block: initialize bio issue time in blk_mq_submit_bio()
bio->issue_time_ns is only used by blk-iolatency, which can only be
enabled for rq-based disk, hence it's not necessary to initialize
the time for bio-based disk.
Meanwhile, if bio is split by blk_crypto_fallback_split_bio_if_needed(),
the issue time is not initialized for new split bio, this can be fixed
as well.
Noted the next patch will optimize better that bio issue time will
only be used when blk-iolatency is really enabled by the disk.
Now that bio->bi_issue is only used by blk-iolatency to get bio issue
time, replace bio_issue with u64 time directly and remove bio_issue to
make code cleaner.
Merge tag 'md-6.18-20250909' of gitolite.kernel.org:pub/scm/linux/kernel/git/mdraid/linux into for-6.18/block
Pull MD changes from Yu Kuai:
"Redundant data is used to enhance data fault tolerance, and the storage
method for redundant data vary depending on the RAID levels. And it's
important to maintain the consistency of redundant data.
Bitmap is used to record which data blocks have been synchronized and
which ones need to be resynchronized or recovered. Each bit in the
bitmap represents a segment of data in the array. When a bit is set,
it indicates that the multiple redundant copies of that data segment
may not be consistent. Data synchronization can be performed based on
the bitmap after power failure or readding a disk. If there is no
bitmap, a full disk synchronization is required.
Due to known performance issues with md-bitmap and the unreasonable
implementations:
- self-managed IO submitting like filemap_write_page();
- global spin_lock
I have decided not to continue optimizing based on the current bitmap
implementation, this new bitmap is invented without locking from IO fast
path and can be used with fast disks.
Key features for the new bitmap:
- IO fastpath is lockless, if user issues lots of write IO to the same
bitmap bit in a short time, only the first write has additional
overhead to update bitmap bit, no additional overhead for the
following writes;
- support only resync or recover written data, means in the case
creating new array or replacing with a new disk, there is no need to
do a full disk resync/recovery;"
* tag 'md-6.18-20250909' of gitolite.kernel.org:pub/scm/linux/kernel/git/mdraid/linux: (24 commits)
md/md-llbitmap: introduce new lockless bitmap
md/md-bitmap: make method bitmap_ops->daemon_work optional
md: add a new recovery_flag MD_RECOVERY_LAZY_RECOVER
md/md-bitmap: add a new method blocks_synced() in bitmap_operations
md/md-bitmap: add a new method skip_sync_blocks() in bitmap_operations
md/md-bitmap: delay registration of bitmap_ops until creating bitmap
md/md-bitmap: add a new sysfs api bitmap_type
md: add a new mddev field 'bitmap_id'
md/md-bitmap: support discard for bitmap ops
md: factor out a helper raid_is_456()
md: add a new parameter 'offset' to md_super_write()
md/md-bitmap: introduce CONFIG_MD_BITMAP
md: check before referencing mddev->bitmap_ops
md/dm-raid: check before referencing mddev->bitmap_ops
md/raid5: check before referencing mddev->bitmap_ops
md/raid10: check before referencing mddev->bitmap_ops
md/raid1: check before referencing mddev->bitmap_ops
md/raid1: check bitmap before behind write
md/md-bitmap: handle the case bitmap is not enabled before end_sync()
md/md-bitmap: handle the case bitmap is not enabled before start_sync()
...
Keith Busch [Wed, 3 Sep 2025 20:27:46 +0000 (13:27 -0700)]
blk-map: provide the bdev to bio if one exists
We can now safely provide a block device when extracting user pages for
driver and user passthrough commands. Set the bdev so the caller doesn't
have to do that later. This has an additional benefit of being able to
extract P2P pages in the passthrough path.
Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Keith Busch [Wed, 3 Sep 2025 19:33:17 +0000 (12:33 -0700)]
blk-mq-dma: bring back p2p request flags
We only need to consider data and metadata dma mapping types separately.
The request and bio integrity payload have enough flag bits to
internally track the mapping type for each. Use these so the caller
doesn't need to track them, and provide separete request and integrity
helpers to the common code. This will make it easier to scale new
mappings, like the proposed MMIO attribute, without burdening the caller
to track such things.
Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Leon Romanovsky <leonro@nvidia.com> Signed-off-by: Keith Busch <kbusch@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Keith Busch [Wed, 3 Sep 2025 19:33:16 +0000 (12:33 -0700)]
blk-integrity: enable p2p source and destination
Set the extraction flags to allow p2p pages for the metadata buffer if
the block device allows it. Similar to data payloads, ensure the bio
does not use merging if we see a p2p page.
Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Keith Busch <kbusch@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Keith Busch [Wed, 27 Aug 2025 14:12:58 +0000 (07:12 -0700)]
iov_iter: remove iov_iter_is_aligned
No more callers.
Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Keith Busch [Wed, 27 Aug 2025 14:12:57 +0000 (07:12 -0700)]
blk-integrity: use simpler alignment check
We're checking length and addresses against the same alignment value, so
use the more simple iterator check.
Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Keith Busch [Wed, 27 Aug 2025 14:12:56 +0000 (07:12 -0700)]
block: remove bdev_iter_is_aligned
No more callers.
Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Keith Busch [Wed, 27 Aug 2025 14:12:55 +0000 (07:12 -0700)]
iomap: simplify direct io validity check
The block layer checks all the segments for validity later, so no need
for an early check. Just reduce it to a simple position and total length
check, and defer the more invasive segment checks to the block layer.
Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Keith Busch [Wed, 27 Aug 2025 14:12:54 +0000 (07:12 -0700)]
block: simplify direct io validity check
The block layer checks all the segments for validity later, so no need
for an early check. Just reduce it to a simple position and total length
check, and defer the more invasive segment checks to the block layer.
Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Keith Busch [Wed, 27 Aug 2025 14:12:53 +0000 (07:12 -0700)]
block: align the bio after building it
Instead of ensuring each vector is block size aligned while constructing
the bio, just ensure the entire size is aligned after it's built. This
makes getting bio pages more flexible to accepting device valid io
vectors that would otherwise get rejected by alignment checks.
Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Keith Busch [Wed, 27 Aug 2025 14:12:52 +0000 (07:12 -0700)]
block: add size alignment to bio_iov_iter_get_pages
The block layer tries to align bio vectors to the block device's logical
block size. Some cases don't have a block device, or we may need to
align to something larger, which we can't derive it from the queue
limits. Have the caller specify what they want, or allow any length
alignment if nothing was specified. Since the most common use case
relies on the block device's limits, a helper function is provided.
Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Keith Busch [Wed, 27 Aug 2025 14:12:51 +0000 (07:12 -0700)]
block: check for valid bio while splitting
We're already iterating every segment, so check these for a valid IO
lengths at the same time. Individual segment lengths will not be checked
on passthrough commands. The read/write command segments must be sized
to the dma alignment.
Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
drivers/block: WQ_PERCPU added to alloc_workqueue users
Currently if a user enqueue a work item using schedule_delayed_work() the
used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use
WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to
schedule_work() that is using system_wq and queue_work(), that makes use
again of WORK_CPU_UNBOUND.
This lack of consistentcy cannot be addressed without refactoring the API.
alloc_workqueue() treats all queues as per-CPU by default, while unbound
workqueues must opt-in via WQ_UNBOUND.
This default is suboptimal: most workloads benefit from unbound queues,
allowing the scheduler to place worker threads where they’re needed and
reducing noise when CPUs are isolated.
This default is suboptimal: most workloads benefit from unbound queues,
allowing the scheduler to place worker threads where they’re needed and
reducing noise when CPUs are isolated.
This patch adds a new WQ_PERCPU flag to explicitly request the use of
the per-CPU behavior. Both flags coexist for one release cycle to allow
callers to transition their calls.
Once migration is complete, WQ_UNBOUND can be removed and unbound will
become the implicit 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.
drivers/block: replace use of system_unbound_wq with system_dfl_wq
Currently if a user enqueue a work item using schedule_delayed_work() the
used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use
WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to
schedule_work() that is using system_wq and queue_work(), that makes use
again of WORK_CPU_UNBOUND.
This lack of consistentcy cannot be addressed without refactoring the API.
system_unbound_wq should be the default workqueue so as not to enforce
locality constraints for random work whenever it's not required.
Adding system_dfl_wq to encourage its use when unbound work should be used.
queue_work() / queue_delayed_work() / mod_delayed_work() will now use the
new unbound wq: whether the user still use the old wq a warn will be
printed along with a wq redirect to the new one.
The old system_unbound_wq will be kept for a few release cycles.
drivers/block: replace use of system_wq with system_percpu_wq
Currently if a user enqueue a work item using schedule_delayed_work() the
used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use
WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to
schedule_work() that is using system_wq and queue_work(), that makes use
again of WORK_CPU_UNBOUND.
This lack of consistentcy cannot be addressed without refactoring the API.
system_unbound_wq should be the default workqueue so as not to enforce
locality constraints for random work whenever it's not required.
Adding system_dfl_wq to encourage its use when unbound work should be used.
queue_work() / queue_delayed_work() / mod_delayed_work() will now use the
new unbound wq: whether the user still use the old wq a warn will be
printed along with a wq redirect to the new one.
The old system_unbound_wq will be kept for a few release cycles.
Ming Lei [Tue, 9 Sep 2025 12:33:10 +0000 (20:33 +0800)]
blk-mq: Document tags_srcu member in blk_mq_tag_set structure
Add missing documentation for the tags_srcu member that was introduced
to defer freeing of tags page_list to prevent use-after-free when
iterating tags.
Fixes htmldocs warning:
WARNING: include/linux/blk-mq.h:536 struct member 'tags_srcu' not described in 'blk_mq_tag_set'
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
block: remove the bi_inline_vecs variable sized array from struct bio
Bios are embedded into other structures, and at least spare is unhappy
about embedding structures with variable sized arrays. There's no
real need to the array anyway, we can replace it with a helper pointing
to the memory just behind the bio, and with the previous cleanups there
is very few site doing anything special with it.
