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path: root/drivers/md/dm.c
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7 daysdm: avoid leaking the caller's thread keyring via the table device fileIngo Blechschmidt
The refactoring in commit a28d893eb327 ("md: port block device access to file") accidentally causes the caller's thread keyring to be kept alive long beyond the caller's lifetime. As a result, "cryptsetup luksSuspend" silently fails to wipe the LUKS volume key from memory. In detail: "cryptsetup luksOpen" uses its supposedly ephemeral thread keyring to pass the volume key to the kernel. dm-crypt's crypt_set_keyring_key() copies the key material into its own crypt_config structure and then drops its own reference to the key in the keyring with key_put(). With this fix, restoring pre-v6.9 behavior, the copy in the thread keyring is then promptly garbage collected, such that exactly one copy of the volume key remains. This single copy is correctly wiped from memory on "cryptsetup luksSuspend". Without this fix, the thread keyring and the volume key in it remains. This second copy is only freed on "luksClose". "luksSuspend" neither knows about this copy nor has any way to remove it, so the key remains recoverable from RAM after a suspend that is documented to have wiped it. This fix should not introduce new security problems, as the code is anyway gated by CAP_SYS_ADMIN. The device-mapper core, not the calling task, is the legitimate owner of this long-lived file. Fixes: a28d893eb327 ("md: port block device access to file") Closes: https://gitlab.com/cryptsetup/cryptsetup/-/work_items/993 Link: https://www.speicherleck.de/iblech/cryptsetup-luksSuspend-issue-reproduction/ Signed-off-by: Ingo Blechschmidt <iblech@speicherleck.de> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org Tested-by: Ondrej Kozina <okozina@redhat.com>
2026-05-18dm: limit target bio polling to one shotFengnan Chang
dm_poll_bio() is the ->poll_bio() callback for a stacked dm device. The caller only knows about the dm queue, so it may decide to do a spinning poll if it thinks a single queue is being polled. Passing those flags unchanged to the mapped clone lets blk_mq_poll() spin on a target queue from inside dm_poll_bio(). With io_uring IOPOLL on a dm-stripe target this can keep a task in dm_poll_bio() -> bio_poll() -> blk_mq_poll() long enough to trigger an RCU CPU stall, before io_uring gets back to io_iopoll_check() and its need_resched() check. Keep dm's ->poll_bio() bounded by forcing one-shot polling for target bios. The caller can invoke dm_poll_bio() again if it wants to keep polling, and it also gets a chance to reap completions or reschedule between passes. Fixes: f22ecf9c14c1 ("blk-mq: delete task running check in blk_hctx_poll()") Signed-off-by: Fengnan Chang <changfengnan@bytedance.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
2026-05-04dm-ima: Fix UAF errors and measuring incorrect contextBenjamin Marzinski
the dm-ima code did not keep the dm_ima_measure_on_* functions from running at the same time. This could lead to various errors. If two processes were updating the device state, one could update the state first, but the other could measure the state first, causing the the current device state to appear incorrect. If a table load happened while a device was resuming, the IMA measurement could report the wrong table being active. And if two dm_ima_measure_on_* functions ran at the same time, one of them could free data that the other was accessing, causing a crash. All the core dm functions that call a dm_ima_measure_on_* function update the device state they want to measure under the _hash_lock, except for do_resume(). But holding the _hash_lock is not a good way to synchronize these functions. It's a global mutex, that is needed in many dm operations, and the dm_ima_measure_* functions can sleep, blocking any dm operation on any device that needs the _hash_lock. To serialize and order the IMA measurement functions, the dm_ima_measurements now has two counters, update_idx and measure_idx. update_idx is incremented while holding the _hash_lock and saved, along with the device name and uuid, in a dm_ima_context struct. Once the _hash_lock is dropped, the dm_ima_measure_* function is called. It waits until measure_idx matches the saved value of update_idx, ensuring that the updates and measurements happen in the same order if there are multiple processes changing the device at the same time. Then it measures the device, updates measure_idx, and wakes up any other process waiting to do a measurement. This makes sure that the measurements are serialized and done in the order that the _hash_lock was acquired in. But they only block other measurements for the same device, which are unlikely to happen at the same time. do_resume() is trickier, because it removes the inactive table while holding the _hash_lock, but doesn't hold it while updating md->map. To make sure it is also ordered, the IMA code grabs the _hash_lock after md->map is updated. Then it makes sure that the device isn't being removed and that another do_resume() hasn't already changed the active table again, and serializes like the other functions do. Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
2026-05-04dm-ima: remove dm_ima_reset_data()Benjamin Marzinski
There's no point in saving the string length of DM_IMA_VERSION_STR. It's a constant, so the compiler will precompute it. dm_create() will already zero out the rest of dm->ima. Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
2026-01-26dm: use bio_clone_blkg_associationMikulas Patocka
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 <chengzhihao1@huawei.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Tested-by: Zhihao Cheng <chengzhihao1@huawei.com>
2026-01-14dm: add WQ_PERCPU to alloc_workqueue usersMarco Crivellari
This continues the effort to refactor workqueue APIs, which began with the introduction of new workqueues and a new alloc_workqueue flag in: commit 128ea9f6ccfb ("workqueue: Add system_percpu_wq and system_dfl_wq") commit 930c2ea566af ("workqueue: Add new WQ_PERCPU flag") The refactoring is going to alter the default behavior of alloc_workqueue() to be unbound by default. With the introduction of the WQ_PERCPU flag (equivalent to !WQ_UNBOUND), any alloc_workqueue() caller that doesn’t explicitly specify WQ_UNBOUND must now use WQ_PERCPU. For more details see the Link tag below. In order to keep alloc_workqueue() behavior identical, explicitly request WQ_PERCPU. Link: https://lore.kernel.org/all/20250221112003.1dSuoGyc@linutronix.de/ Suggested-by: Tejun Heo <tj@kernel.org> Signed-off-by: Marco Crivellari <marco.crivellari@suse.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
2025-12-11Merge tag 'for-6.19/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: - 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 ...
