Re: [PATCH] generic/473: fix expectation properly in out file

[Chengguang Xu <cgxu519@mykernel.net>]

 ---- 在 星期三, 2021-02-24 17:22:35 Su Yue <l@damenly.su> 撰写 ----
 > 
 > On Wed 24 Feb 2021 at 16:51, Chengguang Xu <cgxu519@mykernel.net> 
 > wrote:
 > 
 > >  ---- 在 星期三, 2021-02-24 15:52:17 Su Yue <l@damenly.su> 撰写 
 > >  ----
 > >  >
 > >  > Cc to the author and linux-xfs, since it's xfsprogs related.
 > >  >
 > >  > On Tue 23 Feb 2021 at 21:40, Chengguang Xu 
 > >  > <cgxu519@mykernel.net>
 > >  > wrote:
 > >  >
 > >  > > It seems the expected result of testcase of "Hole + Data"
 > >  > > in generic/473 is not correct, so just fix it properly.
 > >  > >
 > >  >
 > >  > But it's not proper...
 > >  >
 > >  > > Signed-off-by: Chengguang Xu <cgxu519@mykernel.net>
 > >  > > ---
 > >  > >  tests/generic/473.out | 2 +-
 > >  > >  1 file changed, 1 insertion(+), 1 deletion(-)
 > >  > >
 > >  > > diff --git a/tests/generic/473.out b/tests/generic/473.out
 > >  > > index 75816388..f1ee5805 100644
 > >  > > --- a/tests/generic/473.out
 > >  > > +++ b/tests/generic/473.out
 > >  > > @@ -6,7 +6,7 @@ Data + Hole
 > >  > >  1: [256..287]: hole
 > >  > >  Hole + Data
 > >  > >  0: [0..127]: hole
 > >  > > -1: [128..255]: data
 > >  > > +1: [128..135]: data
 > >  > >
 > >  > The line is produced by `$XFS_IO_PROG -c "fiemap -v 0 65k" 
 > >  > $file |
 > >  > _filter_fiemap`.
 > >  > 0-64k is a hole and 64k-128k is a data extent.
 > >  > fiemap ioctl always returns *complete* ranges of extents.
 > >
 > > Manual testing result in latest kernel like below.
 > >
 > > [root@centos test]# uname -a
 > > Linux centos 5.11.0+ #5 SMP Tue Feb 23 21:02:27 CST 2021 x86_64 
 > > x86_64 x86_64 GNU/Linux
 > >
 > > [root@centos test]# xfs_io -V
 > > xfs_io version 5.0.0
 > >
 > > [root@centos test]# stat a
 > >   File: a
 > >   Size: 4194304         Blocks: 0          IO Block: 4096 
 > >   regular file
 > > Device: fc01h/64513d    Inode: 140         Links: 1
 > > Access: (0644/-rw-r--r--)  Uid: (    0/    root)   Gid: (    0/ 
 > > root)
 > > Access: 2021-02-24 16:33:20.235654140 +0800
 > > Modify: 2021-02-24 16:33:25.070641521 +0800
 > > Change: 2021-02-24 16:33:25.070641521 +0800
 > >  Birth: -
 > >
 > > [root@centos test]# xfs_io -c "pwrite 64k 64k" a
 > > wrote 65536/65536 bytes at offset 65536
 > > 64 KiB, 16 ops; 0.0000 sec (992.063 MiB/sec and 253968.2540 
 > > ops/sec)
 > >
 > > [root@VM-8-4-centos test]# xfs_io -c "fiemap -v 0 65k" a
 > > a:
 > >  EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
 > >    0: [0..127]:        hole               128
 > >    1: [128..135]:      360..367             8   0x1
 > >
 > 
 > Sorry, my carelessness. I only checked btrfs implementation but 
 > xfs
 > and ext4 do return the change you made.
 > 

Yeah, it seems there is no bad side effect to show  only specified range of extents
and keep all the same behavior is also good for testing. I can post a fix patch for
this but before that let us to wait some feedback from maintainers and experts.

Thanks,
Chengguang


 > 
 > > [root@centos test]# xfs_io -c "fiemap -v 0 128k" a
 > > a:
 > >  EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
 > >    0: [0..127]:        hole               128
 > >    1: [128..255]:      360..487           128   0x1
 > >
 > >
 > >  >
 > >  > You may ask why the ending hole range is not aligned to 128 
 > >  > in
 > >  > 473.out. Because
 > >  > fiemap ioctl returns nothing of querying holes. xfs_io does 
 > >  > the
 > >  > extra
 > >  > print work for holes.
 > >  >
 > >  > xfsprogs-dev/io/fiemap.c:
 > >  > for holes:
 > >  >  153     if (lstart > llast) {
 > >  >  154         print_hole(0, 0, 0, cur_extent, lflag, true, 
 > >  >  llast,
 > >  >  lstart);
 > >  >  155         cur_extent++;
 > >  >  156         num_printed++;
 > >  >  157     }
 > >  >
 > >  > for the ending hole:
 > >  >   381     if (cur_extent && last_logical < range_end)
 > >  >   382         print_hole(foff_w, boff_w, tot_w, cur_extent, 
 > >  >   lflag,
 > >  >   !vflag,
 > >  >   383                BTOBBT(last_logical), 
 > >  >   BTOBBT(range_end));
 > >  >
 > >  > >  Hole + Data + Hole
 > >  > >  0: [0..127]: hole
 > >  > >  1: [128..255]: data
 > >  >
 > 
 >