From: Miao Xie <miaox@cn.fujitsu.com>
To: Linux Btrfs <linux-btrfs@vger.kernel.org>
Subject: Re: [PATCH V3 1/2] Btrfs: cleanup duplicated division functions
Date: Sun, 23 Sep 2012 17:54:18 +0800 [thread overview]
Message-ID: <505EDC4A.1060709@cn.fujitsu.com> (raw)
In-Reply-To: <20120921152444.GV17430@twin.jikos.cz>
On Fri, 21 Sep 2012 17:24:44 +0200, David Sterba wrote:
> On Fri, Sep 21, 2012 at 05:07:46PM +0800, Miao Xie wrote:
>> --- a/fs/btrfs/ioctl.c
>> +++ b/fs/btrfs/ioctl.c
>> @@ -3335,6 +3335,24 @@ static long btrfs_ioctl_balance(struct file *file, void __user *arg)
>>
>> goto do_balance;
>> }
>> +
>> + if ((bargs->data.flags & BTRFS_BALANCE_ARGS_USAGE) &&
>> + (bargs->data.usage < 0 || bargs->data.usage > 100)) {
>
> the 0 checks belong here
>
>> + ret = -EINVAL;
>> + goto out_bargs;
>> + }
>> +
>> + if ((bargs->meta.flags & BTRFS_BALANCE_ARGS_USAGE) &&
>> + (bargs->meta.usage < 0 || bargs->meta.usage > 100)) {
>> + ret = -EINVAL;
>> + goto out_bargs;
>> + }
>> +
>> + if ((bargs->sys.flags & BTRFS_BALANCE_ARGS_USAGE) &&
>> + (bargs->sys.usage < 0 || bargs->sys.usage > 100)) {
>> + ret = -EINVAL;
>> + goto out_bargs;
>> + }
>> } else {
>> bargs = NULL;
>> }
>> @@ -2347,7 +2335,8 @@ static int chunk_usage_filter(struct btrfs_fs_info *fs_info, u64 chunk_offset,
>> cache = btrfs_lookup_block_group(fs_info, chunk_offset);
>> chunk_used = btrfs_block_group_used(&cache->item);
>>
>> - user_thresh = div_factor_fine(cache->key.offset, bargs->usage);
>> + BUG_ON(bargs->usage < 0 || bargs->usage > 100);
>
> otherwise it reliably crashes here
Sorry, I don't know why it will crash here if we input 0. I tried to input 0,
and it worked well.
I think the only case we must take into account is the users might input the wrong value (>100 or <0)
on the old kernel, and it can be stored into the filesystem. If we mount this filesystem
on the new kernel, some problems may happen.
Thanks
Miao
next prev parent reply other threads:[~2012-09-23 9:54 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-13 10:51 [PATCH 1/2] Btrfs: cleanup duplicated division functions Miao Xie
2012-09-14 13:54 ` David Sterba
2012-09-17 2:21 ` Miao Xie
2012-09-17 12:07 ` Ilya Dryomov
2012-09-17 16:31 ` David Sterba
2012-09-18 3:53 ` Miao Xie
2012-09-20 2:57 ` [PATCH V2 " Miao Xie
2012-09-20 13:28 ` David Sterba
2012-09-21 8:26 ` Miao Xie
2012-09-21 9:07 ` [PATCH V3 " Miao Xie
2012-09-21 15:24 ` David Sterba
2012-09-23 9:54 ` Miao Xie [this message]
2012-09-24 16:33 ` David Sterba
2012-09-23 11:49 ` Ilya Dryomov
2012-09-24 2:05 ` Miao Xie
2012-09-24 16:47 ` David Sterba
2012-09-24 18:42 ` Ilya Dryomov
2012-09-25 10:24 ` Miao Xie
2012-09-27 10:15 ` Miao Xie
2012-09-27 10:19 ` [PATCH V4 " Miao Xie
2012-09-27 16:56 ` Ilya Dryomov
2012-09-28 1:30 ` Miao Xie
2012-09-28 1:49 ` [PATCH V5 " Miao Xie
2012-09-28 10:09 ` David Sterba
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