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2025-10-20dm-verity: use SHA-256 library for SHA-256Eric Biggers
When the hash algorithm is SHA-256 and the verity version is not 0, use the SHA-256 library instead of crypto_shash. This is a prerequisite for making dm-verity interleave the computation of SHA-256 hashes for increased performance. That optimization is available in the SHA-256 library but not in crypto_shash. Even without interleaved hashing, switching to the library also slightly improves performance by itself because it avoids the overhead of crypto_shash, including indirect calls and other API overhead. (Benchmark on x86_64, AMD Zen 5: hashing 4K blocks gets 2.1% faster.) SHA-256 is by far the most common hash algorithm used with dm-verity. It makes sense to optimize for the common case and fall back to the generic crypto layer for uncommon cases, as suggested by Linus: https://lore.kernel.org/r/CAHk-=wgp-fOSsZsYrbyzqCAfEvrt5jQs1jL-97Wc4seMNTUyng@mail.gmail.com Signed-off-by: Eric Biggers <ebiggers@kernel.org> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
2025-10-20dm-crypt: Use MD5 library instead of crypto_shashEric Biggers
The lmk IV mode, which dm-crypt supports for Loop-AES compatibility, involves an MD5 computation. Update its implementation to use the MD5 library API instead of crypto_shash. This has many benefits, such as: - Simpler code. Notably, much of the error-handling code is no longer needed, since the library functions can't fail. - Reduced stack usage. crypt_iv_lmk_one() now allocates only 112 bytes on the stack instead of 520 bytes. - The library functions are strongly typed, preventing bugs like https://lore.kernel.org/r/f1625ddc-e82e-4b77-80c2-dc8e45b54848@gmail.com - Slightly improved performance, as the library provides direct access to the MD5 code without unnecessary overhead such as indirect calls. To preserve the existing behavior of lmk support being disabled when the kernel is booted with "fips=1", make crypt_iv_lmk_ctr() check fips_enabled itself. Previously it relied on crypto_alloc_shash("md5") failing. (I don't know for sure that lmk *actually* needs to be disallowed in FIPS mode; this just preserves the existing behavior.) Signed-off-by: Eric Biggers <ebiggers@kernel.org> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Acked-by: Ard Biesheuvel <ardb@kernel.org>
2025-10-03Merge tag 'for-6.18/dm-changes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm 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 ...
2025-09-06md/md-llbitmap: introduce new lockless bitmapYu Kuai
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 <yukuai3@huawei.com> Reviewed-by: Li Nan <linan122@huawei.com>
2025-09-06md/md-bitmap: introduce CONFIG_MD_BITMAPYu Kuai
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 <yukuai3@huawei.com> Reviewed-by: Xiao Ni <xni@redhat.com>
2025-08-25dm-pcache: add persistent cache target in device-mapperDongsheng Yang
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 <dongsheng.yang@linux.dev> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
2025-04-08Merge tag 'crc-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux 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'
2025-04-04lib/crc: remove CONFIG_LIBCRC32CEric Biggers
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 <hch@lst.de> Reviewed-by: "Martin K. Petersen" <martin.petersen@oracle.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20250401221600.24878-8-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com>
2025-02-03dm-crypt: switch to using the crc32 libraryEric Biggers
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 <ebiggers@google.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
2025-01-13md: reintroduce md-linearYu Kuai
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 <yukuai3@huawei.com> Acked-by: Coly Li <colyli@kernel.org> Acked-by: Mike Snitzer <snitzer@kernel.org> Link: https://lore.kernel.org/r/20250102112841.1227111-1-yukuai1@huaweicloud.com Signed-off-by: Song Liu <song@kernel.org>
2024-07-03dm verity: add support for signature verification with platform keyringLuca Boccassi
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 <bluca@debian.org> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
2024-03-21Merge tag 'kbuild-v6.9' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild 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_<basetarget>.o to take the path relative to $(obj) ...
