diff --git a/Documentation/filesystems/fscrypt.rst b/Documentation/filesystems/fscrypt.rst
index 08c23b60e016471426700c34bca864b7dfc244a5..82efa41b0e6c02eccfe4620a07e0ffa4f693dbb3 100644
--- a/Documentation/filesystems/fscrypt.rst
+++ b/Documentation/filesystems/fscrypt.rst
@@ -191,7 +191,9 @@ Currently, the following pairs of encryption modes are supported:
If unsure, you should use the (AES-256-XTS, AES-256-CTS-CBC) pair.
AES-128-CBC was added only for low-powered embedded devices with
-crypto accelerators such as CAAM or CESA that do not support XTS.
+crypto accelerators such as CAAM or CESA that do not support XTS. To
+use AES-128-CBC, CONFIG_CRYPTO_SHA256 (or another SHA-256
+implementation) must be enabled so that ESSIV can be used.
Adiantum is a (primarily) stream cipher-based mode that is fast even
on CPUs without dedicated crypto instructions. It's also a true
@@ -647,3 +649,42 @@ Note that the precise way that filenames are presented to userspace
without the key is subject to change in the future. It is only meant
as a way to temporarily present valid filenames so that commands like
``rm -r`` work as expected on encrypted directories.
+
+Tests
+=====
+
+To test fscrypt, use xfstests, which is Linux's de facto standard
+filesystem test suite. First, run all the tests in the "encrypt"
+group on the relevant filesystem(s). For example, to test ext4 and
+f2fs encryption using `kvm-xfstests
+<https://github.com/tytso/xfstests-bld/blob/master/Documentation/kvm-quickstart.md>`_::
+
+ kvm-xfstests -c ext4,f2fs -g encrypt
+
+UBIFS encryption can also be tested this way, but it should be done in
+a separate command, and it takes some time for kvm-xfstests to set up
+emulated UBI volumes::
+
+ kvm-xfstests -c ubifs -g encrypt
+
+No tests should fail. However, tests that use non-default encryption
+modes (e.g. generic/549 and generic/550) will be skipped if the needed
+algorithms were not built into the kernel's crypto API. Also, tests
+that access the raw block device (e.g. generic/399, generic/548,
+generic/549, generic/550) will be skipped on UBIFS.
+
+Besides running the "encrypt" group tests, for ext4 and f2fs it's also
+possible to run most xfstests with the "test_dummy_encryption" mount
+option. This option causes all new files to be automatically
+encrypted with a dummy key, without having to make any API calls.
+This tests the encrypted I/O paths more thoroughly. To do this with
+kvm-xfstests, use the "encrypt" filesystem configuration::
+
+ kvm-xfstests -c ext4/encrypt,f2fs/encrypt -g auto
+
+Because this runs many more tests than "-g encrypt" does, it takes
+much longer to run; so also consider using `gce-xfstests
+<https://github.com/tytso/xfstests-bld/blob/master/Documentation/gce-xfstests.md>`_
+instead of kvm-xfstests::
+
+ gce-xfstests -c ext4/encrypt,f2fs/encrypt -g auto
diff --git a/fs/crypto/Kconfig b/fs/crypto/Kconfig
index 24ed99e2eca0b21867cc8e2df487e4a473b69a34..5fdf24877c17854de67a39377026bacf3355e6fd 100644
--- a/fs/crypto/Kconfig
+++ b/fs/crypto/Kconfig
@@ -7,7 +7,6 @@ config FS_ENCRYPTION
select CRYPTO_ECB
select CRYPTO_XTS
select CRYPTO_CTS
- select CRYPTO_SHA256
select KEYS
help
Enable encryption of files and directories. This
diff --git a/fs/crypto/bio.c b/fs/crypto/bio.c
index b46021ebde856b5449296a160406d627b502ab06..82da2510721f6b7189af9026a2854c8dbe089c40 100644
--- a/fs/crypto/bio.c
+++ b/fs/crypto/bio.c
@@ -33,9 +33,8 @@ static void __fscrypt_decrypt_bio(struct bio *bio, bool done)
bio_for_each_segment_all(bv, bio, iter_all) {
struct page *page = bv->bv_page;
- int ret = fscrypt_decrypt_page(page->mapping->host, page,
- PAGE_SIZE, 0, page->index);
-
+ int ret = fscrypt_decrypt_pagecache_blocks(page, bv->bv_len,
+ bv->bv_offset);
if (ret)
SetPageError(page);
else if (done)
@@ -53,9 +52,8 @@ EXPORT_SYMBOL(fscrypt_decrypt_bio);
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 fscrypt_ctx *ctx = container_of(work, struct fscrypt_ctx, work);
+ struct bio *bio = ctx->bio;
__fscrypt_decrypt_bio(bio, true);
fscrypt_release_ctx(ctx);
@@ -64,57 +62,29 @@ static void completion_pages(struct work_struct *work)
void fscrypt_enqueue_decrypt_bio(struct fscrypt_ctx *ctx, struct bio *bio)
{
- INIT_WORK(&ctx->r.work, completion_pages);
- ctx->r.bio = bio;
- fscrypt_enqueue_decrypt_work(&ctx->r.work);
+ INIT_WORK(&ctx->work, completion_pages);
+ ctx->bio = bio;
+ fscrypt_enqueue_decrypt_work(&ctx->work);
}
EXPORT_SYMBOL(fscrypt_enqueue_decrypt_bio);
