<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/linux.git/drivers/md/Kconfig, branch v6.18.21</title>
<subtitle>Linux kernel stable tree (mirror)</subtitle>
<id>https://git.radix-linux.su/kernel/linux.git/atom?h=v6.18.21</id>
<link rel='self' href='https://git.radix-linux.su/kernel/linux.git/atom?h=v6.18.21'/>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/'/>
<updated>2025-10-04T01:48:02+00:00</updated>
<entry>
<title>Merge tag 'for-6.18/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm</title>
<updated>2025-10-04T01:48:02+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2025-10-04T01:48:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=7dbec0bbc3b468310be172f1ce6ddc9411c84952'/>
<id>urn:sha1:7dbec0bbc3b468310be172f1ce6ddc9411c84952</id>
<content type='text'>
Pull device mapper updates from Mikulas Patocka:

 - a new dm-pcache target for read/write caching on persistent memory

 - fix typos in docs

 - misc small refactoring

 - mark dm-error with DM_TARGET_PASSES_INTEGRITY

 - dm-request-based: fix NULL pointer dereference and quiesce_depth out of sync

 - dm-linear: optimize REQ_PREFLUSH

 - dm-vdo: return error on corrupted metadata

 - dm-integrity: support asynchronous hash interface

* tag 'for-6.18/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (27 commits)
  dm raid: use proper md_ro_state enumerators
  dm-integrity: prefer synchronous hash interface
  dm-integrity: enable asynchronous hash interface
  dm-integrity: rename internal_hash
  dm-integrity: add the "offset" argument
  dm-integrity: allocate the recalculate buffer with kmalloc
  dm-integrity: introduce integrity_kmap and integrity_kunmap
  dm-integrity: replace bvec_kmap_local with kmap_local_page
  dm-integrity: use internal variable for digestsize
  dm vdo: return error on corrupted metadata in start_restoring_volume functions
  dm vdo: Update code to use mem_is_zero
  dm: optimize REQ_PREFLUSH with data when using the linear target
  dm-pcache: use int type to store negative error codes
  dm: fix "writen"-&gt;"written"
  dm-pcache: cleanup: fix coding style report by checkpatch.pl
  dm-pcache: remove ctrl_lock for pcache_cache_segment
  dm: fix NULL pointer dereference in __dm_suspend()
  dm: fix queue start/stop imbalance under suspend/load/resume races
  dm-pcache: add persistent cache target in device-mapper
  dm error: mark as DM_TARGET_PASSES_INTEGRITY
  ...
</content>
</entry>
<entry>
<title>md/md-llbitmap: introduce new lockless bitmap</title>
<updated>2025-09-06T09:27:51+00:00</updated>
<author>
<name>Yu Kuai</name>
<email>yukuai3@huawei.com</email>
</author>
<published>2025-08-29T08:04:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=5ab829f1971dc99f2aac10846c378e67fc875abc'/>
<id>urn:sha1:5ab829f1971dc99f2aac10846c378e67fc875abc</id>
<content type='text'>
Redundant data is used to enhance data fault tolerance, and the storage
method for redundant data vary depending on the RAID levels. And it's
important to maintain the consistency of redundant data.

Bitmap is used to record which data blocks have been synchronized and which
ones need to be resynchronized or recovered. Each bit in the bitmap
represents a segment of data in the array. When a bit is set, it indicates
that the multiple redundant copies of that data segment may not be
consistent. Data synchronization can be performed based on the bitmap after
power failure or readding a disk. If there is no bitmap, a full disk
synchronization is required.

Due to known performance issues with md-bitmap and the unreasonable
implementations:

 - self-managed IO submitting like filemap_write_page();
 - global spin_lock

I have decided not to continue optimizing based on the current bitmap
implementation, this new bitmap is invented without locking from IO fast
path and can be used with fast disks.

For designs and details, see the comments in drivers/md-llbitmap.c.