2024-02-20dm vdo: use a proper Makefile for dm-vdoMike Snitzer
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 <snitzer@kernel.org> Signed-off-by: Matthew Sakai <msakai@redhat.com>
2024-02-20dm vdo: enable configuration and building of dm-vdoMatthew Sakai
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 <corwin@hurlbutnet.net> Signed-off-by: J. corwin Coburn <corwin@hurlbutnet.net> Co-developed-by: John Wiele <jwiele@redhat.com> Signed-off-by: John Wiele <jwiele@redhat.com> Signed-off-by: Matthew Sakai <msakai@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2024-02-20treewide: replace or remove redundant def_bool in Kconfig filesMasahiro Yamada
'def_bool X' is a shorthand for 'bool' plus 'default X'. 'def_bool' is redundant where 'bool' is already present, so 'def_bool X' can be replaced with 'default X', or removed if X is 'n'. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-01-11Merge tag 'for-6.8/block-2024-01-08' of git://git.kernel.dk/linuxLinus Torvalds
Pull block updates from Jens Axboe: "Pretty quiet round this time around. This contains: - NVMe updates via Keith: - nvme fabrics spec updates (Guixin, Max) - nvme target udpates (Guixin, Evan) - nvme attribute refactoring (Daniel) - nvme-fc numa fix (Keith) - MD updates via Song: - Fix/Cleanup RCU usage from conf->disks[i].rdev (Yu Kuai) - Fix raid5 hang issue (Junxiao Bi) - Add Yu Kuai as Reviewer of the md subsystem - Remove deprecated flavors (Song Liu) - raid1 read error check support (Li Nan) - Better handle events off-by-1 case (Alex Lyakas) - Efficiency improvements for passthrough (Kundan) - Support for mapping integrity data directly (Keith) - Zoned write fix (Damien) - rnbd fixes (Kees, Santosh, Supriti) - Default to a sane discard size granularity (Christoph) - Make the default max transfer size naming less confusing (Christoph) - Remove support for deprecated host aware zoned model (Christoph) - Misc fixes (me, Li, Matthew, Min, Ming, Randy, liyouhong, Daniel, Bart, Christoph)" * tag 'for-6.8/block-2024-01-08' of git://git.kernel.dk/linux: (78 commits) block: Treat sequential write preferred zone type as invalid block: remove disk_clear_zoned sd: remove the !ZBC && blk_queue_is_zoned case in sd_read_block_characteristics drivers/block/xen-blkback/common.h: Fix spelling typo in comment blk-cgroup: fix rcu lockdep warning in blkg_lookup() blk-cgroup: don't use removal safe list iterators block: floor the discard granularity to the physical block size mtd_blkdevs: use the default discard granularity bcache: use the default discard granularity zram: use the default discard granularity null_blk: use the default discard granularity nbd: use the default discard granularity ubd: use the default discard granularity block: default the discard granularity to sector size bcache: discard_granularity should not be smaller than a sector block: remove two comments in bio_split_discard block: rename and document BLK_DEF_MAX_SECTORS loop: don't abuse BLK_DEF_MAX_SECTORS aoe: don't abuse BLK_DEF_MAX_SECTORS null_blk: don't cap max_hw_sectors to BLK_DEF_MAX_SECTORS ...
2023-12-19md: Remove deprecated CONFIG_MD_FAULTYSong Liu
md-faulty has been marked as deprecated for 2.5 years. Remove it. Cc: Christoph Hellwig <hch@lst.de> Cc: Jens Axboe <axboe@kernel.dk> Cc: Neil Brown <neilb@suse.de> Cc: Guoqing Jiang <guoqing.jiang@linux.dev> Cc: Mateusz Grzonka <mateusz.grzonka@intel.com> Cc: Jes Sorensen <jes@trained-monkey.org> Signed-off-by: Song Liu <song@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Link: https://lore.kernel.org/r/20231214222107.2016042-4-song@kernel.org
2023-12-19md: Remove deprecated CONFIG_MD_MULTIPATHSong Liu
md-multipath has been marked as deprecated for 2.5 years. Remove it. Cc: Christoph Hellwig <hch@lst.de> Cc: Jens Axboe <axboe@kernel.dk> Cc: Neil Brown <neilb@suse.de> Cc: Guoqing Jiang <guoqing.jiang@linux.dev> Cc: Mateusz Grzonka <mateusz.grzonka@intel.com> Cc: Jes Sorensen <jes@trained-monkey.org> Signed-off-by: Song Liu <song@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Link: https://lore.kernel.org/r/20231214222107.2016042-3-song@kernel.org
2023-12-19md: Remove deprecated CONFIG_MD_LINEARSong Liu
md-linear has been marked as deprecated for 2.5 years. Remove it. Cc: Christoph Hellwig <hch@lst.de> Cc: Jens Axboe <axboe@kernel.dk> Cc: Neil Brown <neilb@suse.de> Cc: Guoqing Jiang <guoqing.jiang@linux.dev> Cc: Mateusz Grzonka <mateusz.grzonka@intel.com> Cc: Jes Sorensen <jes@trained-monkey.org> Signed-off-by: Song Liu <song@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Link: https://lore.kernel.org/r/20231214222107.2016042-2-song@kernel.org
2023-12-18dm audit: fix Kconfig so DM_AUDIT depends on BLK_DEV_DMMike Snitzer