-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;
+ const unsigned int blockbits = inode->i_blkbits;
+ const unsigned int blocksize = 1 << blockbits;
+ struct page *ciphertext_page;
struct bio *bio;
int ret, err = 0;
- BUG_ON(inode->i_sb->s_blocksize != PAGE_SIZE);
-
- ctx = fscrypt_get_ctx(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;
- }
+ ciphertext_page = fscrypt_alloc_bounce_page(GFP_NOWAIT);
+ if (!ciphertext_page)
+ return -ENOMEM;
while (len--) {
- err = fscrypt_do_page_crypto(inode, FS_ENCRYPT, lblk,
- ZERO_PAGE(0), ciphertext_page,
- PAGE_SIZE, 0, GFP_NOFS);
+ err = fscrypt_crypt_block(inode, FS_ENCRYPT, lblk,
+ ZERO_PAGE(0), ciphertext_page,
+ blocksize, 0, GFP_NOFS);
if (err)
goto errout;
@@ -124,14 +94,11 @@ int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk,
goto errout;
}
bio_set_dev(bio, inode->i_sb->s_bdev);
- bio->bi_iter.bi_sector =
- pblk << (inode->i_sb->s_blocksize_bits - 9);
+ bio->bi_iter.bi_sector = pblk << (blockbits - 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) {
+ ret = bio_add_page(bio, ciphertext_page, blocksize, 0);
+ if (WARN_ON(ret != blocksize)) {
/* should never happen! */
- WARN_ON(1);
bio_put(bio);
err = -EIO;
goto errout;
@@ -147,7 +114,7 @@ int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk,
}
err = 0;
errout:
- fscrypt_release_ctx(ctx);
+ fscrypt_free_bounce_page(ciphertext_page);
return err;
}
EXPORT_SYMBOL(fscrypt_zeroout_range);
diff --git a/fs/crypto/crypto.c b/fs/crypto/crypto.c
index 335a362ee4468986a6a9483f6230881bd53ddc74..45c3d0427fb253796457bf9591d32912be88a8e8 100644
--- a/fs/crypto/crypto.c
+++ b/fs/crypto/crypto.c
@@ -59,23 +59,16 @@ void fscrypt_enqueue_decrypt_work(struct work_struct *work)
EXPORT_SYMBOL(fscrypt_enqueue_decrypt_work);
/**
- * fscrypt_release_ctx() - Releases an encryption context
- * @ctx: The encryption context to release.
+ * fscrypt_release_ctx() - Release a decryption context
+ * @ctx: The decryption context to release.
*
- * If the encryption context was allocated from the pre-allocated pool, returns
- * it to that pool. Else, frees it.
- *
- * If there's a bounce page in the context, this frees that.
+ * If the decryption context was allocated from the pre-allocated pool, return
+ * it to that pool. Else, free it.
*/
void fscrypt_release_ctx(struct fscrypt_ctx *ctx)
{
unsigned long flags;
- 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;
- }
- ctx->w.control_page = NULL;
if (ctx->flags & FS_CTX_REQUIRES_FREE_ENCRYPT_FL) {
kmem_cache_free(fscrypt_ctx_cachep, ctx);
} else {
@@ -87,12 +80,12 @@ void fscrypt_release_ctx(struct fscrypt_ctx *ctx)
EXPORT_SYMBOL(fscrypt_release_ctx);
/**
- * fscrypt_get_ctx() - Gets an encryption context
+ * fscrypt_get_ctx() - Get a decryption context
* @gfp_flags: The gfp flag for memory allocation
*
- * Allocates and initializes an encryption context.
+ * Allocate and initialize a decryption context.
*
- * Return: A new encryption context on success; an ERR_PTR() otherwise.
+ * Return: A new decryption context on success; an ERR_PTR() otherwise.
*/
struct fscrypt_ctx *fscrypt_get_ctx(gfp_t gfp_flags)
{
@@ -100,14 +93,8 @@ struct fscrypt_ctx *fscrypt_get_ctx(gfp_t gfp_flags)
unsigned long flags;
/*
- * We first try getting the ctx from a free list because in
- * the common case the ctx will have an allocated and
- * initialized crypto tfm, so it's probably a worthwhile
- * optimization. For the bounce page, we first try getting it
- * from the kernel allocator because that's just about as fast
- * as getting it from a list and because a cache of free pages
- * should generally be a "last resort" option for a filesystem
- * to be able to do its job.
+ * First try getting a ctx from the free list so that we don't have to
+ * call into the slab allocator.
*/
spin_lock_irqsave(&fscrypt_ctx_lock, flags);
ctx = list_first_entry_or_null(&fscrypt_free_ctxs,
@@ -123,11 +110,31 @@ struct fscrypt_ctx *fscrypt_get_ctx(gfp_t gfp_flags)
} else {
ctx->flags &= ~FS_CTX_REQUIRES_FREE_ENCRYPT_FL;
}
- ctx->flags &= ~FS_CTX_HAS_BOUNCE_BUFFER_FL;
return ctx;
}
EXPORT_SYMBOL(fscrypt_get_ctx);
+struct page *fscrypt_alloc_bounce_page(gfp_t gfp_flags)
+{
+ return mempool_alloc(fscrypt_bounce_page_pool, gfp_flags);
+}
+
+/**
+ * fscrypt_free_bounce_page() - free a ciphertext bounce page
+ *
+ * Free a bounce page that was allocated by fscrypt_encrypt_pagecache_blocks(),
+ * or by fscrypt_alloc_bounce_page() directly.
