Revision 50338b889dc504c69e0cb316ac92d1b9e51f3c8a authored by Török Edwin on 15 June 2011, 21:06:14 UTC, committed by Al Viro on 16 June 2011, 15:27:39 UTC
Git bisection shows that commit e6bc45d65df8599fdbae73be9cec4ceed274db53 causes
BUG_ONs under high I/O load:
kernel BUG at fs/inode.c:1368!
[ 2862.501007] Call Trace:
[ 2862.501007] [<ffffffff811691d8>] d_kill+0xf8/0x140
[ 2862.501007] [<ffffffff81169c19>] dput+0xc9/0x190
[ 2862.501007] [<ffffffff8115577f>] fput+0x15f/0x210
[ 2862.501007] [<ffffffff81152171>] filp_close+0x61/0x90
[ 2862.501007] [<ffffffff81152251>] sys_close+0xb1/0x110
[ 2862.501007] [<ffffffff814c14fb>] system_call_fastpath+0x16/0x1b
A reliable way to reproduce this bug is:
Login to KDE, run 'rsnapshot sync', and apt-get install openjdk-6-jdk,
and apt-get remove openjdk-6-jdk.
The buggy part of the patch is this:
struct inode *inode = NULL;
.....
- if (nd.last.name[nd.last.len])
- goto slashes;
inode = dentry->d_inode;
- if (inode)
- ihold(inode);
+ if (nd.last.name[nd.last.len] || !inode)
+ goto slashes;
+ ihold(inode)
...
if (inode)
iput(inode); /* truncate the inode here */
If nd.last.name[nd.last.len] is nonzero (and thus goto slashes branch is taken),
and dentry->d_inode is non-NULL, then this code now does an additional iput on
the inode, which is wrong.
Fix this by only setting the inode variable if nd.last.name[nd.last.len] is 0.
Reference: https://lkml.org/lkml/2011/6/15/50
Reported-by: Norbert Preining <preining@logic.at>
Reported-by: Török Edwin <edwintorok@gmail.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Török Edwin <edwintorok@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
1 parent a685e08
compress.c
/*
* Cryptographic API.
*
* Compression operations.
*
* Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
* Software Foundation; either version 2 of the License, or (at your option)
* any later version.
*
*/
#include <linux/types.h>
#include <linux/crypto.h>
#include <linux/errno.h>
#include <linux/string.h>
#include "internal.h"
static int crypto_compress(struct crypto_tfm *tfm,
const u8 *src, unsigned int slen,
u8 *dst, unsigned int *dlen)
{
return tfm->__crt_alg->cra_compress.coa_compress(tfm, src, slen, dst,
dlen);
}
static int crypto_decompress(struct crypto_tfm *tfm,
const u8 *src, unsigned int slen,
u8 *dst, unsigned int *dlen)
{
return tfm->__crt_alg->cra_compress.coa_decompress(tfm, src, slen, dst,
dlen);
}
int crypto_init_compress_ops(struct crypto_tfm *tfm)
{
struct compress_tfm *ops = &tfm->crt_compress;
ops->cot_compress = crypto_compress;
ops->cot_decompress = crypto_decompress;
return 0;
}
void crypto_exit_compress_ops(struct crypto_tfm *tfm)
{
}
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