2025-12-10dm: test for REQ_ATOMIC in dm_accept_partial_bio()Mikulas Patocka
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 <john.g.garry@oracle.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Tested-by: John Garry <john.g.garry@oracle.com>
2025-11-20dm: fix failure when empty flush's bi_sector points beyond the device endMikulas Patocka
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 <mpatocka@redhat.com> Fixes: 2b1c6d7a890a ("dm: optimize REQ_PREFLUSH with data when using the linear target") Reported-by: Zdenek Kabelac <zkabelac@redhat.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org>
2025-11-18dm: Don't warn if IMA_DISABLE_HTABLE is not enabledJon Hunter
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 <jonathanh@nvidia.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
2025-10-20dm: Fix deadlock when reloading a multipath tableBenjamin Marzinski
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 <bmarzins@redhat.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
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 ...
2025-09-18dm: optimize REQ_PREFLUSH with data when using the linear targetMikulas Patocka
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 <mpatocka@redhat.com> Tested-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Bart Van Assche <bvanassche@acm.org>
2025-08-26dm: fix NULL pointer dereference in __dm_suspend()Zheng Qixing
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: <TASK> 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 <zhengqixing@huawei.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
2025-08-26dm: fix queue start/stop imbalance under suspend/load/resume racesZheng Qixing
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: <TASK> 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 <zhengqixing@huawei.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
2025-08-13block: switch ->getgeo() to struct gendiskAl Viro
Instances are happier that way and it makes more sense anyway - the only part of the result that is related to partition we are given is the start sector, and that has been filled in by the caller. Everything else is a function of the disk. Only one instance (DASD) is ever looking at anything other than bdev->bd_disk and that one is trivial to adjust. Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2025-08-04Merge tag 'for-6.17/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: - fix checking for request-based stackable devices (dm-table) - fix corrupt_bio_byte setup checks (dm-flakey) - add support for resync w/o metadata devices (dm raid) - small code simplification (dm, dm-mpath, vm-vdo, dm-raid) - remove support for asynchronous hashes (dm-verity) - close smatch warning (dm-zoned-target) - update the documentation and enable inline-crypto passthrough (dm-thin) * tag 'for-6.17/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm: set DM_TARGET_PASSES_CRYPTO feature for dm-thin dm-thin: update the documentation dm-raid: do not include dm-core.h vdo: omit need_resched() before cond_resched() md: dm-zoned-target: Initialize return variable r to avoid uninitialized use dm-verity: remove support for asynchronous hashes dm-mpath: don't print the "loaded" message if registering fails dm-mpath: make dm_unregister_path_selector return void dm: ima: avoid extra calls to strlen() dm: Simplify dm_io_complete() dm: Remove unnecessary return in dm_zone_endio() dm raid: add support for resync w/o metadata devices dm-flakey: Fix corrupt_bio_byte setup checks dm-table: fix checking for rq stackable devices
2025-07-31Merge tag 'mm-stable-2025-07-30-15-25' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: "As usual, many cleanups. The below blurbiage describes 42 patchsets. 21 of those are partially or fully cleanup work. "cleans up", "cleanup", "maintainability", "rationalizes", etc. I never knew the MM code was so dirty. "mm: ksm: prevent KSM from breaking merging of new VMAs" (Lorenzo Stoakes) addresses an issue with KSM's PR_SET_MEMORY_MERGE mode: newly mapped VMAs were not eligible for merging with existing adjacent VMAs. "mm/damon: introduce DAMON_STAT for simple and practical access monitoring" (SeongJae Park) adds a new kernel module which simplifies the setup and usage of DAMON in production environments. "stop passing a writeback_control to swap/shmem writeout" (Christoph Hellwig) is a cleanup to the writeback code which removes a couple of pointers from struct writeback_control. "drivers/base/node.c: optimization and cleanups" (Donet Tom) contains largely uncorrelated cleanups to the NUMA node setup and management code. "mm: userfaultfd: assorted fixes and cleanups" (Tal Zussman) does some maintenance work on the userfaultfd code. "Readahead tweaks for larger folios" (Ryan Roberts) implements some tuneups for pagecache readahead when it is reading into order>0 folios. "selftests/mm: Tweaks to the cow test" (Mark Brown) provides some cleanups and consistency improvements to the selftests code. "Optimize mremap() for large folios" (Dev Jain) does that. A 37% reduction in execution time was measured in a memset+mremap+munmap microbenchmark. "Remove zero_user()" (Matthew Wilcox) expunges zero_user() in favor of the more modern memzero_page(). "mm/huge_memory: vmf_insert_folio_*() and vmf_insert_pfn_pud() fixes" (David Hildenbrand) addresses some warts which David noticed in the huge page code. These were not known to be causing any issues at this time. "mm/damon: use alloc_migrate_target() for DAMOS_MIGRATE_{HOT,COLD" (SeongJae Park) provides some cleanup and consolidation work in DAMON. "use vm_flags_t consistently" (Lorenzo Stoakes) uses vm_flags_t in places where we were inappropriately using other types. "mm/memfd: Reserve hugetlb folios before allocation" (Vivek Kasireddy) increases the reliability of large page allocation in the memfd code. "mm: Remove pXX_devmap page table