linux-stable/fs/crypto/bio.c

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License cleanup: add SPDX GPL-2.0 license identifier to files with no license Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-01 14:07:57 +00:00
// SPDX-License-Identifier: GPL-2.0
/*
* Utility functions for file contents encryption/decryption on
* block device-based filesystems.
*
* Copyright (C) 2015, Google, Inc.
* Copyright (C) 2015, Motorola Mobility
*/
#include <linux/pagemap.h>
#include <linux/module.h>
#include <linux/bio.h>
#include <linux/namei.h>
#include "fscrypt_private.h"
/**
* fscrypt_decrypt_bio() - decrypt the contents of a bio
* @bio: the bio to decrypt
*
* Decrypt the contents of a "read" bio following successful completion of the
* underlying disk read. The bio must be reading a whole number of blocks of an
* encrypted file directly into the page cache. If the bio is reading the
* ciphertext into bounce pages instead of the page cache (for example, because
* the file is also compressed, so decompression is required after decryption),
* then this function isn't applicable. This function may sleep, so it must be
* called from a workqueue rather than from the bio's bi_end_io callback.
*
* This function sets PG_error on any pages that contain any blocks that failed
* to be decrypted. The filesystem must not mark such pages uptodate.
*/
void fscrypt_decrypt_bio(struct bio *bio)
{
struct bio_vec *bv;
struct bvec_iter_all iter_all;
bio_for_each_segment_all(bv, bio, iter_all) {
struct page *page = bv->bv_page;
int ret = fscrypt_decrypt_pagecache_blocks(page, bv->bv_len,
bv->bv_offset);
if (ret)
SetPageError(page);
}
}
EXPORT_SYMBOL(fscrypt_decrypt_bio);
fscrypt: add inline encryption support Add support for inline encryption to fs/crypto/. With "inline encryption", the block layer handles the decryption/encryption as part of the bio, instead of the filesystem doing the crypto itself via Linux's crypto API. This model is needed in order to take advantage of the inline encryption hardware present on most modern mobile SoCs. To use inline encryption, the filesystem needs to be mounted with '-o inlinecrypt'. Blk-crypto will then be used instead of the traditional filesystem-layer crypto whenever possible to encrypt the contents of any encrypted files in that filesystem. Fscrypt still provides the key and IV to use, and the actual ciphertext on-disk is still the same; therefore it's testable using the existing fscrypt ciphertext verification tests. Note that since blk-crypto has a fallback to Linux's crypto API, and also supports all the encryption modes currently supported by fscrypt, this feature is usable and testable even without actual inline encryption hardware. Per-filesystem changes will be needed to set encryption contexts when submitting bios and to implement the 'inlinecrypt' mount option. This patch just adds the common code. Signed-off-by: Satya Tangirala <satyat@google.com> Reviewed-by: Jaegeuk Kim <jaegeuk@kernel.org> Reviewed-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Theodore Ts'o <tytso@mit.edu> Link: https://lore.kernel.org/r/20200702015607.1215430-3-satyat@google.com Co-developed-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Eric Biggers <ebiggers@google.com>
2020-07-02 01:56:05 +00:00
static int fscrypt_zeroout_range_inline_crypt(const struct inode *inode,
pgoff_t lblk, sector_t pblk,
unsigned int len)
{
const unsigned int blockbits = inode->i_blkbits;
const unsigned int blocks_per_page = 1 << (PAGE_SHIFT - blockbits);
struct bio *bio;
int ret, err = 0;
int num_pages = 0;
/* This always succeeds since __GFP_DIRECT_RECLAIM is set. */
bio = bio_alloc(GFP_NOFS, BIO_MAX_VECS);
