From 58ae74683ae2c07cd717a91799edb50231061938 Mon Sep 17 00:00:00 2001 From: Richard Weinberger Date: Mon, 19 Dec 2016 12:25:32 +0100 Subject: [PATCH] fscrypt: factor out bio specific functions That way we can get rid of the direct dependency on CONFIG_BLOCK. Fixes: d475a507457b ("ubifs: Add skeleton for fscrypto") Reported-by: Arnd Bergmann Reported-by: Randy Dunlap Reviewed-by: Eric Biggers Reviewed-by: Christoph Hellwig Reviewed-by: David Gstir Signed-off-by: Richard Weinberger Signed-off-by: Theodore Ts'o --- 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 +#include +#include +#include +#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 #include #include -#include #include #include #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 */