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Revision e6da7c9fed111ba1243297ee6eda8e24ae11c384 authored by Eric Sandeen on 23 May 2009, 19:30:12 UTC, committed by Felix Blyakher on 02 June 2009, 03:59:38 UTC 
xfs: fix overflow in xfs_growfs_data_private
 
In the case where growing a filesystem would leave the last AG
too small, the fixup code has an overflow in the calculation
of the new size with one fewer ag, because "nagcount" is a 32
bit number.  If the new filesystem has > 2^32 blocks in it
this causes a problem resulting in an EINVAL return from growfs:

 # xfs_io -f -c "truncate 19998630180864" fsfile
 # mkfs.xfs -f -bsize=4096 -dagsize=76288719b,size=3905982455b fsfile
 # mount -o loop fsfile /mnt
 # xfs_growfs /mnt

meta-data=/dev/loop0             isize=256    agcount=52,
agsize=76288719 blks
         =                       sectsz=512   attr=2
data     =                       bsize=4096   blocks=3905982455, imaxpct=5
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0
log      =internal               bsize=4096   blocks=32768, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=0
realtime =none                   extsz=4096   blocks=0, rtextents=0
xfs_growfs: XFS_IOC_FSGROWFSDATA xfsctl failed: Invalid argument

Reported-by: richard.ems@cape-horn-eng.com
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Felix Blyakher <felixb@sgi.com>
Signed-off-by: Felix Blyakher <felixb@sgi.com>
1 parent 1f23920
Raw File
find_last_bit.c 
/* find_last_bit.c: fallback find next bit implementation
 *
 * Copyright (C) 2008 IBM Corporation
 * Written by Rusty Russell <rusty@rustcorp.com.au>
 * (Inspired by David Howell's find_next_bit implementation)
 *
 * 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/bitops.h>
#include <linux/module.h>
#include <asm/types.h>
#include <asm/byteorder.h>

unsigned long find_last_bit(const unsigned long *addr, unsigned long size)
{
	unsigned long words;
	unsigned long tmp;

	/* Start at final word. */
	words = size / BITS_PER_LONG;

	/* Partial final word? */
	if (size & (BITS_PER_LONG-1)) {
		tmp = (addr[words] & (~0UL >> (BITS_PER_LONG
					 - (size & (BITS_PER_LONG-1)))));
		if (tmp)
			goto found;
	}

	while (words) {
		tmp = addr[--words];
		if (tmp) {
found:
			return words * BITS_PER_LONG + __fls(tmp);
		}
	}

	/* Not found */
	return size;
}
EXPORT_SYMBOL(find_last_bit);
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