Re: [PATCH v2] xfs: exercise a failed CoW conversion during writeback

[Andrea Parri <parri.andrea@gmail.com>]

On Mon, Sep 28, 2026 at 09:53:29PM +0800, Zorro Lang wrote:
> > +seq=0
> 
> In fstests, $seq is a core global variable representing the test sequence
> number. Overwriting it here might lead to unexpected side effects with
> framework helpers or cleanup logic. Could we rename this loop variable to
> something else to avoid trouble? If you need, I can help that when I merge
> it.

Good catch, thanks.  Yes, please fold it in when you merge, if that's
fine with you; the rename I had in mind is just:

@@ -48,11 +48,11 @@ _cp_reflink $SCRATCH_MNT/file1 $SCRATCH_MNT/file2
 
 # Dirty several widely separated ranges of file2's CoW extents so that a
 # single writepages() call has to submit more than one ioend.
-seq=0
-while [ $seq -lt $nr ]; do
-	off=$((seq * blksz * 2))
+i=0
+while [ $i -lt $nr ]; do
+	off=$((i * blksz * 2))
 	_pwrite_byte 0x59 $off $blksz $SCRATCH_MNT/file2 >> $seqres.full
-	seq=$((seq + 1))
+	i=$((i + 1))
 done
 
 echo "Inject wb_cow_convert_error"

I'm happy to send a v3 instead if you'd prefer.

Thanks!
  Andrea