[LTP] [PATCH v3] syscalls/sync_file_range: add partial file sync test-cases

[Li Wang]

On Thu, Mar 28, 2019 at 12:57 PM Sumit Garg <sumit.garg@linaro.org> wrote:

> On Wed, 27 Mar 2019 at 20:18, Cyril Hrubis <chrubis@suse.cz> wrote:
> >
> > Hi!
> > Sorry for the long delay.
> >
> > This is altmost perfect, the only problem is that the third test fails
> > on vfat. As far as I can tell the reason is that vfat does not support
> > sparse files, hence seeking to the middle of file and writing there also
> > schedulles I/O to write zeros from the start of the file to the offset
> > we started writing to.
> >
>
> Hmm, I see.
>
> > Following ugly patch solves the problem:
> >
> > diff --git
> a/testcases/kernel/syscalls/sync_file_range/sync_file_range02.c
> b/testcases/kernel/syscalls/sync_file_range/sync_file_range02.c
> > index 334ea5e88..774524c2f 100644
> > --- a/testcases/kernel/syscalls/sync_file_range/sync_file_range02.c
> > +++ b/testcases/kernel/syscalls/sync_file_range/sync_file_range02.c
> > @@ -45,6 +45,12 @@ static void verify_sync_file_range(struct testcase
> *tc)
> >
> >         fd = SAFE_OPEN(tc->fname, O_RDWR|O_CREAT, MODE);
> >
> > +       if (!strcmp(tst_device->fs_type, "vfat")) {
> > +               tst_res(TINFO, "Pre-filling file");
> > +               tst_fill_fd(fd, 0, tc->write_off, 1);
> > +               fsync(fd);
> > +       }
> > +
> >         lseek(fd, tc->write_off, SEEK_SET);
> >
> >
> > So either we limit the tests so that the sync region does not overlap
> with the
> > possible hole at the start of the file and loose some test coverage.
> >
> > Or we can add a function to the test library that would return
> true/false if
> > sparse files are supported for a given FS.
> >
>
> My initial thought behind this test-case was to run sync over a range
> which is partially written. The other partial region not being written
> could either be a hole or already synced data. So pre-fill file in
> case of vfat looks sane option, but how about if we add pre-fill as
> part of setup? Something like:
>

I think this is a bit better. Could u send a new patch version?


> --- a/testcases/kernel/syscalls/sync_file_range/sync_file_range02.c
> +++ b/testcases/kernel/syscalls/sync_file_range/sync_file_range02.c
> @@ -86,6 +86,12 @@ static void setup(void)
>  {
>         if (!check_sync_file_range())
>                 tst_brk(TCONF, "sync_file_range() not supported");
> +
> +       if (!strcmp(tst_device->fs_type, "vfat")) {
> +               tst_res(TINFO, "Pre-filling file");
> +               tst_fill_file(FNAME3, 0, TST_MB, FILE_SZ_MB);
> +               sync();
> +       }
>  }
>
> -Sumit
>
> > --
> > Cyril Hrubis
> > chrubis@suse.cz
>
> --
> Mailing list info: https://lists.linux.it/listinfo/ltp
>


-- 
Regards,
Li Wang
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