Re: [PATCH v3 07/13] generic/1228: Add atomic write multi-fsblock O_[D]SYNC tests

Ojaswin Mujoo
2025-07-23T13:54:37Z

On Thu, Jul 17, 2025 at 09:35:10AM -0700, Darrick J. Wong wrote:

<snip>

> > +verify_atomic_write() {
> > + if [[ "$1" == "shutdown" ]]
> > + then
> > + local do_shutdown=1
> > + fi
> > +
> > + test $bytes_written -eq $awu_max || _fail "atomic write len=$awu_max assertion failed"
> > +
> > + if [[ $do_shutdown -eq "1" ]]
> > + then
> > + echo "Shutting down filesystem" >> $seqres.full
> > + _scratch_shutdown >> $seqres.full
> > + _scratch_cycle_mount >>$seqres.full 2>&1 || _fail "remount failed for Test-3"
> > + fi
> > +
> > + check_data_integrity
> > +}
> > +
> > +mixed_mapping_test() {
> > + prep_mixed_mapping
> > +
> > + echo "+ + Performing O_DSYNC atomic write from 0 to $awu_max" >> $seqres.full
> > + bytes_written=$($XFS_IO_PROG -dc "pwrite -DA -V1 -b $awu_max 0 $awu_max" $testfile | \
> > + grep wrote | awk -F'[/ ]' '{print $2}')
> > +
> > + verify_atomic_write $1
>
> The shutdown happens after the synchronous write completes? If so, then
> what part of recovery is this testing?
>
> --D

Right, it is mostly inspired by [1] where sometimes isize update could
be lost after dio completion. Although this might not exactly be
affected by atomic writes, we added it here out of caution.

[1] https://lore.kernel.org/fstests/434beffaf18d39f898518ea9eb1cea4548e77c3a.1695383715.git.ritesh.list@gmail.com/
>
> > +}
> > +