kernel/linux.git/drivers/md/Makefile, branch v6.19.11

Merge tag 'for-6.18/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

2025-10-04T01:48:02+00:00

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"->"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 ...

md/md-llbitmap: introduce new lockless bitmap

2025-09-06T09:27:51+00:00

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 Reviewed-by: Li Nan

md/md-bitmap: introduce CONFIG_MD_BITMAP

2025-09-06T09:12:22+00:00

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 Reviewed-by: Xiao Ni

dm-pcache: add persistent cache target in device-mapper

2025-08-25T13:25:29+00:00

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 Signed-off-by: Mikulas Patocka

md: reintroduce md-linear

2025-01-13T15:36:29+00:00

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 Acked-by: Coly Li Acked-by: Mike Snitzer Link: https://lore.kernel.org/r/20250102112841.1227111-1-yukuai1@huaweicloud.com Signed-off-by: Song Liu

dm vdo: use a proper Makefile for dm-vdo

2024-02-20T18:43:17+00:00

Requires moving dm-vdo-target.c into drivers/md/dm-vdo/ This change adds a proper drivers/md/dm-vdo/Makefile and eliminates the abnormal use of patsubst in drivers/md/Makefile -- which was the cause of at least one build failure that was reported by the upstream build bot. Also, split out VDO's drivers/md/dm-vdo/Kconfig and include it from drivers/md/Kconfig Signed-off-by: Mike Snitzer Signed-off-by: Matthew Sakai

dm vdo: enable configuration and building of dm-vdo

2024-02-20T18:43:16+00:00

dm-vdo targets are not supported for 32-bit configurations. A vdo target typically requires 1 to 1.5 GB of memory at any given time, which is likely a large fraction of the addressable memory of a 32-bit system. At the same time, the amount of addressable storage attached to a 32-bit system may not be large enough for deduplication to provide much benefit. Because of these concerns, 32-bit platforms are deemed unlikely to benefit from using a vdo target, so dm-vdo is targeted only at 64-bit platforms. Co-developed-by: J. corwin Coburn Signed-off-by: J. corwin Coburn Co-developed-by: John Wiele Signed-off-by: John Wiele Signed-off-by: Matthew Sakai Signed-off-by: Mike Snitzer

md: Remove deprecated CONFIG_MD_FAULTY

2023-12-19T18:37:50+00:00

md-faulty has been marked as deprecated for 2.5 years. Remove it. Cc: Christoph Hellwig Cc: Jens Axboe Cc: Neil Brown Cc: Guoqing Jiang Cc: Mateusz Grzonka Cc: Jes Sorensen Signed-off-by: Song Liu Reviewed-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Link: https://lore.kernel.org/r/20231214222107.2016042-4-song@kernel.org

md: Remove deprecated CONFIG_MD_MULTIPATH

2023-12-19T18:37:41+00:00

md-multipath has been marked as deprecated for 2.5 years. Remove it. Cc: Christoph Hellwig Cc: Jens Axboe Cc: Neil Brown Cc: Guoqing Jiang Cc: Mateusz Grzonka Cc: Jes Sorensen Signed-off-by: Song Liu Reviewed-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Link: https://lore.kernel.org/r/20231214222107.2016042-3-song@kernel.org

md: Remove deprecated CONFIG_MD_LINEAR

2023-12-19T18:16:51+00:00

md-linear has been marked as deprecated for 2.5 years. Remove it. Cc: Christoph Hellwig Cc: Jens Axboe Cc: Neil Brown Cc: Guoqing Jiang Cc: Mateusz Grzonka Cc: Jes Sorensen Signed-off-by: Song Liu Reviewed-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Link: https://lore.kernel.org/r/20231214222107.2016042-2-song@kernel.org