dm-init should allow up to DM_MAX_{DEVICES,TARGETS} for devices/targets,
and not DM_MAX_{DEVICES,TARGETS} - 1.
Fix the checks and also fix the error message when the number of devices
is surpassed.
Fixes: 6bbc923dfc ("dm: add support to directly boot to a mapped device")
Cc: stable@vger.kernel.org
Signed-off-by: Helen Koike <helen.koike@collabora.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
A non const pointer to const cannot be marked initconst.
Mark the array actually const.
Fixes: 6bbc923dfc dm: add support to directly boot to a mapped device
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Add a "create" module parameter, which allows device-mapper targets to
be configured at boot time. This enables early use of DM targets in the
boot process (as the root device or otherwise) without the need of an
initramfs.
The syntax used in the boot param is based on the concise format from
the dmsetup tool to follow the rule of least surprise:
dmsetup table --concise /dev/mapper/lroot
Which is:
dm-mod.create=<name>,<uuid>,<minor>,<flags>,<table>[,<table>+][;<name>,<uuid>,<minor>,<flags>,<table>[,<table>+]+]
Where,
<name> ::= The device name.
<uuid> ::= xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx | ""
<minor> ::= The device minor number | ""
<flags> ::= "ro" | "rw"
<table> ::= <start_sector> <num_sectors> <target_type> <target_args>
<target_type> ::= "verity" | "linear" | ...
For example, the following could be added in the boot parameters:
dm-mod.create="lroot,,,rw, 0 4096 linear 98:16 0, 4096 4096 linear 98:32 0" root=/dev/dm-0
Only the targets that were tested are allowed and the ones that don't
change any block device when the device is create as read-only. For
example, mirror and cache targets are not allowed. The rationale behind
this is that if the user makes a mistake, choosing the wrong device to
be the mirror or the cache can corrupt data.
The only targets initially allowed are:
* crypt
* delay
* linear
* snapshot-origin
* striped
* verity
Co-developed-by: Will Drewry <wad@chromium.org>
Co-developed-by: Kees Cook <keescook@chromium.org>
Co-developed-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Helen Koike <helen.koike@collabora.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