fscrypt: add inline encryption support Add support for inline encryption to fs/crypto/. With "inline encryption", the block layer handles the decryption/encryption as part of the bio, instead of the filesystem doing the crypto itself via Linux's crypto API. This model is needed in order to take advantage of the inline encryption hardware present on most modern mobile SoCs. To use inline encryption, the filesystem needs to be mounted with '-o inlinecrypt'. Blk-crypto will then be used instead of the traditional filesystem-layer crypto whenever possible to encrypt the contents of any encrypted files in that filesystem. Fscrypt still provides the key and IV to use, and the actual ciphertext on-disk is still the same; therefore it's testable using the existing fscrypt ciphertext verification tests. Note that since blk-crypto has a fallback to Linux's crypto API, and also supports all the encryption modes currently supported by fscrypt, this feature is usable and testable even without actual inline encryption hardware. Per-filesystem changes will be needed to set encryption contexts when submitting bios and to implement the 'inlinecrypt' mount option. This patch just adds the common code. Signed-off-by: Satya Tangirala <satyat@google.com> Reviewed-by: Jaegeuk Kim <jaegeuk@kernel.org> Reviewed-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Theodore Ts'o <tytso@mit.edu> Link: https://lore.kernel.org/r/20200702015607.1215430-3-satyat@google.com Co-developed-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Eric Biggers <ebiggers@google.com>
2020-07-02 01:56:05 +00:00
while (len) {
unsigned int blocks_this_page = min(len, blocks_per_page);
unsigned int bytes_this_page = blocks_this_page << blockbits;
if (num_pages == 0) {
fscrypt_set_bio_crypt_ctx(bio, inode, lblk, GFP_NOFS);
bio_set_dev(bio, inode->i_sb->s_bdev);
bio->bi_iter.bi_sector =
pblk << (blockbits - SECTOR_SHIFT);
bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
}
ret = bio_add_page(bio, ZERO_PAGE(0), bytes_this_page, 0);
if (WARN_ON(ret != bytes_this_page)) {
err = -EIO;
goto out;
}
num_pages++;
len -= blocks_this_page;
lblk += blocks_this_page;
pblk += blocks_this_page;
if (num_pages == BIO_MAX_VECS || !len ||
fscrypt: add inline encryption support Add support for inline encryption to fs/crypto/. With "inline encryption", the block layer handles the decryption/encryption as part of the bio, instead of the filesystem doing the crypto itself via Linux's crypto API. This model is needed in order to take advantage of the inline encryption hardware present on most modern mobile SoCs. To use inline encryption, the filesystem needs to be mounted with '-o inlinecrypt'. Blk-crypto will then be used instead of the traditional filesystem-layer crypto whenever possible to encrypt the contents of any encrypted files in that filesystem. Fscrypt still provides the key and IV to use, and the actual ciphertext on-disk is still the same; therefore it's testable using the existing fscrypt ciphertext verification tests. Note that since blk-crypto has a fallback to Linux's crypto API, and also supports all the encryption modes currently supported by fscrypt, this feature is usable and testable even without actual inline encryption hardware. Per-filesystem changes will be needed to set encryption contexts when submitting bios and to implement the 'inlinecrypt' mount option. This patch just adds the common code. Signed-off-by: Satya Tangirala <satyat@google.com> Reviewed-by: Jaegeuk Kim <jaegeuk@kernel.org> Reviewed-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Theodore Ts'o <tytso@mit.edu> Link: https://lore.kernel.org/r/20200702015607.1215430-3-satyat@google.com Co-developed-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Eric Biggers <ebiggers@google.com>
2020-07-02 01:56:05 +00:00
!fscrypt_mergeable_bio(bio, inode, lblk)) {
err = submit_bio_wait(bio);
if (err)
goto out;
bio_reset(bio);
num_pages = 0;
}
}
out:
bio_put(bio);
return err;
}
/**
* fscrypt_zeroout_range() - zero out a range of blocks in an encrypted file
* @inode: the file's inode
* @lblk: the first file logical block to zero out
* @pblk: the first filesystem physical block to zero out
* @len: number of blocks to zero out
*
* Zero out filesystem blocks in an encrypted regular file on-disk, i.e. write
* ciphertext blocks which decrypt to the all-zeroes block. The blocks must be
* both logically and physically contiguous. It's also assumed that the
* filesystem only uses a single block device, ->s_bdev.
*
* Note that since each block uses a different IV, this involves writing a
* different ciphertext to each block; we can't simply reuse the same one.
*
* Return: 0 on success; -errno on failure.
