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
pcompress.c
/*
* Cryptographic API.
*
* Partial (de)compression operations.
*
* Copyright 2008 Sony Corporation
*
* 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; version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program.
* If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/crypto.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/seq_file.h>
#include <linux/string.h>
#include <crypto/compress.h>
#include <crypto/internal/compress.h>
#include "internal.h"
static int crypto_pcomp_init(struct crypto_tfm *tfm, u32 type, u32 mask)
{
return 0;
}
static unsigned int crypto_pcomp_extsize(struct crypto_alg *alg)
{
return alg->cra_ctxsize;
}
static int crypto_pcomp_init_tfm(struct crypto_tfm *tfm)
{
return 0;
}
static void crypto_pcomp_show(struct seq_file *m, struct crypto_alg *alg)
__attribute__ ((unused));
static void crypto_pcomp_show(struct seq_file *m, struct crypto_alg *alg)
{
seq_printf(m, "type : pcomp\n");
}
static const struct crypto_type crypto_pcomp_type = {
.extsize = crypto_pcomp_extsize,
.init = crypto_pcomp_init,
.init_tfm = crypto_pcomp_init_tfm,
#ifdef CONFIG_PROC_FS
.show = crypto_pcomp_show,
#endif
.maskclear = ~CRYPTO_ALG_TYPE_MASK,
.maskset = CRYPTO_ALG_TYPE_MASK,
.type = CRYPTO_ALG_TYPE_PCOMPRESS,
.tfmsize = offsetof(struct crypto_pcomp, base),
};
struct crypto_pcomp *crypto_alloc_pcomp(const char *alg_name, u32 type,
u32 mask)
{
return crypto_alloc_tfm(alg_name, &crypto_pcomp_type, type, mask);
}
EXPORT_SYMBOL_GPL(crypto_alloc_pcomp);
int crypto_register_pcomp(struct pcomp_alg *alg)
{
struct crypto_alg *base = &alg->base;
base->cra_type = &crypto_pcomp_type;
base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
base->cra_flags |= CRYPTO_ALG_TYPE_PCOMPRESS;
return crypto_register_alg(base);
}
EXPORT_SYMBOL_GPL(crypto_register_pcomp);
int crypto_unregister_pcomp(struct pcomp_alg *alg)
{
return crypto_unregister_alg(&alg->base);
}
EXPORT_SYMBOL_GPL(crypto_unregister_pcomp);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Partial (de)compression type");
MODULE_AUTHOR("Sony Corporation");
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