bit and pfn_t type" (Alistair Popple) removes several now-unneeded PFN_* flags. "mm/damon: decouple sysfs from core" (SeongJae Park) implememnts some cleanup and maintainability work in the DAMON sysfs layer. "madvise cleanup" (Lorenzo Stoakes) does quite a lot of cleanup/maintenance work in the madvise() code. "madvise anon_name cleanups" (Vlastimil Babka) provides additional cleanups on top or Lorenzo's effort. "Implement numa node notifier" (Oscar Salvador) creates a standalone notifier for NUMA node memory state changes. Previously these were lumped under the more general memory on/offline notifier. "Make MIGRATE_ISOLATE a standalone bit" (Zi Yan) cleans up the pageblock isolation code and fixes a potential issue which doesn't seem to cause any problems in practice. "selftests/damon: add python and drgn based DAMON sysfs functionality tests" (SeongJae Park) adds additional drgn- and python-based DAMON selftests which are more comprehensive than the existing selftest suite. "Misc rework on hugetlb faulting path" (Oscar Salvador) fixes a rather obscure deadlock in the hugetlb fault code and follows that fix with a series of cleanups. "cma: factor out allocation logic from __cma_declare_contiguous_nid" (Mike Rapoport) rationalizes and cleans up the highmem-specific code in the CMA allocator. "mm/migration: rework movable_ops page migration (part 1)" (David Hildenbrand) provides cleanups and future-preparedness to the migration code. "mm/damon: add trace events for auto-tuned monitoring intervals and DAMOS quota" (SeongJae Park) adds some tracepoints to some DAMON auto-tuning code. "mm/damon: fix misc bugs in DAMON modules" (SeongJae Park) does that. "mm/damon: misc cleanups" (SeongJae Park) also does what it claims. "mm: folio_pte_batch() improvements" (David Hildenbrand) cleans up the large folio PTE batching code. "mm/damon/vaddr: Allow interleaving in migrate_{hot,cold} actions" (SeongJae Park) facilitates dynamic alteration of DAMON's inter-node allocation policy. "Remove unmap_and_put_page()" (Vishal Moola) provides a couple of page->folio conversions. "mm: per-node proactive reclaim" (Davidlohr Bueso) implements a per-node control of proactive reclaim - beyond the current memcg-based implementation. "mm/damon: remove damon_callback" (SeongJae Park) replaces the damon_callback interface with a more general and powerful damon_call()+damos_walk() interface. "mm/mremap: permit mremap() move of multiple VMAs" (Lorenzo Stoakes) implements a number of mremap cleanups (of course) in preparation for adding new mremap() functionality: newly permit the remapping of multiple VMAs when the user is specifying MREMAP_FIXED. It still excludes some specialized situations where this cannot be performed reliably. "drop hugetlb_free_pgd_range()" (Anthony Yznaga) switches some sparc hugetlb code over to the generic version and removes the thus-unneeded hugetlb_free_pgd_range(). "mm/damon/sysfs: support periodic and automated stats update" (SeongJae Park) augments the present userspace-requested update of DAMON sysfs monitoring files. Automatic update is now provided, along with a tunable to control the update interval. "Some randome fixes and cleanups to swapfile" (Kemeng Shi) does what is claims. "mm: introduce snapshot_page" (Luiz Capitulino and David Hildenbrand) provides (and uses) a means by which debug-style functions can grab a copy of a pageframe and inspect it locklessly without tripping over the races inherent in operating on the live pageframe directly. "use per-vma locks for /proc/pid/maps reads" (Suren Baghdasaryan) addresses the large contention issues which can be triggered by reads from that procfs file. Latencies are reduced by more than half in some situations. The series also introduces several new selftests for the /proc/pid/maps interface. "__folio_split() clean up" (Zi Yan) cleans up __folio_split()! "Optimize mprotect() for large folios" (Dev Jain) provides some quite large (>3x) speedups to mprotect() when dealing with large folios. "selftests/mm: reuse FORCE_READ to replace "asm volatile("" : "+r" (XXX));" and some cleanup" (wang lian) does some cleanup work in the selftests code. "tools/testing: expand mremap testing" (Lorenzo Stoakes) extends the mremap() selftest in several ways, including adding more checking of Lorenzo's recently added "permit mremap() move of multiple VMAs" feature. "selftests/damon/sysfs.py: test all parameters" (SeongJae Park) extends the DAMON sysfs interface selftest so that it tests all possible user-requested parameters. Rather than the present minimal subset" * tag 'mm-stable-2025-07-30-15-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (370 commits) MAINTAINERS: add missing headers to mempory policy & migration section MAINTAINERS: add missing file to cgroup section MAINTAINERS: add MM MISC section, add missing files to MISC and CORE MAINTAINERS: add missing zsmalloc file MAINTAINERS: add missing files to page alloc section MAINTAINERS: add missing shrinker files MAINTAINERS: move memremap.[ch] to hotplug section MAINTAINERS: add missing mm_slot.h file THP section MAINTAINERS: add missing interval_tree.c to memory mapping section MAINTAINERS: add missing percpu-internal.h file to per-cpu section mm/page_alloc: remove trace_mm_alloc_contig_migrate_range_info() selftests/damon: introduce _common.sh to host shared function selftests/damon/sysfs.py: test runtime reduction of DAMON parameters selftests/damon/sysfs.py: test non-default parameters runtime commit selftests/damon/sysfs.py: generalize DAMON context commit assertion selftests/damon/sysfs.py: generalize monitoring attributes commit assertion selftests/damon/sysfs.py: generalize DAMOS schemes commit assertion selftests/damon/sysfs.py: test DAMOS filters commitment selftests/damon/sysfs.py: generalize DAMOS scheme commit assertion selftests/damon/sysfs.py: test DAMOS destinations commitment ...