*/
int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk,
sector_t pblk, unsigned int len)
{
const unsigned int blockbits = inode->i_blkbits;
const unsigned int blocksize = 1 << blockbits;
const unsigned int blocks_per_page_bits = PAGE_SHIFT - blockbits;
const unsigned int blocks_per_page = 1 << blocks_per_page_bits;
struct page *pages[16]; /* write up to 16 pages at a time */
unsigned int nr_pages;
unsigned int i;
unsigned int offset;
struct bio *bio;
int ret, err;
if (len == 0)
return 0;
fscrypt: add inline encryption support Add support for inline encryption to fs/crypto/. With "inline encryption", the block layer handles the decryption/encryption as part of the bio, instead of the filesystem doing the crypto itself via Linux's crypto API. This model is needed in order to take advantage of the inline encryption hardware present on most modern mobile SoCs. To use inline encryption, the filesystem needs to be mounted with '-o inlinecrypt'. Blk-crypto will then be used instead of the traditional filesystem-layer crypto whenever possible to encrypt the contents of any encrypted files in that filesystem. Fscrypt still provides the key and IV to use, and the actual ciphertext on-disk is still the same; therefore it's testable using the existing fscrypt ciphertext verification tests. Note that since blk-crypto has a fallback to Linux's crypto API, and also supports all the encryption modes currently supported by fscrypt, this feature is usable and testable even without actual inline encryption hardware. Per-filesystem changes will be needed to set encryption contexts when submitting bios and to implement the 'inlinecrypt' mount option. This patch just adds the common code. Signed-off-by: Satya Tangirala <satyat@google.com> Reviewed-by: Jaegeuk Kim <jaegeuk@kernel.org> Reviewed-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Theodore Ts'o <tytso@mit.edu> Link: https://lore.kernel.org/r/20200702015607.1215430-3-satyat@google.com Co-developed-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Eric Biggers <ebiggers@google.com>
2020-07-02 01:56:05 +00:00
if (fscrypt_inode_uses_inline_crypto(inode))
return fscrypt_zeroout_range_inline_crypt(inode, lblk, pblk,
len);
BUILD_BUG_ON(ARRAY_SIZE(pages) > BIO_MAX_VECS);
nr_pages = min_t(unsigned int, ARRAY_SIZE(pages),
(len + blocks_per_page - 1) >> blocks_per_page_bits);
/*
* We need at least one page for ciphertext. Allocate the first one
* from a mempool, with __GFP_DIRECT_RECLAIM set so that it can't fail.
*
* Any additional page allocations are allowed to fail, as they only
* help performance, and waiting on the mempool for them could deadlock.
*/
for (i = 0; i < nr_pages; i++) {
pages[i] = fscrypt_alloc_bounce_page(i == 0 ? GFP_NOFS :
GFP_NOWAIT | __GFP_NOWARN);
if (!pages[i])
break;
}
nr_pages = i;
if (WARN_ON(nr_pages <= 0))
return -EINVAL;
/* This always succeeds since __GFP_DIRECT_RECLAIM is set. */
bio = bio_alloc(GFP_NOFS, nr_pages);
do {
bio_set_dev(bio, inode->i_sb->s_bdev);
bio->bi_iter.bi_sector = pblk << (blockbits - 9);
bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
i = 0;
offset = 0;
do {
err = fscrypt_crypt_block(inode, FS_ENCRYPT, lblk,
ZERO_PAGE(0), pages[i],
blocksize, offset, GFP_NOFS);
if (err)
goto out;
lblk++;
pblk++;
len--;
offset += blocksize;
if (offset == PAGE_SIZE || len == 0) {
ret = bio_add_page(bio, pages[i++], offset, 0);
if (WARN_ON(ret != offset)) {
err = -EIO;
goto out;
}
offset = 0;
}
} while (i != nr_pages && len != 0);
err = submit_bio_wait(bio);
if (err)
goto out;
bio_reset(bio);
} while (len != 0);
err = 0;
out:
bio_put(bio);
for (i = 0; i < nr_pages; i++)
fscrypt_free_bounce_page(pages[i]);
return err;
}
EXPORT_SYMBOL(fscrypt_zeroout_range);