On 2014-02-17 11:42, Ryusuke Konishi wrote:
> On Mon, 17 Feb 2014 10:06:56 +0100, Andreas Rohner wrote:
>> Hi Ryusuke,
>>
>> On 2014-02-17 04:00, Ryusuke Konishi wrote:
>>>> + segnum >= nilfs->ns_nsegments ||
>>>
>>> This is bad too, because userland programs usually don't know the
>>> segment structure of NILFS. When we specify the partition size to
>>> range->len, FITRIM can fail due to this check.
>>>
>>> The upper limit of (range->start + range->len) should be
>>> the block device size.
>>
>> ext4 also checks the range structure like that. Besides couldn't it be
>> possible, that the block device is bigger than the file system?
>
> As I mentioned in my second mail, I misunderstood the meaning of this
> check at first.
>
> As you pointed out, the block device size may be bigger than the file
> system size after shrinking the file system. So, sbp->s_dev_size
> should be used for for this check. But it is a bit complicated since
> the current nilfs object doesn't have on-memory copy of it.
>
> It is OK to use nilfs->ns_nsegments as its alternative.
Ok, just to be clear. According to your second mail it should look
something like this in nilfs_sufile_trim_fs():
if (segnum >= nilfs->ns_nsegments)
goto out;
And in nilfs_ioctl_trim_fs():
if (range.len < nilfs->ns_blocksize ||
range.start >= (nilfs->ns_nsegments *
nilfs->ns_blocks_per_segment) <<
nilfs->ns_blocksize_bits)
return -EINVAL;
Is that correct?
Regards,
Andreas Rohner
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