Commit d358e525 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'for-6.19/dm-changes' of... 

Merge tag 'for-6.19/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper updates from Mikulas Patocka:

 - convert crypto_shash users to direct crypto library use with simpler
   and faster code and reduced stack usage (Eric Biggers):

     - the dm-verity SHA-256 conversion also teaches it to do two-way
       interleaved hashing for added performance

     - dm-crypt MD5 conversion (used for Loop-AES compatibility)

 - added document for for takeover/reshape raid1 -> raid5 examples (Heinz Mauelshagen)

 - fix dm-vdo kerneldoc warnings (Matthew Sakai)

 - various random fixes and cleanups

* tag 'for-6.19/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (29 commits)
  dm pcache: fix segment info indexing
  dm pcache: fix cache info indexing
  dm-pcache: advance slot index before writing slot
  dm raid: add documentation for takeover/reshape raid1 -> raid5 table line examples
  dm log-writes: Add missing set_freezable() for freezable kthread
  dm-raid: fix possible NULL dereference with undefined raid type
  dm-snapshot: fix 'scheduling while atomic' on real-time kernels
  dm: ignore discard return value
  MAINTAINERS: add Benjamin Marzinski as a device mapper maintainer
  dm-mpath: Simplify the setup_scsi_dh code
  dm vdo: fix kerneldoc warnings
  dm-bufio: align write boundary on physical block size
  dm-crypt: enable DM_TARGET_ATOMIC_WRITES
  dm: test for REQ_ATOMIC in dm_accept_partial_bio()
  dm-verity: remove useless mempool
  dm-verity: disable recursive forward error correction
  dm-ebs: Mark full buffer dirty even on partial write
  dm mpath: enable DM_TARGET_ATOMIC_WRITES
  dm verity fec: Expose corrected block count via status
  dm: Don't warn if IMA_DISABLE_HTABLE is not enabled
  ...
parents 8c8081cc 13ea55ea

Documentation/admin-guide/device-mapper/dm-raid.rst

+73 −7
Original line number Diff line number Diff line
@@ -20,10 +20,10 @@ The target is named "raid" and it accepts the following parameters:: 
  raid0		RAID0 striping (no resilience)

  raid1		RAID1 mirroring

  raid4		RAID4 with dedicated last parity disk

  raid5_n 	RAID5 with dedicated last parity disk supporting takeover

  raid5_n 	RAID5 with dedicated last parity disk supporting takeover from/to raid1

		Same as raid4



		- Transitory layout

		- Transitory layout for takeover from/to raid1

  raid5_la	RAID5 left asymmetric



		- rotating parity 0 with data continuation
@@ -48,8 +48,8 @@ The target is named "raid" and it accepts the following parameters:: 
  raid6_n_6	RAID6 with dedicate parity disks



		- parity and Q-syndrome on the last 2 disks;

		  layout for takeover from/to raid4/raid5_n

  raid6_la_6	Same as "raid_la" plus dedicated last Q-syndrome disk

		  layout for takeover from/to raid0/raid4/raid5_n

  raid6_la_6	Same as "raid_la" plus dedicated last Q-syndrome disk supporting takeover from/to raid5



		- layout for takeover from raid5_la from/to raid6

  raid6_ra_6	Same as "raid5_ra" dedicated last Q-syndrome disk
@@ -173,9 +173,9 @@ The target is named "raid" and it accepts the following parameters:: 
		The delta_disks option value (-251 < N < +251) triggers

		device removal (negative value) or device addition (positive

		value) to any reshape supporting raid levels 4/5/6 and 10.

		RAID levels 4/5/6 allow for addition of devices (metadata

		and data device tuple), raid10_near and raid10_offset only

		allow for device addition. raid10_far does not support any

		RAID levels 4/5/6 allow for addition and removal of devices

                (metadata and data device tuple), raid10_near and raid10_offset

                only allow for device addition. raid10_far does not support any

		reshaping at all.

		A minimum of devices have to be kept to enforce resilience,

		which is 3 devices for raid4/5 and 4 devices for raid6.
@@ -372,6 +372,72 @@ to safely enable discard support for RAID 4/5/6: 
    'devices_handle_discards_safely'





Takeover/Reshape Support

------------------------

The target natively supports these two types of MDRAID conversions:



o Takeover: Converts an array from one RAID level to another



o Reshape: Changes the internal layout while maintaining the current RAID level



Each operation is only valid under specific constraints imposed by the existing array's layout and configuration.





