Commit Graph

899 Commits

Author SHA1 Message Date
Ingo Blechschmidt
981ccd97f7 dm: avoid leaking the caller's thread keyring via the table device file
The refactoring in commit a28d893eb3 ("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: a28d893eb3 ("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>
2026-07-08 22:33:35 +02:00
Fengnan Chang
5aa0f9231c dm: limit target bio polling to one shot
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: f22ecf9c14 ("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>
2026-05-18 14:27:11 +02:00
Benjamin Marzinski
5534cac9b5 dm-ima: Fix UAF errors and measuring incorrect context
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>
2026-05-04 14:53:09 +02:00
Benjamin Marzinski
8904a3de87 dm-ima: remove dm_ima_reset_data()
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>
2026-05-04 14:52:18 +02:00
Mikulas Patocka
2df8b310bc dm: use bio_clone_blkg_association
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 ca522482e3 ("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: ca522482e3 ("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>
2026-01-26 15:36:22 +01:00
Marco Crivellari
d488086867 dm: add WQ_PERCPU to alloc_workqueue users
This continues the effort to refactor workqueue APIs, which began with
the introduction of new workqueues and a new alloc_workqueue flag in:

   commit 128ea9f6cc ("workqueue: Add system_percpu_wq and system_dfl_wq")
   commit 930c2ea566 ("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>
2026-01-14 13:16:00 +01:00
Linus Torvalds
d358e52546 small dm code refactoring
fix deadlock when reloading a multipath table
 
 don't warn if IMA_DISABLE_HTABLE is not enabled
 
 test for REQ_ATOMIC in dm_accept_partial_bio()
 
 ignore discard return value
 
 MAINTAINERS: add Benjamin Marzinski as a device mapper maintainer
 
 dm-bufio: align write boundary on physical block size
 
 dm-crypt: use the MD5 library directly
 
 dm-crypt: use folio_nr_pages() instead of shift operation
 
 dm-crypt: enable DM_TARGET_ATOMIC_WRITES
 
 dm-verity: remove log message with shash driver name
 
 dm-verity: use the SHA-256 library directly
 
 dm-verity: use 2-way interleaved SHA-256 hashing when supported
 
 dm-verity: expose corrected block count via status
 
 dm-verity: disable recursive forward error correction
 
 dm-verity: remove useless mempool
 
 dm-mpath: enable DM_TARGET_ATOMIC_WRITES
 
 dm-mpath: simplify the setup_scsi_dh code
 
 dm-ebs: mark full buffer dirty even on partial write
 
 dm-vdo: fix kerneldoc warnings
 
 dm-snapshot: fix 'scheduling while atomic' on real-time kernels
 
 dm-raid: fix possible NULL dereference with undefined raid type
 
 dm raid: add documentation for takeover/reshape raid1 -> raid5 table line examples
 
 dm-log-writes: add missing set_freezable() for freezable kthread
 
 dm-pcache: fixes in indexing code
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Merge tag 'for-6.19/dm-changes' of 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
  ...
2025-12-11 12:13:29 +09:00
Mikulas Patocka
de67c139b3 dm: test for REQ_ATOMIC in dm_accept_partial_bio()
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>
2025-12-10 19:28:12 +01:00
Mikulas Patocka
a612d24e85 dm: fix failure when empty flush's bi_sector points beyond the device end
An empty flush bio can have arbitrary bi_sector. The commit 2b1c6d7a89
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: 2b1c6d7a89 ("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>
2025-11-20 19:50:42 +01:00
Jon Hunter
c82faa8934 dm: Don't warn if IMA_DISABLE_HTABLE is not enabled
Commit f1cd6cb24b ("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>
2025-11-18 18:24:25 +01:00
Benjamin Marzinski
be4addb191 dm: Fix deadlock when reloading a multipath table
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>
2025-10-20 15:26:57 +02:00
Linus Torvalds
7dbec0bbc3 dm docs: fix typos
dm, dm-ima, dm-bufio, dm-vdo, dm-raid: small refactoring
 
