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-rw-r--r--fs/crypto/crypto.c163
1 files changed, 91 insertions, 72 deletions
diff --git a/fs/crypto/crypto.c b/fs/crypto/crypto.c
index 6a837e4b80..328470d40d 100644
--- a/fs/crypto/crypto.c
+++ b/fs/crypto/crypto.c
@@ -39,7 +39,7 @@ static mempool_t *fscrypt_bounce_page_pool = NULL;
static struct workqueue_struct *fscrypt_read_workqueue;
static DEFINE_MUTEX(fscrypt_init_mutex);
-struct kmem_cache *fscrypt_info_cachep;
+struct kmem_cache *fscrypt_inode_info_cachep;
void fscrypt_enqueue_decrypt_work(struct work_struct *work)
{
@@ -49,6 +49,13 @@ EXPORT_SYMBOL(fscrypt_enqueue_decrypt_work);
struct page *fscrypt_alloc_bounce_page(gfp_t gfp_flags)
{
+ if (WARN_ON_ONCE(!fscrypt_bounce_page_pool)) {
+ /*
+ * Oops, the filesystem called a function that uses the bounce
+ * page pool, but it didn't set needs_bounce_pages.
+ */
+ return NULL;
+ }
return mempool_alloc(fscrypt_bounce_page_pool, gfp_flags);
}
@@ -70,44 +77,44 @@ void fscrypt_free_bounce_page(struct page *bounce_page)
EXPORT_SYMBOL(fscrypt_free_bounce_page);
/*
- * Generate the IV for the given logical block number within the given file.
- * For filenames encryption, lblk_num == 0.
+ * Generate the IV for the given data unit index within the given file.
+ * For filenames encryption, index == 0.
*
* Keep this in sync with fscrypt_limit_io_blocks(). fscrypt_limit_io_blocks()
* needs to know about any IV generation methods where the low bits of IV don't
- * simply contain the lblk_num (e.g., IV_INO_LBLK_32).
+ * simply contain the data unit index (e.g., IV_INO_LBLK_32).
*/
-void fscrypt_generate_iv(union fscrypt_iv *iv, u64 lblk_num,
- const struct fscrypt_info *ci)
+void fscrypt_generate_iv(union fscrypt_iv *iv, u64 index,
+ const struct fscrypt_inode_info *ci)
{
u8 flags = fscrypt_policy_flags(&ci->ci_policy);
memset(iv, 0, ci->ci_mode->ivsize);
if (flags & FSCRYPT_POLICY_FLAG_IV_INO_LBLK_64) {
- WARN_ON_ONCE(lblk_num > U32_MAX);
+ WARN_ON_ONCE(index > U32_MAX);
WARN_ON_ONCE(ci->ci_inode->i_ino > U32_MAX);
- lblk_num |= (u64)ci->ci_inode->i_ino << 32;
+ index |= (u64)ci->ci_inode->i_ino << 32;
} else if (flags & FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32) {
- WARN_ON_ONCE(lblk_num > U32_MAX);
- lblk_num = (u32)(ci->ci_hashed_ino + lblk_num);
+ WARN_ON_ONCE(index > U32_MAX);
+ index = (u32)(ci->ci_hashed_ino + index);
} else if (flags & FSCRYPT_POLICY_FLAG_DIRECT_KEY) {
memcpy(iv->nonce, ci->ci_nonce, FSCRYPT_FILE_NONCE_SIZE);
}
- iv->lblk_num = cpu_to_le64(lblk_num);
+ iv->index = cpu_to_le64(index);
}
-/* 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)
+/* Encrypt or decrypt a single "data unit" of file contents. */
+int fscrypt_crypt_data_unit(const struct fscrypt_inode_info *ci,
+ fscrypt_direction_t rw, u64 index,
+ 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;
DECLARE_CRYPTO_WAIT(wait);
struct scatterlist dst, src;
- struct fscrypt_info *ci = inode->i_crypt_info;
struct crypto_skcipher *tfm = ci->ci_enc_key.tfm;
int res = 0;
@@ -116,7 +123,7 @@ int fscrypt_crypt_block(const struct inode *inode, fscrypt_direction_t rw,
if (WARN_ON_ONCE(len % FSCRYPT_CONTENTS_ALIGNMENT != 0))
return -EINVAL;
- fscrypt_generate_iv(&iv, lblk_num, ci);
+ fscrypt_generate_iv(&iv, index, ci);
req = skcipher_request_alloc(tfm, gfp_flags);
if (!req)
@@ -137,28 +144,29 @@ int fscrypt_crypt_block(const struct inode *inode, fscrypt_direction_t rw,
res = crypto_wait_req(crypto_skcipher_encrypt(req), &wait);
skcipher_request_free(req);
if (res) {
- fscrypt_err(inode, "%scryption failed for block %llu: %d",
- (rw == FS_DECRYPT ? "De" : "En"), lblk_num, res);
+ fscrypt_err(ci->ci_inode,
+ "%scryption failed for data unit %llu: %d",
+ (rw == FS_DECRYPT ? "De" : "En"), index, res);
return res;
}
return 0;
}
/**
- * 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. See details below.