+ */
+void fscrypt_free_bounce_page(struct page *bounce_page)
+{
+ if (!bounce_page)
+ return;
+ set_page_private(bounce_page, (unsigned long)NULL);
+ ClearPagePrivate(bounce_page);
+ mempool_free(bounce_page, fscrypt_bounce_page_pool);
+}
+EXPORT_SYMBOL(fscrypt_free_bounce_page);
+
void fscrypt_generate_iv(union fscrypt_iv *iv, u64 lblk_num,
const struct fscrypt_info *ci)
{
@@ -141,10 +148,11 @@ void fscrypt_generate_iv(union fscrypt_iv *iv, u64 lblk_num,
crypto_cipher_encrypt_one(ci->ci_essiv_tfm, iv->raw, iv->raw);
}
-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)
+/* Encrypt or decrypt a single filesystem block of file contents */
+int fscrypt_crypt_block(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)
{
union fscrypt_iv iv;
struct skcipher_request *req = NULL;
@@ -154,7 +162,10 @@ int fscrypt_do_page_crypto(const struct inode *inode, fscrypt_direction_t rw,
struct crypto_skcipher *tfm = ci->ci_ctfm;
int res = 0;
- BUG_ON(len == 0);
+ if (WARN_ON_ONCE(len <= 0))
+ return -EINVAL;
+ if (WARN_ON_ONCE(len % FS_CRYPTO_BLOCK_SIZE != 0))
+ return -EINVAL;
fscrypt_generate_iv(&iv, lblk_num, ci);
@@ -186,126 +197,158 @@ int fscrypt_do_page_crypto(const struct inode *inode, fscrypt_direction_t rw,
return 0;
}
-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)
- return ERR_PTR(-ENOMEM);
- ctx->flags |= FS_CTX_HAS_BOUNCE_BUFFER_FL;
- return ctx->w.bounce_page;
-}
-
/**
- * fscypt_encrypt_page() - Encrypts a page
- * @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 @page using the ctx encryption context. Performs encryption
- * either in-place or into a newly allocated bounce page.
- * Called on the page write path.
+ * fscrypt_encrypt_pagecache_blocks() - Encrypt filesystem blocks from a pagecache page
+ * @page: The locked pagecache page containing the block(s) to encrypt
+ * @len: Total size of the block(s) to encrypt. Must be a nonzero
+ * multiple of the filesystem's block size.
+ * @offs: Byte offset within @page of the first block to encrypt. Must be
+ * a multiple of the filesystem's block size.
+ * @gfp_flags: Memory allocation flags
*
- * 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.
+ * A new bounce page is allocated, and the specified block(s) are encrypted into
+ * it. In the bounce page, the ciphertext block(s) will be located at the same
+ * offsets at which the plaintext block(s) were located in the source page; any
+ * other parts of the bounce page will be left uninitialized. However, normally
+ * blocksize == PAGE_SIZE and the whole page is encrypted at once.
*
- * 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.
+ * This is for use by the filesystem's ->writepages() method.
*
- * Return: A page with the encrypted content on success. Else, an
- * error value or NULL.
+ * Return: the new encrypted bounce page on success; an ERR_PTR() on failure
*/
-struct page *fscrypt_encrypt_page(const struct inode *inode,
- struct page *page,
- unsigned int len,
- unsigned int offs,
- u64 lblk_num, gfp_t gfp_flags)
+struct page *fscrypt_encrypt_pagecache_blocks(struct page *page,
+ unsigned int len,
+ unsigned int offs,
+ gfp_t gfp_flags)
{
- struct fscrypt_ctx *ctx;
- struct page *ciphertext_page = page;
+ const struct inode *inode = page->mapping->host;
+ const unsigned int blockbits = inode->i_blkbits;
+ const unsigned int blocksize = 1 << blockbits;
+ struct page *ciphertext_page;
+ u64 lblk_num = ((u64)page->index << (PAGE_SHIFT - blockbits)) +
+ (offs >> blockbits);
+ unsigned int i;
int err;
- BUG_ON(len % FS_CRYPTO_BLOCK_SIZE != 0);
+ if (WARN_ON_ONCE(!PageLocked(page)))
+ return ERR_PTR(-EINVAL);
- if (inode->i_sb->s_cop->flags & FS_CFLG_OWN_PAGES) {
- /* with inplace-encryption we just encrypt the page */
- err = fscrypt_do_page_crypto(inode, FS_ENCRYPT, lblk_num, page,
- ciphertext_page, len, offs,
- gfp_flags);
- if (err)
- return ERR_PTR(err);
+ if (WARN_ON_ONCE(len <= 0 || !IS_ALIGNED(len | offs, blocksize)))
+ return ERR_PTR(-EINVAL);
- return ciphertext_page;
- }
-
- BUG_ON(!PageLocked(page));
-
- ctx = fscrypt_get_ctx(gfp_flags);
- if (IS_ERR(ctx))
- return ERR_CAST(ctx);
-
- /* The encryption operation will require a bounce page. */
- ciphertext_page = fscrypt_alloc_bounce_page(ctx, gfp_flags);
- if (IS_ERR(ciphertext_page))
- goto errout;
+ ciphertext_page = fscrypt_alloc_bounce_page(gfp_flags);
+ if (!ciphertext_page)
+ return ERR_PTR(-ENOMEM);
- ctx->w.control_page = page;
- 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;
+ for (i = offs; i < offs + len; i += blocksize, lblk_num++) {
+ err = fscrypt_crypt_block(inode, FS_ENCRYPT, lblk_num,
+ page, ciphertext_page,
+ blocksize, i, gfp_flags);
+ if (err) {
+ fscrypt_free_bounce_page(ciphertext_page);
+ return ERR_PTR(err);
+ }
}
SetPagePrivate(ciphertext_page);
- set_page_private(ciphertext_page, (unsigned long)ctx);
- lock_page(ciphertext_page);
+ set_page_private(ciphertext_page, (unsigned long)page);
return ciphertext_page;
+}
+EXPORT_SYMBOL(fscrypt_encrypt_pagecache_blocks);
-errout:
- fscrypt_release_ctx(ctx);
- return ciphertext_page;
+/**
+ * fscrypt_encrypt_block_inplace() - Encrypt a filesystem block in-place
+ * @inode: The inode to which this block belongs
+ * @page: The page containing the block to encrypt
+ * @len: Size of block to encrypt. Doesn't need to be a multiple of the
+ * fs block size, but must be a multiple of FS_CRYPTO_BLOCK_SIZE.