 dm-error: mark it with DM_TARGET_PASSES_INTEGRITY
 
 dm-pcache: a new target for read/write caching on persistent memory
 
 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
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Merge tag 'for-6.18/dm-changes' of 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
  ...
2025-10-03 18:48:02 -07:00
Mikulas Patocka
2b1c6d7a89 dm: optimize REQ_PREFLUSH with data when using the linear target
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>
2025-09-18 12:58:02 +02:00
Zheng Qixing
8d33a030c5 dm: fix NULL pointer dereference in __dm_suspend()
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: c4576aed8d ("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>
2025-08-26 16:46:52 +02:00
Zheng Qixing
7f597c2cdb dm: fix queue start/stop imbalance under suspend/load/resume races
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: e70feb8b3e ("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>
2025-08-26 16:46:32 +02:00
Al Viro
4fc8728aa3 block: switch ->getgeo() to struct gendisk
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>
2025-08-13 02:59:29 -04:00
Linus Torvalds
d632ab86af dm-table: fix checking for request-based stackable devices
dm-flakey: fix corrupt_bio_byte setup checks
 
 dm raid: add support for resync w/o metadata devices
 
 dm, dm-mpath, vm-vdo, dm-raid: small code simplification
 
 dm-verity: remove support for asynchronous hashes
 
 dm-zoned-target: close smatch warning
 
 dm-thin: update the documentation
 
 dm-thin: enable inline-crypto passthrough
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Merge tag 'for-6.17/dm-changes' of 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
2025-08-04 08:58:53 -07:00
Linus Torvalds
beace86e61 Summary of significant series in this pull request:
- The 4 patch series "mm: ksm: prevent KSM from breaking merging of new
   VMAs" from 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.
 
 - The 4 patch series "mm/damon: introduce DAMON_STAT for simple and
   practical access monitoring" from SeongJae Park adds a new kernel module
   which simplifies the setup and usage of DAMON in production
   environments.
 
 - The 6 patch series "stop passing a writeback_control to swap/shmem
   writeout" from Christoph Hellwig is a cleanup to the writeback code
   which removes a couple of pointers from struct writeback_control.
 
 - The 7 patch series "drivers/base/node.c: optimization and cleanups"
   from Donet Tom contains largely uncorrelated cleanups to the NUMA node
   setup and management code.
 
 - The 4 patch series "mm: userfaultfd: assorted fixes and cleanups" from
   Tal Zussman does some maintenance work on the userfaultfd code.
 
 - The 5 patch series "Readahead tweaks for larger folios" from Ryan
   Roberts implements some tuneups for pagecache readahead when it is
   reading into order>0 folios.
 
 - The 4 patch series "selftests/mm: Tweaks to the cow test" from Mark
   Brown provides some cleanups and consistency improvements to the
   selftests code.
 
 - The 4 patch series "Optimize mremap() for large folios" from Dev Jain
   does that.  A 37% reduction in execution time was measured in a
   memset+mremap+munmap microbenchmark.
 
 - The 5 patch series "Remove zero_user()" from Matthew Wilcox expunges
   zero_user() in favor of the more modern memzero_page().
 
 - The 3 patch series "mm/huge_memory: vmf_insert_folio_*() and
   vmf_insert_pfn_pud() fixes" from 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.
 
 - The 3 patch series "mm/damon: use alloc_migrate_target() for
   DAMOS_MIGRATE_{HOT,COLD" from SeongJae Park provides some cleanup and
   consolidation work in DAMON.
 
 - The 3 patch series "use vm_flags_t consistently" from Lorenzo Stoakes
   uses vm_flags_t in places where we were inappropriately using other
   types.
 
 - The 3 patch series "mm/memfd: Reserve hugetlb folios before
   allocation" from Vivek Kasireddy increases the reliability of large page
   allocation in the memfd code.
 
 - The 14 patch series "mm: Remove pXX_devmap page table bit and pfn_t
   type" from Alistair Popple removes several now-unneeded PFN_* flags.
 
 - The 5 patch series "mm/damon: decouple sysfs from core" from SeongJae
   Park implememnts some cleanup and maintainability work in the DAMON
   sysfs layer.
 
 - The 5 patch series "madvise cleanup" from Lorenzo Stoakes does quite a
   lot of cleanup/maintenance work in the madvise() code.
 
 - The 4 patch series "madvise anon_name cleanups" from Vlastimil Babka
   provides additional cleanups on top or Lorenzo's effort.
 
 - The 11 patch series "Implement numa node notifier" from Oscar Salvador
   creates a standalone notifier for NUMA node memory state changes.
   Previously these were lumped under the more general memory on/offline
   notifier.
 
 - The 6 patch series "Make MIGRATE_ISOLATE a standalone bit" from Zi Yan
   cleans up the pageblock isolation code and fixes a potential issue which
   doesn't seem to cause any problems in practice.
 
