Re: [PATCH v4 0/2] mmap dio and DAX

[Xiong Zhou <xzhou@redhat.com>]

On Tue, Jan 24, 2017 at 03:28:55PM -0700, Ross Zwisler wrote:
> On Fri, Jan 20, 2017 at 02:15:48PM +0800, Xiong Zhou wrote:
> > common/rc         : requires SCRATCH_DEV support DAX
> > src/t_mmap_dio.c  : intro mmap and O_DIRECT rw through files
> > tests/generic/405 : IO between DAX/non-DAX mountpoints
> > tests/xfs/138     : IO between DAX/non-DAX xfs files(per-inode flag)
> > 
> > v2 :
> >   Merge helper function changes into the first patch;
> >   Rewrite _require_dax, check options for sure;
> >   Print msg in t_mmap_dio.c to show which test going wrong;
> >   Empty mount options and check after mount to ensure we
> > wont mount with wrong option;
> >   Remove unnecessary leading underscore and _fail;
> >   Use xfs_io instead of dd;
> >   Other minor fixes.
> > 
> > v3:
> >  close fds in C test programme for clean up.
> > 
> > v4:
> >  Test both buffered and O_DIRECT IO;
> >  Fix arg numbers in C test programme;
> >  Fix fs options check after mount.
> >  Cc Jeff Moyer since this test is based on his code.
> >  (Sorry for the late cc!)
> > 
> > Test status:
> >   Both cases not run on normal block device;
> >   Both cases PASS on ramdisk based pmem devices;
> >   DIO in both cases FAIL on brd based ramdisk with:
> >   DIO in both cases FAIL on nvdimm devices with:
> >     +write(Bad address) len 1024 dio dax to nondax
> >     +write(Bad address) len 4096 dio dax to nondax
> >     +write(Bad address) len 16777216 dio dax to nondax
> >     +write(Bad address) len 67108864 dio dax to nondax
> > 
> >   I've reported this to nvdimm list.
> >   https://lists.01.org/pipermail/linux-nvdimm/2017-January/008600.html
> > 
> > Xiong Zhou (2):
> >   xfs: test per-inode DAX flag by IO
> >   generic: test mmap io through DAX and non-DAX
> > 
> >  .gitignore            |   1 +
> >  common/rc             |  13 ++++++
> >  src/Makefile          |   2 +-
> >  src/t_mmap_dio.c      | 105 ++++++++++++++++++++++++++++++++++++++++++++
> >  tests/generic/405     | 119 ++++++++++++++++++++++++++++++++++++++++++++++++++
> >  tests/generic/405.out |   2 +
> >  tests/generic/group   |   1 +
> >  tests/xfs/138         | 116 ++++++++++++++++++++++++++++++++++++++++++++++++
> >  tests/xfs/138.out     |   2 +
> >  tests/xfs/group       |   1 +
> >  10 files changed, 361 insertions(+), 1 deletion(-)
> >  create mode 100644 src/t_mmap_dio.c
> >  create mode 100755 tests/generic/405
> >  create mode 100644 tests/generic/405.out
> >  create mode 100755 tests/xfs/138
> >  create mode 100644 tests/xfs/138.out
> > 
> > -- 
> > 1.8.3.1
> 
> I just wanted to let you know that I'm testing with these new xfstests right
> now, and so far I've been unable to successfully get any PMD faults.  I'm
> looking into why that is right now, and should hopefully have some changes so
> we can do both PTE and PMD testing with this set.

Thank you very much for looking into this!

Adding a printk msg in dax_iomap_pmd_fault in fs/dax.c shows that
these 2 cases called this function, so do __radix_tree_insert
in lib/radix-tree.c with order > 0.  I must have missed something..

> 
> Also, it looks like the test number "generic/405" was already used in
> xfstests/master by this commit:
> 
> 66768bc generic/405: test mkfs against thin provision device
> 
> So this may need to be generic/406. :)

Ya, i can update this or Eryu can handle it while applying.

Thanks,
Xiong