+ * @offs: Byte offset within @page at which the block to encrypt begins
+ * @lblk_num: Filesystem logical block number of the block, i.e. the 0-based
+ * number of the block within the file
+ * @gfp_flags: Memory allocation flags
+ *
+ * Encrypt a possibly-compressed filesystem block that is located in an
+ * arbitrary page, not necessarily in the original pagecache page. The @inode
+ * and @lblk_num must be specified, as they can't be determined from @page.
+ *
+ * Return: 0 on success; -errno on failure
+ */
+int fscrypt_encrypt_block_inplace(const struct inode *inode, struct page *page,
+ unsigned int len, unsigned int offs,
+ u64 lblk_num, gfp_t gfp_flags)
+{
+ return fscrypt_crypt_block(inode, FS_ENCRYPT, lblk_num, page, page,
+ len, offs, gfp_flags);
}
-EXPORT_SYMBOL(fscrypt_encrypt_page);
+EXPORT_SYMBOL(fscrypt_encrypt_block_inplace);
/**
- * 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 (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.
+ * fscrypt_decrypt_pagecache_blocks() - Decrypt filesystem blocks in a pagecache page
+ * @page: The locked pagecache page containing the block(s) to decrypt
+ * @len: Total size of the block(s) to decrypt. Must be a nonzero
+ * multiple of the filesystem's block size.
+ * @offs: Byte offset within @page of the first block to decrypt. Must be
+ * a multiple of the filesystem's block size.
*
- * Decrypts page in-place using the ctx encryption context.
+ * The specified block(s) are decrypted in-place within the pagecache page,
+ * which must still be locked and not uptodate. Normally, blocksize ==
+ * PAGE_SIZE and the whole page is decrypted at once.
*
- * Called from the read completion callback.
+ * This is for use by the filesystem's ->readpages() method.
*
- * Return: Zero on success, non-zero otherwise.
+ * Return: 0 on success; -errno on failure
*/
-int fscrypt_decrypt_page(const struct inode *inode, struct page *page,
- unsigned int len, unsigned int offs, u64 lblk_num)
+int fscrypt_decrypt_pagecache_blocks(struct page *page, unsigned int len,
+ unsigned int offs)
{
- if (!(inode->i_sb->s_cop->flags & FS_CFLG_OWN_PAGES))
- BUG_ON(!PageLocked(page));
+ const struct inode *inode = page->mapping->host;
+ const unsigned int blockbits = inode->i_blkbits;
+ const unsigned int blocksize = 1 << blockbits;
+ u64 lblk_num = ((u64)page->index << (PAGE_SHIFT - blockbits)) +
+ (offs >> blockbits);
+ unsigned int i;
+ int err;
+
+ if (WARN_ON_ONCE(!PageLocked(page)))
+ return -EINVAL;
+
+ if (WARN_ON_ONCE(len <= 0 || !IS_ALIGNED(len | offs, blocksize)))
+ return -EINVAL;
+
+ for (i = offs; i < offs + len; i += blocksize, lblk_num++) {
+ err = fscrypt_crypt_block(inode, FS_DECRYPT, lblk_num, page,
+ page, blocksize, i, GFP_NOFS);
+ if (err)
+ return err;
+ }
+ return 0;
+}
+EXPORT_SYMBOL(fscrypt_decrypt_pagecache_blocks);
- return fscrypt_do_page_crypto(inode, FS_DECRYPT, lblk_num, page, page,
- len, offs, GFP_NOFS);
+/**
+ * fscrypt_decrypt_block_inplace() - Decrypt a filesystem block in-place
+ * @inode: The inode to which this block belongs
+ * @page: The page containing the block to decrypt
+ * @len: Size of block to decrypt. Doesn't need to be a multiple of the
+ * fs block size, but must be a multiple of FS_CRYPTO_BLOCK_SIZE.
+ * @offs: Byte offset within @page at which the block to decrypt begins
+ * @lblk_num: Filesystem logical block number of the block, i.e. the 0-based
+ * number of the block within the file
+ *
+ * Decrypt a possibly-compressed filesystem block that is located in an
+ * arbitrary page, not necessarily in the original pagecache page. The @inode
+ * and @lblk_num must be specified, as they can't be determined from @page.