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2023-08-02fs: add CONFIG_BUFFER_HEADChristoph Hellwig
Add a new config option that controls building the buffer_head code, and select it from all file systems and stacking drivers that need it. For the block device nodes and alternative iomap based buffered I/O path is provided when buffer_head support is not enabled, and iomap needs a a small tweak to define the IOMAP_F_BUFFER_HEAD flag to 0 to not call into the buffer_head code when it doesn't exist. Otherwise this is just Kconfig and ifdef changes. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20230801172201.1923299-7-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-07-27md: deprecate bitmap file supportChristoph Hellwig
The support for bitmaps on files is a very bad idea abusing various kernel APIs, and fundamentally requires the file to not be on the actual array without a way to check that this is actually the case. Add a deprecation warning to see if we might be able to eventually drop it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230615064840.629492-12-hch@lst.de
2023-07-27md: make bitmap file support optionalChristoph Hellwig
The support for write intent bitmaps in files on an external files in md is a hot mess that abuses ->bmap to map file offsets into physical device objects, and also abuses buffer_heads in a creative way. Make this code optional so that MD can be built into future kernels without buffer_head support, and so that we can eventually deprecate it. Note this does not affect the internal bitmap support, which has none of the problems. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230615064840.629492-11-hch@lst.de
2023-03-15Merge branch 'md-fixes' of ↵Jens Axboe
https://git.kernel.org/pub/scm/linux/kernel/git/song/md into block-6.3 Pull MD fixes from Song: "This set contains two fixes for old issues (by Neil) and one fix for 6.3 (by Xiao)." * 'md-fixes' of https://git.kernel.org/pub/scm/linux/kernel/git/song/md: md: select BLOCK_LEGACY_AUTOLOAD md: avoid signed overflow in slot_store() md: Free resources in __md_stop
2023-03-15md: select BLOCK_LEGACY_AUTOLOADNeilBrown
When BLOCK_LEGACY_AUTOLOAD is not enable, mdadm is not able to activate new arrays unless "CREATE names=yes" appears in mdadm.conf As this is a regression we need to always enable BLOCK_LEGACY_AUTOLOAD for when MD is selected - at least until mdadm is updated and the updates widely available. Cc: stable@vger.kernel.org # v5.18+ Fixes: fbdee71bb5d8 ("block: deprecate autoloading based on dev_t") Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Song Liu <song@kernel.org>
2023-02-02drivers/md: Remove "select SRCU"Paul E. McKenney
Now that the SRCU Kconfig option is unconditionally selected, there is no longer any point in selecting it. Therefore, remove the "select SRCU" Kconfig statements. Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Cc: Song Liu <song@kernel.org> Cc: Alasdair Kergon <agk@redhat.com> Cc: Mike Snitzer <snitzer@kernel.org> Cc: <dm-devel@redhat.com> Cc: <linux-raid@vger.kernel.org> Acked-by: Mike Snitzer <snitzer@kernel.org> Reviewed-by: John Ogness <john.ogness@linutronix.de>
2022-02-16blk-mq: make the blk-mq stacking code optionalChristoph Hellwig
The code to stack blk-mq drivers is only used by dm-multipath, and will preferably stay that way. Make it optional and only selected by device mapper, so that the buildbots more easily catch abuses like the one that slipped in in the ufs driver in the last merged window. Another positive side effects is that kernel builds without device mapper shrink a little bit as well. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Link: https://lore.kernel.org/r/20220215100540.3892965-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-27dm integrity: log audit events for dm-integrity targetMichael Weiß
dm-integrity signals integrity violations by returning I/O errors to user space. To identify integrity violations by a controlling instance, the kernel audit subsystem can be used to emit audit events to user space. We use the new dm-audit submodule allowing to emit audit events on relevant I/O errors. The construction and destruction of integrity device mappings are also relevant for auditing a system. Thus, those events are also logged as audit events. Signed-off-by: Michael Weiß <michael.weiss@aisec.fraunhofer.de> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2021-10-27dm: introduce audit event module for device mapperMichael Weiß