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: John Garry <john.g.garry@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Han Guangjiang [Fri, 5 Sep 2025 10:24:11 +0000 (18:24 +0800)]
blk-throttle: fix access race during throttle policy activation
On repeated cold boots we occasionally hit a NULL pointer crash in
blk_should_throtl() when throttling is consulted before the throttle
policy is fully enabled for the queue. Checking only q->td != NULL is
insufficient during early initialization, so blkg_to_pd() for the
throttle policy can still return NULL and blkg_to_tg() becomes NULL,
which later gets dereferenced.
Genjian Zhang [Fri, 15 Aug 2025 09:07:32 +0000 (17:07 +0800)]
null_blk: Fix the description of the cache_size module argument
When executing modinfo null_blk, there is an error in the description
of module parameter mbps, and the output information of cache_size is
incomplete.The output of modinfo before and after applying this patch
is as follows:
Before:
[...]
parm: cache_size:ulong
[...]
parm: mbps:Cache size in MiB for memory-backed device.
Default: 0 (none) (uint)
[...]
After:
[...]
parm: cache_size:Cache size in MiB for memory-backed device.
Default: 0 (none) (ulong)
[...]
parm: mbps:Limit maximum bandwidth (in MiB/s).
Default: 0 (no limit) (uint)
[...]
Fixes: 058efe000b31 ("null_blk: add module parameters for 4 options") Signed-off-by: Genjian Zhang <zhanggenjian@kylinos.cn> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Ming Lei [Sat, 30 Aug 2025 02:18:23 +0000 (10:18 +0800)]
blk-mq: Replace tags->lock with SRCU for tag iterators
Replace the spinlock in blk_mq_find_and_get_req() with an SRCU read lock
around the tag iterators.
This is done by:
- Holding the SRCU read lock in blk_mq_queue_tag_busy_iter(),
blk_mq_tagset_busy_iter(), and blk_mq_hctx_has_requests().
- Removing the now-redundant tags->lock from blk_mq_find_and_get_req().
This change fixes lockup issue in scsi_host_busy() in case of shost->host_blocked.
Also avoids big tags->lock when reading disk sysfs attribute `inflight`.
Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Ming Lei [Sat, 30 Aug 2025 02:18:22 +0000 (10:18 +0800)]
blk-mq: Defer freeing flush queue to SRCU callback
The freeing of the flush queue/request in blk_mq_exit_hctx() can race with
tag iterators that may still be accessing it. To prevent a potential
use-after-free, the deallocation should be deferred until after a grace
period. With this way, we can replace the big tags->lock in tags iterator
code path with srcu for solving the issue.
This patch introduces an SRCU-based deferred freeing mechanism for the
flush queue.
The changes include:
- Adding a `rcu_head` to `struct blk_flush_queue`.
- Creating a new callback function, `blk_free_flush_queue_callback`,
to handle the actual freeing.
- Replacing the direct call to `blk_free_flush_queue()` in
`blk_mq_exit_hctx()` with `call_srcu()`, using the `tags_srcu`
instance to ensure synchronization with tag iterators.
Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Ming Lei [Sat, 30 Aug 2025 02:18:21 +0000 (10:18 +0800)]
blk-mq: Defer freeing of tags page_list to SRCU callback
Tag iterators can race with the freeing of the request pages(tags->page_list),
potentially leading to use-after-free issues.
Defer the freeing of the page list and the tags structure itself until
after an SRCU grace period has passed. This ensures that any concurrent
tag iterators have completed before the memory is released. With this
way, we can replace the big tags->lock in tags iterator code path with
srcu for solving the issue.
This is achieved by:
- Adding a new `srcu_struct tags_srcu` to `blk_mq_tag_set` to protect
tag map iteration.
- Adding an `rcu_head` to `struct blk_mq_tags` to be used with
`call_srcu`.
- Moving the page list freeing logic and the `kfree(tags)` call into a
new callback function, `blk_mq_free_tags_callback`.
- In `blk_mq_free_tags`, invoking `call_srcu` to schedule the new
callback for deferred execution.
The read-side protection for the tag iterators will be added in a
subsequent patch.
Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Ming Lei [Sat, 30 Aug 2025 02:18:20 +0000 (10:18 +0800)]
blk-mq: Pass tag_set to blk_mq_free_rq_map/tags
To prepare for converting the tag->rqs freeing to be SRCU-based, the
tag_set is needed in the freeing helper functions.
This patch adds 'struct blk_mq_tag_set *' as the first parameter to
blk_mq_free_rq_map() and blk_mq_free_tags(), and updates all their call
sites.
This allows access to the tag_set's SRCU structure in the next step,
which will be used to free the tag maps after a grace period.
No functional change is intended in this patch.
Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Ming Lei [Sat, 30 Aug 2025 02:18:19 +0000 (10:18 +0800)]
blk-mq: Move flush queue allocation into blk_mq_init_hctx()
Move flush queue allocation into blk_mq_init_hctx() and its release into
blk_mq_exit_hctx(), and prepare for replacing tags->lock with SRCU to
draining inflight request walking. blk_mq_exit_hctx() is the last chance
for us to get valid `tag_set` reference, and we need to add one SRCU to
`tag_set` for freeing flush request via call_srcu().
