There's filefrag already, and that works, but, it's output is very
inconsistent between various OS release versions, and it has already
meant that we'd needed to adjust tests to account for these little
but insignificant changes. A lot more work than useful. It's even
more changed in el9.
This adds `scoutfs get-fiemap FILE` and prints out block extent
info with flags that we care about as an abbreviated letter: U for
Unwritten, L for Last, and O for Unknown (as in, "offline").
The -P/--physical and -L/--logical options turn off logical or physical
offset display, in case you only want to see the offsets in either
units. You can pass -b/--byte to display offsets and lengths in
byte values. The block size will then be obtained from fstat() of
the queried file (4096 for scoutfs).
I've removed all uses of filefrag from our scoutfs tests. Xfstests
still calls it but their internal diff takes care of that issue.
Where needed and appropriate, the tests are adjusted so that the output
of `scoutfs get-fiemap` is as close as it can to what it used to be,
so that reading the test results allows the quick view of what might
have been going wrong.
There are some output strings I have not bothered to update because
there's no real value to updating every output string to match,
and we just adjust the golden file accordingly.
Signed-off-by: Auke Kok <auke.kok@versity.com>
Data preallocation attempts to allocate large aligned regions of
extents. It tried to fill the hole around a write offset that
didn't contain an extent. It missed the case where there can be
multiple extents between the start of the region and the hole.
It could try to overwrite these additional existing extents and writes
could return EINVAL.
We fix this by trimming the preallocation to start at the write offset
if there are any extents in the region before the write offset. The
data preallocation test output has to be updated now that allocation
extents won't grow towards the start of the region when there are
existing extents.
Signed-off-by: Zach Brown <zab@versity.com>
Add a test which exercises filling holes in prealloc regions when the
_contig_only prealloc option is not set.
Signed-off-by: Zach Brown <zab@versity.com>
