[PATCH v2] fscrypt: Factor out bio specific functions
Richard Weinberger
richard at nod.at
Mon Dec 19 03:25:32 PST 2016
That way we can get rid of the direct dependency on CONFIG_BLOCK.
Reported-by: Arnd Bergmann <arnd at arndb.de>
Reported-by: Randy Dunlap <rdunlap at infradead.org>
Suggested-by: Christoph Hellwig <hch at infradead.org>
Fixes: d475a507457b ("ubifs: Add skeleton for fscrypto")
Signed-off-by: Richard Weinberger <richard at nod.at>
---
Changes since v1:
- Moved fscrypt_zeroout_range() also to bio.c
---
fs/crypto/Kconfig | 1 -
fs/crypto/Makefile | 1 +
fs/crypto/bio.c | 145 ++++++++++++++++++++++++++++++++++++++++
fs/crypto/crypto.c | 157 +++++---------------------------------------
fs/crypto/fscrypt_private.h | 16 ++++-
include/linux/fscrypto.h | 11 ++--
6 files changed, 184 insertions(+), 147 deletions(-)
create mode 100644 fs/crypto/bio.c
diff --git a/fs/crypto/Kconfig b/fs/crypto/Kconfig
index f514978f6688..08b46e6e3995 100644
--- a/fs/crypto/Kconfig
+++ b/fs/crypto/Kconfig
@@ -1,6 +1,5 @@
config FS_ENCRYPTION
tristate "FS Encryption (Per-file encryption)"
- depends on BLOCK
select CRYPTO
select CRYPTO_AES
select CRYPTO_CBC
diff --git a/fs/crypto/Makefile b/fs/crypto/Makefile
index f17684c48739..9f6607f17b53 100644
--- a/fs/crypto/Makefile
+++ b/fs/crypto/Makefile
@@ -1,3 +1,4 @@
obj-$(CONFIG_FS_ENCRYPTION) += fscrypto.o
fscrypto-y := crypto.o fname.o policy.o keyinfo.o
+fscrypto-$(CONFIG_BLOCK) += bio.o
diff --git a/fs/crypto/bio.c b/fs/crypto/bio.c
new file mode 100644
index 000000000000..a409a84f1bca
--- /dev/null
+++ b/fs/crypto/bio.c
@@ -0,0 +1,145 @@
+/*
+ * This contains encryption functions for per-file encryption.
+ *
+ * Copyright (C) 2015, Google, Inc.
+ * Copyright (C) 2015, Motorola Mobility
+ *
+ * Written by Michael Halcrow, 2014.
+ *
+ * Filename encryption additions
+ * Uday Savagaonkar, 2014
+ * Encryption policy handling additions
+ * Ildar Muslukhov, 2014
+ * Add fscrypt_pullback_bio_page()
+ * Jaegeuk Kim, 2015.
+ *
+ * This has not yet undergone a rigorous security audit.
+ *
+ * The usage of AES-XTS should conform to recommendations in NIST
+ * Special Publication 800-38E and IEEE P1619/D16.
+ */
+
+#include <linux/pagemap.h>
+#include <linux/module.h>
+#include <linux/bio.h>
+#include <linux/namei.h>
+#include "fscrypt_private.h"
+
+/*
+ * Call fscrypt_decrypt_page on every single page, reusing the encryption
+ * context.