Link: https://lore.kernel.org/linux-raid/20250829080426.1441678-12-yukuai1@huaweicloud.com
Signed-off-by: Yu Kuai &lt;yukuai3@huawei.com&gt;
Reviewed-by: Li Nan &lt;linan122@huawei.com&gt;
</content>
</entry>
<entry>
<title>md/md-bitmap: introduce CONFIG_MD_BITMAP</title>
<updated>2025-09-06T09:12:22+00:00</updated>
<author>
<name>Yu Kuai</name>
<email>yukuai3@huawei.com</email>
</author>
<published>2025-07-07T01:27:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=c27474ac1d4609af3c1c38ccac252c2575b47b9e'/>
<id>urn:sha1:c27474ac1d4609af3c1c38ccac252c2575b47b9e</id>
<content type='text'>
Now that all implementations are internal, it's sensible to add a config
option for md-bitmap, and it's a good way for isolation.

Link: https://lore.kernel.org/linux-raid/20250707012711.376844-16-yukuai1@huaweicloud.com
Signed-off-by: Yu Kuai &lt;yukuai3@huawei.com&gt;
Reviewed-by: Xiao Ni &lt;xni@redhat.com&gt;
</content>
</entry>
<entry>
<title>dm-pcache: add persistent cache target in device-mapper</title>
<updated>2025-08-25T13:25:29+00:00</updated>
<author>
<name>Dongsheng Yang</name>
<email>dongsheng.yang@linux.dev</email>
</author>
<published>2025-08-12T08:24:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=1d57628ff95b32d5cfa8d8f50e07690c161e9cf0'/>
<id>urn:sha1:1d57628ff95b32d5cfa8d8f50e07690c161e9cf0</id>
<content type='text'>
This patch introduces dm-pcache, a new DM target that places a DAX-
capable persistent-memory device in front of any slower block device and
uses it as a high-throughput, low-latency  cache.

Design highlights
-----------------
- DAX data path – data is copied directly between DRAM and the pmem
  mapping, bypassing the block layer’s overhead.

- Segmented, crash-consistent layout
  - all layout metadata are dual-replicated CRC-protected.
  - atomic kset flushes; key replay on mount guarantees cache integrity
    even after power loss.

- Striped multi-tree index
  - Multi‑tree indexing for high parallelism.
  - overlap-resolution logic ensures non-intersecting cached extents.

- Background services
  - write-back worker flushes dirty keys in order, preserving backing-device
    crash consistency. This is important for checkpoint in cloud storage.
  - garbage collector reclaims clean segments when utilisation exceeds a
    tunable threshold.

- Data integrity – optional CRC32 on cached payload; metadata always protected.

Comparison with existing block-level caches
---------------------------------------------------------------------------------------------------------------------------------
| Feature                          | pcache (this patch)             | bcache                       | dm-writecache             |
|----------------------------------|---------------------------------|------------------------------|---------------------------|
| pmem access method               | DAX                             | bio (block I/O)              | DAX                       |
| Write latency (4 K rand-write)   | ~5 µs                           | ~20 µs                       | ~5 µs                     |
| Concurrency                      | multi subtree index             | global index tree            | single tree + wc_lock     |
| IOPS (4K randwrite, 32 numjobs)  | 2.1 M                           | 352 K                        | 283 K                     |
| Read-cache support               | YES                             | YES                          | NO                        |
| Deployment                       | no re-format of backend         | backend devices must be      | no re-format of backend   |
|                                  |                                 | reformatted                  |                           |
| Write-back ordering              | log-structured;                 | no ordering guarantee        | no ordering guarantee     |
|                                  | preserves app-IO-order          |                              |                           |
| Data integrity checks            | metadata + data CRC(optional)   | metadata CRC only            | none                      |
---------------------------------------------------------------------------------------------------------------------------------

Signed-off-by: Dongsheng Yang &lt;dongsheng.yang@linux.dev&gt;
Signed-off-by: Mikulas Patocka &lt;mpatocka@redhat.com&gt;
</content>
</entry>
<entry>
<title>Merge tag 'crc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux</title>
<updated>2025-04-08T19:09:28+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2025-04-08T19:09:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=97c484ccb804ac07f8be80d66a250a260cc9339e'/>
<id>urn:sha1:97c484ccb804ac07f8be80d66a250a260cc9339e</id>
<content type='text'>
Pull CRC cleanups from Eric Biggers:
 "Finish cleaning up the CRC kconfig options by removing the remaining
  unnecessary prompts and an unnecessary 'default y', removing
  CONFIG_LIBCRC32C, and documenting all the CRC library options"

