dm init: Handle minors larger than 255

dm_parse_device_entry() simply copies the minor number into dmi.dev, but
the dev_t format splits the minor number between the lowest 8 bytes and
highest 12 byt

dm init: Handle minors larger than 255

dm_parse_device_entry() simply copies the minor number into dmi.dev, but
the dev_t format splits the minor number between the lowest 8 bytes and
highest 12 bytes. If the minor number is larger than 255, part of it
will end up getting treated as the major number

Fix this by checking that the minor number is valid and then encoding it
as a dev_t.

Signed-off-by: Benjamin Marzinski <[email protected]>
Signed-off-by: Mikulas Patocka <[email protected]>

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dm: open code dm_get_dev_t in dm_init_init

dm_init_init is called from early boot code, and thus lookup_bdev
will never succeed. Just open code that call to early_lookup_bdev
instead.

Signed-off-b

dm: open code dm_get_dev_t in dm_init_init

dm_init_init is called from early boot code, and thus lookup_bdev
will never succeed. Just open code that call to early_lookup_bdev
instead.

Signed-off-by: Christoph Hellwig <[email protected]>
Reviewed-by: Mike Snitzer <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

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dm: avoid inline filenames

Signed-off-by: Heinz Mauelshagen <[email protected]>
Signed-off-by: Mike Snitzer <[email protected]>

dm: use fsleep() instead of msleep() for deterministic sleep duration

Signed-off-by: Heinz Mauelshagen <[email protected]>
Signed-off-by: Mike Snitzer <[email protected]>

dm: add missing SPDX-License-Indentifiers

'GPL-2.0-only' is used instead of 'GPL-2.0' because SPDX has
deprecated its use.

Suggested-by: John Wiele <[email protected]>
Signed-off-by: Heinz Mauelsha

dm: add missing SPDX-License-Indentifiers

'GPL-2.0-only' is used instead of 'GPL-2.0' because SPDX has
deprecated its use.

Suggested-by: John Wiele <[email protected]>
Signed-off-by: Heinz Mauelshagen <[email protected]>
Signed-off-by: Mike Snitzer <[email protected]>

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dm init: add dm-mod.waitfor to wait for asynchronously probed block devices

Just calling wait_for_device_probe() is not enough to ensure that
asynchronously probed block devices are available (E.G.

dm init: add dm-mod.waitfor to wait for asynchronously probed block devices

Just calling wait_for_device_probe() is not enough to ensure that
asynchronously probed block devices are available (E.G. mmc, usb), so
add a "dm-mod.waitfor=<device1>[,..,<deviceN>]" parameter to get
dm-init to explicitly wait for specific block devices before
initializing the tables with logic similar to the rootwait logic that
was introduced with commit cc1ed7542c8c ("init: wait for
asynchronously scanned block devices").

E.G. with dm-verity on mmc using:
dm-mod.waitfor="PARTLABEL=hash-a,PARTLABEL=root-a"

[ 0.671671] device-mapper: init: waiting for all devices to be available before creating mapped devices
[ 0.671679] device-mapper: init: waiting for device PARTLABEL=hash-a ...
[ 0.710695] mmc0: new HS200 MMC card at address 0001
[ 0.711158] mmcblk0: mmc0:0001 004GA0 3.69 GiB
[ 0.715954] mmcblk0boot0: mmc0:0001 004GA0 partition 1 2.00 MiB
[ 0.722085] mmcblk0boot1: mmc0:0001 004GA0 partition 2 2.00 MiB
[ 0.728093] mmcblk0rpmb: mmc0:0001 004GA0 partition 3 512 KiB, chardev (249:0)
[ 0.738274] mmcblk0: p1 p2 p3 p4 p5 p6 p7
[ 0.751282] device-mapper: init: waiting for device PARTLABEL=root-a ...
[ 0.751306] device-mapper: init: all devices available
[ 0.751683] device-mapper: verity: sha256 using implementation "sha256-generic"
[ 0.759344] device-mapper: ioctl: dm-0 (vroot) is ready
[ 0.766540] VFS: Mounted root (squashfs filesystem) readonly on device 254:0.