+ */
+static void completion_pages(struct work_struct *work)
+{
+ struct fscrypt_ctx *ctx =
+ container_of(work, struct fscrypt_ctx, r.work);
+ struct bio *bio = ctx->r.bio;
+ struct bio_vec *bv;
+ int i;
+
+ bio_for_each_segment_all(bv, bio, i) {
+ struct page *page = bv->bv_page;
+ int ret = fscrypt_decrypt_page(page->mapping->host, page,
+ PAGE_SIZE, 0, page->index);
+
+ if (ret) {
+ WARN_ON_ONCE(1);
+ SetPageError(page);
+ } else {
+ SetPageUptodate(page);
+ }
+ unlock_page(page);
+ }
+ fscrypt_release_ctx(ctx);
+ bio_put(bio);
+}
+
+void fscrypt_decrypt_bio_pages(struct fscrypt_ctx *ctx, struct bio *bio)
+{
+ INIT_WORK(&ctx->r.work, completion_pages);
+ ctx->r.bio = bio;
+ queue_work(fscrypt_read_workqueue, &ctx->r.work);
+}
+EXPORT_SYMBOL(fscrypt_decrypt_bio_pages);
+
+void fscrypt_pullback_bio_page(struct page **page, bool restore)
+{
+ struct fscrypt_ctx *ctx;
+ struct page *bounce_page;
+
+ /* The bounce data pages are unmapped. */
+ if ((*page)->mapping)
+ return;
+
+ /* The bounce data page is unmapped. */
+ bounce_page = *page;
+ ctx = (struct fscrypt_ctx *)page_private(bounce_page);
+
+ /* restore control page */
+ *page = ctx->w.control_page;
+
+ if (restore)
+ fscrypt_restore_control_page(bounce_page);
+}
+EXPORT_SYMBOL(fscrypt_pullback_bio_page);
+
+int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk,
+ sector_t pblk, unsigned int len)
+{
+ struct fscrypt_ctx *ctx;
+ struct page *ciphertext_page = NULL;
+ struct bio *bio;
+ int ret, err = 0;
+
+ BUG_ON(inode->i_sb->s_blocksize != PAGE_SIZE);
+
+ ctx = fscrypt_get_ctx(inode, GFP_NOFS);
+ if (IS_ERR(ctx))
+ return PTR_ERR(ctx);
+
+ ciphertext_page = fscrypt_alloc_bounce_page(ctx, GFP_NOWAIT);
+ if (IS_ERR(ciphertext_page)) {
+ err = PTR_ERR(ciphertext_page);
+ goto errout;
+ }
+
+ while (len--) {
+ err = fscrypt_do_page_crypto(inode, FS_ENCRYPT, lblk,
+ ZERO_PAGE(0), ciphertext_page,
+ PAGE_SIZE, 0, GFP_NOFS);
+ if (err)
+ goto errout;
+
+ bio = bio_alloc(GFP_NOWAIT, 1);
+ if (!bio) {
+ err = -ENOMEM;
+ goto errout;
+ }
+ bio->bi_bdev = inode->i_sb->s_bdev;
+ bio->bi_iter.bi_sector =
+ pblk << (inode->i_sb->s_blocksize_bits - 9);
+ bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
+ ret = bio_add_page(bio, ciphertext_page,
+ inode->i_sb->s_blocksize, 0);
+ if (ret != inode->i_sb->s_blocksize) {
+ /* should never happen! */
+ WARN_ON(1);
+ bio_put(bio);
+ err = -EIO;
+ goto errout;
+ }
+ err = submit_bio_wait(bio);
+ if ((err == 0) && bio->bi_error)
+ err = -EIO;
+ bio_put(bio);
+ if (err)
+ goto errout;
+ lblk++;
+ pblk++;
+ }
+ err = 0;
+errout:
+ fscrypt_release_ctx(ctx);
+ return err;
+}
+EXPORT_SYMBOL(fscrypt_zeroout_range);
diff --git a/fs/crypto/crypto.c b/fs/crypto/crypto.c
index ac8e4f6a3773..02a7a9286449 100644
--- a/fs/crypto/crypto.c
+++ b/fs/crypto/crypto.c
@@ -24,7 +24,6 @@
#include <linux/module.h>
#include <linux/scatterlist.h>
#include <linux/ratelimit.h>
-#include <linux/bio.h>
#include <linux/dcache.h>
#include <linux/namei.h>
#include "fscrypt_private.h"
@@ -44,7 +43,7 @@ static mempool_t *fscrypt_bounce_page_pool = NULL;
static LIST_HEAD(fscrypt_free_ctxs);
static DEFINE_SPINLOCK(fscrypt_ctx_lock);
-static struct workqueue_struct *fscrypt_read_workqueue;
+struct workqueue_struct *fscrypt_read_workqueue;
static DEFINE_MUTEX(fscrypt_init_mutex);
static struct kmem_cache *fscrypt_ctx_cachep;
@@ -141,16 +140,10 @@ static void page_crypt_complete(struct crypto_async_request *req, int res)
complete(&ecr->completion);
}
-typedef enum {
- FS_DECRYPT = 0,
- FS_ENCRYPT,
-} fscrypt_direction_t;
-