+ * fscrypt_encrypt_pagecache_blocks() - Encrypt data from a pagecache page
+ * @page: the locked pagecache page containing the data to encrypt
+ * @len: size of the data to encrypt, in bytes
+ * @offs: offset within @page of the data to encrypt, in bytes
+ * @gfp_flags: memory allocation flags; see details below
+ *
+ * This allocates a new bounce page and encrypts the given data into it. The
+ * length and offset of the data must be aligned to the file's crypto data unit
+ * size. Alignment to the filesystem block size fulfills this requirement, as
+ * the filesystem block size is always a multiple of the data unit size.
*
- * 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 the bounce page, the ciphertext data will be located at the same offset at
+ * which the plaintext data was located in the source page. Any other parts of
+ * the bounce page will be left uninitialized.
*
* This is for use by the filesystem's ->writepages() method.
*
@@ -176,28 +184,29 @@ struct page *fscrypt_encrypt_pagecache_blocks(struct page *page,
{
const struct inode *inode = page->mapping->host;
- const unsigned int blockbits = inode->i_blkbits;
- const unsigned int blocksize = 1 << blockbits;
+ const struct fscrypt_inode_info *ci = inode->i_crypt_info;
+ const unsigned int du_bits = ci->ci_data_unit_bits;
+ const unsigned int du_size = 1U << du_bits;
struct page *ciphertext_page;
- u64 lblk_num = ((u64)page->index << (PAGE_SHIFT - blockbits)) +
- (offs >> blockbits);
+ u64 index = ((u64)page->index << (PAGE_SHIFT - du_bits)) +
+ (offs >> du_bits);
unsigned int i;
int err;
if (WARN_ON_ONCE(!PageLocked(page)))
return ERR_PTR(-EINVAL);
- if (WARN_ON_ONCE(len <= 0 || !IS_ALIGNED(len | offs, blocksize)))
+ if (WARN_ON_ONCE(len <= 0 || !IS_ALIGNED(len | offs, du_size)))
return ERR_PTR(-EINVAL);
ciphertext_page = fscrypt_alloc_bounce_page(gfp_flags);
if (!ciphertext_page)
return ERR_PTR(-ENOMEM);
- 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);
+ for (i = offs; i < offs + len; i += du_size, index++) {
+ err = fscrypt_crypt_data_unit(ci, FS_ENCRYPT, index,
+ page, ciphertext_page,
+ du_size, i, gfp_flags);
if (err) {
fscrypt_free_bounce_page(ciphertext_page);
return ERR_PTR(err);
@@ -224,30 +233,33 @@ EXPORT_SYMBOL(fscrypt_encrypt_pagecache_blocks);
* 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.
*
+ * This is not compatible with fscrypt_operations::supports_subblock_data_units.
+ *
* 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);
+ if (WARN_ON_ONCE(inode->i_sb->s_cop->supports_subblock_data_units))
+ return -EOPNOTSUPP;
+ return fscrypt_crypt_data_unit(inode->i_crypt_info, FS_ENCRYPT,
+ lblk_num, page, page, len, offs,
+ gfp_flags);
}
EXPORT_SYMBOL(fscrypt_encrypt_block_inplace);
/**
- * fscrypt_decrypt_pagecache_blocks() - Decrypt filesystem blocks in a
- * pagecache folio
- * @folio: The locked pagecache folio 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 @folio of the first block to decrypt. Must be
- * a multiple of the filesystem's block size.
