On Tue, Apr 16, 2024 at 02:35:55AM +0100, Al Viro wrote: > > drivers/s390/block/dasd_ioctl.c | 5 +++-- > > 1 file changed, 3 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/s390/block/dasd_ioctl.c b/drivers/s390/block/dasd_ioctl.c > > index 7e0ed7032f76..c1201590f343 100644 > > --- a/drivers/s390/block/dasd_ioctl.c > > +++ b/drivers/s390/block/dasd_ioctl.c > > @@ -215,8 +215,9 @@ dasd_format(struct dasd_block *block, struct format_data_t *fdata) > > * enabling the device later. > > */ > > if (fdata->start_unit == 0) { > > - block->gdp->part0->bd_inode->i_blkbits = > > - blksize_bits(fdata->blksize); > > + rc = set_blocksize(block->gdp->part0, fdata->blksize); > > Could somebody (preferably s390 folks) explain what is going on in > dasd_format()? The change in this commit is *NOT* an equivalent > transformation - mainline does not evict the page cache of device. > > Is that > * intentional behaviour in mainline version, possibly broken > by this patch > * a bug in mainline accidentally fixed by this patch > * something else? > > And shouldn't there be an exclusion between that and having a filesystem > on a partition of that disk currently mounted? CC-ing Stefan and Jan. Thanks!