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Revision 082cd4ec240b8734a82a89ffb890216ac98fec68 authored by Ye Bin on 06 May 2021, 14:10:42 UTC, committed by Theodore Ts'o on 06 June 2021, 14:09:55 UTC 
ext4: fix bug on in ext4_es_cache_extent as ext4_split_extent_at failed
 
We got follow bug_on when run fsstress with injecting IO fault:
[130747.323114] kernel BUG at fs/ext4/extents_status.c:762!
[130747.323117] Internal error: Oops - BUG: 0 [#1] SMP
......
[130747.334329] Call trace:
[130747.334553]  ext4_es_cache_extent+0x150/0x168 [ext4]
[130747.334975]  ext4_cache_extents+0x64/0xe8 [ext4]
[130747.335368]  ext4_find_extent+0x300/0x330 [ext4]
[130747.335759]  ext4_ext_map_blocks+0x74/0x1178 [ext4]
[130747.336179]  ext4_map_blocks+0x2f4/0x5f0 [ext4]
[130747.336567]  ext4_mpage_readpages+0x4a8/0x7a8 [ext4]
[130747.336995]  ext4_readpage+0x54/0x100 [ext4]
[130747.337359]  generic_file_buffered_read+0x410/0xae8
[130747.337767]  generic_file_read_iter+0x114/0x190
[130747.338152]  ext4_file_read_iter+0x5c/0x140 [ext4]
[130747.338556]  __vfs_read+0x11c/0x188
[130747.338851]  vfs_read+0x94/0x150
[130747.339110]  ksys_read+0x74/0xf0

This patch's modification is according to Jan Kara's suggestion in:
https://patchwork.ozlabs.org/project/linux-ext4/patch/20210428085158.3728201-1-yebin10@huawei.com/
"I see. Now I understand your patch. Honestly, seeing how fragile is trying
to fix extent tree after split has failed in the middle, I would probably
go even further and make sure we fix the tree properly in case of ENOSPC
and EDQUOT (those are easily user triggerable).  Anything else indicates a
HW problem or fs corruption so I'd rather leave the extent tree as is and
don't try to fix it (which also means we will not create overlapping
extents)."

Cc: stable@kernel.org
Signed-off-by: Ye Bin <yebin10@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20210506141042.3298679-1-yebin10@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
1 parent b45f189
Raw File
sha256_generic.c 
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Crypto API wrapper for the generic SHA256 code from lib/crypto/sha256.c
 *
 * Copyright (c) Jean-Luc Cooke <jlcooke@certainkey.com>
 * Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
 * SHA224 Support Copyright 2007 Intel Corporation <jonathan.lynch@intel.com>
 */
#include <crypto/internal/hash.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/types.h>
#include <crypto/sha2.h>
#include <crypto/sha256_base.h>
#include <asm/byteorder.h>
#include <asm/unaligned.h>

const u8 sha224_zero_message_hash[SHA224_DIGEST_SIZE] = {
	0xd1, 0x4a, 0x02, 0x8c, 0x2a, 0x3a, 0x2b, 0xc9, 0x47,
	0x61, 0x02, 0xbb, 0x28, 0x82, 0x34, 0xc4, 0x15, 0xa2,
	0xb0, 0x1f, 0x82, 0x8e, 0xa6, 0x2a, 0xc5, 0xb3, 0xe4,
	0x2f
};
EXPORT_SYMBOL_GPL(sha224_zero_message_hash);

const u8 sha256_zero_message_hash[SHA256_DIGEST_SIZE] = {
	0xe3, 0xb0, 0xc4, 0x42, 0x98, 0xfc, 0x1c, 0x14,
	0x9a, 0xfb, 0xf4, 0xc8, 0x99, 0x6f, 0xb9, 0x24,
	0x27, 0xae, 0x41, 0xe4, 0x64, 0x9b, 0x93, 0x4c,
	0xa4, 0x95, 0x99, 0x1b, 0x78, 0x52, 0xb8, 0x55
};
EXPORT_SYMBOL_GPL(sha256_zero_message_hash);

static int crypto_sha256_init(struct shash_desc *desc)
{
	sha256_init(shash_desc_ctx(desc));
	return 0;
}

static int crypto_sha224_init(struct shash_desc *desc)
{
	sha224_init(shash_desc_ctx(desc));
	return 0;
}

int crypto_sha256_update(struct shash_desc *desc, const u8 *data,
			  unsigned int len)
{
	sha256_update(shash_desc_ctx(desc), data, len);
	return 0;
}
EXPORT_SYMBOL(crypto_sha256_update);

static int crypto_sha256_final(struct shash_desc *desc, u8 *out)
{
	if (crypto_shash_digestsize(desc->tfm) == SHA224_DIGEST_SIZE)
		sha224_final(shash_desc_ctx(desc), out);
	else
		sha256_final(shash_desc_ctx(desc), out);
	return 0;
}

int crypto_sha256_finup(struct shash_desc *desc, const u8 *data,
			unsigned int len, u8 *hash)
{
	sha256_update(shash_desc_ctx(desc), data, len);
	return crypto_sha256_final(desc, hash);
}
EXPORT_SYMBOL(crypto_sha256_finup);

static struct shash_alg sha256_algs[2] = { {
	.digestsize	=	SHA256_DIGEST_SIZE,
	.init		=	crypto_sha256_init,
	.update		=	crypto_sha256_update,
	.final		=	crypto_sha256_final,
	.finup		=	crypto_sha256_finup,
	.descsize	=	sizeof(struct sha256_state),
	.base		=	{
		.cra_name	=	"sha256",
		.cra_driver_name=	"sha256-generic",
		.cra_priority	=	100,
		.cra_blocksize	=	SHA256_BLOCK_SIZE,
		.cra_module	=	THIS_MODULE,
	}
}, {
	.digestsize	=	SHA224_DIGEST_SIZE,
	.init		=	crypto_sha224_init,
	.update		=	crypto_sha256_update,
	.final		=	crypto_sha256_final,
	.finup		=	crypto_sha256_finup,
	.descsize	=	sizeof(struct sha256_state),
	.base		=	{
		.cra_name	=	"sha224",
		.cra_driver_name=	"sha224-generic",
		.cra_priority	=	100,
		.cra_blocksize	=	SHA224_BLOCK_SIZE,
		.cra_module	=	THIS_MODULE,
	}
} };

static int __init sha256_generic_mod_init(void)
{
	return crypto_register_shashes(sha256_algs, ARRAY_SIZE(sha256_algs));
}

static void __exit sha256_generic_mod_fini(void)
{
	crypto_unregister_shashes(sha256_algs, ARRAY_SIZE(sha256_algs));
}

subsys_initcall(sha256_generic_mod_init);
module_exit(sha256_generic_mod_fini);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("SHA-224 and SHA-256 Secure Hash Algorithm");

MODULE_ALIAS_CRYPTO("sha224");
MODULE_ALIAS_CRYPTO("sha224-generic");
MODULE_ALIAS_CRYPTO("sha256");
MODULE_ALIAS_CRYPTO("sha256-generic");
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