2025-07-17dm: split write BIOs on zone boundaries when zone append is not emulatedShin'ichiro Kawasaki
Commit 2df7168717b7 ("dm: Always split write BIOs to zoned device limits") updates the device-mapper driver to perform splits for the write BIOs. However, it did not address the cases where DM targets do not emulate zone append, such as in the cases of dm-linear or dm-flakey. For these targets, when the write BIOs span across zone boundaries, they trigger WARN_ON_ONCE(bio_straddles_zones(bio)) in blk_zone_wplug_handle_write(). This results in I/O errors. The errors are reproduced by running blktests test case zbd/004 using zoned dm-linear or dm-flakey devices. To avoid the I/O errors, handle the write BIOs regardless whether DM targets emulate zone append or not, so that all write BIOs are split at zone boundaries. For that purpose, drop the check for zone append emulation in dm_zone_bio_needs_split(). Its argument 'md' is no longer used then drop it also. Fixes: 2df7168717b7 ("dm: Always split write BIOs to zoned device limits") Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Mikulas Patocka <mpatocka@redhat.com> Link: https://lore.kernel.org/r/20250717103539.37279-1-shinichiro.kawasaki@wdc.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-07-09mm: remove callers of pfn_t functionalityAlistair Popple
All PFN_* pfn_t flags have been removed. Therefore there is no longer a need for the pfn_t type and all uses can be replaced with normal pfns. Link: https://lkml.kernel.org/r/bbedfa576c9822f8032494efbe43544628698b1f.1750323463.git-series.apopple@nvidia.com Signed-off-by: Alistair Popple <apopple@nvidia.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Balbir Singh <balbirs@nvidia.com> Cc: Björn Töpel <bjorn@kernel.org> Cc: Björn Töpel <bjorn@rivosinc.com> Cc: Chunyan Zhang <zhang.lyra@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Deepak Gupta <debug@rivosinc.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Inki Dae <m.szyprowski@samsung.com> Cc: John Groves <john@groves.net> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-06-30dm: Check for forbidden splitting of zone write operationsDamien Le Moal
DM targets must not split zone append and write operations using dm_accept_partial_bio() as doing so is forbidden for zone append BIOs, breaks zone append emulation using regular write BIOs and potentially creates deadlock situations with queue freeze operations. Modify dm_accept_partial_bio() to add missing BUG_ON() checks for all these cases, that is, check that the BIO is a write or write zeroes operation. This change packs all the zone related checks together under a static_branch_unlikely(&zoned_enabled) and done only if the target is a zoned device. Fixes: f211268ed1f9 ("dm: Use the block layer zone append emulation") Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Mikulas Patocka <mpatocka@redhat.com> Link: https://lore.kernel.org/r/20250625093327.548866-6-dlemoal@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-06-30dm: Always split write BIOs to zoned device limitsDamien Le Moal
Any zoned DM target that requires zone append emulation will use the block layer zone write plugging. In such case, DM target drivers must not split BIOs using dm_accept_partial_bio() as doing so can potentially lead to deadlocks with queue freeze operations. Regular write operations used to emulate zone append operations also cannot be split by the target driver as that would result in an invalid writen sector value return using the BIO sector. In order for zoned DM target drivers to avoid such incorrect BIO splitting, we must ensure that large BIOs are split before being passed to the map() function of the target, thus guaranteeing that the limits for the mapped device are not exceeded. dm-crypt and dm-flakey are the only target drivers supporting zoned devices and using dm_accept_partial_bio(). In the case of dm-crypt, this function is used to split BIOs to the internal max_write_size limit (which will be suppressed in a different patch). However, since crypt_alloc_buffer() uses a bioset allowing only up to BIO_MAX_VECS (256) vectors in a BIO. The dm-crypt device max_segments limit, which is not set and so default to BLK_MAX_SEGMENTS (128), must thus be respected and write BIOs split accordingly. In the case of dm-flakey, since zone append emulation is not required, the block layer zone write plugging is not used and no splitting of BIOs required. Modify the function dm_zone_bio_needs_split() to use the block layer helper function bio_needs_zone_write_plugging() to force a call to bio_split_to_limits() in dm_split_and_process_bio(). This allows DM target drivers to avoid using dm_accept_partial_bio() for write operations on zoned DM devices. Fixes: f211268ed1f9 ("dm: Use the block layer zone append emulation") Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20250625093327.548866-4-dlemoal@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-06-30block: Introduce bio_needs_zone_write_plugging()Damien Le Moal
In preparation for fixing device mapper zone write handling, introduce the inline helper function bio_needs_zone_write_plugging() to test if a BIO requires handling through zone write plugging using the function blk_zone_plug_bio(). This function returns true for any write (op_is_write(bio) == true) operation directed at a zoned block device using zone write plugging, that is, a block device with a disk that has a zone write plug hash table. This helper allows simplifying the check on entry to blk_zone_plug_bio() and used in to protect calls to it for blk-mq devices and DM devices. Fixes: f211268ed1f9 ("dm: Use the block layer zone append emulation") Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20250625093327.548866-3-dlemoal@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-06-27dm: Simplify dm_io_complete()Damien Le Moal
