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 {
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)
{
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,
} 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)
{
memset(iv, 0, ci->ci_mode->ivsize);
iv->lblk_num = cpu_to_le64(lblk_num);
- if (ci->ci_flags & FS_POLICY_FLAG_DIRECT_KEY)
+ if (fscrypt_is_direct_key_policy(&ci->ci_policy))
memcpy(iv->nonce, ci->ci_nonce, FS_KEY_DERIVATION_NONCE_SIZE);
if (ci->ci_essiv_tfm != NULL)
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;
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);
res = crypto_wait_req(crypto_skcipher_encrypt(req), &wait);
skcipher_request_free(req);
if (res) {
- fscrypt_err(inode->i_sb,
- "%scryption failed for inode %lu, block %llu: %d",
- (rw == FS_DECRYPT ? "de" : "en"),
- inode->i_ino, lblk_num, res);
+ fscrypt_err(inode, "%scryption failed for block %llu: %d",
+ (rw == FS_DECRYPT ? "De" : "En"), lblk_num, res);
return res;
}
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 (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);
-
- return ciphertext_page;
- }
-
- BUG_ON(!PageLocked(page));
+ if (WARN_ON_ONCE(!PageLocked(page)))
+ return ERR_PTR(-EINVAL);
- ctx = fscrypt_get_ctx(gfp_flags);
- if (IS_ERR(ctx))
- return ERR_CAST(ctx);
+ if (WARN_ON_ONCE(len <= 0 || !IS_ALIGNED(len | offs, blocksize)))
+ return ERR_PTR(-EINVAL);
- /* 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;
- return fscrypt_do_page_crypto(inode, FS_DECRYPT, lblk_num, page, page,
- len, offs, GFP_NOFS);
+ 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_page);
+EXPORT_SYMBOL(fscrypt_decrypt_pagecache_blocks);
+
+/**
+ * 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_block_inplace);
/*
* Validate dentries in encrypted directories to make sure we aren't potentially
.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;
return res;
}
-void fscrypt_msg(struct super_block *sb, const char *level,
+void fscrypt_msg(const struct inode *inode, const char *level,
const char *fmt, ...)
{
static DEFINE_RATELIMIT_STATE(rs, DEFAULT_RATELIMIT_INTERVAL,
va_start(args, fmt);
vaf.fmt = fmt;
vaf.va = &args;
- if (sb)
- printk("%sfscrypt (%s): %pV\n", level, sb->s_id, &vaf);
+ if (inode)
+ printk("%sfscrypt (%s, inode %lu): %pV\n",
+ level, inode->i_sb->s_id, inode->i_ino, &vaf);
else
printk("%sfscrypt: %pV\n", level, &vaf);
va_end(args);
*/
static int __init fscrypt_init(void)
{
+ int err = -ENOMEM;
+
/*
* Use an unbound workqueue to allow bios to be decrypted in parallel
* even when they happen to complete on the same CPU. This sacrifices
if (!fscrypt_info_cachep)
goto fail_free_ctx;
+ err = fscrypt_init_keyring();
+ if (err)
+ goto fail_free_info;
+
return 0;
+fail_free_info:
+ kmem_cache_destroy(fscrypt_info_cachep);
fail_free_ctx:
kmem_cache_destroy(fscrypt_ctx_cachep);
fail_free_queue:
destroy_workqueue(fscrypt_read_workqueue);
fail:
- return -ENOMEM;
-}
-module_init(fscrypt_init)
-
-/**
- * fscrypt_exit() - Shutdown the fs encryption system
- */
-static void __exit fscrypt_exit(void)
-{
- fscrypt_destroy();
-
- if (fscrypt_read_workqueue)
- destroy_workqueue(fscrypt_read_workqueue);
- kmem_cache_destroy(fscrypt_ctx_cachep);
- kmem_cache_destroy(fscrypt_info_cachep);
-
- fscrypt_essiv_cleanup();
+ return err;
}
-module_exit(fscrypt_exit);
-
-MODULE_LICENSE("GPL");
+late_initcall(fscrypt_init)
projects / linux.git / blobdiff