Signed-off-by: Peter Korsgaard <[email protected]>
Signed-off-by: Mike Snitzer <[email protected]>

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dm init: Set file local variable static

Declare dm_allowed_targets as static to avoid the warning:

drivers/md/dm-init.c:39:12: warning: symbol 'dm_allowed_targets' was
not declared. Should it be st

dm init: Set file local variable static

Declare dm_allowed_targets as static to avoid the warning:

drivers/md/dm-init.c:39:12: warning: symbol 'dm_allowed_targets' was
not declared. Should it be static?

when compiling with C=1.

Signed-off-by: Damien Le Moal <[email protected]>
Signed-off-by: Mike Snitzer <[email protected]>

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docs: device-mapper: move it to the admin-guide

The DM support describes lots of aspects related to mapped
disk partitions from the userspace PoV.

Signed-off-by: Mauro Carvalho Chehab <mchehab+sams

docs: device-mapper: move it to the admin-guide

The DM support describes lots of aspects related to mapped
disk partitions from the userspace PoV.

Signed-off-by: Mauro Carvalho Chehab <[email protected]>

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dm init: remove trailing newline from calls to DMERR() and DMINFO()

These printing macros already add a trailing newline, so having another
one here just makes for blank lines when these prints are

dm init: remove trailing newline from calls to DMERR() and DMINFO()

These printing macros already add a trailing newline, so having another
one here just makes for blank lines when these prints are enabled.
Remove these needless newlines.

Fixes: 6bbc923dfcf5 ("dm: add support to directly boot to a mapped device")
Signed-off-by: Stephen Boyd <[email protected]>
Signed-off-by: Mike Snitzer <[email protected]>

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dm init: fix incorrect uses of kstrndup()

Fix 2 kstrndup() calls with incorrect argument order.

Fixes: 6bbc923dfcf5 ("dm: add support to directly boot to a mapped device")
Cc: [email protected]

dm init: fix incorrect uses of kstrndup()

Fix 2 kstrndup() calls with incorrect argument order.

Fixes: 6bbc923dfcf5 ("dm: add support to directly boot to a mapped device")
Cc: [email protected] # v5.1
Signed-off-by: Gen Zhang <[email protected]>
Signed-off-by: Mike Snitzer <[email protected]>

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docs: convert docs to ReST and rename to *.rst

The conversion is actually:
- add blank lines and indentation in order to identify paragraphs;
- fix tables markups;
- add some lists markups;

docs: convert docs to ReST and rename to *.rst

The conversion is actually:
- add blank lines and indentation in order to identify paragraphs;
- fix tables markups;
- add some lists markups;
- mark literal blocks;
- adjust title markups.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.

Signed-off-by: Mauro Carvalho Chehab <[email protected]>
Acked-by: Bjorn Helgaas <[email protected]>
Acked-by: Mark Brown <[email protected]>
Signed-off-by: Jonathan Corbet <[email protected]>

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dm init: fix max devices/targets checks

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

dm init: fix max devices/targets checks

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: 6bbc923dfcf57d ("dm: add support to directly boot to a mapped device")
Cc: [email protected]
Signed-off-by: Helen Koike <[email protected]>
Signed-off-by: Mike Snitzer <[email protected]>

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dm init: fix const confusion for dm_allowed_targets array

A non const pointer to const cannot be marked initconst.
Mark the array actually const.

Fixes: 6bbc923dfcf5 dm: add support to directly boo

dm init: fix const confusion for dm_allowed_targets array

A non const pointer to const cannot be marked initconst.
Mark the array actually const.

Fixes: 6bbc923dfcf5 dm: add support to directly boot to a mapped device
Signed-off-by: Andi Kleen <[email protected]>
Signed-off-by: Mike Snitzer <[email protected]>

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dm: add support to directly boot to a mapped device

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
boo

dm: add support to directly boot to a mapped device

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 <[email protected]>
Co-developed-by: Kees Cook <[email protected]>
Co-developed-by: Enric Balletbo i Serra <[email protected]>
Signed-off-by: Helen Koike <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Signed-off-by: Mike Snitzer <[email protected]>

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