The local variable first_requeue is not needed since it is always equal to dm_io_flagged(io, DM_IO_WAS_SPLIT). Call __dm_io_complete() passing this value directly and remove first_requeue. Also declare dm_io_complete() as inline to make sure it is inlined in its single call site, thus avoiding the cost of a function call. Signed-off-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
2025-05-04dm: Allow .prepare_ioctl to handle ioctls directlyKevin Wolf
This adds a 'bool *forward' parameter to .prepare_ioctl, which allows device mapper targets to accept ioctls to themselves instead of the underlying device. If the target already fully handled the ioctl, it sets *forward to false and device mapper won't forward it to the underlying device any more. In order for targets to actually know what the ioctl is about and how to handle it, pass also cmd and arg. As long as targets restrict themselves to interpreting ioctls of type DM_IOCTL, this is a backwards compatible change because previously, any such ioctl would have been passed down through all device mapper layers until it reached a device that can't understand the ioctl and would return an error. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Benjamin Marzinski <bmarzins@redhat.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
2025-05-04dm: use generic functions instead of disable_discard and disable_write_zeroesMikulas Patocka
A small code cleanup: use blk_queue_disable_discard and blk_queue_disable_write_zeroes instead of disable_discard and disable_write_zeroes. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
2025-05-04dm: limit swapping tables for devices with zone write plugsBenjamin Marzinski
dm_revalidate_zones() only allowed new or previously unzoned devices to call blk_revalidate_disk_zones(). If the device was already zoned, disk->nr_zones would always equal md->nr_zones, so dm_revalidate_zones() returned without doing any work. This would make the zoned settings for the device not match the new table. If the device had zone write plug resources, it could run into errors like bdev_zone_is_seq() reading invalid memory because disk->conv_zones_bitmap was the wrong size. If the device doesn't have any zone write plug resources, calling blk_revalidate_disk_zones() will always correctly update device. If blk_revalidate_disk_zones() fails, it can still overwrite or clear the current disk->nr_zones value. In this case, DM must restore the previous value of disk->nr_zones, so that the zoned settings will continue to match the previous value that it fell back to. If the device already has zone write plug resources, blk_revalidate_disk_zones() will not correctly update them, if it is called for arbitrary zoned device changes. Since there is not much need for this ability, the easiest solution is to disallow any table reloads that change the zoned settings, for devices that already have zone plug resources. Specifically, if a device already has zone plug resources allocated, it can only switch to another zoned table that also emulates zone append. Also, it cannot change the device size or the zone size. A device can switch to an error target. Fixes: bb37d77239af2 ("dm: introduce zone append emulation") Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Tested-by: Damien Le Moal <dlemoal@kernel.org> Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
2025-04-11dm: free table mempools if not used in __bindBenjamin Marzinski
With request-based dm, the mempools don't need reloading when switching tables, but the unused table mempools are not freed until the active table is finally freed. Free them immediately if they are not needed. Fixes: 29dec90a0f1d9 ("dm: fix bio_set allocation") Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Tested-by: Damien Le Moal <dlemoal@kernel.org> Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
2025-04-11dm: don't change md if dm_table_set_restrictions() failsBenjamin Marzinski
__bind was changing the disk capacity, geometry and mempools of the mapped device before calling dm_table_set_restrictions() which could fail, forcing dm to drop the new table. Failing here would leave the device using the old table but with the wrong capacity and mempools. Move dm_table_set_restrictions() earlier in __bind(). Since it needs the capacity to be set, save the old version and restore it on failure. Fixes: bb37d77239af2 ("dm: introduce zone append emulation") Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Tested-by: Damien Le Moal <dlemoal@kernel.org> Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
2025-02-24dm: fix unconditional IO throttle caused by REQ_PREFLUSHJinliang Zheng
When a bio with REQ_PREFLUSH is submitted to dm, __send_empty_flush() generates a flush_bio with REQ_OP_WRITE | REQ_PREFLUSH | REQ_SYNC, which causes the flush_bio to be throttled by wbt_wait(). An example from v5.4, similar problem also exists in upstream: crash> bt 2091206 PID: 2091206 TASK: ffff2050df92a300 CPU: 109 COMMAND: "kworker/u260:0" #0 [ffff800084a2f7f0] __switch_to at ffff80004008aeb8 #1 [ffff800084a2f820] __schedule at ffff800040bfa0c4 #2 [ffff800084a2f880] schedule at ffff800040bfa4b4 #3 [ffff800084a2f8a0] io_schedule at ffff800040bfa9c4 #4 [ffff800084a2f8c0] rq_qos_wait at ffff8000405925bc #5 [ffff800084a2f940] wbt_wait at ffff8000405bb3a0 #6 [ffff800084a2f9a0] __rq_qos_throttle at ffff800040592254 #7 [ffff800084a2f9c0] blk_mq_make_request at ffff80004057cf38 #8 [ffff800084a2fa60] generic_make_request at ffff800040570138 #9 [ffff800084a2fae0] submit_bio at ffff8000405703b4 #10 [ffff800084a2fb50] xlog_write_iclog at ffff800001280834 [xfs] #11 [ffff800084a2fbb0] xlog_sync at ffff800001280c3c [xfs] #12 [ffff800084a2fbf0] xlog_state_release_iclog at ffff800001280df4 [xfs] #13 [ffff800084a2fc10] xlog_write at ffff80000128203c [xfs] #14 [ffff800084a2fcd0] xlog_cil_push at ffff8000012846dc [xfs] #15 [ffff800084a2fda0] xlog_cil_push_work at ffff800001284a2c [xfs] #16 [ffff800084a2fdb0] process_one_work at ffff800040111d08 #17 [ffff800084a2fe00] worker_thread at ffff8000401121cc #18 [ffff800084a2fe70] kthread at ffff800040118de4 After commit 2def2845cc33 ("xfs: don't allow log IO to be throttled"), the metadata submitted by xlog_write_iclog() should not be throttled. But due to the existence of the dm layer, throttling flush_bio indirectly causes the metadata bio to be throttled. Fix this by conditionally adding REQ_IDLE to flush_bio.bi_opf, which makes wbt_should_throttle() return false to avoid wbt_wait(). Signed-off-by: Jinliang Zheng <alexjlzheng@tencent.com> Reviewed-by: Tianxiang Peng <txpeng@tencent.com> Reviewed-by: Hao Peng <flyingpeng@tencent.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
2025-01-17dm: Ensure cloned bio is same length for atomic writeJohn Garry
For an atomic write, a cloned bio must be same length as the original bio, i.e. no splitting. Error in case it is not. Per-dm device queue limits should be setup to ensure that this does not happen, but error this case as an insurance policy. Signed-off-by: John Garry <john.g.garry@oracle.com> Reviewed-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
2025-01-17dm: disable REQ_NOWAIT for flushesMikulas Patocka
REQ_NOWAIT for flushes cannot be easily supported by device mapper because it may allocate multiple bios and its impossible to undo if one of those allocations wants to wait. So, this patch disables REQ_NOWAIT flushes in device mapper and we always return EAGAIN. Previously, the code accepted REQ_NOWAIT flushes, but the non-blocking execution was not guaranteed. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
2025-01-17dm: remove useless test in alloc_multiple_biosMikulas Patocka
The test gfp_flag & GFP_NOWAIT was always true, because both GFP_NOIO and GFP_NOWAIT include the flag __GFP_KSWAPD_RECLAIM. Luckily, this oversight didn't result in any harm; the loop always started with "try = 0". This patch removes the faulty test and explicitly starts the loop with "try = 0" (so that we don't hold the mutex in the first iteration). Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
2024-11-20dm: add support for get_unique_idBenjamin Coddington
This adds support to obtain a device's unique id through dm, similar to the existing ioctl and persistent resevation handling. We limit this to single-target devices. This enables knfsd to export pNFS SCSI luns that have been exported from multipath devices. Signed-off-by: Benjamin Coddington <bcodding@redhat.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-11-20dm: Remove unused dm_set_md_typeDr. David Alan Gilbert
dm_set_md_type() has been unused since commit ba30585936b0 ("dm: move setting md->type into dm_setup_md_queue") Remove it. Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
2024-10-15dm: fix a crash if blk_alloc_disk failsMikulas Patocka
If blk_alloc_disk fails, the variable md->disk is set to an error value. cleanup_mapped_device will see that md->disk is non-NULL and it will attempt to access it, causing a crash on this statement "md->disk->private_data = NULL;". Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reported-by: Chenyuan Yang <chenyuan0y@gmail.com> Closes: https://marc.info/?l=dm-devel&m=172824125004329&w=2 Cc: stable@vger.kernel.org Reviewed-by: Nitesh Shetty <nj.shetty@samsung.com>
2024-09-15Revert "dm: requeue IO if mapping table not yet available"Mikulas Patocka
This reverts commit fa247089de9936a46e290d4724cb5f0b845600f5. The following sequence of commands causes a livelock - there will be workqueue process looping and consuming 100% CPU: dmsetup create --notable test truncate -s 1MiB testdata losetup /dev/loop0 testdata dmsetup load test --table '0 2048 linear /dev/loop0 0' dd if=/dev/zero of=/dev/dm-0 bs=16k count=1 conv=fdatasync The livelock is caused by the commit fa247089de99. The commit claims that it fixes a race condition, however, it is unknown what the actual race condition is and what program is involved in the race condition. When the inactive table is loaded, the nodes /dev/dm-0 and /sys/block/dm-0 are created. /dev/dm-0 has zero size at this point. When the device is suspended and resumed, the nodes /dev/mapper/test and /dev/disk/* are created. If some program opens a block device before it is created by dmsetup or lvm, the program is buggy, so dm could just report an error as it used to do before. Reported-by: Zdenek Kabelac <zkabelac@redhat.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Fixes: fa247089de99 ("dm: requeue IO if mapping table not yet available")
2024-08-13dm suspend: return -ERESTARTSYS instead of -EINTRMikulas Patocka
This commit changes device mapper, so that it returns -ERESTARTSYS instead of -EINTR when it is interrupted by a signal (so that the ioctl can be restarted). The manpage signal(7) says that the ioctl function should be restarted if the signal was handled with SA_RESTART. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org
2024-07-22Merge tag 'for-6.11/block-post-20240722' of git://git.kernel.dk/linuxLinus Torvalds
