----- 原始邮件 ----- > 发件人: "Eric Sandeen" <sandeen@xxxxxxxxxxx> > 收件人: "Dave Chinner" <david@xxxxxxxxxxxxx>, "Eric Sandeen" <sandeen@xxxxxxxxxx> > 抄送: "Zorro Lang" <zlang@xxxxxxxxxx>, fstests@xxxxxxxxxxxxxxx > 发送时间: 星期三, 2015年 8 月 19日 上午 7:03:45 > 主题: Re: [PATCH] xfs/194: fix the exception when run on 4k sector drives > > On 8/18/15 5:43 PM, Dave Chinner wrote: > > On Tue, Aug 18, 2015 at 05:33:05PM -0500, Eric Sandeen wrote: > >> On 8/18/15 5:28 PM, Dave Chinner wrote: > >>> On Wed, Aug 19, 2015 at 01:21:51AM +0800, Zorro Lang wrote: > >>>> @@ -50,6 +50,16 @@ rm -f $seqres.full > >>>> # For this test we use block size = 1/8 page size > >>>> pgsize=`$here/src/feature -s` > >>>> blksize=`expr $pgsize / 8` > >>>> +secsize=`_min_dio_alignment $SCRATCH_DEV` > >>>> + > >>>> +# The minimal blksize can't less than sector size, So if > >>>> +# blksize < secsize, we should adjust blksize and pgsize number. > >>>> +# Of course, if we adjust pgsize, pgsize won't equal to the > >>>> +# real page size of system. > >>>> +if [ $blksize -lt $secsize ];then > >>>> + blksize=$secsize > >>>> + pgsize=`expr $blksize \* 8` > >>>> +fi > >>> > >>> No, this is wrong. the page size stays fixed at the machine page > >>> size. We are testing *sub-page block sizes* here and the sector size > >>> must be <= page size. Increasing the "page size" to larger than the > >>> machine page size does not make the kernel use larger page sizes. > >>> > >>> IOWs, if you've got sector size = page size (e.g. 4k sector device) > >>> then no matter what you say $pgsize is, the kernel will see a block > >>> size = page size test. Yes, I know I can't change page size. So I said "for sure the consistency of test result, I repair pgsize(already not real page size) number according to the new blksize." in git commit message. Eric said in xfs/194 "Test mapping around/over holes for sub-page blocks", If the sector size = page size, I have no idea how to make sub-page blocks. So in this situation, I set pgsize=`expr $blksize \* 8` just for the test output suit for 194.out. Or we don't care pgsize, just set blksize=`_min_dio_alignment $SCRATCH_DEV`, and then replace all $pgsize to `expr $blksize \* 8`. If page size > blksize, that's good. If not, we can't do more things about that, so just make it run pass. > >>> > >>> This whole chunk of code can simply be replaced with: > >>> > >>> blksize=`_min_dio_alignment $SCRATCH_DEV` > >>> > >>> Because that's what we actually need to test... > >> > >> That won't work either, because we could easily get 512 from that. > > > > If 'blockdev --getss $dev' returns 512, then the device supports 512 > > byte IOs and so it is fine to do 512 byte IOs in the test. > > > >> and then this test: > >> > >> # Now try the same thing but write a sector in the middle of that hole > >> # If things go badly stale data will be exposed either side. > >> # This is most interesting for block size > 512 (page size > 4096) > >> > >> # We *should* get: > >> # |1100|HHHH|33HH|HHHH|2222|----|----|----| > >> > >> echo "== Test 4 ==" > >> xfs_io \ > >> -c "pwrite -S 0x11 -b $pgsize 0 $pgsize" \ > >> -c "mmap -r 0 $blksize" -c "mread 0 $blksize" -c "munmap" \ > >> -c "truncate `expr $blksize / 2`" \ > >> -c "truncate `expr $blksize + 1`" \ > >> -c "pwrite -S 0x22 -b $blksize `expr $pgsize / 2` $blksize" \ > >> -c "pwrite -S 0x33 -b 512 `expr $blksize \* 2` 512" \ > >> -t -d -f $SCRATCH_MNT/testfile4 >> $seqres.full > >> > >> will be impossible. > >> > >> AFAICT everything works except for that explicit 512-byte IO. > > > > Right. That hard coded 512 needs to change to $blksize, because > > blksize is now equal to the sector size. I thought this would be > > obvious to the reader, so I didn't comment on it. > > if that last IO is $blksize, and blocksize == sector size, then the > test won't be testing what it's designed to test here, i.e. a > sub-block direct IO write. What do you think about loop device? If page size(4k) = sector size(4k), how about use loop device? I think it will be 512 sector size as default? Thanks, Zorro > > # We *should* get: > # |1100|HHHH|33HH|HHHH|2222|----|----|----| > ^^ > this > > -Eric > > -- To unsubscribe from this list: send the line "unsubscribe fstests" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
