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>
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>
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>
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>
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>
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>
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>
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>
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>
Just a simpler wrapper around bio_init for callers that want to
initialize a bio with inline bvecs.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull vfs fixes from Christian Brauner:
"fuse:
- Prevent opening of non-regular backing files.
Fuse doesn't support non-regular files anyway.
- Check whether copy_file_range() returns a larger size than
requested.
- Prevent overflow in copy_file_range() as fuse currently only
supports 32-bit sized copies.
- Cache the blocksize value if the server returned a new value as
inode->i_blkbits isn't modified directly anymore.
- Fix i_blkbits handling for iomap partial writes.
By default i_blkbits is set to PAGE_SIZE which causes iomap to mark
the whole folio as uptodate even on a partial write. But fuseblk
filesystems support choosing a blocksize smaller than PAGE_SIZE
risking data corruption. Simply enforce PAGE_SIZE as blocksize for
fuseblk's internal inode for now.
- Prevent out-of-bounds acces in fuse_dev_write() when the number of
bytes to be retrieved is truncated to the fc->max_pages limit.
virtiofs:
- Fix page faults for DAX page addresses.
Misc:
- Tighten file handle decoding from userns.
Check that the decoded dentry itself has a valid idmapping in the
user namespace.
- Fix mount-notify selftests.
- Fix some indentation errors.
- Add an FMODE_ flag to indicate IOCB_HAS_METADATA availability.
This will be moved to an FOP_* flag with a bit more rework needed
for that to happen not suitable for a fix.
- Don't silently ignore metadata for sync read/write.
- Don't pointlessly log warning when reading coredump sysctls"
* tag 'vfs-6.17-rc6.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
fuse: virtio_fs: fix page fault for DAX page address
selftests/fs/mount-notify: Fix compilation failure.
fhandle: use more consistent rules for decoding file handle from userns
fuse: Block access to folio overlimit
fuse: fix fuseblk i_blkbits for iomap partial writes
fuse: reflect cached blocksize if blocksize was changed
fuse: prevent overflow in copy_file_range return value
fuse: check if copy_file_range() returns larger than requested size
fuse: do not allow mapping a non-regular backing file
coredump: don't pointlessly check and spew warnings
fs: fix indentation style
block: don't silently ignore metadata for sync read/write
fs: add a FMODE_ flag to indicate IOCB_HAS_METADATA availability
Please enter a commit message to explain why this merge is necessary,
especially if it merges an updated upstream into a topic branch.
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.
Unable to handle kernel NULL pointer dereference
at virtual address 0000000000000156
...
pc : submit_bio_noacct+0x14c/0x4c8
lr : submit_bio_noacct+0x48/0x4c8
sp : ffff800087f0b690
x29: ffff800087f0b690 x28: 0000000000005f90 x27: ffff00068af393c0
x26: 0000000000080000 x25: 000000000002fbc0 x24: ffff000684ddcc70
x23: 0000000000000000 x22: 0000000000000000 x21: 0000000000000000
x20: 0000000000080000 x19: ffff000684ddcd08 x18: ffffffffffffffff
x17: 0000000000000000 x16: ffff80008132a550 x15: 0000ffff98020fff
x14: 0000000000000000 x13: 1fffe000d11d7021 x12: ffff000688eb810c
x11: ffff00077ec4bb80 x10: ffff000688dcb720 x9 : ffff80008068ef60
x8 : 00000a6fb8a86e85 x7 : 000000000000111e x6 : 0000000000000002
x5 : 0000000000000246 x4 : 0000000000015cff x3 : 0000000000394500
x2 : ffff000682e35e40 x1 : 0000000000364940 x0 : 000000000000001a
Call trace:
submit_bio_noacct+0x14c/0x4c8
verity_map+0x178/0x2c8
__map_bio+0x228/0x250
dm_submit_bio+0x1c4/0x678
__submit_bio+0x170/0x230
submit_bio_noacct_nocheck+0x16c/0x388
submit_bio_noacct+0x16c/0x4c8
submit_bio+0xb4/0x210
f2fs_submit_read_bio+0x4c/0xf0
f2fs_mpage_readpages+0x3b0/0x5f0
f2fs_readahead+0x90/0xe8
Tighten blk_throtl_activated() to also require that the throttle policy
bit is set on the queue:
return q->td != NULL &&
test_bit(blkcg_policy_throtl.plid, q->blkcg_pols);
This prevents blk_should_throtl() from accessing throttle group state
until policy data has been attached to blkgs.