Pull block integrity mapping updates from Jens Axboe: "A set of cleanups and fixes for the block integrity support. Sent separately from the main block changes from last week, as they depended on later fixes in the 6.10-rc cycle" * tag 'for-6.11/block-post-20240722' of git://git.kernel.dk/linux: block: don't free the integrity payload in bio_integrity_unmap_free_user block: don't free submitter owned integrity payload on I/O completion block: call bio_integrity_unmap_free_user from blk_rq_unmap_user block: don't call bio_uninit from bio_endio block: also return bio_integrity_payload * from stubs block: split integrity support out of bio.h
2024-07-19Merge tag 'for-6.11/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: - Optimize processing of flush bios in the dm-linear and dm-stripe targets - Dm-io cleansups and refactoring - Remove unused 'struct thunk' in dm-cache - Handle minor device numbers > 255 in dm-init - Dm-verity refactoring & enabling platform keyring - Fix warning in dm-raid - Improve dm-crypt performance - split bios to smaller pieces, so that They could be processed concurrently - Stop using blk_limits_io_{min,opt} - Dm-vdo cleanup and refactoring - Remove max_write_zeroes_granularity and max_secure_erase_granularity - Dm-multipath cleanup & refactoring - Add dm-crypt and dm-integrity support for non-power-of-2 sector size - Fix reshape in dm-raid - Make dm_block_validator const * tag 'for-6.11/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (33 commits) dm vdo: fix a minor formatting issue in vdo.rst dm vdo int-map: fix kerneldoc formatting dm vdo repair: add missing kerneldoc fields dm: Constify struct dm_block_validator dm-integrity: introduce the Inline mode dm: introduce the target flag mempool_needs_integrity dm raid: fix stripes adding reshape size issues dm raid: move _get_reshape_sectors() as prerequisite to fixing reshape size issues dm-crypt: support for per-sector NVMe metadata dm mpath: don't call dm_get_device in multipath_message dm: factor out helper function from dm_get_device dm-verity: fix dm_is_verity_target() when dm-verity is builtin dm: Remove max_secure_erase_granularity dm: Remove max_write_zeroes_granularity dm vdo indexer: use swap() instead of open coding it dm vdo: remove unused struct 'uds_attribute' dm: stop using blk_limits_io_{min,opt} dm-crypt: limit the size of encryption requests dm verity: add support for signature verification with platform keyring dm-raid: Fix WARN_ON_ONCE check for sync_thread in raid_resume ...
2024-07-10dm: Remove max_secure_erase_granularityDamien Le Moal
The max_secure_erase_granularity boolean of struct dm_target is used in __process_abnormal_io() but never set by any target. Remove this field and the dead code using it. Signed-off-by: Damien Le Moal <dlemoal@kernel.org> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
2024-07-10dm: Remove max_write_zeroes_granularityDamien Le Moal
The max_write_zeroes_granularity boolean of struct dm_target is used in __process_abnormal_io() but never set by any target. Remove this field and the dead code using it. Signed-off-by: Damien Le Moal <dlemoal@kernel.org> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
2024-07-05dm: handle REQ_OP_ZONE_RESET_ALLDamien Le Moal
This commit implements processing of the REQ_OP_ZONE_RESET_ALL operation for zoned mapped devices. Given that this operation always has a BIO sector of 0 and a 0 size, processing through the regular BIO __split_and_process_bio() function does not work because this function would always select the first target. Instead, handling of this operation is implemented using the function __send_zone_reset_all(). Similarly to the __send_empty_flush() function, the new __send_zone_reset_all() function manually goes through all targets of a mapped device table doing the following: 1) If the target can natively support REQ_OP_ZONE_RESET_ALL, __send_duplicate_bios() is used to forward the reset all operation to the target. This case is handled with the __send_zone_reset_all_native() function. 2) For other targets, the function __send_zone_reset_all_emulated() is executed to emulate the execution of REQ_OP_ZONE_RESET_ALL using regular REQ_OP_ZONE_RESET operations. Targets that can natively support REQ_OP_ZONE_RESET_ALL are identified using the new target field zone_reset_all_supported. This boolean is set to true in for targets that have reliable zone limits, that is, targets that map all sequential write required zones of their zoned device(s). Setting this field is handled in dm_set_zones_restrictions() and device_get_zone_resource_limits(). For targets with unreliable zone limits, REQ_OP_ZONE_RESET_ALL must be emulated (case 2 above). This is implemented with __send_zone_reset_all_emulated() and is similar to the block layer function blkdev_zone_reset_all_emulated(): first a report zones is done for the zones of the target to identify zones that need reset, that is, any sequential write required zone that is not already empty. This is done using a bitmap and the function dm_zone_get_reset_bitmap() which sets to 1 the bit corresponding to a zone that needs reset. Next, this zone bitmap is inspected and a clone BIO modified to use the REQ_OP_ZONE_RESET operation issued for any zone with its bit set in the zone bitmap. This implementation is more efficient than what the block layer does with blkdev_zone_reset_all_emulated(), which is always used for DM zoned devices currently: as we can natively use REQ_OP_ZONE_RESET_ALL on targets mapping all sequential write required zones, resetting all zones of a zoned mapped device can be much faster compared to always emulating this operation using regular per-zone reset. In the worst case, this implementation is as-efficient as the block layer emulation. This reduction in the time it takes to reset all zones of a zoned mapped device depends directly on the mapped device targets mapping (reliable zone limits or not). Signed-off-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20240704052816.623865-4-dlemoal@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-07-05dm: Refactor is_abnormal_io()Damien Le Moal
