Skip to main content

Browse the archive

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
ecdh_helper.c 
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (c) 2016, Intel Corporation
 * Authors: Salvatore Benedetto <salvatore.benedetto@intel.com>
 */
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/err.h>
#include <linux/string.h>
#include <crypto/ecdh.h>
#include <crypto/kpp.h>

#define ECDH_KPP_SECRET_MIN_SIZE (sizeof(struct kpp_secret) + 2 * sizeof(short))

static inline u8 *ecdh_pack_data(void *dst, const void *src, size_t sz)
{
	memcpy(dst, src, sz);
	return dst + sz;
}

static inline const u8 *ecdh_unpack_data(void *dst, const void *src, size_t sz)
{
	memcpy(dst, src, sz);
	return src + sz;
}

unsigned int crypto_ecdh_key_len(const struct ecdh *params)
{
	return ECDH_KPP_SECRET_MIN_SIZE + params->key_size;
}
EXPORT_SYMBOL_GPL(crypto_ecdh_key_len);

int crypto_ecdh_encode_key(char *buf, unsigned int len,
			   const struct ecdh *params)
{
	u8 *ptr = buf;
	struct kpp_secret secret = {
		.type = CRYPTO_KPP_SECRET_TYPE_ECDH,
		.len = len
	};

	if (unlikely(!buf))
		return -EINVAL;

	if (len != crypto_ecdh_key_len(params))
		return -EINVAL;

	ptr = ecdh_pack_data(ptr, &secret, sizeof(secret));
	ptr = ecdh_pack_data(ptr, &params->curve_id, sizeof(params->curve_id));
	ptr = ecdh_pack_data(ptr, &params->key_size, sizeof(params->key_size));
	ecdh_pack_data(ptr, params->key, params->key_size);

	return 0;
}
EXPORT_SYMBOL_GPL(crypto_ecdh_encode_key);

int crypto_ecdh_decode_key(const char *buf, unsigned int len,
			   struct ecdh *params)
{
	const u8 *ptr = buf;
	struct kpp_secret secret;

	if (unlikely(!buf || len < ECDH_KPP_SECRET_MIN_SIZE))
		return -EINVAL;

	ptr = ecdh_unpack_data(&secret, ptr, sizeof(secret));
	if (secret.type != CRYPTO_KPP_SECRET_TYPE_ECDH)
		return -EINVAL;

	if (unlikely(len < secret.len))
		return -EINVAL;

	ptr = ecdh_unpack_data(&params->curve_id, ptr, sizeof(params->curve_id));
	ptr = ecdh_unpack_data(&params->key_size, ptr, sizeof(params->key_size));
	if (secret.len != crypto_ecdh_key_len(params))
		return -EINVAL;

	/* Don't allocate memory. Set pointer to data
	 * within the given buffer
	 */
	params->key = (void *)ptr;

	return 0;
}
EXPORT_SYMBOL_GPL(crypto_ecdh_decode_key);
back to top