Revision 6946bd636364effce06ea46fe8f8cd6e2edb004e authored by Peter Zijlstra on 27 August 2006, 08:23:31 UTC, committed by Linus Torvalds on 27 August 2006, 18:01:29 UTC
On Wed, 2006-08-09 at 07:57 +0200, Rolf Eike Beer wrote:
> =============================================
> [ INFO: possible recursive locking detected ]
> ---------------------------------------------
> parted/7929 is trying to acquire lock:
>  (&bdev->bd_mutex){--..}, at: [<c105eb8d>] __blkdev_put+0x1e/0x13c
>
> but task is already holding lock:
>  (&bdev->bd_mutex){--..}, at: [<c105eec6>] do_open+0x72/0x3a8
>
> other info that might help us debug this:
> 1 lock held by parted/7929:
>  #0:  (&bdev->bd_mutex){--..}, at: [<c105eec6>] do_open+0x72/0x3a8
> stack backtrace:
>  [<c1003aad>] show_trace_log_lvl+0x58/0x15b
>  [<c100495f>] show_trace+0xd/0x10
>  [<c1004979>] dump_stack+0x17/0x1a
>  [<c102dee5>] __lock_acquire+0x753/0x99c
>  [<c102e3b0>] lock_acquire+0x4a/0x6a
>  [<c1204501>] mutex_lock_nested+0xc8/0x20c
>  [<c105eb8d>] __blkdev_put+0x1e/0x13c
>  [<c105ecc4>] blkdev_put+0xa/0xc
>  [<c105f18a>] do_open+0x336/0x3a8
>  [<c105f21b>] blkdev_open+0x1f/0x4c
>  [<c1057b40>] __dentry_open+0xc7/0x1aa
>  [<c1057c91>] nameidata_to_filp+0x1c/0x2e
>  [<c1057cd1>] do_filp_open+0x2e/0x35
>  [<c1057dd7>] do_sys_open+0x38/0x68
>  [<c1057e33>] sys_open+0x16/0x18
>  [<c1002845>] sysenter_past_esp+0x56/0x8d

OK, I'm having a look here; its all new to me so bear with me.

blkdev_open() calls
  do_open(bdev, ...,BD_MUTEX_NORMAL) and takes
    mutex_lock_nested(&bdev->bd_mutex, BD_MUTEX_NORMAL)

then something fails, and we're thrown to:

out_first: where
    if (bdev != bdev->bd_contains)
      blkdev_put(bdev->bd_contains) which is
        __blkdev_put(bdev->bd_contains, BD_MUTEX_NORMAL) which does
          mutex_lock_nested(&bdev->bd_contains->bd_mutex, BD_MUTEX_NORMAL) <--- lockdep trigger

When going to out_first, dbev->bd_contains is either bdev or whole, and
since we take the branch it must be whole. So it seems to me the
following patch would be the right one:

[akpm@osdl.org: compile fix]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: NeilBrown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
1 parent 7334bb4
Raw File
ntfs.h
/*
 * ntfs.h - Defines for NTFS Linux kernel driver. Part of the Linux-NTFS
 *	    project.
 *
 * Copyright (c) 2001-2005 Anton Altaparmakov
 * Copyright (C) 2002 Richard Russon
 *
 * This program/include file 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.
 *
 * This program/include file 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 (in the main directory of the Linux-NTFS
 * distribution in the file COPYING); if not, write to the Free Software
 * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#ifndef _LINUX_NTFS_H
#define _LINUX_NTFS_H

#include <linux/stddef.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/compiler.h>
#include <linux/fs.h>
#include <linux/nls.h>
#include <linux/smp.h>
#include <linux/pagemap.h>

#include "types.h"
#include "volume.h"
#include "layout.h"

typedef enum {
	NTFS_BLOCK_SIZE		= 512,
	NTFS_BLOCK_SIZE_BITS	= 9,
	NTFS_SB_MAGIC		= 0x5346544e,	/* 'NTFS' */
	NTFS_MAX_NAME_LEN	= 255,
	NTFS_MAX_ATTR_NAME_LEN	= 255,
	NTFS_MAX_CLUSTER_SIZE	= 64 * 1024,	/* 64kiB */
	NTFS_MAX_PAGES_PER_CLUSTER = NTFS_MAX_CLUSTER_SIZE / PAGE_CACHE_SIZE,
} NTFS_CONSTANTS;