To be able to send auditing events to user space, we introduce a generic dm-audit module. It provides helper functions to emit audit events through the kernel audit subsystem. We claim the AUDIT_DM_CTRL type=1336 and AUDIT_DM_EVENT type=1337 out of the audit event messages range in the corresponding userspace api in 'include/uapi/linux/audit.h' for those events. AUDIT_DM_CTRL is used to provide information about creation and destruction of device mapper targets which are triggered by user space admin control actions. AUDIT_DM_EVENT is used to provide information about actual errors during operation of the mapped device, showing e.g. integrity violations in audit log. Following commits to device mapper targets actually will make use of this to emit those events in relevant cases. The audit logs look like this if executing the following simple test: # dd if=/dev/zero of=test.img bs=1M count=1024 # losetup -f test.img # integritysetup -vD format --integrity sha256 -t 32 /dev/loop0 # integritysetup open -D /dev/loop0 --integrity sha256 integritytest # integritysetup status integritytest # integritysetup close integritytest # integritysetup open -D /dev/loop0 --integrity sha256 integritytest # integritysetup status integritytest # dd if=/dev/urandom of=/dev/loop0 bs=512 count=1 seek=100000 # dd if=/dev/mapper/integritytest of=/dev/null ------------------------- audit.log from auditd type=UNKNOWN[1336] msg=audit(1630425039.363:184): module=integrity op=ctr ppid=3807 pid=3819 auid=1000 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=pts2 ses=3 comm="integritysetup" exe="/sbin/integritysetup" subj==unconfined dev=254:3 error_msg='success' res=1 type=UNKNOWN[1336] msg=audit(1630425039.471:185): module=integrity op=dtr ppid=3807 pid=3819 auid=1000 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=pts2 ses=3 comm="integritysetup" exe="/sbin/integritysetup" subj==unconfined dev=254:3 error_msg='success' res=1 type=UNKNOWN[1336] msg=audit(1630425039.611:186): module=integrity op=ctr ppid=3807 pid=3819 auid=1000 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=pts2 ses=3 comm="integritysetup" exe="/sbin/integritysetup" subj==unconfined dev=254:3 error_msg='success' res=1 type=UNKNOWN[1336] msg=audit(1630425054.475:187): module=integrity op=dtr ppid=3807 pid=3819 auid=1000 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=pts2 ses=3 comm="integritysetup" exe="/sbin/integritysetup" subj==unconfined dev=254:3 error_msg='success' res=1 type=UNKNOWN[1336] msg=audit(1630425073.171:191): module=integrity op=ctr ppid=3807 pid=3883 auid=1000 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=pts2 ses=3 comm="integritysetup" exe="/sbin/integritysetup" subj==unconfined dev=254:3 error_msg='success' res=1 type=UNKNOWN[1336] msg=audit(1630425087.239:192): module=integrity op=dtr ppid=3807 pid=3902 auid=1000 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=pts2 ses=3 comm="integritysetup" exe="/sbin/integritysetup" subj==unconfined dev=254:3 error_msg='success' res=1 type=UNKNOWN[1336] msg=audit(1630425093.755:193): module=integrity op=ctr ppid=3807 pid=3906 auid=1000 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=pts2 ses=3 comm="integritysetup" exe="/sbin/integritysetup" subj==unconfined dev=254:3 error_msg='success' res=1 type=UNKNOWN[1337] msg=audit(1630425112.119:194): module=integrity op=integrity-checksum dev=254:3 sector=77480 res=0 type=UNKNOWN[1337] msg=audit(1630425112.119:195): module=integrity op=integrity-checksum dev=254:3 sector=77480 res=0 type=UNKNOWN[1337] msg=audit(1630425112.119:196): module=integrity op=integrity-checksum dev=254:3 sector=77480 res=0 type=UNKNOWN[1337] msg=audit(1630425112.119:197): module=integrity op=integrity-checksum dev=254:3 sector=77480 res=0 type=UNKNOWN[1337] msg=audit(1630425112.119:198): module=integrity op=integrity-checksum dev=254:3 sector=77480 res=0 type=UNKNOWN[1337] msg=audit(1630425112.119:199): module=integrity op=integrity-checksum dev=254:3 sector=77480 res=0 type=UNKNOWN[1337] msg=audit(1630425112.119:200): module=integrity op=integrity-checksum dev=254:3 sector=77480 res=0 type=UNKNOWN[1337] msg=audit(1630425112.119:201): module=integrity op=integrity-checksum dev=254:3 sector=77480 res=0 type=UNKNOWN[1337] msg=audit(1630425112.119:202): module=integrity op=integrity-checksum dev=254:3 sector=77480 res=0 type=UNKNOWN[1337] msg=audit(1630425112.119:203): module=integrity op=integrity-checksum dev=254:3 sector=77480 res=0 Signed-off-by: Michael Weiß <michael.weiss@aisec.fraunhofer.de> Signed-off-by: Paul Moore <paul@paul-moore.com> # fix audit.h numbering Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2021-08-16dm: make EBS depend on !HIGHMEMChristoph Hellwig