It is safe to move flush queue & request release into blk_mq_exit_hctx(),
because blk_mq_clear_flush_rq_mapping() clears the flush request
reference int driver tags inflight request table, meantime inflight
request walking is drained.
Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Yu Kuai [Fri, 29 Aug 2025 08:04:26 +0000 (16:04 +0800)]
md/md-llbitmap: introduce new lockless bitmap
Redundant data is used to enhance data fault tolerance, and the storage
method for redundant data vary depending on the RAID levels. And it's
important to maintain the consistency of redundant data.
Bitmap is used to record which data blocks have been synchronized and which
ones need to be resynchronized or recovered. Each bit in the bitmap
represents a segment of data in the array. When a bit is set, it indicates
that the multiple redundant copies of that data segment may not be
consistent. Data synchronization can be performed based on the bitmap after
power failure or readding a disk. If there is no bitmap, a full disk
synchronization is required.
Due to known performance issues with md-bitmap and the unreasonable
implementations:
- self-managed IO submitting like filemap_write_page();
- global spin_lock
I have decided not to continue optimizing based on the current bitmap
implementation, this new bitmap is invented without locking from IO fast
path and can be used with fast disks.
For designs and details, see the comments in drivers/md-llbitmap.c.
Yu Kuai [Fri, 29 Aug 2025 08:04:25 +0000 (16:04 +0800)]
md/md-bitmap: make method bitmap_ops->daemon_work optional
daemon_work() will be called by daemon thread, on the one hand, daemon
thread doesn't have strict wake-up time; on the other hand, too much
work are put to daemon thread, like handle sync IO, handle failed
or specail normal IO, handle recovery, and so on. Hence daemon thread
may be too busy to clear dirty bits in time.
Make bitmap_ops->daemon_work() optional and following patches will use
separate async work to clear dirty bits for the new bitmap.
Yu Kuai [Fri, 29 Aug 2025 08:04:23 +0000 (16:04 +0800)]
md/md-bitmap: add a new method blocks_synced() in bitmap_operations
Currently, raid456 must perform a whole array initial recovery to build
initail xor data, then IO to the array won't have to read all the blocks
in underlying disks.
This behavior will affect IO performance a lot, and nowadays there are
huge disks and the initial recovery can take a long time. Hence llbitmap
will support lazy initial recovery in following patches. This method is
used to check if data blocks is synced or not, if not then IO will still
have to read all blocks for raid456.
Yu Kuai [Fri, 29 Aug 2025 08:04:22 +0000 (16:04 +0800)]
md/md-bitmap: add a new method skip_sync_blocks() in bitmap_operations
This method is used to check if blocks can be skipped before calling
into pers->sync_request(), llbitmap will use this method to skip
resync for unwritten/clean data blocks, and recovery/check/repair for
unwritten data blocks;
Yu Kuai [Fri, 29 Aug 2025 08:04:18 +0000 (16:04 +0800)]
md/md-bitmap: support discard for bitmap ops
Use two new methods {start, end}_discard in bitmap_ops and a new field 'rw'
in struct md_io_clone to handle discard IO, prepare to support new md
bitmap.
Since all bitmap functions to hanlde write IO are the same, also add
typedef to make code cleaner.
Yu Kuai [Fri, 29 Aug 2025 08:04:16 +0000 (16:04 +0800)]
md: add a new parameter 'offset' to md_super_write()
The parameter is always set to 0 for now, following patches will use
this helper to write llbitmap to underlying disks, allow writing
dirty sectors instead of the whole page.
Also rename md_super_write to md_write_metadata since there is nothing
super-block specific.
behind write rely on bitmap, because the number of IO are recorded in
bitmap->behind_writes, and callers rely on bitmap_wait_behind_writes()
to wait for IO to be done.
However, currently callers doesn't check if bitmap is enabeld before
calling into behind methods. Hence if behind write start without bitmap,
readers will not wait for slow write IO to be done and old data can be
read in some corner cases.
md/md-bitmap: add a new parameter 'flush' to bitmap_ops->enabled
The method is only used from raid1/raid10 IO path, to check if write
bio should be pluged, the parameter is always set to true for now,
following patch will use this helper in other context like updating
superblock.
Yu Kuai [Thu, 21 Aug 2025 06:06:12 +0000 (14:06 +0800)]
blk-mq: fix blk_mq_tags double free while nr_requests grown
In the case user trigger tags grow by queue sysfs attribute nr_requests,
hctx->sched_tags will be freed directly and replaced with a new
allocated tags, see blk_mq_tag_update_depth().
The problem is that hctx->sched_tags is from elevator->et->tags, while
et->tags is still the freed tags, hence later elevator exit will try to
free the tags again, causing kernel panic.
Fix this problem by replacing et->tags with new allocated tags as well.
Noted there are still some long term problems that will require some
refactor to be fixed thoroughly[1].