* tag 'crc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux:
  lib/crc: remove CONFIG_LIBCRC32C
  lib/crc: document all the CRC library kconfig options
  lib/crc: remove unnecessary prompt for CONFIG_CRC_ITU_T
  lib/crc: remove unnecessary prompt for CONFIG_CRC_T10DIF
  lib/crc: remove unnecessary prompt for CONFIG_CRC16
  lib/crc: remove unnecessary prompt for CONFIG_CRC_CCITT
  lib/crc: remove unnecessary prompt for CONFIG_CRC32 and drop 'default y'
</content>
</entry>
<entry>
<title>lib/crc: remove CONFIG_LIBCRC32C</title>
<updated>2025-04-04T18:31:42+00:00</updated>
<author>
<name>Eric Biggers</name>
<email>ebiggers@google.com</email>
</author>
<published>2025-04-01T22:16:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=b261d2222063a9a8b9ec284244c285f2998ee01e'/>
<id>urn:sha1:b261d2222063a9a8b9ec284244c285f2998ee01e</id>
<content type='text'>
Now that LIBCRC32C does nothing besides select CRC32, make every option
that selects LIBCRC32C instead select CRC32 directly.  Then remove
LIBCRC32C.

Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: "Martin K. Petersen" &lt;martin.petersen@oracle.com&gt;
Acked-by: Ard Biesheuvel &lt;ardb@kernel.org&gt;
Link: https://lore.kernel.org/r/20250401221600.24878-8-ebiggers@kernel.org
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
</content>
</entry>
<entry>
<title>dm-crypt: switch to using the crc32 library</title>
<updated>2025-02-03T13:10:10+00:00</updated>
<author>
<name>Eric Biggers</name>
<email>ebiggers@google.com</email>
</author>
<published>2025-01-27T22:15:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=f656fa4013388a52d1fdd82268955c5e7be63ad2'/>
<id>urn:sha1:f656fa4013388a52d1fdd82268955c5e7be63ad2</id>
<content type='text'>
Now that the crc32() library function takes advantage of
architecture-specific optimizations, it is unnecessary to go through the
crypto API.  Just use crc32().  This is much simpler, and it improves
performance due to eliminating the crypto API overhead.  (However, this
only affects the TCW IV mode of dm-crypt, which is a compatibility mode
that is rarely used compared to other dm-crypt modes.)

Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Signed-off-by: Mikulas Patocka &lt;mpatocka@redhat.com&gt;
</content>
</entry>
<entry>
<title>md: reintroduce md-linear</title>
<updated>2025-01-13T15:36:29+00:00</updated>
<author>
<name>Yu Kuai</name>
<email>yukuai3@huawei.com</email>
</author>
<published>2025-01-02T11:28:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=127186cfb184eaccdfe948e6da66940cfa03efc5'/>
<id>urn:sha1:127186cfb184eaccdfe948e6da66940cfa03efc5</id>
<content type='text'>
THe md-linear is removed by commit 849d18e27be9 ("md: Remove deprecated
CONFIG_MD_LINEAR") because it has been marked as deprecated for a long
time.

However, md-linear is used widely for underlying disks with different size,
sadly we didn't know this until now, and it's true useful to create
partitions and assemble multiple raid and then append one to the other.

People have to use dm-linear in this case now, however, they will prefer
to minimize the number of involved modules.