__ebs_rw_bvec use page_address on the submitted bios data, and thus can't deal with highmem. Disable the target on highmem configs. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210804095634.460779-4-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-09block: make the block holder code optionalChristoph Hellwig
Move the block holder code into a separate file as it is not in any way related to the other block_dev.c code, and add a new selectable config option for it so that we don't have to build it without any remapped drivers selected. The Kconfig symbol contains a _DEPRECATED suffix to match the comments added in commit 49731baa41df ("block: restore multiple bd_link_disk_holder() support"). Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Link: https://lore.kernel.org/r/20210804094147.459763-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-06-14md: mark some personalities as deprecatedGuoqing Jiang
Mark the three personalities (linear, fault and multipath) as deprecated because: 1. people can use dm multipath or nvme multipath. 2. linear is already deprecated in MODULE_ALIAS. 3. no one actively using fault. Signed-off-by: Guoqing Jiang <jiangguoqing@kylinos.cn> Signed-off-by: Song Liu <song@kernel.org>
2021-02-03dm crypt: support using trusted keysAhmad Fatoum
Commit 27f5411a718c ("dm crypt: support using encrypted keys") extended dm-crypt to allow use of "encrypted" keys along with "user" and "logon". Along the same lines, teach dm-crypt to support "trusted" keys as well. Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2021-01-04dm zoned: select CONFIG_CRC32Arnd Bergmann
Without crc32 support, this driver fails to link: arm-linux-gnueabi-ld: drivers/md/dm-zoned-metadata.o: in function `dmz_write_sb': dm-zoned-metadata.c:(.text+0xe98): undefined reference to `crc32_le' arm-linux-gnueabi-ld: drivers/md/dm-zoned-metadata.o: in function `dmz_check_sb': dm-zoned-metadata.c:(.text+0x7978): undefined reference to `crc32_le' Fixes: 3b1a94c88b79 ("dm zoned: drive-managed zoned block device target") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2021-01-04dm integrity: select CRYPTO_SKCIPHERAnthony Iliopoulos
The integrity target relies on skcipher for encryption/decryption, but certain kernel configurations may not enable CRYPTO_SKCIPHER, leading to compilation errors due to unresolved symbols. Explicitly select CRYPTO_SKCIPHER for DM_INTEGRITY, since it is unconditionally dependent on it. Signed-off-by: Anthony Iliopoulos <ailiop@suse.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-12-04dm mpath: add IO affinity path selectorMike Christie
This patch adds a path selector that selects paths based on a CPU to path mapping the user passes in and what CPU we are executing on. The primary user for this PS is where the app is optimized to use specific CPUs so other PSs undo the apps handy work, and the storage and it's transport are not a bottlneck. For these io-affinity PS setups a path's transport/interconnect perf is not going to flucuate a lot and there is no major differences between paths, so QL/HST smarts do not help and RR always messes up what the app is trying to do. On a system with 16 cores, where you have a job per CPU: fio --filename=/dev/dm-0 --direct=1 --rw=randrw --bs=4k \ --ioengine=libaio --iodepth=128 --numjobs=16 and a dm-multipath device setup where each CPU is mapped to one path: // When in mq mode I had to set dm_mq_nr_hw_queues=$NUM_PATHS. // Bio mode also showed similar results. 0 16777216 multipath 0 0 1 1 io-affinity 0 16 1 8:16 1 8:32 2 8:64 4 8:48 8 8:80 10 8:96 20 8:112 40 8:128 80 8:144 100 8:160 200 8:176 400 8:192 800 8:208 1000 8:224 2000 8:240 4000 65:0 8000 we can see a IOPs increase of 25%. The percent increase depends on the device and interconnect. For a slower/medium speed path/device that can do around 180K IOPs a path if you ran that fio command to it directly we saw a 25% increase like above. Slower path'd devices that could do around 90K per path showed maybe around a 2 - 5% increase. If you use something like null_blk or scsi_debug which can multi-million IOPs and hack it up so each device they export shows up as a path then you see 50%+ increases. Signed-off-by: Mike Christie <michael.christie@oracle.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-12-04dm verity: Add support for signature verification with 2nd keyringMickaël Salaün
Add a new configuration DM_VERITY_VERIFY_ROOTHASH_SIG_SECONDARY_KEYRING to enable dm-verity signatures to be verified against the secondary trusted keyring. Instead of relying on the builtin trusted keyring (with hard-coded certificates), the second trusted keyring can include certificate authorities from the builtin trusted keyring and child certificates loaded at run time. Using the secondary trusted keyring enables to use dm-verity disks (e.g. loop devices) signed by keys which did not exist at kernel build time, leveraging the certificate chain of trust model. In practice, this makes it possible to update certificates without kernel update and reboot, aligning with module and kernel (kexec) signature verification which already use the secondary trusted keyring. Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-07-05Replace HTTP links with HTTPS ones: LVMAlexander A. Klimov
