Re: [PATCH 3/4] brd: Fix all partitions BUGs

From: Ross Zwisler
Date: Thu Aug 07 2014 - 14:58:00 EST


On Wed, 2014-08-06 at 14:33 +0300, Boaz Harrosh wrote:
> This patch fixes up brd's partitions scheme, now enjoying all worlds.
>
> The MAIN fix here is that currently if one fdisks some partitions,
> a BAD bug will make all partitions point to the same start-end sector
> ie: 0 - brd_size And an mkfs of any partition would trash the partition
> table and the other partition.
>
> Another fix is that "mount -U uuid" did not work, because of the
> GENHD_FL_SUPPRESS_PARTITION_INFO flag.
>
> So NOW the logic goes like this:
> * max_part - Just says how many minors to reserve between devices
> But in any way, there can be as many partition as requested.
> If minors between devices ends, then dynamic 259-major ids will
> be allocated on the fly.
> The default is now max_part=1, which means all partitions devt
> will be from the dynamic major-range.
> (If persistent partition minors is needed use max_part=)
>
> * Creation of new devices on the fly still/always work:
> mknod /path/devnod b 1 X
> fdisk -l /path/devnod
> Will create a new device if (X / max_part) was not already
> created before. (Just as before)
>
> partitions on the dynamically created device will work as well
> Same logic applies with minors as with the pre-created ones.
>
> TODO: dynamic grow of device size, maybe through sysfs. So each
> device can have it's own size.
>
> Signed-off-by: Boaz Harrosh <boaz@xxxxxxxxxxxxx>


Tested-by: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx>


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/