-static int do_page_crypto(const struct inode *inode,
- fscrypt_direction_t rw, u64 lblk_num,
- struct page *src_page, struct page *dest_page,
- unsigned int len, unsigned int offs,
- gfp_t gfp_flags)
+int fscrypt_do_page_crypto(const struct inode *inode, fscrypt_direction_t rw,
+ u64 lblk_num, struct page *src_page,
+ struct page *dest_page, unsigned int len,
+ unsigned int offs, gfp_t gfp_flags)
{
struct {
__le64 index;
@@ -205,7 +198,8 @@ static int do_page_crypto(const struct inode *inode,
return 0;
}
-static struct page *alloc_bounce_page(struct fscrypt_ctx *ctx, gfp_t gfp_flags)
+struct page *fscrypt_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)
@@ -260,9 +254,9 @@ struct page *fscrypt_encrypt_page(const struct inode *inode,
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,
- len, offs, gfp_flags);
+ err = fscrypt_do_page_crypto(inode, FS_ENCRYPT, lblk_num, page,
+ ciphertext_page, len, offs,
+ gfp_flags);
if (err)
return ERR_PTR(err);
@@ -276,14 +270,14 @@ struct page *fscrypt_encrypt_page(const struct inode *inode,
return (struct page *)ctx;
/* The encryption operation will require a bounce page. */
- ciphertext_page = alloc_bounce_page(ctx, gfp_flags);
+ ciphertext_page = fscrypt_alloc_bounce_page(ctx, gfp_flags);
if (IS_ERR(ciphertext_page))
goto errout;
ctx->w.control_page = page;
- err = do_page_crypto(inode, FS_ENCRYPT, lblk_num,
- page, ciphertext_page,
- len, offs, gfp_flags);
+ err = fscrypt_do_page_crypto(inode, FS_ENCRYPT, lblk_num,
+ page, ciphertext_page, len, offs,
+ gfp_flags);
if (err) {
ciphertext_page = ERR_PTR(err);
goto errout;
@@ -320,72 +314,11 @@ int fscrypt_decrypt_page(const struct inode *inode, struct page *page,
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);
+ return fscrypt_do_page_crypto(inode, FS_DECRYPT, lblk_num, page, page,
+ len, offs, GFP_NOFS);
}
EXPORT_SYMBOL(fscrypt_decrypt_page);
-int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk,
- sector_t pblk, unsigned int len)
-{
- struct fscrypt_ctx *ctx;
- struct page *ciphertext_page = NULL;
- struct bio *bio;
- int ret, err = 0;
-
- BUG_ON(inode->i_sb->s_blocksize != PAGE_SIZE);
-
- ctx = fscrypt_get_ctx(inode, GFP_NOFS);
- if (IS_ERR(ctx))
- return PTR_ERR(ctx);
-
- ciphertext_page = alloc_bounce_page(ctx, GFP_NOWAIT);
- if (IS_ERR(ciphertext_page)) {
- err = PTR_ERR(ciphertext_page);
- goto errout;
- }
-
- while (len--) {
- err = do_page_crypto(inode, FS_ENCRYPT, lblk,
- ZERO_PAGE(0), ciphertext_page,
- PAGE_SIZE, 0, GFP_NOFS);
- if (err)
- goto errout;
-
- bio = bio_alloc(GFP_NOWAIT, 1);
- if (!bio) {
- err = -ENOMEM;
- goto errout;
- }
- bio->bi_bdev = inode->i_sb->s_bdev;
- bio->bi_iter.bi_sector =
- pblk << (inode->i_sb->s_blocksize_bits - 9);
- bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
- ret = bio_add_page(bio, ciphertext_page,
- inode->i_sb->s_blocksize, 0);
- if (ret != inode->i_sb->s_blocksize) {
- /* should never happen! */
- WARN_ON(1);
- bio_put(bio);
- err = -EIO;
- goto errout;
- }
- err = submit_bio_wait(bio);
- if ((err == 0) && bio->bi_error)
- err = -EIO;
- bio_put(bio);
- if (err)
- goto errout;
- lblk++;
- pblk++;
- }
- err = 0;
-errout:
- fscrypt_release_ctx(ctx);
- return err;
-}
-EXPORT_SYMBOL(fscrypt_zeroout_range);
-
/*
* Validate dentries for encrypted directories to make sure we aren't
* potentially caching stale data after a key has been added or
@@ -442,64 +375,6 @@ const struct dentry_operations fscrypt_d_ops = {
};
EXPORT_SYMBOL(fscrypt_d_ops);
-/*
- * Call fscrypt_decrypt_page on every single page, reusing the encryption
- * context.