Rationale: Reduces attack surface on kernel devs opening the links for MITM as HTTPS traffic is much harder to manipulate. Deterministic algorithm: For each file: If not .svg: For each line: If doesn't contain `\bxmlns\b`: For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`: If both the HTTP and HTTPS versions return 200 OK and serve the same content: Replace HTTP with HTTPS. Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de> Link: https://lore.kernel.org/r/20200627103138.71885-1-grandmaster@al2klimov.de Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-06-14treewide: replace '---help---' in Kconfig files with 'help'Masahiro Yamada
Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over '---help---'"), the number of '---help---' has been gradually decreasing, but there are still more than 2400 instances. This commit finishes the conversion. While I touched the lines, I also fixed the indentation. There are a variety of indentation styles found. a) 4 spaces + '---help---' b) 7 spaces + '---help---' c) 8 spaces + '---help---' d) 1 space + 1 tab + '---help---' e) 1 tab + '---help---' (correct indentation) f) 1 tab + 1 space + '---help---' g) 1 tab + 2 spaces + '---help---' In order to convert all of them to 1 tab + 'help', I ran the following commend: $ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/' Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-05-15dm mpath: add Historical Service Time Path SelectorKhazhismel Kumykov
This new selector keeps an exponential moving average of the service time for each path (losely defined as delta between start_io and end_io), and uses this along with the number of inflight requests to estimate future service time for a path. Since we don't have a prober to account for temporally slow paths, re-try "slow" paths every once in a while (num_paths * historical_service_time). To account for fast paths transitioning to slow, if a path has not completed any request within (num_paths * historical_service_time), limit the number of outstanding requests. To account for low volume situations where number of inflight IOs would be zero, the last finish time of each path is factored in. Signed-off-by: Khazhismel Kumykov <khazhy@google.com> Co-developed-by: Gabriel Krisman Bertazi <krisman@collabora.com> Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-05-15dm: add emulated block size targetHeinz Mauelshagen
This new target is similar to the linear target except that it emulates a smaller logical block size on a device with a larger logical block size. Its main purpose is to emulate 512 byte sectors on 4K native disks (i.e. 512e). See Documentation/admin-guide/device-mapper/dm-ebs.rst for details. Reviewed-by: Damien Le Moal <DamienLeMoal@wdc.com> Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Randy Dunlap <rdunlap@infradead.org> [Kconfig fixes] Signed-off-by: Zheng Bin <zhengbin13@huawei.com> [static fixes] Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-05-15dm crypt: support using encrypted keysDmitry Baryshkov
Allow one to use "encrypted" in addition to "user" and "logon" key types for device encryption. Signed-off-by: Dmitry Baryshkov <dmitry_baryshkov@mentor.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-11-20dm: Fix Kconfig indentationKrzysztof Kozlowski
Adjust indentation from spaces to tab (+optional two spaces) as in coding style with command like: $ sed -e 's/^ /\t/' -i */Kconfig Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-09-12dm: add clone targetNikos Tsironis
Add the dm-clone target, which allows cloning of arbitrary block devices. dm-clone produces a one-to-one copy of an existing, read-only source device into a writable destination device: It presents a virtual block device which makes all data appear immediately, and redirects reads and writes accordingly. The main use case of dm-clone is to clone a potentially remote, high-latency, read-only, archival-type block device into a writable, fast, primary-type device for fast, low-latency I/O. The cloned device is visible/mountable immediately and the copy of the source device to the destination device happens in the background, in parallel with user I/O. When the cloning completes, the dm-clone table can be removed altogether and be replaced, e.g., by a linear table, mapping directly to the destination device. For further information and examples of how to use dm-clone, please read Documentation/admin-guide/device-mapper/dm-clone.rst Suggested-by: Vangelis Koukis <vkoukis@arrikto.com> Co-developed-by: Ilias Tsitsimpis <iliastsi@arrikto.com> Signed-off-by: Ilias Tsitsimpis <iliastsi@arrikto.com> Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-09-03dm crypt: switch to ESSIV crypto API templateArd Biesheuvel
Replace the explicit ESSIV handling in the dm-crypt driver with calls into the crypto API, which now possesses the capability to perform this processing within the crypto subsystem. Note that we reorder the AEAD cipher_api string parsing with the TFM instantiation: this is needed because cipher_api is mangled by the ESSIV handling, and throws off the parsing of "authenc(" otherwise. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Milan Broz <gmazyland@gmail.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-08-23dm verity: add root hash pkcs#7 signature verificationJaskaran Khurana
The verification is to support cases where the root hash is not secured by Trusted Boot, UEFI Secureboot or similar technologies. One of the use cases for this is for dm-verity volumes mounted after boot, the root hash provided during the creation of the dm-verity volume has to be secure and thus in-kernel validation implemented here will be used before we trust the root hash and allow the block device to be created. The signature being provided for verification must verify the root hash and must be trusted by the builtin keyring for verification to succeed. The hash is added as a key of type "user" and the description is passed to the kernel so it can look it up and use it for verification. Adds CONFIG_DM_VERITY_VERIFY_ROOTHASH_SIG which can be turned on if root hash verification is needed. Kernel commandline dm_verity module parameter 'require_signatures' will indicate whether to force root hash signature verification (for all dm verity volumes). Signed-off-by: Jaskaran Khurana <jaskarankhurana@linux.microsoft.com> Tested-and-Reviewed-by: Milan Broz <gmazyland@gmail.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-07-15docs: device-mapper: move it to the admin-guideMauro Carvalho Chehab
The DM support describes lots of aspects related to mapped disk partitions from the userspace PoV. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-06-14docs: convert docs to ReST and rename to *.rstMauro Carvalho Chehab
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 <mchehab+samsung@kernel.org> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Mark Brown <broonie@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-05-21treewide: Add SPDX license identifier - Makefile/KconfigThomas Gleixner
Add SPDX license identifiers to all Make/Kconfig files which: - Have no license information of any form These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-30dm: add dust targetBryan Gurney
Add the dm-dust target, which simulates the behavior of bad sectors at arbitrary locations, and the ability to enable the emulation of the read failures at an arbitrary time. This target behaves similarly to a linear target. At a given time, the user can send a message to the target to start failing read requests on specific blocks. When the failure behavior is enabled, reads of blocks configured "bad" will fail with EIO. Writes of blocks configured "bad" will result in the following: 1. Remove the block from the "bad block list". 2. Successfully complete the write. After this point, the block will successfully contain the written data, and will service reads and writes normally. This emulates the behavior of a "remapped sector" on a hard disk drive. dm-dust provides logging of which blocks have been added or removed to the "bad block list", as well as logging when a block has been removed from the bad block list. These messages can be used alongside the messages from the driver using a dm-dust device to analyze the driver's behavior when a read fails at a given time. (This logging can be reduced via a "quiet" mode, if desired.) NOTE: If the block size is larger than 512 bytes, only the first sector of each "dust block" is detected. Placing a limiting layer above a dust target, to limit the minimum I/O size to the dust block size, will ensure proper emulation of the given large block size. Signed-off-by: Bryan Gurney <bgurney@redhat.com> Co-developed-by: Joe Shimkus <jshimkus@redhat.com> Co-developed-by: John Dorminy <jdorminy@redhat.com> Co-developed-by: John Pittman <jpittman@redhat.com> Co-developed-by: Thomas Jaskiewicz <tjaskiew@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>