 - The 5 patch series "selftests/damon: add python and drgn based DAMON
   sysfs functionality tests" from SeongJae Park adds additional drgn- and
   python-based DAMON selftests which are more comprehensive than the
   existing selftest suite.
 
 - The 5 patch series "Misc rework on hugetlb faulting path" from Oscar
   Salvador fixes a rather obscure deadlock in the hugetlb fault code and
   follows that fix with a series of cleanups.
 
 - The 3 patch series "cma: factor out allocation logic from
   __cma_declare_contiguous_nid" from Mike Rapoport rationalizes and cleans
   up the highmem-specific code in the CMA allocator.
 
 - The 28 patch series "mm/migration: rework movable_ops page migration
   (part 1)" from David Hildenbrand provides cleanups and
   future-preparedness to the migration code.
 
 - The 2 patch series "mm/damon: add trace events for auto-tuned
   monitoring intervals and DAMOS quota" from SeongJae Park adds some
   tracepoints to some DAMON auto-tuning code.
 
 - The 6 patch series "mm/damon: fix misc bugs in DAMON modules" from
   SeongJae Park does that.
 
 - The 6 patch series "mm/damon: misc cleanups" from SeongJae Park also
   does what it claims.
 
 - The 4 patch series "mm: folio_pte_batch() improvements" from David
   Hildenbrand cleans up the large folio PTE batching code.
 
 - The 13 patch series "mm/damon/vaddr: Allow interleaving in
   migrate_{hot,cold} actions" from SeongJae Park facilitates dynamic
   alteration of DAMON's inter-node allocation policy.
 
 - The 3 patch series "Remove unmap_and_put_page()" from Vishal Moola
   provides a couple of page->folio conversions.
 
 - The 4 patch series "mm: per-node proactive reclaim" from Davidlohr
   Bueso implements a per-node control of proactive reclaim - beyond the
   current memcg-based implementation.
 
 - The 14 patch series "mm/damon: remove damon_callback" from SeongJae
   Park replaces the damon_callback interface with a more general and
   powerful damon_call()+damos_walk() interface.
 
 - The 10 patch series "mm/mremap: permit mremap() move of multiple VMAs"
   from 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.
 
 - The 3 patch series "drop hugetlb_free_pgd_range()" from Anthony Yznaga
   switches some sparc hugetlb code over to the generic version and removes
   the thus-unneeded hugetlb_free_pgd_range().
 
 - The 4 patch series "mm/damon/sysfs: support periodic and automated
   stats update" from 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.
 
 - The 4 patch series "Some randome fixes and cleanups to swapfile" from
   Kemeng Shi does what is claims.
 
 - The 4 patch series "mm: introduce snapshot_page" from 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.
 
 - The 6 patch series "use per-vma locks for /proc/pid/maps reads" from
   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.
 
 - The 6 patch series "__folio_split() clean up" from Zi Yan cleans up
   __folio_split()!
 
 - The 7 patch series "Optimize mprotect() for large folios" from Dev
   Jain provides some quite large (>3x) speedups to mprotect() when dealing
   with large folios.
 
 - The 2 patch series "selftests/mm: reuse FORCE_READ to replace "asm
   volatile("" : "+r" (XXX));" and some cleanup" from wang lian does some
   cleanup work in the selftests code.
 
 - The 3 patch series "tools/testing: expand mremap testing" from 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.
 