Use a single switch-case to simplify is_abnormal_io() and make this function more readable and easier to modify. Signed-off-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20240704052816.623865-3-dlemoal@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-07-03block: split integrity support out of bio.hChristoph Hellwig
Split struct bio_integrity_payload and the related prototypes out of bio.h into a separate bio-integrity.h header so that it is only pulled in by the few places that need it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Anuj Gupta <anuj20.g@samsung.com> Reviewed-by: Kanchan Joshi <joshi.k@samsung.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20240702151047.1746127-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-26dm: optimize flushesMikulas Patocka
Device mapper sends flush bios to all the targets and the targets send it to the underlying device. That may be inefficient, for example if a table contains 10 linear targets pointing to the same physical device, then device mapper would send 10 flush bios to that device - despite the fact that only one bio would be sufficient. This commit optimizes the flush behavior. It introduces a per-target variable flush_bypasses_map - it is set when the target supports flush optimization - currently, the dm-linear and dm-stripe targets support it. When all the targets in a table have flush_bypasses_map, flush_bypasses_map on the table is set. __send_empty_flush tests if the table has flush_bypasses_map - and if it has, no flush bios are sent to the targets via the "map" method and the list dm_table->devices is iterated and the flush bios are sent to each member of the list. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Mike Snitzer <snitzer@kernel.org> Suggested-by: Yang Yang <yang.yang@vivo.com>
2024-06-20block: Generalize chunk_sectors support as boundary supportJohn Garry
The purpose of the chunk_sectors limit is to ensure that a mergeble request fits within the boundary of the chunck_sector value. Such a feature will be useful for other request_queue boundary limits, so generalize the chunk_sectors merge code. This idea was proposed by Hannes Reinecke. Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: John Garry <john.g.garry@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Acked-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Link: https://lore.kernel.org/r/20240620125359.2684798-3-john.g.garry@oracle.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-19block: move the io_stat flag setting to queue_limitsChristoph Hellwig
Move the io_stat flag into the queue_limits feature field so that it can be set atomically with the queue frozen. Simplify md and dm to set the flag unconditionally instead of avoiding setting a simple flag for cases where it already is set by other means, which is a bit pointless. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Hannes Reinecke <hare@suse.de> Link: https://lore.kernel.org/r/20240617060532.127975-17-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-21Merge tag 'for-6.10/dm-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device mapper fixes from Mike Snitzer: - Fix DM discard regressions due to DM core switching over to using queue_limits_set() without DM core and targets first being updated to set (and stack) discard limits in terms of max_hw_discard_sectors and not max_discard_sectors - Fix stable@ DM integrity discard support to set device's discard_granularity limit to the device's logical block size * tag 'for-6.10/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm: always manage discard support in terms of max_hw_discard_sectors dm-integrity: set discard_granularity to logical block size
2024-05-20dm: always manage discard support in terms of max_hw_discard_sectorsMike Snitzer
Commit 4f563a64732d ("block: add a max_user_discard_sectors queue limit") changed block core to set max_discard_sectors to: min(lim->max_hw_discard_sectors, lim->max_user_discard_sectors) Since commit 1c0e720228ad ("dm: use queue_limits_set") it was reported dm-thinp was failing in a few fstests (generic/347 and generic/405) with the first WARN_ON_ONCE in dm_cell_key_has_valid_range() being reported, e.g.: WARNING: CPU: 1 PID: 30 at drivers/md/dm-bio-prison-v1.c:128 dm_cell_key_has_valid_range+0x3d/0x50 blk_set_stacking_limits() sets max_user_discard_sectors to UINT_MAX, so given how block core now sets max_discard_sectors (detailed above) it follows that blk_stack_limits() stacks up the underlying device's max_hw_discard_sectors and max_discard_sectors is set to match it. If max_hw_discard_sectors exceeds dm's BIO_PRISON_MAX_RANGE, then dm_cell_key_has_valid_range() will trigger the warning with: WARN_ON_ONCE(key->block_end - key->block_begin > BIO_PRISON_MAX_RANGE) Aside from this warning, the discard will fail. Fix this and other DM issues by governing discard support in terms of max_hw_discard_sectors instead of max_discard_sectors. Reported-by: Theodore Ts'o <tytso@mit.edu> Fixes: 1c0e720228ad ("dm: use queue_limits_set") Signed-off-by: Mike Snitzer <snitzer@kernel.org>