- */
-static void completion_pages(struct work_struct *work)
-{
- struct fscrypt_ctx *ctx =
- container_of(work, struct fscrypt_ctx, r.work);
- struct bio *bio = ctx->r.bio;
- struct bio_vec *bv;
- int i;
-
- bio_for_each_segment_all(bv, bio, i) {
- struct page *page = bv->bv_page;
- int ret = fscrypt_decrypt_page(page->mapping->host, page,
- PAGE_SIZE, 0, page->index);
-
- if (ret) {
- WARN_ON_ONCE(1);
- SetPageError(page);
- } else {
- SetPageUptodate(page);
- }
- unlock_page(page);
- }
- fscrypt_release_ctx(ctx);
- bio_put(bio);
-}
-
-void fscrypt_decrypt_bio_pages(struct fscrypt_ctx *ctx, struct bio *bio)
-{
- INIT_WORK(&ctx->r.work, completion_pages);
- ctx->r.bio = bio;
- queue_work(fscrypt_read_workqueue, &ctx->r.work);
-}
-EXPORT_SYMBOL(fscrypt_decrypt_bio_pages);
-
-void fscrypt_pullback_bio_page(struct page **page, bool restore)
-{
- struct fscrypt_ctx *ctx;
- struct page *bounce_page;
-
- /* The bounce data pages are unmapped. */
- if ((*page)->mapping)
- return;
-
- /* The bounce data page is unmapped. */
- bounce_page = *page;
- ctx = (struct fscrypt_ctx *)page_private(bounce_page);
-
- /* restore control page */
- *page = ctx->w.control_page;
-
- if (restore)
- fscrypt_restore_control_page(bounce_page);
-}
-EXPORT_SYMBOL(fscrypt_pullback_bio_page);
-
void fscrypt_restore_control_page(struct page *page)
{
struct fscrypt_ctx *ctx;
diff --git a/fs/crypto/fscrypt_private.h b/fs/crypto/fscrypt_private.h
index aeab032d7d35..7bff7b4c7498 100644
--- a/fs/crypto/fscrypt_private.h
+++ b/fs/crypto/fscrypt_private.h
@@ -71,6 +71,11 @@ struct fscrypt_info {
u8 ci_master_key[FS_KEY_DESCRIPTOR_SIZE];
};
+typedef enum {
+ FS_DECRYPT = 0,
+ FS_ENCRYPT,
+} fscrypt_direction_t;
+
#define FS_CTX_REQUIRES_FREE_ENCRYPT_FL 0x00000001
#define FS_CTX_HAS_BOUNCE_BUFFER_FL 0x00000002
@@ -85,7 +90,16 @@ struct fscrypt_completion_result {
/* crypto.c */
-int fscrypt_initialize(unsigned int cop_flags);
+extern int fscrypt_initialize(unsigned int cop_flags);
+extern struct workqueue_struct *fscrypt_read_workqueue;
+extern int fscrypt_do_page_crypto(const struct inode *inode,
+ fscrypt_direction_t rw, u64 lblk_num,
+ struct page *src_page,
+ struct page *dest_page,
+ unsigned int len, unsigned int offs,
+ gfp_t gfp_flags);
+extern struct page *fscrypt_alloc_bounce_page(struct fscrypt_ctx *ctx,
+ gfp_t gfp_flags);
/* keyinfo.c */
extern int fscrypt_get_crypt_info(struct inode *);
diff --git a/include/linux/fscrypto.h b/include/linux/fscrypto.h
index c074b670aa99..2a2815702095 100644
--- a/include/linux/fscrypto.h
+++ b/include/linux/fscrypto.h
@@ -174,11 +174,8 @@ extern struct page *fscrypt_encrypt_page(const struct inode *, struct page *,
u64, gfp_t);
extern int fscrypt_decrypt_page(const struct inode *, struct page *, unsigned int,
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 *);
-extern int fscrypt_zeroout_range(const struct inode *, pgoff_t, sector_t,
- unsigned int);
+
/* policy.c */
extern int fscrypt_ioctl_set_policy(struct file *, const void __user *);
extern int fscrypt_ioctl_get_policy(struct file *, void __user *);
@@ -201,6 +198,12 @@ extern int fscrypt_fname_disk_to_usr(struct inode *, u32, u32,
const struct fscrypt_str *, struct fscrypt_str *);
extern int fscrypt_fname_usr_to_disk(struct inode *, const struct qstr *,
struct fscrypt_str *);
+
+/* bio.c */
+extern void fscrypt_decrypt_bio_pages(struct fscrypt_ctx *, struct bio *);
+extern void fscrypt_pullback_bio_page(struct page **, bool);
+extern int fscrypt_zeroout_range(const struct inode *, pgoff_t, sector_t,
+ unsigned int);
#endif
/* crypto.c */
--
2.10.2
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