[LTP] [PATCH 2/3] swapon04: Add test for discard flags

[Li Wang]

> > this is interesting. Also I notice how it's hard to read the logs, so
> > I need a TINFO before the checks. But technically, this could be a kernel
> > bug: can you please add a sync() before stat() while we are getting the
> > blocks_after? We might need to flush the cache before reading the blocks.
> > 
> > 	fd = SAFE_OPEN(BACKING_FILE, O_RDONLY);
> > 	SAFE_FSYNC(fd);
> > 	SAFE_CLOSE(fd);
> 
> sorry, this should stay after the tst_fill_file()

Great, this works!

I think the fsync after tst_fill_file() ensures all allocated blocks are
flushed to disk, so stat() reflects the real block count.

Feel free to add my RBT with this change applied:

Reviewed-by: Li Wang <li.wang@linux.dev>

-- 
Regards,
Li Wang