On Thu, 2008-09-04 at 09:26 +0200, Jens Axboe wrote: > On Fri, Aug 29 2008, Andrew Patterson wrote: > > This is version 2 of a patch series I submitted back in May 2008. This > > version now checks for device size changes in the rescan_partitions() > > routine. Which in turn is called when a device is opened and in the > > BLKRRPART ioctl. > > > > I am resubmitting this patch series as I got little response the > > previous time. Al Viro has told me offline that he would look at it this > > time. > > > > This patch series handles online disk resizes that are currently not > > completely recognized by the kernel using the existing revalidate_disk > > routines. An online resize can occur when growing or shrinking a > > Fibre Channel LUN or perhaps by adding a disk to an existing RAID > > volume. > > > > The kernel currently recognizes a device size change when the > > lower-level revalidate_disk routines are called; however, the block > > layer does not use the new size while it has any current openers on > > the device. So, for example, if LVM has an volume open on the device, > > you will generally not see the size change until after a reboot. We > > fix this problem by creating a wrapper to be used with lower-level > > revalidate_disk routines. This wrapper first calls the lower-level > > driver's revalidate_disk routine. It then compares the gendisk > > capacity to the block devices inode size. If there is a difference, we > > adjust the block device's size. If the size has changed, we then flush > > the disk for safety. The size is also checked in rescan_partitions > > which is called when the device is opened or when the BLKRRPART ioctl > > is called. > > > > There are several ways to "kick off" a device size change: > > > > 1. For SCSI devices do: > > > > # echo 1 > /sys/class/scsi_device/<device>/device/rescan > > > > or > > > > # blockdev --rereadpt <device file> > > > > 2. Other devices (not device mapper) > > > > # blockdev --rereadpt <device file> > > > > I have tested this patch on SCSI and SmartArray (cciss) > > devices. Device mapper still does not recognize device size changes > > until the device is restarted. > > > > Jeff Moyer and Andy Ryan have done some light testing on the previous > > version of this series. > > > > This patch set has been tested with scsi-misc-2.6. It also applies to > > linux-next with some minor, obvious changes. > > This version looks sane to me. Care to resend against for-2.6.28 of the > block repo? Will do. Thanks Andrew -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
