insmod sbd.ko error ?? [LWN.net]

insmod sbd.ko error ??

Posted May 23, 2006 6:01 UTC (Tue) by sahib (guest, #37878)
In reply to: insmod sbd.ko error ?? by gg940231
Parent article: A simple block driver

HI
ITS ALI, I ALSO ENCOUNTERED THE SAME ERROR WHILE LOADING THAT SIMPLE BLOCK DEVICE DRIVER THAT SHOWS MSG LIKE "sbd0: unknown partition table" yet i came to know that it is due to the (add_disk)function call in the init function add_disk is necessary as it provide a block disk for block I/O's. now i am trying to solve it further if u have solved it! let me know coz i am also trying to learn this.
ALI(SAHIB)

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insmod sbd.ko error ??

Posted Aug 13, 2007 8:48 UTC (Mon) by midhun001 (guest, #46739) [Link]

Hi All,

Even I got the same error. Please share it with me if you tion for this.

-Midhun

insmod sbd.ko error ??

Posted Nov 3, 2007 0:39 UTC (Sat) by rbartlett (guest, #48846) [Link]

The "sbd0: unknown partition table" is normal.  The allocated memory is uninitialized when the
module is first loaded so it can't contain a valid partition table.  You can either use sfdisk
or mkfs to create a partition table or file system in the allocated memory.  If mkfs is used,
the driver may subsequently be mounted.

I had to make a few minor changes to the driver to get it to this point.  I had to add the
following line to the sbd_ops structure:
".getgeo = sbd_blk_getgeo"
Then I had to create a function sbd_blk_getgeo with the code from the HDIO_GETGEO case from
the sbd_ioctl function.  This was because sfdisk complained that "Disk /dev/sbd0: cannot get
geometry".

The last thing I had to do was change "geo.start = 4" to geo.start = 0".  This was because
sfdisk complained that "Warning: start=4 - this looks like a partition rather than the entire
disk. Using fdisk on it is probably meaningless."

Once these changes were made, I was able to use sfdisk and mkfs on the device and mount it as
well.