[dm-devel] [PATCHv3] dm-verity: Add error handling modes for corrupted blocks

[Mike Snitzer]

On Wed, Mar 18, 2015 at 11:52 AM, Sami Tolvanen <samitolvanen at google.com> wrote:
> Add device specific modes to dm-verity to specify how corrupted
> blocks should be handled. The following modes are defined:
>
>   - DM_VERITY_MODE_EIO is the default behavior, where reading a
>     corrupted block results in -EIO.
>
>   - DM_VERITY_MODE_LOGGING only logs corrupted blocks, but does
>     not block the read.
>
>   - DM_VERITY_MODE_RESTART calls kernel_restart when a corrupted
>     block is discovered.
>
> In addition, each mode sends a uevent to notify userspace of
> corruption and to allow further recovery actions.
>
> The driver defaults to previous behavior (DM_VERITY_MODE_EIO)
> and other modes can be enabled with an additional parameter to
> the verity table.
>
> Signed-off-by: Sami Tolvanen <samitolvanen at google.com>

I staged this v3 with a few additional fixes (mainly whitespace and
nits) but I did need to export dm_disk() otherwise building dm-verity
as a module would fail.

See:
https://git.kernel.org/cgit/linux/kernel/git/device-mapper/linux-dm.git/commit/?h=for-next&id=cf987c1bc5d4c7c6aeed3648118eaa008c1abf8d