Fixes: a3166c5170 ("blk-throttle: delay initialization until configuration")
Co-developed-by: Liang Jie <liangjie@lixiang.com>
Signed-off-by: Liang Jie <liangjie@lixiang.com>
Signed-off-by: Han Guangjiang <hanguangjiang@lixiang.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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>
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>
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>
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>
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>
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: f5a6604f7a ("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>
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: 77f1e0a52d ("bfq: update internal depth state when queue depth changes")
Fixes: 39823b47bb ("block/mq-deadline: Fix the tag reservation code")
Fixes: 42e6c6ce03 ("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>
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
With the introduction of clone3 in commit 7f192e3cd3 ("fork: add
clone3") the effective bit width of clone_flags on all architectures was
increased from 32-bit to 64-bit, with a new type of u64 for the flags.
However, for most consumers of clone_flags the interface was not
changed from the previous type of unsigned long.
While this works fine as long as none of the new 64-bit flag bits
(CLONE_CLEAR_SIGHAND and CLONE_INTO_CGROUP) are evaluated, this is still
undesirable in terms of the principle of least surprise.
Thus, this commit fixes all relevant interfaces of callees to
sys_clone3/copy_process (excluding the architecture-specific
copy_thread) to consistently pass clone_flags as u64, so that
no truncation to 32-bit integers occurs on 32-bit architectures.
Signed-off-by: Simon Schuster <schuster.simon@siemens-energy.com>
Link: https://lore.kernel.org/20250901-nios2-implement-clone3-v2-2-53fcf5577d57@siemens-energy.com
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>
fuse fixes for 6.17-rc5
* tag 'fuse-fixes-6.17-rc5' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: (6 commits)
fuse: Block access to folio overlimit
fuse: fix fuseblk i_blkbits for iomap partial writes
fuse: reflect cached blocksize if blocksize was changed
fuse: prevent overflow in copy_file_range return value
fuse: check if copy_file_range() returns larger than requested size
fuse: do not allow mapping a non-regular backing file
Link: https://lore.kernel.org/CAJfpeguEVMMyw_zCb+hbOuSxdE2Z3Raw=SJsq=Y56Ae6dn2W3g@mail.gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
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: 477e19dedc ("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>
If preparing a write bio fails then blk_zone_wplug_bio_work() calls
bio_endio() with zwplug->lock held. If a device mapper driver is stacked
on top of the zoned block device then this results in nested locking of
zwplug->lock. The resulting lockdep complaint is a false positive
because this is nested locking and not recursive locking. Suppress this
false positive by calling blk_zone_wplug_bio_io_error() without holding
zwplug->lock. This is safe because no code in
blk_zone_wplug_bio_io_error() depends on zwplug->lock being held. This
patch suppresses the following lockdep complaint:
WARNING: possible recursive locking detected
--------------------------------------------
kworker/3:0H/46 is trying to acquire lock:
ffffff882968b830 (&zwplug->lock){-...}-{2:2}, at: blk_zone_write_plug_bio_endio+0x64/0x1f0
but task is already holding lock:
ffffff88315bc230 (&zwplug->lock){-...}-{2:2}, at: blk_zone_wplug_bio_work+0x8c/0x48c
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&zwplug->lock);
lock(&zwplug->lock);
*** DEADLOCK ***
May be due to missing lock nesting notation
3 locks held by kworker/3:0H/46:
#0: ffffff8809486758 ((wq_completion)sdd_zwplugs){+.+.}-{0:0}, at: process_one_work+0x1bc/0x65c
#1: ffffffc085de3d70 ((work_completion)(&zwplug->bio_work)){+.+.}-{0:0}, at: process_one_work+0x1e4/0x65c
#2: ffffff88315bc230 (&zwplug->lock){-...}-{2:2}, at: blk_zone_wplug_bio_work+0x8c/0x48c
stack backtrace:
CPU: 3 UID: 0 PID: 46 Comm: kworker/3:0H Tainted: G W OE 6.12.38-android16-5-maybe-dirty-4k #1 8b362b6f76e3645a58cd27d86982bce10d150025
Tainted: [W]=WARN, [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
