On Thu, Jun 27, 2019 at 11:23:09AM -0700, Darrick J. Wong wrote: > On Thu, Jun 27, 2019 at 12:48:30PM +0200, Christoph Hellwig wrote: > > There is no real problem merging ioends that go beyond i_size into an > > ioend that doesn't. We just need to move the append transaction to the > > base ioend. Also use the opportunity to use a real error code instead > > of the magic 1 to cancel the transactions, and write a comment > > explaining the scheme. > > > > Signed-off-by: Christoph Hellwig <hch@xxxxxx> > > Reading through this patch, I have a feeling it fixes the crash that > Zorro has been seeing occasionally with generic/475... So you think for some reason the disk i_size changes underneath and thus the xfs_ioend_is_append misfired vs the actual transaction allocations? I didn't even think of that, but using the different checks sure sounds dangerous. So yes, we'd either need to backport my patch, or at least replace the checks in xfs_ioend_can_merge with direct checks of io_append_trans.