kernel/linux.git/drivers/md/dm.c, branch v6.19.11

dm: use bio_clone_blkg_association

2026-02-26T23:01:07+00:00

[ Upstream commit 2df8b310bcfe76827fd71092f58a2493ee6590b0 ] The origin bio carries blk-cgroup information which could be set from foreground(task_css(css) - wbc->wb->blkcg_css), so the blkcg won't control buffer io since commit ca522482e3eaf ("dm: pass NULL bdev to bio_alloc_clone"). The synchronous io is still under control by blkcg, because 'bio->bi_blkg' is set by io submitting task which has been added into 'cgroup.procs'. Fix it by using bio_clone_blkg_association when submitting a cloned bio. Link: https://bugzilla.kernel.org/show_bug.cgi?id=220985 Fixes: ca522482e3eaf ("dm: pass NULL bdev to bio_alloc_clone") Reported-by: Zhihao Cheng Signed-off-by: Mikulas Patocka Tested-by: Zhihao Cheng Signed-off-by: Sasha Levin

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

2025-12-11T03:13:29+00:00

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 ...

dm: test for REQ_ATOMIC in dm_accept_partial_bio()

2025-12-10T18:28:12+00:00

Any bio with REQ_ATOMIC flag set should never be split or partially completed, so BUG_ON() on this scenario in dm_accept_partial_bio() (whose intent is to allow partial completions). Also, we must reject atomic bio to targets that don't support them, otherwise this BUG could be triggered by stray bios that have the REQ_ATOMIC set. Signed-off-by: John Garry Signed-off-by: Mikulas Patocka Tested-by: John Garry

dm: fix failure when empty flush's bi_sector points beyond the device end

2025-11-20T18:50:42+00:00

An empty flush bio can have arbitrary bi_sector. The commit 2b1c6d7a890a introduced a regression that device mapper would fail an empty flush bio with -EIO if the sector pointed beyond the end of the device. The commit introduced an optimization, that optimization would pass flushes to __split_and_process_bio and __split_and_process_bio is not prepared to handle empty bios. Fix this bug by passing only non-empty flushes to __split_and_process_bio - non-empty flushes must have valid bi_sector. Empty bios will go through __send_empty_flush, as they did before the optimization. This problem can be reproduced by running the lvm2 test: make check_local T=lvconvert-thin.sh LVM_TEST_PREFER_BRD=0 Signed-off-by: Mikulas Patocka Fixes: 2b1c6d7a890a ("dm: optimize REQ_PREFLUSH with data when using the linear target") Reported-by: Zdenek Kabelac Reviewed-by: Bart Van Assche

dm: Don't warn if IMA_DISABLE_HTABLE is not enabled

2025-11-18T17:24:25+00:00

Commit f1cd6cb24b6b ("dm ima: add a warning in dm_init if duplicate ima events are not measured") added a warning message if CONFIG_IMA is enabled but CONFIG_IMA_DISABLE_HTABLE is not to inform users. When enabling CONFIG_IMA, CONFIG_IMA_DISABLE_HTABLE is disabled by default and so warning is seen. Therefore, it seems more appropriate to make this an INFO level message than warning. If this truly is a warning, then maybe CONFIG_IMA_DISABLE_HTABLE should default to y if CONFIG_IMA is enabled. Signed-off-by: Jon Hunter Signed-off-by: Mikulas Patocka

dm: Fix deadlock when reloading a multipath table

2025-10-20T13:26:57+00:00

Request-based devices (dm-multipath) queue I/O in blk-mq on noflush suspends. Any queued IO will make it impossible to freeze the queue. If a process attempts to update the queue limits while there is queued IO, it can be get stuck holding the limits lock, while unable to freeze the queue. If device-mapper then attempts to update the limits during a table swap, it will deadlock trying to grab the limits lock while making it impossible to flush the IO. Disallow updating the queue limits during a table swap, when updating an immutable request-based dm device (dm-multipath) during a noflush suspend. It is userspace's responsibility to make sure that the new table uses the same limits as the existing table if it asks for a noflush suspend. Signed-off-by: Benjamin Marzinski Signed-off-by: Mikulas Patocka