Hardware name: Spacecraft board based on MALIBU (DT)
Workqueue: sdd_zwplugs blk_zone_wplug_bio_work
Call trace:
dump_backtrace+0xfc/0x17c
show_stack+0x18/0x28
dump_stack_lvl+0x40/0xa0
dump_stack+0x18/0x24
print_deadlock_bug+0x38c/0x398
__lock_acquire+0x13e8/0x2e1c
lock_acquire+0x134/0x2b4
_raw_spin_lock_irqsave+0x5c/0x80
blk_zone_write_plug_bio_endio+0x64/0x1f0
bio_endio+0x9c/0x240
__dm_io_complete+0x214/0x260
clone_endio+0xe8/0x214
bio_endio+0x218/0x240
blk_zone_wplug_bio_work+0x204/0x48c
process_one_work+0x26c/0x65c
worker_thread+0x33c/0x498
kthread+0x110/0x134
ret_from_fork+0x10/0x20
Cc: stable@vger.kernel.org
Cc: Damien Le Moal <dlemoal@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Fixes: dd291d77cc ("block: Introduce zone write plugging")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20250825182720.1697203-1-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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 c125311d96
("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>
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>
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>
A recent lockdep[1] splat observed while running blktest block/005
reveals a potential deadlock caused by the cpu_hotplug_lock dependency
on ->freeze_lock. This dependency was introduced by commit 033b667a82
("block: blk-rq-qos: guard rq-qos helpers by static key").
That change added a static key to avoid fetching q->rq_qos when
neither blk-wbt nor blk-iolatency is configured. The static key
dynamically patches kernel text to a NOP when disabled, eliminating
overhead of fetching q->rq_qos in the I/O hot path. However, enabling
a static key at runtime requires acquiring both cpu_hotplug_lock and
jump_label_mutex. When this happens after the queue has already been
frozen (i.e., while holding ->freeze_lock), it creates a locking
dependency from cpu_hotplug_lock to ->freeze_lock, which leads to a
potential deadlock reported by lockdep [1].
To resolve this, replace the static key mechanism with q->queue_flags:
QUEUE_FLAG_QOS_ENABLED. This flag is evaluated in the fast path before
accessing q->rq_qos. If the flag is set, we proceed to fetch q->rq_qos;
otherwise, the access is skipped.
Since q->queue_flags is commonly accessed in IO hotpath and resides in
the first cacheline of struct request_queue, checking it imposes minimal
overhead while eliminating the deadlock risk.
This change avoids the lockdep splat without introducing performance
regressions.
[1] https://lore.kernel.org/linux-block/4fdm37so3o4xricdgfosgmohn63aa7wj3ua4e5vpihoamwg3ui@fq42f5q5t5ic/
Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Closes: https://lore.kernel.org/linux-block/4fdm37so3o4xricdgfosgmohn63aa7wj3ua4e5vpihoamwg3ui@fq42f5q5t5ic/
Fixes: 033b667a82 ("block: blk-rq-qos: guard rq-qos helpers by static key")
Tested-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20250814082612.500845-4-nilay@linux.ibm.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
rq_qos_add() increments the block_rq_qos static key when a QoS
policy is attached. When a QoS policy is removed via rq_qos_del(),
we must symmetrically decrement the static key. If this removal drops
the last QoS policy from the queue (q->rq_qos becomes NULL), the
static branch can be disabled and the jump label patched to a NOP,
avoiding overhead on the hot path.
This change ensures rq_qos_add()/rq_qos_del() keep the
block_rq_qos static key balanced and prevents leaving the branch
permanently enabled after the last policy is removed.
Fixes: 033b667a82 ("block: blk-rq-qos: guard rq-qos helpers by static key")
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20250814082612.500845-3-nilay@linux.ibm.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Commit 5989bfe6ac ("block: restore two stage elevator switch while
running nr_hw_queue update") reintroduced a lockdep warning by calling
blk_mq_freeze_queue_nomemsave() before switching the I/O scheduler.
The function blk_mq_elv_switch_none() calls elevator_change_done().
Running this while the queue is frozen causes a lockdep warning.
Fix this by reordering the operations: first, switch the I/O scheduler
to 'none', and then freeze the queue. This ensures that elevator_change_done()
is not called on an already frozen queue. And this way is safe because
elevator_set_none() does freeze queue before switching to none.