+ *
+ * Return: 0 on success; -errno on failure
+ */
+int fscrypt_decrypt_block_inplace(const struct inode *inode, struct page *page,
+ unsigned int len, unsigned int offs,
+ u64 lblk_num)
+{
+ return fscrypt_crypt_block(inode, FS_DECRYPT, lblk_num, page, page,
+ len, offs, GFP_NOFS);
}
-EXPORT_SYMBOL(fscrypt_decrypt_page);
+EXPORT_SYMBOL(fscrypt_decrypt_block_inplace);
/*
* Validate dentries in encrypted directories to make sure we aren't potentially
@@ -355,18 +398,6 @@ const struct dentry_operations fscrypt_d_ops = {
.d_revalidate = fscrypt_d_revalidate,
};
-void fscrypt_restore_control_page(struct page *page)
-{
- struct fscrypt_ctx *ctx;
-
- ctx = (struct fscrypt_ctx *)page_private(page);
- set_page_private(page, (unsigned long)NULL);
- ClearPagePrivate(page);
- unlock_page(page);
- fscrypt_release_ctx(ctx);
-}
-EXPORT_SYMBOL(fscrypt_restore_control_page);
-
static void fscrypt_destroy(void)
{
struct fscrypt_ctx *pos, *n;
diff --git a/fs/crypto/fname.c b/fs/crypto/fname.c
index eccea3d8f92345965854cd624692c66cefe37fb9..00d150ff30332bea40f6d1a8cac62261c760822e 100644
--- a/fs/crypto/fname.c
+++ b/fs/crypto/fname.c
@@ -12,7 +12,6 @@
*/
#include <linux/scatterlist.h>
-#include <linux/ratelimit.h>
#include <crypto/skcipher.h>
#include "fscrypt_private.h"
diff --git a/fs/crypto/fscrypt_private.h b/fs/crypto/fscrypt_private.h
index 7da2761595933bbaa372eb8338f00d59e39e0b3d..8978eec9d766dde75d65a1af12039d429b13bbd1 100644
--- a/fs/crypto/fscrypt_private.h
+++ b/fs/crypto/fscrypt_private.h
@@ -94,7 +94,6 @@ typedef enum {
} fscrypt_direction_t;
#define FS_CTX_REQUIRES_FREE_ENCRYPT_FL 0x00000001
-#define FS_CTX_HAS_BOUNCE_BUFFER_FL 0x00000002
static inline bool fscrypt_valid_enc_modes(u32 contents_mode,
u32 filenames_mode)
@@ -117,14 +116,12 @@ static inline bool fscrypt_valid_enc_modes(u32 contents_mode,
/* crypto.c */
extern struct kmem_cache *fscrypt_info_cachep;
extern int fscrypt_initialize(unsigned int cop_flags);
-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);
+extern int fscrypt_crypt_block(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(gfp_t gfp_flags);
extern const struct dentry_operations fscrypt_d_ops;
extern void __printf(3, 4) __cold
diff --git a/fs/crypto/hooks.c b/fs/crypto/hooks.c
index bd525f7573a49ce4f238848596627095adf14cbf..c1d6715d88e93c3742537040ccbe636e2fab1727 100644
--- a/fs/crypto/hooks.c
+++ b/fs/crypto/hooks.c
@@ -5,7 +5,6 @@
* Encryption hooks for higher-level filesystem operations.
*/
-#include <linux/ratelimit.h>
#include "fscrypt_private.h"
/**
diff --git a/fs/crypto/keyinfo.c b/fs/crypto/keyinfo.c
index dcd91a3fbe49a082ca60e2d08cf53dd70d5aded8..207ebed918c159b712a2f780f8a468fdbf654fde 100644
--- a/fs/crypto/keyinfo.c
+++ b/fs/crypto/keyinfo.c
@@ -12,7 +12,6 @@
#include <keys/user-type.h>
#include <linux/hashtable.h>
#include <linux/scatterlist.h>
-#include <linux/ratelimit.h>
#include <crypto/aes.h>
#include <crypto/algapi.h>
#include <crypto/sha.h>
diff --git a/fs/crypto/policy.c b/fs/crypto/policy.c
index d536889ac31bfe211d4c92fa6611e9a1fd9fc3f5..4941fe8471ceff03cea2032890b0e16318eff8fb 100644
--- a/fs/crypto/policy.c
+++ b/fs/crypto/policy.c
@@ -81,6 +81,8 @@ int fscrypt_ioctl_set_policy(struct file *filp, const void __user *arg)
if (ret == -ENODATA) {
if (!S_ISDIR(inode->i_mode))
ret = -ENOTDIR;
+ else if (IS_DEADDIR(inode))
+ ret = -ENOENT;
else if (!inode->i_sb->s_cop->empty_dir(inode))
ret = -ENOTEMPTY;
else
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index c7f77c643008558938ed0cf5d23698863d1ca931..f65357735a1ad06e068a25446fdd13e5e8a428a6 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1164,8 +1164,9 @@ static int ext4_block_write_begin(struct page *page, loff_t pos, unsigned len,
int err = 0;
unsigned blocksize = inode->i_sb->s_blocksize;
unsigned bbits;
- struct buffer_head *bh, *head, *wait[2], **wait_bh = wait;
- bool decrypt = false;
+ struct buffer_head *bh, *head, *wait[2];
+ int nr_wait = 0;
+ int i;
BUG_ON(!PageLocked(page));
BUG_ON(from > PAGE_SIZE);
@@ -1217,23 +1218,32 @@ static int ext4_block_write_begin(struct page *page, loff_t pos, unsigned len,
!buffer_unwritten(bh) &&
(block_start < from || block_end > to)) {
ll_rw_block(REQ_OP_READ, 0, 1, &bh);
- *wait_bh++ = bh;
- decrypt = IS_ENCRYPTED(inode) && S_ISREG(inode->i_mode);
+ wait[nr_wait++] = bh;
}
}
/*
* If we issued read requests, let them complete.