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 ...

dm: optimize REQ_PREFLUSH with data when using the linear target

2025-09-18T10:58:02+00:00

If the table has only linear targets and there is just one underlying device, we can optimize REQ_PREFLUSH with data - we don't have to split it to two bios - a flush and a write. We can pass it to the linear target directly. Signed-off-by: Mikulas Patocka Tested-by: Bart Van Assche Reviewed-by: Bart Van Assche

dm: fix NULL pointer dereference in __dm_suspend()

2025-08-26T14:46:52+00:00

There is a race condition between dm device suspend and table load that can lead to null pointer dereference. The issue occurs when suspend is invoked before table load completes: BUG: kernel NULL pointer dereference, address: 0000000000000054 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 6 PID: 6798 Comm: dmsetup Not tainted 6.6.0-g7e52f5f0ca9b #62 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.1-2.fc37 04/01/2014 RIP: 0010:blk_mq_wait_quiesce_done+0x0/0x50 Call Trace: blk_mq_quiesce_queue+0x2c/0x50 dm_stop_queue+0xd/0x20 __dm_suspend+0x130/0x330 dm_suspend+0x11a/0x180 dev_suspend+0x27e/0x560 ctl_ioctl+0x4cf/0x850 dm_ctl_ioctl+0xd/0x20 vfs_ioctl+0x1d/0x50 __se_sys_ioctl+0x9b/0xc0 __x64_sys_ioctl+0x19/0x30 x64_sys_call+0x2c4a/0x4620 do_syscall_64+0x9e/0x1b0 The issue can be triggered as below: T1 T2 dm_suspend table_load __dm_suspend dm_setup_md_queue dm_mq_init_request_queue blk_mq_init_allocated_queue => q->mq_ops = set->ops; (1) dm_stop_queue / dm_wait_for_completion => q->tag_set NULL pointer! (2) => q->tag_set = set; (3) Fix this by checking if a valid table (map) exists before performing request-based suspend and waiting for target I/O. When map is NULL, skip these table-dependent suspend steps. Even when map is NULL, no I/O can reach any target because there is no table loaded; I/O submitted in this state will fail early in the DM layer. Skipping the table-dependent suspend logic in this case is safe and avoids NULL pointer dereferences. Fixes: c4576aed8d85 ("dm: fix request-based dm's use of dm_wait_for_completion") Cc: stable@vger.kernel.org Signed-off-by: Zheng Qixing Signed-off-by: Mikulas Patocka

dm: fix queue start/stop imbalance under suspend/load/resume races

2025-08-26T14:46:32+00:00

When suspend and load run concurrently, before q->mq_ops is set in blk_mq_init_allocated_queue(), __dm_suspend() skip dm_stop_queue(). As a result, the queue's quiesce depth is not incremented. Later, once table load has finished and __dm_resume() runs, which triggers q->quiesce_depth ==0 warning in blk_mq_unquiesce_queue(): Call Trace: dm_start_queue+0x16/0x20 [dm_mod] __dm_resume+0xac/0xb0 [dm_mod] dm_resume+0x12d/0x150 [dm_mod] do_resume+0x2c2/0x420 [dm_mod] dev_suspend+0x30/0x130 [dm_mod] ctl_ioctl+0x402/0x570 [dm_mod] dm_ctl_ioctl+0x23/0x30 [dm_mod] Fix this by explicitly tracking whether the request queue was stopped in __dm_suspend() via a new DMF_QUEUE_STOPPED flag. Only call dm_start_queue() in __dm_resume() if the queue was actually stopped. Fixes: e70feb8b3e68 ("blk-mq: support concurrent queue quiesce/unquiesce") Cc: stable@vger.kernel.org Signed-off-by: Zheng Qixing Signed-off-by: Mikulas Patocka