+ * fscrypt_decrypt_pagecache_blocks() - Decrypt data from a pagecache folio
+ * @folio: the pagecache folio containing the data to decrypt
+ * @len: size of the data to decrypt, in bytes
+ * @offs: offset within @folio of the data to decrypt, in bytes
*
- * The specified block(s) are decrypted in-place within the pagecache folio,
- * which must still be locked and not uptodate.
- *
- * This is for use by the filesystem's ->readahead() method.
+ * Decrypt data that has just been read from an encrypted file. The data must
+ * be located in a pagecache folio that is still locked and not yet uptodate.
+ * The length and offset of the data must be aligned to the file's crypto data
+ * unit size. Alignment to the filesystem block size fulfills this requirement,
+ * as the filesystem block size is always a multiple of the data unit size.
*
* Return: 0 on success; -errno on failure
*/
@@ -255,25 +267,26 @@ int fscrypt_decrypt_pagecache_blocks(struct folio *folio, size_t len,
size_t offs)
{
const struct inode *inode = folio->mapping->host;
- const unsigned int blockbits = inode->i_blkbits;
- const unsigned int blocksize = 1 << blockbits;
- u64 lblk_num = ((u64)folio->index << (PAGE_SHIFT - blockbits)) +
- (offs >> blockbits);
+ const struct fscrypt_inode_info *ci = inode->i_crypt_info;
+ const unsigned int du_bits = ci->ci_data_unit_bits;
+ const unsigned int du_size = 1U << du_bits;
+ u64 index = ((u64)folio->index << (PAGE_SHIFT - du_bits)) +
+ (offs >> du_bits);
size_t i;
int err;
if (WARN_ON_ONCE(!folio_test_locked(folio)))
return -EINVAL;
- if (WARN_ON_ONCE(len <= 0 || !IS_ALIGNED(len | offs, blocksize)))
+ if (WARN_ON_ONCE(len <= 0 || !IS_ALIGNED(len | offs, du_size)))
return -EINVAL;
- for (i = offs; i < offs + len; i += blocksize, lblk_num++) {
+ for (i = offs; i < offs + len; i += du_size, index++) {
struct page *page = folio_page(folio, i >> PAGE_SHIFT);
- err = fscrypt_crypt_block(inode, FS_DECRYPT, lblk_num, page,
- page, blocksize, i & ~PAGE_MASK,
- GFP_NOFS);
+ err = fscrypt_crypt_data_unit(ci, FS_DECRYPT, index, page,
+ page, du_size, i & ~PAGE_MASK,
+ GFP_NOFS);
if (err)
return err;
}
@@ -295,14 +308,19 @@ EXPORT_SYMBOL(fscrypt_decrypt_pagecache_blocks);
* 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.
*
+ * This is not compatible with fscrypt_operations::supports_subblock_data_units.
+ *
* 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);
+ if (WARN_ON_ONCE(inode->i_sb->s_cop->supports_subblock_data_units))
+ return -EOPNOTSUPP;
+ return fscrypt_crypt_data_unit(inode->i_crypt_info, FS_DECRYPT,
+ lblk_num, page, page, len, offs,
+ GFP_NOFS);
}
EXPORT_SYMBOL(fscrypt_decrypt_block_inplace);
@@ -325,7 +343,7 @@ int fscrypt_initialize(struct super_block *sb)
return 0;
/* No need to allocate a bounce page pool if this FS won't use it. */
- if (sb->s_cop->flags & FS_CFLG_OWN_PAGES)
+ if (!sb->s_cop->needs_bounce_pages)
return 0;
mutex_lock(&fscrypt_init_mutex);
@@ -391,18 +409,19 @@ static int __init fscrypt_init(void)
if (!fscrypt_read_workqueue)
goto fail;
- fscrypt_info_cachep = KMEM_CACHE(fscrypt_info, SLAB_RECLAIM_ACCOUNT);
- if (!fscrypt_info_cachep)
+ fscrypt_inode_info_cachep = KMEM_CACHE(fscrypt_inode_info,
+ SLAB_RECLAIM_ACCOUNT);
+ if (!fscrypt_inode_info_cachep)
goto fail_free_queue;
err = fscrypt_init_keyring();
if (err)
- goto fail_free_info;
+ goto fail_free_inode_info;
return 0;
-fail_free_info:
- kmem_cache_destroy(fscrypt_info_cachep);
+fail_free_inode_info:
+ kmem_cache_destroy(fscrypt_inode_info_cachep);
fail_free_queue:
destroy_workqueue(fscrypt_read_workqueue);
fail: