigned int len,
+ unsigned int offs,
+ u64 lblk_num, gfp_t gfp_flags)
{
struct fscrypt_ctx *ctx;
- struct page *ciphertext_page = plaintext_page;
+ struct page *ciphertext_page = page;
int err;
- BUG_ON(plaintext_len % FS_CRYPTO_BLOCK_SIZE != 0);
+ BUG_ON(len % FS_CRYPTO_BLOCK_SIZE != 0);
if (inode->i_sb->s_cop->flags & FS_CFLG_INPLACE_ENCRYPTION) {
/* with inplace-encryption we just encrypt the page */
- err = do_page_crypto(inode, FS_ENCRYPT, index,
- plaintext_page, ciphertext_page,
- plaintext_len, plaintext_offset,
- gfp_flags);
+ err = do_page_crypto(inode, FS_ENCRYPT, lblk_num,
+ page, ciphertext_page,
+ len, offs, gfp_flags);
if (err)
return ERR_PTR(err);
@@ -267,11 +278,10 @@ struct page *fscrypt_encrypt_page(const struct inode *inode,
if (IS_ERR(ciphertext_page))
goto errout;
- ctx->w.control_page = plaintext_page;
- err = do_page_crypto(inode, FS_ENCRYPT, index,
- plaintext_page, ciphertext_page,
- plaintext_len, plaintext_offset,
- gfp_flags);
+ ctx->w.control_page = page;
+ err = do_page_crypto(inode, FS_ENCRYPT, lblk_num,
+ page, ciphertext_page,
+ len, offs, gfp_flags);
if (err) {
ciphertext_page = ERR_PTR(err);
goto errout;
@@ -289,11 +299,12 @@ EXPORT_SYMBOL(fscrypt_encrypt_page);
/**
* fscrypt_decrypt_page() - Decrypts a page in-place
- * @inode: Encrypted inode to decrypt.
- * @page: The page to decrypt. Must be locked.
- * @len: Number of bytes in @page to be decrypted.
- * @offs: Start of data in @page.
- * @index: Index for encryption.
+ * @inode: The corresponding inode for the page to decrypt.
+ * @page: The page to decrypt. Must be locked in case
+ * it is a writeback page.
+ * @len: Number of bytes in @page to be decrypted.
+ * @offs: Start of data in @page.
+ * @lblk_num: Logical block number.
*
* Decrypts page in-place using the ctx encryption context.
*
@@ -302,10 +313,10 @@ EXPORT_SYMBOL(fscrypt_encrypt_page);
* Return: Zero on success, non-zero otherwise.
*/
int fscrypt_decrypt_page(const struct inode *inode, struct page *page,
- unsigned int len, unsigned int offs, pgoff_t index)
+ unsigned int len, unsigned int offs, u64 lblk_num)
{
- return do_page_crypto(inode, FS_DECRYPT, index, page, page, len, offs,
- GFP_NOFS);
+ return do_page_crypto(inode, FS_DECRYPT, lblk_num, page, page, len,
+ offs, GFP_NOFS);
}
EXPORT_SYMBOL(fscrypt_decrypt_page);
diff --git a/include/linux/fscrypto.h b/include/linux/fscrypto.h
index 98c71e973a96..e9648b62eca6 100644
--- a/include/linux/fscrypto.h
+++ b/include/linux/fscrypto.h
@@ -250,9 +250,9 @@ extern struct fscrypt_ctx *fscrypt_get_ctx(const struct inode *, gfp_t);
extern void fscrypt_release_ctx(struct fscrypt_ctx *);
extern struct page *fscrypt_encrypt_page(const struct inode *, struct page *,
unsigned int, unsigned int,
- pgoff_t, gfp_t);
+ u64, gfp_t);
extern int fscrypt_decrypt_page(const struct inode *, struct page *, unsigned int,
- unsigned int, pgoff_t);
+ unsigned int, u64);
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 *);
@@ -299,14 +299,14 @@ static inline struct page *fscrypt_notsupp_encrypt_page(const struct inode *i,
struct page *p,
unsigned int len,
unsigned int offs,
- pgoff_t index, gfp_t f)
+ u64 lblk_num, gfp_t f)
{
return ERR_PTR(-EOPNOTSUPP);
}
static inline int fscrypt_notsupp_decrypt_page(const struct inode *i, struct page *p,
unsigned int len, unsigned int offs,
- pgoff_t index)
+ u64 lblk_num)
{
return -EOPNOTSUPP;
}
--
2.10.1
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 <[email protected]>
---
fs/crypto/crypto.c | 11 ++++++++---
fs/ext4/inode.c | 1 -
fs/f2fs/data.c | 1 -
include/linux/fscrypto.h | 2 +-
4 files changed, 9 insertions(+), 6 deletions(-)
diff --git a/fs/crypto/crypto.c b/fs/crypto/crypto.c
index 8805ec5d7de2..6f5c3a8df70b 100644
--- a/fs/crypto/crypto.c
+++ b/fs/crypto/crypto.c
@@ -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);
}
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 1485ac273bfb..fb2b514f675b 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3744,7 +3744,6 @@ 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);
- BUG_ON(!PageLocked(page));
WARN_ON_ONCE(fscrypt_decrypt_page(page->mapping->host,
page, PAGE_SIZE, 0, page->index));
}
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 435590c4b341..9f0ba90b92e4 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -1194,7 +1194,6 @@ int do_write_data_page(struct f2fs_io_info *fio)
f2fs_wait_on_encrypted_page_writeback(F2FS_I_SB(inode),
fio->old_blkaddr);
retry_encrypt:
- BUG_ON(!PageLocked(fio->page));
fio->encrypted_page = fscrypt_encrypt_page(inode, fio->page,
PAGE_SIZE, 0,
fio->page->index,
diff --git a/include/linux/fscrypto.h b/include/linux/fscrypto.h
index e9648b62eca6..65be74f3afb6 100644
--- a/include/linux/fscrypto.h
+++ b/include/linux/fscrypto.h
@@ -156,7 +156,7 @@ struct fscrypt_name {
/*
* fscrypt superblock flags
*/
-#define FS_CFLG_INPLACE_ENCRYPTION (1U << 1)
+#define FS_CFLG_OWN_PAGES (1U << 1)
/*
* crypto opertions for filesystems
--
2.10.1
In case of in-place encryption fscrypt_ctx was allocated but never
released. Since we don't need it for in-place encryption, we skip
allocating it.
Fixes: 1c7dcf69eea3 ("fscrypt: Add in-place encryption mode")
Signed-off-by: David Gstir <[email protected]>
---
fs/crypto/crypto.c | 30 +++++++++++++++++++-----------
1 file changed, 19 insertions(+), 11 deletions(-)
diff --git a/fs/crypto/crypto.c b/fs/crypto/crypto.c
index 3c1124beae28..8536ac0b50d3 100644
--- a/fs/crypto/crypto.c
+++ b/fs/crypto/crypto.c
@@ -246,16 +246,26 @@ struct page *fscrypt_encrypt_page(const struct inode *inode,
BUG_ON(plaintext_len % FS_CRYPTO_BLOCK_SIZE != 0);
+ if (inode->i_sb->s_cop->flags & FS_CFLG_INPLACE_ENCRYPTION) {
+ /* with inplace-encryption we just encrypt the page */
+ err = do_page_crypto(inode, FS_ENCRYPT, index,
+ plaintext_page, ciphertext_page,
+ plaintext_len, plaintext_offset,
+ gfp_flags);
+ if (err)
+ return ERR_PTR(err);
+
+ return ciphertext_page;
+ }
+
ctx = fscrypt_get_ctx(inode, gfp_flags);
if (IS_ERR(ctx))
return (struct page *)ctx;
- if (!(inode->i_sb->s_cop->flags & FS_CFLG_INPLACE_ENCRYPTION)) {
- /* The encryption operation will require a bounce page. */
- ciphertext_page = alloc_bounce_page(ctx, gfp_flags);
- if (IS_ERR(ciphertext_page))
- goto errout;
- }
+ /* The encryption operation will require a bounce page. */
+ ciphertext_page = alloc_bounce_page(ctx, gfp_flags);
+ if (IS_ERR(ciphertext_page))
+ goto errout;
ctx->w.control_page = plaintext_page;
err = do_page_crypto(inode, FS_ENCRYPT, index,
@@ -266,11 +276,9 @@ struct page *fscrypt_encrypt_page(const struct inode *inode,
ciphertext_page = ERR_PTR(err);
goto errout;
}
- if (!(inode->i_sb->s_cop->flags & FS_CFLG_INPLACE_ENCRYPTION)) {
- SetPagePrivate(ciphertext_page);
- set_page_private(ciphertext_page, (unsigned long)ctx);
- lock_page(ciphertext_page);
- }
+ SetPagePrivate(ciphertext_page);
+ set_page_private(ciphertext_page, (unsigned long)ctx);
+ lock_page(ciphertext_page);
return ciphertext_page;
errout:
--
2.10.1
On Tue, Dec 06, 2016 at 11:53:52PM +0100, David Gstir wrote:
> This series applies on top of Ted's fscrypt tree[0] addresses the review
> comments from Eric.
This patch series have been added to the fsbranch of the ext4.git
tree, thanks.
- Ted