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Commit 6c24337f authored by Linus Torvalds's avatar Linus Torvalds
Browse files
Pull fscrypt updates from Ted Ts'o:
 "Various cleanups for the file system encryption feature"

* tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/fscrypt:
  fscrypt: constify struct fscrypt_operations
  fscrypt: properly declare on-stack completion
  fscrypt: split supp and notsupp declarations into their own headers
  fscrypt: remove redundant assignment of res
  fscrypt: make fscrypt_operations.key_prefix a string
  fscrypt: remove unused 'mode' member of fscrypt_ctx
  ext4: don't allow encrypted operations without keys
  fscrypt: make test_dummy_encryption require a keyring key
  fscrypt: factor out bio specific functions
  fscrypt: pass up error codes from ->get_context()
  fscrypt: remove user-triggerable warning messages
  fscrypt: use EEXIST when file already uses different policy
  fscrypt: use ENOTDIR when setting encryption policy on nondirectory
  fscrypt: use ENOKEY when file cannot be created w/o key
parents 786856b6 6f69f0ed
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+1 −1
Original line number Diff line number Diff line
@@ -5281,7 +5281,7 @@ M: Jaegeuk Kim <jaegeuk@kernel.org>
L:	linux-fsdevel@vger.kernel.org
S:	Supported
F:	fs/crypto/
F:	include/linux/fscrypto.h
F:	include/linux/fscrypt*.h

F2FS FILE SYSTEM
M:	Jaegeuk Kim <jaegeuk@kernel.org>
+0 −1
Original line number Diff line number Diff line
config FS_ENCRYPTION
	tristate "FS Encryption (Per-file encryption)"
	depends on BLOCK
	select CRYPTO
	select CRYPTO_AES
	select CRYPTO_CBC
+1 −0
Original line number Diff line number Diff line
obj-$(CONFIG_FS_ENCRYPTION)	+= fscrypto.o

fscrypto-y := crypto.o fname.o policy.o keyinfo.o
fscrypto-$(CONFIG_BLOCK) += bio.o

fs/crypto/bio.c

0 → 100644
+145 −0
Original line number Diff line number Diff line
/*
 * 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);
+16 −141
Original line number Diff line number Diff line
@@ -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;
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