/* Global variables. */

/* Slab caches (from super.c). */
extern struct kmem_cache *ntfs_name_cache;
extern struct kmem_cache *ntfs_inode_cache;
extern struct kmem_cache *ntfs_big_inode_cache;
extern struct kmem_cache *ntfs_attr_ctx_cache;
extern struct kmem_cache *ntfs_index_ctx_cache;

/* The various operations structs defined throughout the driver files. */
extern const struct address_space_operations ntfs_aops;
extern const struct address_space_operations ntfs_mst_aops;

extern const struct  file_operations ntfs_file_ops;
extern struct inode_operations ntfs_file_inode_ops;

extern const struct  file_operations ntfs_dir_ops;
extern struct inode_operations ntfs_dir_inode_ops;

extern const struct  file_operations ntfs_empty_file_ops;
extern struct inode_operations ntfs_empty_inode_ops;

extern struct export_operations ntfs_export_ops;

/**
 * NTFS_SB - return the ntfs volume given a vfs super block
 * @sb:		VFS super block
 *
 * NTFS_SB() returns the ntfs volume associated with the VFS super block @sb.
 */
static inline ntfs_volume *NTFS_SB(struct super_block *sb)
{
	return sb->s_fs_info;
}

/* Declarations of functions and global variables. */

/* From fs/ntfs/compress.c */
extern int ntfs_read_compressed_block(struct page *page);
extern int allocate_compression_buffers(void);
extern void free_compression_buffers(void);

/* From fs/ntfs/super.c */
#define default_upcase_len 0x10000
extern struct mutex ntfs_lock;

typedef struct {
	int val;
	char *str;
} option_t;
extern const option_t on_errors_arr[];

/* From fs/ntfs/mst.c */
extern int post_read_mst_fixup(NTFS_RECORD *b, const u32 size);
extern int pre_write_mst_fixup(NTFS_RECORD *b, const u32 size);
extern void post_write_mst_fixup(NTFS_RECORD *b);

/* From fs/ntfs/unistr.c */
extern BOOL ntfs_are_names_equal(const ntfschar *s1, size_t s1_len,
		const ntfschar *s2, size_t s2_len,
		const IGNORE_CASE_BOOL ic,
		const ntfschar *upcase, const u32 upcase_size);
extern int ntfs_collate_names(const ntfschar *name1, const u32 name1_len,
		const ntfschar *name2, const u32 name2_len,
		const int err_val, const IGNORE_CASE_BOOL ic,
		const ntfschar *upcase, const u32 upcase_len);
extern int ntfs_ucsncmp(const ntfschar *s1, const ntfschar *s2, size_t n);
extern int ntfs_ucsncasecmp(const ntfschar *s1, const ntfschar *s2, size_t n,
		const ntfschar *upcase, const u32 upcase_size);
extern void ntfs_upcase_name(ntfschar *name, u32 name_len,
		const ntfschar *upcase, const u32 upcase_len);
extern void ntfs_file_upcase_value(FILE_NAME_ATTR *file_name_attr,
		const ntfschar *upcase, const u32 upcase_len);
extern int ntfs_file_compare_values(FILE_NAME_ATTR *file_name_attr1,
		FILE_NAME_ATTR *file_name_attr2,
		const int err_val, const IGNORE_CASE_BOOL ic,
		const ntfschar *upcase, const u32 upcase_len);
extern int ntfs_nlstoucs(const ntfs_volume *vol, const char *ins,
		const int ins_len, ntfschar **outs);
extern int ntfs_ucstonls(const ntfs_volume *vol, const ntfschar *ins,
		const int ins_len, unsigned char **outs, int outs_len);

/* From fs/ntfs/upcase.c */
extern ntfschar *generate_default_upcase(void);

static inline int ntfs_ffs(int x)
{
	int r = 1;

	if (!x)
		return 0;
	if (!(x & 0xffff)) {
		x >>= 16;
		r += 16;
	}
	if (!(x & 0xff)) {
		x >>= 8;
		r += 8;
	}
	if (!(x & 0xf)) {
		x >>= 4;
		r += 4;
	}
	if (!(x & 3)) {
		x >>= 2;
		r += 2;
	}
	if (!(x & 1)) {
		x >>= 1;
		r += 1;
	}
	return r;
}

#endif /* _LINUX_NTFS_H */
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