*/
- while (wait_bh > wait) {
- wait_on_buffer(*--wait_bh);
- if (!buffer_uptodate(*wait_bh))
+ for (i = 0; i < nr_wait; i++) {
+ wait_on_buffer(wait[i]);
+ if (!buffer_uptodate(wait[i]))
err = -EIO;
}
- if (unlikely(err))
+ if (unlikely(err)) {
page_zero_new_buffers(page, from, to);
- else if (decrypt)
- err = fscrypt_decrypt_page(page->mapping->host, page,
- PAGE_SIZE, 0, page->index);
+ } else if (IS_ENCRYPTED(inode) && S_ISREG(inode->i_mode)) {
+ for (i = 0; i < nr_wait; i++) {
+ int err2;
+
+ err2 = fscrypt_decrypt_pagecache_blocks(page, blocksize,
+ bh_offset(wait[i]));
+ if (err2) {
+ clear_buffer_uptodate(wait[i]);
+ err = err2;
+ }
+ }
+ }
+
return err;
}
#endif
@@ -4065,9 +4075,8 @@ static int __ext4_block_zero_page_range(handle_t *handle,
if (S_ISREG(inode->i_mode) && IS_ENCRYPTED(inode)) {
/* 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->mapping->host,
- page, PAGE_SIZE, 0, page->index));
+ WARN_ON_ONCE(fscrypt_decrypt_pagecache_blocks(
+ page, blocksize, bh_offset(bh)));
}
}
if (ext4_should_journal_data(inode)) {
diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c
index 4690618a92e93f133ba3c176b4757a9976805b32..a18a47a2a1d1ac26ed9c4bf6ce33bde942be4f1a 100644
--- a/fs/ext4/page-io.c
+++ b/fs/ext4/page-io.c
@@ -66,9 +66,7 @@ static void ext4_finish_bio(struct bio *bio)
bio_for_each_segment_all(bvec, bio, iter_all) {
struct page *page = bvec->bv_page;
-#ifdef CONFIG_FS_ENCRYPTION
- struct page *data_page = NULL;
-#endif
+ struct page *bounce_page = NULL;
struct buffer_head *bh, *head;
unsigned bio_start = bvec->bv_offset;
unsigned bio_end = bio_start + bvec->bv_len;
@@ -78,13 +76,10 @@ static void ext4_finish_bio(struct bio *bio)
if (!page)
continue;
-#ifdef CONFIG_FS_ENCRYPTION
- if (!page->mapping) {
- /* The bounce data pages are unmapped. */
- data_page = page;
- fscrypt_pullback_bio_page(&page, false);
+ if (fscrypt_is_bounce_page(page)) {
+ bounce_page = page;
+ page = fscrypt_pagecache_page(bounce_page);
}
-#endif
if (bio->bi_status) {
SetPageError(page);
@@ -111,10 +106,7 @@ static void ext4_finish_bio(struct bio *bio)
bit_spin_unlock(BH_Uptodate_Lock, &head->b_state);
local_irq_restore(flags);
if (!under_io) {
-#ifdef CONFIG_FS_ENCRYPTION
- if (data_page)
- fscrypt_restore_control_page(data_page);
-#endif
+ fscrypt_free_bounce_page(bounce_page);
end_page_writeback(page);
}
}
@@ -415,7 +407,7 @@ int ext4_bio_write_page(struct ext4_io_submit *io,
struct writeback_control *wbc,
bool keep_towrite)
{
- struct page *data_page = NULL;
+ struct page *bounce_page = NULL;
struct inode *inode = page->mapping->host;
unsigned block_start;
struct buffer_head *bh, *head;
@@ -475,14 +467,22 @@ int ext4_bio_write_page(struct ext4_io_submit *io,
bh = head = page_buffers(page);
+ /*
+ * If any blocks are being written to an encrypted file, encrypt them
+ * into a bounce page. For simplicity, just encrypt until the last
+ * block which might be needed. This may cause some unneeded blocks
+ * (e.g. holes) to be unnecessarily encrypted, but this is rare and
+ * can't happen in the common case of blocksize == PAGE_SIZE.
