Re: [PATCH 16/17] block: use iomap for writes to block devices

[Christoph Hellwig]

On Fri, May 19, 2023 at 04:22:01PM +0200, Hannes Reinecke wrote:
> I'm hitting this during booting:
> [    5.016324]  <TASK>
> [    5.030256]  iomap_iter+0x11a/0x350
> [    5.030264]  iomap_readahead+0x1eb/0x2c0
> [    5.030272]  read_pages+0x5d/0x220
> [    5.030279]  page_cache_ra_unbounded+0x131/0x180
> [    5.030284]  filemap_get_pages+0xff/0x5a0
> [    5.030292]  filemap_read+0xca/0x320
> [    5.030296]  ? aa_file_perm+0x126/0x500
> [    5.040216]  ? touch_atime+0xc8/0x150
> [    5.040224]  blkdev_read_iter+0xb0/0x150
> [    5.040228]  vfs_read+0x226/0x2d0
> [    5.040234]  ksys_read+0xa5/0xe0
> [    5.040238]  do_syscall_64+0x5b/0x80
>
> Maybe we should consider this patch:

As willy said this should be taken care of by the i_size check.
Did you run with just this patch set or some of the large block
size experiments on top which might change the variables?

I'll repost the series today without any chances in the area, and
if you can reproduce it with just that series we need to root
cause it, so please send your kernel and VM config along for the
next report.