Takeover:

linear -> raid1 with N >= 2 mirrors

raid0 -> raid4 (add dedicated parity device)

raid0 -> raid5 (add dedicated parity device)

raid0 -> raid10 with near layout and N >= 2 mirror groups (raid0 stripes have to become first member within mirror groups)

raid1 -> linear

raid1 -> raid5 with 2 mirrors

raid4 -> raid5 w/ rotating parity

raid5 with dedicated parity device -> raid4

raid5 -> raid6 (with dedicated Q-syndrome)

raid6 (with dedicated Q-syndrome) -> raid5

raid10 with near layout and even number of disks -> raid0 (select any in-sync device from each mirror group)



Reshape:

linear: not possible

raid0:  not possible

raid1:  change number of mirrors

raid4:  add and remove stripes (minimum 3), change stripesize

raid5:  add and remove stripes (minimum 3, special case 2 for raid1 takeover), change rotating parity algorithms, change stripesize

raid6:  add and remove stripes (minimum 4), change rotating syndrome algorithms, change stripesize

raid10 near:   add stripes (minimum 4), change stripesize, no stripe removal possible, change to offset layout

raid10 offset: add stripes, change stripesize, no stripe removal possible, change to near layout

raid10 far:    not possible



Table line examples:



### raid1 -> raid5

#

# 2 devices limitation in raid1.

# raid5 personality is able to just map 2 like raid1.

# Reshape after takeover to change to full raid5 layout



  0 1960886272 raid raid1 3 0 region_size 2048 2 /dev/dm-0 /dev/dm-1 /dev/dm-2 /dev/dm-3



# dm-0 and dm-2 are e.g. 4MiB large metadata devices, dm-1 and dm-3 have to be at least 1960886272 big.

#

# Table line to takeover to raid5



  0 1960886272 raid raid5 3 0 region_size 2048 2 /dev/dm-0 /dev/dm-1 /dev/dm-2 /dev/dm-3



# Add required out-of-place reshape space to the beginniong of the given 2 data devices,

# allocate another metadata/data device tuple with the same sizes for the parity space

# and zero the first 4K of the metadata device.

#

# Example table of the out-of-place reshape space addition for one data device, e.g. dm-1



  0 8192 linear 8:0 0 1960903888 #  <- must be free space segment

  8192 1960886272 linear 8:0 0 2048 # previous data segment



# Mapping table for e.g. raid5_rs reshape causing the size of the raid device to double-fold once the reshape finishes.

# Check the status output (e.g. "dmsetup status $RaidDev") for progess.



  0 $((2 * 1960886272)) raid raid5 7 0 region_size 2048 data_offset 8192 delta_disk 1 2 /dev/dm-0 /dev/dm-1 /dev/dm-2 /dev/dm-3





Version History

---------------

Documentation/admin-guide/device-mapper/verity.rst

+4 −2
Original line number Diff line number Diff line
@@ -236,8 +236,10 @@ is available at the cryptsetup project's wiki page 


Status

======

V (for Valid) is returned if every check performed so far was valid.

1. V (for Valid) is returned if every check performed so far was valid.

   If any check failed, C (for Corruption) is returned.

2. Number of corrected blocks by Forward Error Correction.

   '-' if Forward Error Correction is not enabled.



Example

=======

MAINTAINERS

+1 −0
Original line number Diff line number Diff line
@@ -7225,6 +7225,7 @@ DEVICE-MAPPER (LVM) 
M:	Alasdair Kergon <agk@redhat.com>

M:	Mike Snitzer <snitzer@kernel.org>

M:	Mikulas Patocka <mpatocka@redhat.com>

M:	Benjamin Marzinski <bmarzins@redhat.com>

L:	dm-devel@lists.linux.dev

S:	Maintained

Q:	http://patchwork.kernel.org/project/dm-devel/list/

drivers/md/Kconfig

+2 −0
Original line number Diff line number Diff line
@@ -299,6 +299,7 @@ config DM_CRYPT 
	select CRYPTO

	select CRYPTO_CBC

	select CRYPTO_ESSIV

	select CRYPTO_LIB_MD5 # needed by lmk IV mode

	help

	  This device-mapper target allows you to create a device that

	  transparently encrypts the data on it. You'll need to activate
@@ -546,6 +547,7 @@ config DM_VERITY 
	depends on BLK_DEV_DM

	select CRYPTO

	select CRYPTO_HASH

	select CRYPTO_LIB_SHA256

	select DM_BUFIO

	help

	  This device-mapper target creates a read-only device that

drivers/md/dm-bufio.c

+6 −4
Original line number Diff line number Diff line
@@ -1374,7 +1374,7 @@ static void submit_io(struct dm_buffer *b, enum req_op op, unsigned short ioprio 
{

	unsigned int n_sectors;

	sector_t sector;

	unsigned int offset, end;

	unsigned int offset, end, align;



	b->end_io = end_io;
@@ -1388,9 +1388,11 @@ static void submit_io(struct dm_buffer *b, enum req_op op, unsigned short ioprio 
			b->c->write_callback(b);

		offset = b->write_start;

		end = b->write_end;

		offset &= -DM_BUFIO_WRITE_ALIGN;

		end += DM_BUFIO_WRITE_ALIGN - 1;

		end &= -DM_BUFIO_WRITE_ALIGN;

		align = max(DM_BUFIO_WRITE_ALIGN,

			bdev_physical_block_size(b->c->bdev));

		offset &= -align;

		end += align - 1;

		end &= -align;

		if (unlikely(end > b->c->block_size))

			end = b->c->block_size;