Re: [Libguestfs] nbdkit test-checkwrite.sh failing occasionally on ppc64le

On Wed, Jul 13, 2022 at 03:10:37PM +0200, Laszlo Ersek wrote: > On 07/13/22 13:27, Richard W.M. Jones wrote: > > > > It's not 100% reproducible, but it seems to happen reasonably often. > > Unfortunately it only happens on ppc64le (so far). The error message > > lacks sufficient detail to tell what's going on. > > > > nbdkit: backend.c:624: backend_pread: Assertion `backend_valid_range (c, offset, count)' failed. > > nbdkit: backend.c:624: backend_pread: Assertion `backend_valid_range (c, offset, count)' failed. > > > > Full log attached. > > "tests/disk" has size 105923072. > > Considering all the count=... offset=... lines in the last section of > the log, there isn't one line where backend_valid_range(): > > return count > 0 && offset <= c->exportsize && > offset + count <= c->exportsize; > > would return false. > > I've printed a table, with offset, count, and offset+count colums, from > the log entries, then sorted the table three times separately, each time > by a different column. I got the following min and max elements: > > offset count offset+count > --------- --------- ----------- > 0 105923072 105923072 (min by offset) > 105906176 16896 105923072 (max by offset) > 0 4096 4096 (min by count) > 0 105923072 105923072 (max by count) > 0 4096 4096 (min by end) > 105906176 16896 105923072 (max by end) > > All of these look valid... I think you'll have to look at the coredump > with gdb. Indeed - unfortunately the coredump is on a Fedora build system :-( I'll reserve a POWER machine later (unless someone gets there first).