[1] https://lore.kernel.org/all/20250815080216.410665-1-yukuai1@huaweicloud.com/ Fixes: f5a6604f7a44 ("block: fix lockdep warning caused by lock dependency in elv_iosched_store") Signed-off-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Nilay Shroff <nilay@linux.ibm.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Li Nan <linan122@huawei.com> Link: https://lore.kernel.org/r/20250821060612.1729939-3-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
Yu Kuai [Thu, 21 Aug 2025 06:06:11 +0000 (14:06 +0800)]
blk-mq: fix elevator depth_updated method
Current depth_updated has some problems:
1) depth_updated() will be called for each hctx, while all elevators
will update async_depth for the disk level, this is not related to hctx;
2) In blk_mq_update_nr_requests(), if previous hctx update succeed and
this hctx update failed, q->nr_requests will not be updated, while
async_depth is already updated with new nr_reqeuests in previous
depth_updated();
3) All elevators are using q->nr_requests to calculate async_depth now,
however, q->nr_requests is still the old value when depth_updated() is
called from blk_mq_update_nr_requests();
Those problems are first from error path, then mq-deadline, and recently
for bfq and kyber, fix those problems by:
- pass in request_queue instead of hctx;
- move depth_updated() after q->nr_requests is updated in
blk_mq_update_nr_requests();
- add depth_updated() call inside init_sched() method to initialize
async_depth;
- remove init_hctx() method for mq-deadline and bfq that is useless now;
Fixes: 77f1e0a52d26 ("bfq: update internal depth state when queue depth changes") Fixes: 39823b47bbd4 ("block/mq-deadline: Fix the tag reservation code") Fixes: 42e6c6ce03fd ("lib/sbitmap: convert shallow_depth from one word to the whole sbitmap") Signed-off-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Li Nan <linan122@huawei.com> Reviewed-by: Nilay Shroff <nilay@linux.ibm.com> Link: https://lore.kernel.org/r/20250821060612.1729939-2-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
ublk_ch_uring_cmd_local() is a thin wrapper around __ublk_ch_uring_cmd()
that copies the ublksrv_io_cmd from user-mapped memory to the stack
using READ_ONCE(). This ublksrv_io_cmd is passed by pointer to
__ublk_ch_uring_cmd() and __ublk_ch_uring_cmd() is a large function
unlikely to be inlined, so __ublk_ch_uring_cmd() will have to load the
ublksrv_io_cmd fields back from the stack. Inline __ublk_ch_uring_cmd()
into ublk_ch_uring_cmd_local() and load the ublksrv_io_cmd fields into
local variables with READ_ONCE(). This allows the compiler to delay
loading the fields until they are needed and choose whether to store
them in registers or on the stack.
Merge tag 'pull-getgeo' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs into for-6.18/block
Pull struct block_device getgeo changes from Al.
"switching ->getgeo() from struct block_device to struct gendisk
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>"
* tag 'pull-getgeo' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
block: switch ->getgeo() to struct gendisk
scsi: switch ->bios_param() to passing gendisk
scsi: switch scsi_bios_ptable() and scsi_partsize() to gendisk
Qianfeng Rong [Tue, 2 Sep 2025 13:09:30 +0000 (21:09 +0800)]
block: use int to store blk_stack_limits() return value
Change the 'ret' variable in blk_stack_limits() from unsigned int to int,
as it needs to store negative value -1.
Storing the negative error codes in unsigned type, or performing equality
comparisons (e.g., ret == -1), doesn't cause an issue at runtime [1] but
can be confusing. Additionally, assigning negative error codes to unsigned
type may trigger a GCC warning when the -Wsign-conversion flag is enabled.
Use the new `NullTerminatedFormatter` to write the name of a `GenDisk` to
the name buffer. This new formatter automatically adds a trailing null
marker after the written characters, so we don't need to append that at the
call site any longer.
rust: configfs: re-export `configfs_attrs` from `configfs` module
Re-export `configfs_attrs` from `configfs` module, so that users can import
the macro from the `configfs` module rather than the root of the `kernel`
crate.
Add `NullTerminatedFormatter`, a formatter that writes a null terminated
string to an array or slice buffer. Because this type needs to manage the
trailing null marker, the existing formatters cannot be used to implement
this type.
Yu Kuai [Mon, 11 Aug 2025 06:56:28 +0000 (14:56 +0800)]
brd: use page reference to protect page lifetime
As discussed [1], hold rcu for copying data from/to page is too heavy,
it's better to protect page with rcu around for page lookup and then
grab a reference to prevent page to be freed by discard.