Fixes: 849d18e27be9 ("md: Remove deprecated CONFIG_MD_LINEAR")
Cc: stable@vger.kernel.org
Signed-off-by: Yu Kuai &lt;yukuai3@huawei.com&gt;
Acked-by: Coly Li &lt;colyli@kernel.org&gt;
Acked-by: Mike Snitzer &lt;snitzer@kernel.org&gt;
Link: https://lore.kernel.org/r/20250102112841.1227111-1-yukuai1@huaweicloud.com
Signed-off-by: Song Liu &lt;song@kernel.org&gt;
</content>
</entry>
<entry>
<title>dm verity: add support for signature verification with platform keyring</title>
<updated>2024-07-03T19:41:11+00:00</updated>
<author>
<name>Luca Boccassi</name>
<email>bluca@debian.org</email>
</author>
<published>2024-07-02T16:16:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=6fce1f40e95182ebbfe1ee3096b8fc0b37903269'/>
<id>urn:sha1:6fce1f40e95182ebbfe1ee3096b8fc0b37903269</id>
<content type='text'>
Add a new configuration CONFIG_DM_VERITY_VERIFY_ROOTHASH_SIG_PLATFORM_KEYRING
that enables verifying dm-verity signatures using the platform keyring,
which is populated using the UEFI DB certificates. This is useful for
self-enrolled systems that do not use MOK, as the secondary keyring which
is already used for verification, if the relevant kconfig is enabled, is
linked to the machine keyring, which gets its certificates loaded from MOK.
On datacenter/virtual/cloud deployments it is more common to deploy one's
own certificate chain directly in DB on first boot in unattended mode,
rather than relying on MOK, as the latter typically requires interactive
authentication to enroll, and is more suited for personal machines.

Default to the same value as DM_VERITY_VERIFY_ROOTHASH_SIG_SECONDARY_KEYRING
if not otherwise specified, as it is likely that if one wants to use
MOK certificates to verify dm-verity volumes, DB certificates are
going to be used too. Keys in DB are allowed to load a full kernel
already anyway, so they are already highly privileged.

Signed-off-by: Luca Boccassi &lt;bluca@debian.org&gt;
Signed-off-by: Mikulas Patocka &lt;mpatocka@redhat.com&gt;
</content>
</entry>
<entry>
<title>Merge tag 'kbuild-v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild</title>
<updated>2024-03-21T21:41:00+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-03-21T21:41:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=1d35aae78ffe739bf46c2bf9dea7b51a4eebfbe0'/>
<id>urn:sha1:1d35aae78ffe739bf46c2bf9dea7b51a4eebfbe0</id>
<content type='text'>
Pull Kbuild updates from Masahiro Yamada:

 - Generate a list of built DTB files (arch/*/boot/dts/dtbs-list)

 - Use more threads when building Debian packages in parallel

 - Fix warnings shown during the RPM kernel package uninstallation

 - Change OBJECT_FILES_NON_STANDARD_*.o etc. to take a relative path to
   Makefile

 - Support GCC's -fmin-function-alignment flag

 - Fix a null pointer dereference bug in modpost

 - Add the DTB support to the RPM package

 - Various fixes and cleanups in Kconfig

* tag 'kbuild-v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (67 commits)
  kconfig: tests: test dependency after shuffling choices
  kconfig: tests: add a test for randconfig with dependent choices
  kconfig: tests: support KCONFIG_SEED for the randconfig runner
  kbuild: rpm-pkg: add dtb files in kernel rpm
  kconfig: remove unneeded menu_is_visible() call in conf_write_defconfig()
  kconfig: check prompt for choice while parsing
  kconfig: lxdialog: remove unused dialog colors
  kconfig: lxdialog: fix button color for blackbg theme
  modpost: fix null pointer dereference
  kbuild: remove GCC's default -Wpacked-bitfield-compat flag
  kbuild: unexport abs_srctree and abs_objtree
  kbuild: Move -Wenum-{compare-conditional,enum-conversion} into W=1
  kconfig: remove named choice support
  kconfig: use linked list in get_symbol_str() to iterate over menus
  kconfig: link menus to a symbol
  kbuild: fix inconsistent indentation in top Makefile
  kbuild: Use -fmin-function-alignment when available
  alpha: merge two entries for CONFIG_ALPHA_GAMMA
  alpha: merge two entries for CONFIG_ALPHA_EV4
  kbuild: change DTC_FLAGS_&lt;basetarget&gt;.o to take the path relative to $(obj)
  ...
</content>
</entry>
</feed>
