Problem with size after growing a device on 3ware-9500

["Lars Michael Jogbäck" <lm@jogback.se>]

Hi,

I don't know really which subsystem this, so I'm sending this to the 
linux-ide list.
Please direct me to a more appropriate place if this is not correct.

I'm using a 3ware 9500 with Linux 2.6.18.1. I've grown the HW 
raid5-array and here is where the problem begins. After the card had 
expanded the array, I used "blockdev --rereadpt /dev/sdn" to get the 
kernel to recognize the now larger device. The last step was to do a 
"pvresize /dev/sdn". The problem is that pvresize still thought that the 
device was at the original size.

 From the lvm mailinglist I found out that pvresize used the same 
mechanism as "blockdev" (ioctl BLKGETSIZE64) to get the size of the 
disks, so I tested this and found that blockdev also reported the device 
to have the wrong size.

So, if I do:
# cat /sys/block/sdn/size
5859250176

and

# blockdev --getsize64 /dev/sdn
2499946741760
# blockdev --getss /dev/sdn
512
# expr 2499946741760 / 512
4882708480

Apparently /sys/block/sdk/size is updated with the new size, but 
whatever "ioctl BLKGETSIZE64" is querying is not. If I reboot, 
everything works correctly.

Shouldn't it be possible to extend the size of a disk without rebooting?

Best Regards,
/LM