Li Nan [Tue, 26 Aug 2025 08:48:54 +0000 (16:48 +0800)]
blk-mq: check kobject state_in_sysfs before deleting in blk_mq_unregister_hctx
In __blk_mq_update_nr_hw_queues() the return value of
blk_mq_sysfs_register_hctxs() is not checked. If sysfs creation for hctx
fails, later changing the number of hw_queues or removing disk will
trigger the following warning:
kernfs: can not remove 'nr_tags', no directory
WARNING: CPU: 2 PID: 637 at fs/kernfs/dir.c:1707 kernfs_remove_by_name_ns+0x13f/0x160
Call Trace:
remove_files.isra.1+0x38/0xb0
sysfs_remove_group+0x4d/0x100
sysfs_remove_groups+0x31/0x60
__kobject_del+0x23/0xf0
kobject_del+0x17/0x40
blk_mq_unregister_hctx+0x5d/0x80
blk_mq_sysfs_unregister_hctxs+0x94/0xd0
blk_mq_update_nr_hw_queues+0x124/0x760
nullb_update_nr_hw_queues+0x71/0xf0 [null_blk]
nullb_device_submit_queues_store+0x92/0x120 [null_blk]
kobjct_del() was called unconditionally even if sysfs creation failed.
Fix it by checkig the kobject creation statusbefore deleting it.
Fixes: 477e19dedc9d ("blk-mq: adjust debugfs and sysfs register when updating nr_hw_queues") Signed-off-by: Li Nan <linan122@huawei.com> Reviewed-by: Yu Kuai <yukuai3@huawei.com> Link: https://lore.kernel.org/r/20250826084854.1030545-1-linan666@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
Andy Shevchenko [Mon, 25 Aug 2025 16:32:56 +0000 (18:32 +0200)]
floppy: Replace custom SZ_64K constant
There are only two headers using the K_64 custom constant. Moreover,
its usage tangles a code because the constant is defined in the C
file, while users are in the headers. Replace it with well defined
SZ_64K from sizes.h.
Bart Van Assche [Mon, 25 Aug 2025 15:14:24 +0000 (08:14 -0700)]
block: Move a misplaced comment in queue_wb_lat_store()
blk_mq_quiesce_queue() does not wait for pending I/O to finish. Freezing
a queue waits for pending I/O to finish. Hence move the comment that
refers to waiting for pending I/O above the call that freezes the
request queue. This patch moves this comment back to the position where
it was when this comment was introduced. See also commit c125311d96b1
("blk-wbt: don't maintain inflight counts if disabled").
Cc: Christoph Hellwig <hch@lst.de> Cc: Nilay Shroff <nilay@linux.ibm.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20250825151424.1653910-1-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
Keith Busch [Wed, 13 Aug 2025 15:31:53 +0000 (08:31 -0700)]
nvme-pci: convert metadata mapping to dma iter
Aligns data and metadata to the similar dma mapping scheme and removes
one more user of the scatter-gather dma mapping.
Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20250813153153.3260897-10-kbusch@meta.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
Keith Busch [Wed, 13 Aug 2025 15:31:52 +0000 (08:31 -0700)]
nvme-pci: create common sgl unmapping helper
This can be reused by metadata sgls once that starts using the blk-mq
dma api.
Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20250813153153.3260897-9-kbusch@meta.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
Keith Busch [Wed, 13 Aug 2025 15:31:51 +0000 (08:31 -0700)]
blk-integrity: use iterator for mapping sg
Modify blk_rq_map_integrity_sg to use the blk-mq mapping iterator. This
produces more efficient code and converges the integrity mapping
implementations to reduce future maintenance burdens.
The function implementation moves from blk-integrity.c to blk-mq-dma.c
in order to use the types and functions private to that file.
Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20250813153153.3260897-8-kbusch@meta.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
Keith Busch [Wed, 13 Aug 2025 15:31:50 +0000 (08:31 -0700)]
blk-mq-dma: add scatter-less integrity data DMA mapping
Similar to regular data, introduce more efficient integrity mapping
helpers that does away with the scatterlist structure. This uses the
block mapping iterator to add IOVA segments if IOMMU is enabled, or maps
directly if not. This also supports P2P segements if integrity data ever
wants to allocate that type of memory.
Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Kanchan Joshi <joshi.k@samsung.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20250813153153.3260897-7-kbusch@meta.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
Keith Busch [Wed, 13 Aug 2025 15:31:48 +0000 (08:31 -0700)]
blk-mq: remove REQ_P2PDMA flag
It's not serving any particular purpose. pci_p2pdma_state() already has
all the appropriate checks, so the config and flag checks are not
guarding anything.
Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Kanchan Joshi <joshi.k@samsung.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20250813153153.3260897-5-kbusch@meta.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
Keith Busch [Wed, 13 Aug 2025 15:31:46 +0000 (08:31 -0700)]
blk-mq-dma: provide the bio_vec array being iterated
This will make it easier to add different sources of the bvec array,
like for upcoming integrity support, rather than assume to use the bio's
bi_io_vec. It also makes iterating "special" payloads more in common
with iterating normal payloads.
Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Kanchan Joshi <joshi.k@samsung.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20250813153153.3260897-3-kbusch@meta.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
Keith Busch [Wed, 13 Aug 2025 15:31:45 +0000 (08:31 -0700)]
blk-mq-dma: create blk_map_iter type
The req_iterator happens to have a similar fields to what the dma
iterator needs, but we're not necessarily iterating a request's
bi_io_vec. Create a new type that can be amended for additional future
use.
Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Kanchan Joshi <joshi.k@samsung.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20250813153153.3260897-2-kbusch@meta.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
Linus Torvalds [Sun, 24 Aug 2025 14:13:05 +0000 (10:13 -0400)]
Merge tag 'perf_urgent_for_v6.17_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fix from Borislav Petkov:
- Fix a case where the events throttling logic operates on inactive
events
* tag 'perf_urgent_for_v6.17_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf: Avoid undefined behavior from stopping/starting inactive events
Linus Torvalds [Sun, 24 Aug 2025 13:52:28 +0000 (09:52 -0400)]
Merge tag 'x86_urgent_for_v6.17_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Borislav Petkov:
- Fix the GDS mitigation detection on some machines after the recent
attack vectors conversion
- Filter out the invalid machine reset reason value -1 when running as
a guest as in such cases the reason why the machine was rebooted does
not make a whole lot of sense
- Init the resource control machinery on Hygon hw in order to avoid a
division by zero and to actually enable the feature on hw which
supports it
* tag 'x86_urgent_for_v6.17_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/bugs: Fix GDS mitigation selecting when mitigation is off
x86/CPU/AMD: Ignore invalid reset reason value
x86/cpu/hygon: Add missing resctrl_cpu_detect() in bsp_init helper
Linus Torvalds [Sun, 24 Aug 2025 13:43:50 +0000 (09:43 -0400)]
Merge tag 'modules-6.17-rc3.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux
Pull modules fix from Daniel Gomez:
"This includes a fix part of the KSPP (Kernel Self Protection Project)
to replace the deprecated and unsafe strcpy() calls in the kernel
parameter string handler and sysfs parameters for built-in modules.
Single commit, no functional changes"
* tag 'modules-6.17-rc3.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux:
params: Replace deprecated strcpy() with strscpy() and memcpy()
Linus Torvalds [Sat, 23 Aug 2025 15:27:31 +0000 (11:27 -0400)]
Merge tag 'char-misc-6.17-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc/iio fixes from Greg KH:
"Here are a small number of char/misc/iio and other driver fixes for
6.17-rc3. Included in here are:
- IIO driver bugfixes for reported issues
- bunch of comedi driver fixes
- most core bugfix
- fpga driver bugfix
- cdx driver bugfix
All of these have been in linux-next this week with no reported
issues"
* tag 'char-misc-6.17-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
most: core: Drop device reference after usage in get_channel()
comedi: Make insn_rw_emulate_bits() do insn->n samples
comedi: Fix use of uninitialized memory in do_insn_ioctl() and do_insnlist_ioctl()
comedi: pcl726: Prevent invalid irq number
cdx: Fix off-by-one error in cdx_rpmsg_probe()
fpga: zynq_fpga: Fix the wrong usage of dma_map_sgtable()
iio: pressure: bmp280: Use IS_ERR() in bmp280_common_probe()
iio: light: as73211: Ensure buffer holes are zeroed
iio: adc: rzg2l_adc: Set driver data before enabling runtime PM
iio: adc: rzg2l: Cleanup suspend/resume path
iio: adc: ad7380: fix missing max_conversion_rate_hz on adaq4381-4
iio: adc: bd79124: Add GPIOLIB dependency
iio: imu: inv_icm42600: change invalid data error to -EBUSY
iio: adc: ad7124: fix channel lookup in syscalib functions
iio: temperature: maxim_thermocouple: use DMA-safe buffer for spi_read()
iio: adc: ad7173: prevent scan if too many setups requested
iio: proximity: isl29501: fix buffered read on big-endian systems
iio: accel: sca3300: fix uninitialized iio scan data
Linus Torvalds [Sat, 23 Aug 2025 15:21:56 +0000 (11:21 -0400)]
Merge tag 'usb-6.17-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
Pull USB fixes from Greg KH:
"Here are some small USB driver fixes for 6.17-rc3 to resolve a bunch
of reported issues. Included in here are:
- typec driver fixes
- dwc3 new device id
- dwc3 driver fixes
- new usb-storage driver quirks
- xhci driver fixes
- other tiny USB driver fixes to resolve bugs
All of these have been in linux-next this week with no reported issues"
* tag 'usb-6.17-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
usb: xhci: fix host not responding after suspend and resume
usb: xhci: Fix slot_id resource race conflict
usb: typec: fusb302: Revert incorrect threaded irq fix
USB: core: Update kerneldoc for usb_hcd_giveback_urb()
usb: typec: maxim_contaminant: re-enable cc toggle if cc is open and port is clean
usb: typec: maxim_contaminant: disable low power mode when reading comparator values
usb: dwc3: Remove WARN_ON for device endpoint command timeouts
USB: storage: Ignore driver CD mode for Realtek multi-mode Wi-Fi dongles
usb: storage: realtek_cr: Use correct byte order for bcs->Residue
usb: chipidea: imx: improve usbmisc_imx7d_pullup()
kcov, usb: Don't disable interrupts in kcov_remote_start_usb_softirq()
usb: dwc3: pci: add support for the Intel Wildcat Lake
usb: dwc3: Ignore late xferNotReady event to prevent halt timeout
USB: storage: Add unusual-devs entry for Novatek NTK96550-based camera
usb: core: hcd: fix accessing unmapped memory in SINGLE_STEP_SET_FEATURE test
usb: renesas-xhci: Fix External ROM access timeouts
usb: gadget: tegra-xudc: fix PM use count underflow
usb: quirks: Add DELAY_INIT quick for another SanDisk 3.2Gen1 Flash Drive
Linus Torvalds [Sat, 23 Aug 2025 14:11:34 +0000 (10:11 -0400)]
Merge tag 'trace-v6.17-rc2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing fixes from Steven Rostedt:
- Fix rtla and latency tooling pkg-config errors
If libtraceevent and libtracefs is installed, but their corresponding
'.pc' files are not installed, it reports that the libraries are
missing and confuses the developer. Instead, report that the
pkg-config files are missing and should be installed.
