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
fips.c 
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * FIPS 200 support.
 *
 * Copyright (c) 2008 Neil Horman <nhorman@tuxdriver.com>
 */

#include <linux/export.h>
#include <linux/fips.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sysctl.h>
#include <linux/notifier.h>

int fips_enabled;
EXPORT_SYMBOL_GPL(fips_enabled);

ATOMIC_NOTIFIER_HEAD(fips_fail_notif_chain);
EXPORT_SYMBOL_GPL(fips_fail_notif_chain);

/* Process kernel command-line parameter at boot time. fips=0 or fips=1 */
static int fips_enable(char *str)
{
	fips_enabled = !!simple_strtol(str, NULL, 0);
	printk(KERN_INFO "fips mode: %s\n",
		fips_enabled ? "enabled" : "disabled");
	return 1;
}

__setup("fips=", fips_enable);

static struct ctl_table crypto_sysctl_table[] = {
	{
		.procname       = "fips_enabled",
		.data           = &fips_enabled,
		.maxlen         = sizeof(int),
		.mode           = 0444,
		.proc_handler   = proc_dointvec
	},
	{}
};

static struct ctl_table crypto_dir_table[] = {
	{
		.procname       = "crypto",
		.mode           = 0555,
		.child          = crypto_sysctl_table
	},
	{}
};

static struct ctl_table_header *crypto_sysctls;

static void crypto_proc_fips_init(void)
{
	crypto_sysctls = register_sysctl_table(crypto_dir_table);
}

static void crypto_proc_fips_exit(void)
{
	unregister_sysctl_table(crypto_sysctls);
}

void fips_fail_notify(void)
{
	if (fips_enabled)
		atomic_notifier_call_chain(&fips_fail_notif_chain, 0, NULL);
}
EXPORT_SYMBOL_GPL(fips_fail_notify);

static int __init fips_init(void)
{
	crypto_proc_fips_init();
	return 0;
}

static void __exit fips_exit(void)
{
	crypto_proc_fips_exit();
}

subsys_initcall(fips_init);
module_exit(fips_exit);
back to top