On Thu, May 11, 2017 at 01:35:07PM +0200, Andreas Gruenbacher wrote:
> src/seek_sanity_test (test generic/285) assumes that after preallocating
> space in a file with fallocate, fseek SEEK_HOLE / SEEK_DATA will still
> report the allocated space as a hole. On filesystems without unwritten
> extent support, that space will be reported as data, though.
>
> Tested on ext4, xfs, and gfs2 + patches for fseek SEEK_HOLE / SEEK_DATA
> support.
The idea seems fine to me, but I'm not that familiar with SEEK_DATA/HOLE
support, it'd be great if someone else could help review this patch.
Some of my thoughts inline.
>
> Signed-off-by: Andreas Gruenbacher <agruenba@xxxxxxxxxx>
> ---
> src/seek_sanity_test.c | 35 +++++++++++++++++++++++++++++++++++
> 1 file changed, 35 insertions(+)
>
> diff --git a/src/seek_sanity_test.c b/src/seek_sanity_test.c
> index a6dd48c..0d7fa0a 100644
> --- a/src/seek_sanity_test.c
> +++ b/src/seek_sanity_test.c
> @@ -37,6 +37,7 @@
>
> static blksize_t alloc_size;
> int default_behavior = 0;
> +int unwritten_extents = 0;
> char *base_file_path;
>
> static void get_file_system(int fd)
> @@ -282,6 +283,11 @@ static int test09(int fd, int testnum)
> int bufsz = alloc_size;
> int filsz = 8 << 20;
>
> + if (!unwritten_extents) {
> + fprintf(stdout, "Test skipped\n");
> + goto out;
> + }
> +
> /*
> * HOLE - unwritten DATA in dirty page - HOLE -
> * unwritten DATA in writeback page
> @@ -338,6 +344,11 @@ static int test08(int fd, int testnum)
> int bufsz = alloc_size;
> int filsz = 4 << 20;
>
> + if (!unwritten_extents) {
> + fprintf(stdout, "Test skipped\n");
> + goto out;
> + }
> +
> /* HOLE - unwritten DATA in writeback page */
> /* Each unit is bufsz */
> buf = do_malloc(bufsz);
> @@ -387,6 +398,11 @@ static int test07(int fd, int testnum)
> int bufsz = alloc_size;
> int filsz = 4 << 20;
>
> + if (!unwritten_extents) {
> + fprintf(stdout, "Test skipped\n");
> + goto out;
> + }
> +
> /* HOLE - unwritten DATA in dirty page */
> /* Each unit is bufsz */
> buf = do_malloc(bufsz);
> @@ -776,6 +792,25 @@ static int test_basic_support(void)
> fprintf(stderr, "File system supports the default behavior.\n");
> }
>
> + ftruncate(fd, 0);
> + if (fallocate(fd, 0, 0, alloc_size) == -1) {
> + if (errno == EOPNOTSUPP) {
> + fprintf(stderr, "File system does not support fallocate.");
> + } else {
> + fprintf(stderr, "ERROR %d: Failed to preallocate "
> + "space to %ld bytes.", errno, (long) alloc_size);
> + }
Use do_fallocate here? It already did the EOPNOTSUPP check. And
introduce another flag, e.g. prealloc, to save the fallocate support
status? So that test0[7-9] don't have to do the EOPNOTSUPP check again.
> + fprintf(stderr, " Skipping unwritten extent tests.\n");
> + goto out;
> + } else {
> + pos = lseek(fd, 0, SEEK_DATA);
Hmm, it's hard to tell if it's a bug in lseek or the fs doesn't support
unwritten extents, because we're going to test lseek SEEK_DATA/HOLE
interface.
How about using fiemap and check the FIEMAP_EXTENT_UNWRITTEN flag? Only
falling back to lseek if fiemap is not supported?
Thanks,
Eryu
> + if (pos == 0) {
> + fprintf(stderr, "File system does not support unwritten extents.\n");
> + goto out;
> + }
> + }
> + unwritten_extents = 1;
> +
> printf("\n");
>
> out:
> --
> 2.7.4
>
> --
> 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
--
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