- Fix overflow bug of the parser in trace_get_user()
trace_get_user() uses the parsing functions to parse the user space
strings. If the parser fails due to incorrect processing, it doesn't
terminate the buffer with a nul byte. Add a "failed" flag to the
parser that gets set when parsing fails and is used to know if the
buffer is fine to use or not.
- Remove a semicolon that was at an end of a comment line
- Fix register_ftrace_graph() to unregister the pm notifier on error
The register_ftrace_graph() registers a pm notifier but there's an
error path that can exit the function without unregistering it. Since
the function returns an error, it will never be unregistered.
- Allocate and copy ftrace hash for reader of ftrace filter files
When the set_ftrace_filter or set_ftrace_notrace files are open for
read, an iterator is created and sets its hash pointer to the
associated hash that represents filtering or notrace filtering to it.
The issue is that the hash it points to can change while the
iteration is happening. All the locking used to access the tracer's
hashes are released which means those hashes can change or even be
freed. Using the hash pointed to by the iterator can cause UAF bugs
or similar.
Have the read of these files allocate and copy the corresponding
hashes and use that as that will keep them the same while the
iterator is open. This also simplifies the code as opening it for
write already does an allocate and copy, and now that the read is
doing the same, there's no need to check which way it was opened on
the release of the file, and the iterator hash can always be freed.
- Fix function graph to copy args into temp storage
The output of the function graph tracer shows both the entry and the
exit of a function. When the exit is right after the entry, it
combines the two events into one with the output of "function();",
instead of showing:
function() {
}
In order to do this, the iterator descriptor that reads the events
includes storage that saves the entry event while it peaks at the
next event in the ring buffer. The peek can free the entry event so
the iterator must store the information to use it after the peek.
With the addition of function graph tracer recording the args, where
the args are a dynamic array in the entry event, the temp storage
does not save them. This causes the args to be corrupted or even
cause a read of unsafe memory.
Add space to save the args in the temp storage of the iterator.
- Fix race between ftrace_dump and reading trace_pipe
ftrace_dump() is used when a crash occurs where the ftrace buffer
will be printed to the console. But it can also be triggered by
sysrq-z. If a sysrq-z is triggered while a task is reading trace_pipe
it can cause a race in the ftrace_dump() where it checks if the
buffer has content, then it checks if the next event is available,
and then prints the output (regardless if the next event was
available or not). Reading trace_pipe at the same time can cause it
to not be available, and this triggers a WARN_ON in the print. Move
the printing into the check if the next event exists or not
* tag 'trace-v6.17-rc2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
ftrace: Also allocate and copy hash for reading of filter files
ftrace: Fix potential warning in trace_printk_seq during ftrace_dump
fgraph: Copy args in intermediate storage with entry
trace/fgraph: Fix the warning caused by missing unregister notifier
ring-buffer: Remove redundant semicolons
tracing: Limit access to parser->buffer when trace_get_user failed
rtla: Check pkg-config install
tools/latency-collector: Check pkg-config install
Linus Torvalds [Sat, 23 Aug 2025 13:04:32 +0000 (09:04 -0400)]
Merge tag 'driver-core-6.17-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core
Pull driver core fixes from Danilo Krummrich:
- Fix swapped handling of lru_gen and lru_gen_full debugfs files in
vmscan
- Fix debugfs mount options (uid, gid, mode) being silently ignored
- Fix leak of devres action in the unwind path of Devres::new()
- Documentation:
- Expand and fix documentation of (outdated) Device, DeviceContext
and generic driver infrastructure
- Fix C header link of faux device abstractions
- Clarify expected interaction with the security team
- Smooth text flow in the security bug reporting process
documentation
* tag 'driver-core-6.17-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core:
Documentation: smooth the text flow in the security bug reporting process
Documentation: clarify the expected collaboration with security bugs reporters
debugfs: fix mount options not being applied
rust: devres: fix leaking call to devm_add_action()
rust: faux: fix C header link
driver: rust: expand documentation for driver infrastructure
device: rust: expand documentation for Device
device: rust: expand documentation for DeviceContext
mm/vmscan: fix inverted polarity in lru_gen_seq_show()
projects / thirdparty / kernel / stable.git / log