 - The 22 patch series "selftests/damon/sysfs.py: test all parameters"
   from SeongJae Park extends the DAMON sysfs interface selftest so that it
   tests all possible user-requested parameters.  Rather than the present
   minimal subset.
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Merge tag 'mm-stable-2025-07-30-15-25' of 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
  ...
2025-07-31 14:57:54 -07:00
Shin'ichiro Kawasaki
675f940576 dm: split write BIOs on zone boundaries when zone append is not emulated
Commit 2df7168717 ("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: 2df7168717 ("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>
2025-07-17 06:03:03 -06:00
Alistair Popple
21aa65bf82 mm: remove callers of pfn_t functionality
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>
2025-07-09 22:42:19 -07:00
Damien Le Moal
409f9287da dm: Check for forbidden splitting of zone write operations
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: f211268ed1 ("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>
2025-06-30 15:50:32 -06:00
Damien Le Moal
2df7168717 dm: Always split write BIOs to zoned device limits
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: f211268ed1 ("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>
2025-06-30 15:50:31 -06:00
Damien Le Moal
f70291411b block: Introduce bio_needs_zone_write_plugging()
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: f211268ed1 ("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>
2025-06-30 15:50:31 -06:00
Damien Le Moal
548d88f74e dm: Simplify dm_io_complete()
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>
2025-06-27 12:59:22 +02:00
Kevin Wolf
4862c8861d dm: Allow .prepare_ioctl to handle ioctls directly
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>
2025-05-04 11:35:05 +02:00
Mikulas Patocka
f1e24048ed dm: use generic functions instead of disable_discard and disable_write_zeroes
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>
2025-05-04 11:35:05 +02:00
Benjamin Marzinski
121218bef4 dm: limit swapping tables for devices with zone write plugs
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: bb37d77239 ("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>
2025-05-04 11:35:05 +02:00
Benjamin Marzinski
e8819e7f03 dm: free table mempools if not used in __bind
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: 29dec90a0f ("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>
2025-04-11 13:38:50 +02:00
Benjamin Marzinski
9eb7109a5b dm: don't change md if dm_table_set_restrictions() fails
__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: bb37d77239 ("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>
2025-04-11 13:38:39 +02:00
Jinliang Zheng
88f7f56d16 dm: fix unconditional IO throttle caused by REQ_PREFLUSH
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 2def2845cc ("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>
2025-02-24 12:09:44 +01:00
John Garry
5f430e3408 dm: Ensure cloned bio is same length for atomic write
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>
2025-01-17 22:24:01 +01:00
Mikulas Patocka
cd6521d03f dm: disable REQ_NOWAIT for flushes
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>
2025-01-17 22:05:39 +01:00
Mikulas Patocka
6942348d1b dm: remove useless test in alloc_multiple_bios
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>
2025-01-17 22:05:39 +01:00
Benjamin Coddington
d5f01ace54 dm: add support for get_unique_id
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>
2024-11-20 11:38:04 +01:00
Dr. David Alan Gilbert
feb83afa4e dm: Remove unused dm_set_md_type
dm_set_md_type() has been unused since commit
ba30585936 ("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>
2024-11-20 11:38:04 +01:00
Mikulas Patocka
fed13a5478 dm: fix a crash if blk_alloc_disk fails
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>
2024-10-15 13:37:17 +02:00
Mikulas Patocka
c8691cd0fc Revert "dm: requeue IO if mapping table not yet available"
This reverts commit fa247089de.

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 fa247089de. 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: fa247089de ("dm: requeue IO if mapping table not yet available")
2024-09-15 21:02:54 +02:00
Mikulas Patocka
1e1fd567d3 dm suspend: return -ERESTARTSYS instead of -EINTR
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
2024-08-13 13:50:45 +02:00
Linus Torvalds
0256994887 for-6.11/block-post-20240722
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Merge tag 'for-6.11/block-post-20240722' of git://git.kernel.dk/linux

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
2024-07-22 11:04:09 -07:00
Linus Torvalds
661fb4e68c - 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
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Merge tag 'for-6.11/dm-changes' of 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
  ...
2024-07-19 10:48:44 -07:00
Damien Le Moal
9d45db03ac dm: Remove max_secure_erase_granularity
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>
2024-07-10 13:10:06 +02:00
Damien Le Moal
396a27e912 dm: Remove max_write_zeroes_granularity
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>
2024-07-10 13:10:06 +02:00
Damien Le Moal
81e7706345 dm: handle REQ_OP_ZONE_RESET_ALL
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>
2024-07-05 00:42:04 -06:00
Damien Le Moal
ae7e965b36 dm: Refactor is_abnormal_io()
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>
2024-07-05 00:42:04 -06:00
Christoph Hellwig
da042a3655 block: split integrity support out of bio.h
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>
2024-07-03 10:21:15 -06:00
Mikulas Patocka
aaa53168cb dm: optimize flushes
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>
2024-06-26 11:32:39 -04:00
John Garry
f70167a7a6 block: Generalize chunk_sectors support as boundary support
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>
2024-06-20 15:19:17 -06:00
Christoph Hellwig
cdb2497918 block: move the io_stat flag setting to queue_limits
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>
2024-06-19 07:58:28 -06:00
Linus Torvalds
856726396d - 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.
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Merge tag 'for-6.10/dm-fixes' of 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
2024-05-21 11:43:11 -07:00
Mike Snitzer
825d8bbd2f dm: always manage discard support in terms of max_hw_discard_sectors
Commit 4f563a6473 ("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 1c0e720228 ("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: 1c0e720228 ("dm: use queue_limits_set")
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2024-05-20 15:51:19 -04:00