Re: [PATCH] generic/285: Add more SEEK_HOLE tests

[Eryu Guan <eguan@redhat.com>]

On Thu, May 11, 2017 at 06:48:09PM +0200, Jan Kara wrote:
> Add tests for bugs found in ext4 & xfs SEEK_HOLE implementations
> fixed by following patches:
> 
> xfs: Fix missed holes in SEEK_HOLE implementation
> ext4: Fix SEEK_HOLE
> 
> Signed-off-by: Jan Kara <jack@suse.cz>

This will cause ext4 and xfs start to fail with current linus tree and
appear as a new regression. So we usually don't add new tests to
existing cases.

But seek_sanity_test.c deals with different SEEK_DATA/HOLE implentations
nicely, which would be a bit tricky to do in a new test by shell, and it
has all the infrastructures for new tests like this. So I think I'd
prefer merging this patch as is, and document the false regression alert
in release announce email.

I'm including this patch in release testing now, please shout if ext4
and/or xfs developers have different thoughts, there'll be around two
days before new release :)

Thanks,
Eryu

> ---
>  src/seek_sanity_test.c | 96 ++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 96 insertions(+)
> 
> diff --git a/src/seek_sanity_test.c b/src/seek_sanity_test.c
> index a6dd48cc257b..86a9397fa7e9 100644
> --- a/src/seek_sanity_test.c
> +++ b/src/seek_sanity_test.c
> @@ -246,6 +246,100 @@ out:
>  }
>  
>  /*
> + * test file with unwritten extents, only have pagevec worth of dirty pages
> + * in page cache, a hole and then another page.
> + */
> +static int test14(int fd, int testnum)
> +{
> +	int ret = 0;
> +	char *buf = NULL;
> +	int bufsz = sysconf(_SC_PAGE_SIZE) * 14;
> +	int filsz = 4 << 20;
> +
> +	/* HOLE - unwritten DATA in dirty page */
> +	/* Each unit is bufsz */
> +	buf = do_malloc(bufsz);
> +	if (!buf)
> +		goto out;
> +	memset(buf, 'a', bufsz);
> +
> +	/* preallocate 4M space to file */
> +	ret = do_fallocate(fd, 0, filsz, 0);
> +	if (ret < 0) {
> +		/* Report success if fs doesn't support fallocate */
> +		if (errno == EOPNOTSUPP) {
> +			fprintf(stdout, "Test skipped as fs doesn't support fallocate.\n");
> +			ret = 0;
> +		}
> +		goto out;
> +	}
> +
> +	ret = do_pwrite(fd, buf, bufsz, 0);
> +	if (ret)
> +		goto out;
> +
> +	ret = do_pwrite(fd, buf, bufsz, 3 * bufsz);
> +	if (ret)
> +		goto out;
> +
> +	/* offset at the beginning */
> +	ret += do_lseek(testnum,  1, fd, filsz, SEEK_HOLE, 0, bufsz);
> +	ret += do_lseek(testnum,  2, fd, filsz, SEEK_HOLE, 1, bufsz);
> +	ret += do_lseek(testnum,  2, fd, filsz, SEEK_HOLE, 3 * bufsz, 4 * bufsz);
> +	ret += do_lseek(testnum,  3, fd, filsz, SEEK_DATA, 0, 0);
> +	ret += do_lseek(testnum,  4, fd, filsz, SEEK_DATA, 1, 1);
> +	ret += do_lseek(testnum,  3, fd, filsz, SEEK_DATA, bufsz, 3 * bufsz);
> +
> +out:
> +	do_free(buf);
> +	return ret;
> +}
> +
> +/*
> + * test file with unwritten extents, only have pagevec worth of dirty pages
> + * in page cache.
> + */
> +static int test13(int fd, int testnum)
> +{
> +	int ret = 0;
> +	char *buf = NULL;
> +	int bufsz = sysconf(_SC_PAGE_SIZE) * 14;
> +	int filsz = 4 << 20;
> +
> +	/* HOLE - unwritten DATA in dirty page */
> +	/* Each unit is bufsz */
> +	buf = do_malloc(bufsz);
> +	if (!buf)
> +		goto out;
> +	memset(buf, 'a', bufsz);
> +
> +	/* preallocate 4M space to file */
> +	ret = do_fallocate(fd, 0, filsz, 0);
> +	if (ret < 0) {
> +		/* Report success if fs doesn't support fallocate */
> +		if (errno == EOPNOTSUPP) {
> +			fprintf(stdout, "Test skipped as fs doesn't support fallocate.\n");
> +			ret = 0;
> +		}
> +		goto out;
> +	}
> +
> +	ret = do_pwrite(fd, buf, bufsz, 0);
> +	if (ret)
> +		goto out;
> +
> +	/* offset at the beginning */
> +	ret += do_lseek(testnum,  1, fd, filsz, SEEK_HOLE, 0, bufsz);
> +	ret += do_lseek(testnum,  2, fd, filsz, SEEK_HOLE, 1, bufsz);
> +	ret += do_lseek(testnum,  3, fd, filsz, SEEK_DATA, 0, 0);
> +	ret += do_lseek(testnum,  4, fd, filsz, SEEK_DATA, 1, 1);
> +
> +out:
> +	do_free(buf);
> +	return ret;
> +}
> +
> +/*
>   * Test huge file to check for overflows of block counts due to usage of
>   * 32-bit types.
>   */
> @@ -678,6 +772,8 @@ struct testrec seek_tests[] = {
>         { 10, test10, "Test a huge file for offset overflow" },
>         { 11, test11, "Test a huge file for block number signed" },
>         { 12, test12, "Test a huge file for block number overflow" },
> +       { 13, test13, "Test file with unwritten extents, only have pagevec dirty pages" },
> +       { 14, test14, "Test file with unwritten extents, small hole after pagevec dirty pages" },
>  };
>  
>  static int run_test(struct testrec *tr)
> -- 
> 2.12.0
> 
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