+ */
if (IS_ENCRYPTED(inode) && S_ISREG(inode->i_mode) && nr_to_submit) {
gfp_t gfp_flags = GFP_NOFS;
+ unsigned int enc_bytes = round_up(len, i_blocksize(inode));
retry_encrypt:
- data_page = fscrypt_encrypt_page(inode, page, PAGE_SIZE, 0,
- page->index, gfp_flags);
- if (IS_ERR(data_page)) {
- ret = PTR_ERR(data_page);
+ bounce_page = fscrypt_encrypt_pagecache_blocks(page, enc_bytes,
+ 0, gfp_flags);
+ if (IS_ERR(bounce_page)) {
+ ret = PTR_ERR(bounce_page);
if (ret == -ENOMEM && wbc->sync_mode == WB_SYNC_ALL) {
if (io->io_bio) {
ext4_io_submit(io);
@@ -491,7 +491,7 @@ int ext4_bio_write_page(struct ext4_io_submit *io,
gfp_flags |= __GFP_NOFAIL;
goto retry_encrypt;
}
- data_page = NULL;
+ bounce_page = NULL;
goto out;
}
}
@@ -500,8 +500,7 @@ int ext4_bio_write_page(struct ext4_io_submit *io,
do {
if (!buffer_async_write(bh))
continue;
- ret = io_submit_add_bh(io, inode,
- data_page ? data_page : page, bh);
+ ret = io_submit_add_bh(io, inode, bounce_page ?: page, bh);
if (ret) {
/*
* We only get here on ENOMEM. Not much else
@@ -517,8 +516,7 @@ int ext4_bio_write_page(struct ext4_io_submit *io,
/* Error stopped previous loop? Clean up buffers... */
if (ret) {
out:
- if (data_page)
- fscrypt_restore_control_page(data_page);
+ fscrypt_free_bounce_page(bounce_page);
printk_ratelimited(KERN_ERR "%s: ret = %d\n", __func__, ret);
redirty_page_for_writepage(wbc, page);
do {
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index eda4181d20926bd59903f9feea6e57f5108612dc..a546ac8685ea64d5f787d9b8c84cfe1e9a009e48 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -185,7 +185,7 @@ static void f2fs_write_end_io(struct bio *bio)
continue;
}
- fscrypt_pullback_bio_page(&page, true);
+ fscrypt_finalize_bounce_page(&page);
if (unlikely(bio->bi_status)) {
mapping_set_error(page->mapping, -EIO);
@@ -362,10 +362,9 @@ static bool __has_merged_page(struct f2fs_bio_info *io, struct inode *inode,
bio_for_each_segment_all(bvec, io->bio, iter_all) {
- if (bvec->bv_page->mapping)
- target = bvec->bv_page;
- else
- target = fscrypt_control_page(bvec->bv_page);
+ target = bvec->bv_page;
+ if (fscrypt_is_bounce_page(target))
+ target = fscrypt_pagecache_page(target);
if (inode && inode == target->mapping->host)
return true;
@@ -1727,8 +1726,9 @@ static int encrypt_one_page(struct f2fs_io_info *fio)
f2fs_wait_on_block_writeback(inode, fio->old_blkaddr);
retry_encrypt:
- fio->encrypted_page = fscrypt_encrypt_page(inode, fio->page,
- PAGE_SIZE, 0, fio->page->index, gfp_flags);
+ fio->encrypted_page = fscrypt_encrypt_pagecache_blocks(fio->page,
+ PAGE_SIZE, 0,
+ gfp_flags);
if (IS_ERR(fio->encrypted_page)) {
/* flush pending IOs and wait for a while in the ENOMEM case */
if (PTR_ERR(fio->encrypted_page) == -ENOMEM) {
@@ -1900,8 +1900,7 @@ int f2fs_do_write_data_page(struct f2fs_io_info *fio)
err = f2fs_inplace_write_data(fio);
if (err) {
if (f2fs_encrypted_file(inode))
- fscrypt_pullback_bio_page(&fio->encrypted_page,
- true);
+ fscrypt_finalize_bounce_page(&fio->encrypted_page);
if (PageWriteback(page))
end_page_writeback(page);
} else {
diff --git a/fs/ubifs/crypto.c b/fs/ubifs/crypto.c
index 4aaedf2d7f442237ec34e760f27e48c1736db5ed..22be7aeb96c4fe121b6963888de66408f972c86c 100644
--- a/fs/ubifs/crypto.c
+++ b/fs/ubifs/crypto.c
@@ -29,8 +29,8 @@ int ubifs_encrypt(const struct inode *inode, struct ubifs_data_node *dn,
{
struct ubifs_info *c = inode->i_sb->s_fs_info;
void *p = &dn->data;
- struct page *ret;
unsigned int pad_len = round_up(in_len, UBIFS_CIPHER_BLOCK_SIZE);
+ int err;
ubifs_assert(c, pad_len <= *out_len);
dn->compr_size = cpu_to_le16(in_len);
@@ -39,11 +39,11 @@ int ubifs_encrypt(const struct inode *inode, struct ubifs_data_node *dn,
if (pad_len != in_len)
memset(p + in_len, 0, pad_len - in_len);
- ret = fscrypt_encrypt_page(inode, virt_to_page(&dn->data), pad_len,
- offset_in_page(&dn->data), block, GFP_NOFS);
- if (IS_ERR(ret)) {
- ubifs_err(c, "fscrypt_encrypt_page failed: %ld", PTR_ERR(ret));
- return PTR_ERR(ret);
+ err = fscrypt_encrypt_block_inplace(inode, virt_to_page(p), pad_len,
+ offset_in_page(p), block, GFP_NOFS);
+ if (err) {
+ ubifs_err(c, "fscrypt_encrypt_block_inplace() failed: %d", err);
+ return err;
}
*out_len = pad_len;
@@ -64,10 +64,11 @@ int ubifs_decrypt(const struct inode *inode, struct ubifs_data_node *dn,
}
ubifs_assert(c, dlen <= UBIFS_BLOCK_SIZE);
- err = fscrypt_decrypt_page(inode, virt_to_page(&dn->data), dlen,
- offset_in_page(&dn->data), block);
+ err = fscrypt_decrypt_block_inplace(inode, virt_to_page(&dn->data),
+ dlen, offset_in_page(&dn->data),
+ block);
if (err) {
- ubifs_err(c, "fscrypt_decrypt_page failed: %i", err);
+ ubifs_err(c, "fscrypt_decrypt_block_inplace() failed: %d", err);
return err;
}
*out_len = clen;
diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h
index f7680ef1abd2d3d88e41f705a65febe79bc7f1cb..bd8f207a2fb68bc4de62d0a6445a74810fd1578f 100644
--- a/include/linux/fscrypt.h
+++ b/include/linux/fscrypt.h
@@ -63,16 +63,13 @@ struct fscrypt_operations {
unsigned int max_namelen;
};
+/* Decryption work */
struct fscrypt_ctx {
union {
- struct {
- struct page *bounce_page; /* Ciphertext page */
- struct page *control_page; /* Original page */
- } w;
struct {
struct bio *bio;
struct work_struct work;
- } r;
+ };
struct list_head free_list; /* Free list */
};
u8 flags; /* Flags */
@@ -106,18 +103,33 @@ static inline void fscrypt_handle_d_move(struct dentry *dentry)
extern void fscrypt_enqueue_decrypt_work(struct work_struct *);
extern struct fscrypt_ctx *fscrypt_get_ctx(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,
- u64, gfp_t);
-extern int fscrypt_decrypt_page(const struct inode *, struct page *, unsigned int,
- unsigned int, u64);
-static inline struct page *fscrypt_control_page(struct page *page)
+extern struct page *fscrypt_encrypt_pagecache_blocks(struct page *page,
+ unsigned int len,
+ unsigned int offs,
+ gfp_t gfp_flags);
+extern int fscrypt_encrypt_block_inplace(const struct inode *inode,
+ struct page *page, unsigned int len,
+ unsigned int offs, u64 lblk_num,
+ gfp_t gfp_flags);
+
+extern int fscrypt_decrypt_pagecache_blocks(struct page *page, unsigned int len,
+ unsigned int offs);
+extern int fscrypt_decrypt_block_inplace(const struct inode *inode,
+ struct page *page, unsigned int len,
+ unsigned int offs, u64 lblk_num);
+
+static inline bool fscrypt_is_bounce_page(struct page *page)
+{
+ return page->mapping == NULL;
+}
+
+static inline struct page *fscrypt_pagecache_page(struct page *bounce_page)
{
- return ((struct fscrypt_ctx *)page_private(page))->w.control_page;
+ return (struct page *)page_private(bounce_page);
}
-extern void fscrypt_restore_control_page(struct page *);
+extern void fscrypt_free_bounce_page(struct page *bounce_page);
/* policy.c */
extern int fscrypt_ioctl_set_policy(struct file *, const void __user *);
@@ -223,7 +235,6 @@ static inline bool fscrypt_match_name(const struct fscrypt_name *fname,
extern void fscrypt_decrypt_bio(struct bio *);
extern void fscrypt_enqueue_decrypt_bio(struct fscrypt_ctx *ctx,
struct bio *bio);
-extern void fscrypt_pullback_bio_page(struct page **, bool);
extern int fscrypt_zeroout_range(const struct inode *, pgoff_t, sector_t,
unsigned int);
@@ -283,32 +294,51 @@ static inline void fscrypt_release_ctx(struct fscrypt_ctx *ctx)
return;
}
-static inline struct page *fscrypt_encrypt_page(const struct inode *inode,
+static inline struct page *fscrypt_encrypt_pagecache_blocks(struct page *page,
+ unsigned int len,
+ unsigned int offs,
+ gfp_t gfp_flags)
+{
+ return ERR_PTR(-EOPNOTSUPP);
+}
+
+static inline int fscrypt_encrypt_block_inplace(const struct inode *inode,
struct page *page,
unsigned int len,
- unsigned int offs,
- u64 lblk_num, gfp_t gfp_flags)
+ unsigned int offs, u64 lblk_num,
+ gfp_t gfp_flags)
{
- return ERR_PTR(-EOPNOTSUPP);
+ return -EOPNOTSUPP;
+}
+
+static inline int fscrypt_decrypt_pagecache_blocks(struct page *page,
+ unsigned int len,
+ unsigned int offs)
+{
+ return -EOPNOTSUPP;
}
-static inline int fscrypt_decrypt_page(const struct inode *inode,
- struct page *page,
- unsigned int len, unsigned int offs,
- u64 lblk_num)
+static inline int fscrypt_decrypt_block_inplace(const struct inode *inode,
+ struct page *page,
+ unsigned int len,
+ unsigned int offs, u64 lblk_num)
{
return -EOPNOTSUPP;
}
-static inline struct page *fscrypt_control_page(struct page *page)
+static inline bool fscrypt_is_bounce_page(struct page *page)
+{
+ return false;
+}
+
+static inline struct page *fscrypt_pagecache_page(struct page *bounce_page)
{
WARN_ON_ONCE(1);
return ERR_PTR(-EINVAL);
}
-static inline void fscrypt_restore_control_page(struct page *page)
+static inline void fscrypt_free_bounce_page(struct page *bounce_page)
{
- return;
}
/* policy.c */
@@ -410,11 +440,6 @@ static inline void fscrypt_enqueue_decrypt_bio(struct fscrypt_ctx *ctx,
{
}
-static inline void fscrypt_pullback_bio_page(struct page **page, bool restore)
-{
- return;
-}
-
static inline int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk,
sector_t pblk, unsigned int len)
{
@@ -692,4 +717,15 @@ static inline int fscrypt_encrypt_symlink(struct inode *inode,
return 0;
}
+/* If *pagep is a bounce page, free it and set *pagep to the pagecache page */
+static inline void fscrypt_finalize_bounce_page(struct page **pagep)
+{
+ struct page *page = *pagep;
+
+ if (fscrypt_is_bounce_page(page)) {
+ *pagep = fscrypt_pagecache_page(page);
+ fscrypt_free_bounce_page(page);
+ }
+}
+
#endif /* _LINUX_FSCRYPT_H */