Also we still have to rely on blk_mq_elv_switch_back() for switching
back, and it has to cover unfrozen queue case.
Cc: Nilay Shroff <nilay@linux.ibm.com>
Cc: Yu Kuai <yukuai3@huawei.com>
Fixes: 5989bfe6ac ("block: restore two stage elevator switch while running nr_hw_queue update")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Link: https://lore.kernel.org/r/20250815131737.331692-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The block fops don't try to handle metadata for synchronous requests,
probably because the completion handler looks at dio->iocb which is not
valid for synchronous requests.
But silently ignoring metadata (or warning in case of
__blkdev_direct_IO_simple) is a really bad idea as that can cause
silent data corruption if a user ever shows up.
Instead simply handle metadata for synchronous requests as the completion
handler can simply check for bio_integrity() as the block layer default
integrity will already be freed at this point, and thus bio_integrity()
will only return true for user mapped integrity.
Fixes: 3d8b5a22d4 ("block: add support to pass user meta buffer")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/20250819082517.2038819-3-hch@lst.de
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
The commit 245618f8e4 ("block: protect wbt_lat_usec using
q->elevator_lock") protected wbt_enable_default() with
q->elevator_lock; however, it also placed wbt_enable_default()
before blk_queue_flag_set(QUEUE_FLAG_REGISTERED, q);, resulting
in wbt failing to be enabled.
Moreover, the protection of wbt_enable_default() by q->elevator_lock
was removed in commit 78c271344b ("block: move wbt_enable_default()
out of queue freezing from sched ->exit()"), so we can directly fix
this issue by placing wbt_enable_default() after
blk_queue_flag_set(QUEUE_FLAG_REGISTERED, q);.
Additionally, this issue also causes the inability to read the
wbt_lat_usec file, and the scenario is as follows:
root@q:/sys/block/sda/queue# cat wbt_lat_usec
cat: wbt_lat_usec: Invalid argument
root@q:/data00/sjc/linux# ls /sys/kernel/debug/block/sda/rqos
cannot access '/sys/kernel/debug/block/sda/rqos': No such file or directory
root@q:/data00/sjc/linux# find /sys -name wbt
/sys/kernel/debug/tracing/events/wbt
After testing with this patch, wbt can be enabled normally.
Signed-off-by: Julian Sun <sunjunchao@bytedance.com>
Cc: stable@vger.kernel.org
Fixes: 245618f8e4 ("block: protect wbt_lat_usec using q->elevator_lock")
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250812154257.57540-1-sunjunchao@bytedance.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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>
Device-mapper can call add_disk() multiple times for the same gendisk
due to its two-phase creation process (dm create + dm load). This leads
to kobject double initialization errors when the underlying iSCSI devices
become temporarily unavailable and then reappear.
However, if the first add_disk() call fails and is retried, the queue_kobj
gets initialized twice, causing:
kobject: kobject (ffff88810c27bb90): tried to init an initialized object,
something is seriously wrong.
Call Trace:
<TASK>
dump_stack_lvl+0x5b/0x80
kobject_init.cold+0x43/0x51
blk_register_queue+0x46/0x280
add_disk_fwnode+0xb5/0x280
dm_setup_md_queue+0x194/0x1c0
table_load+0x297/0x2d0
ctl_ioctl+0x2a2/0x480
dm_ctl_ioctl+0xe/0x20
__x64_sys_ioctl+0xc7/0x110
do_syscall_64+0x72/0x390
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Fix this by separating kobject initialization from sysfs registration:
- Initialize queue_kobj early during gendisk allocation
- add_disk() only adds the already-initialized kobject to sysfs
- del_gendisk() removes from sysfs but doesn't destroy the kobject
- Final cleanup happens when the disk is released
Fixes: 2bd85221a6 ("block: untangle request_queue refcounting from sysfs")
Reported-by: Li Lingfeng <lilingfeng3@huawei.com>
Closes: https://lore.kernel.org/all/83591d0b-2467-433c-bce0-5581298eb161@huawei.com/
Signed-off-by: Zheng Qixing <zhengqixing@huawei.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Link: https://lore.kernel.org/r/20250808053609.3237836-1-zhengqixing@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull more block updates from Jens Axboe:
- MD pull request via Yu:
- mddev null-ptr-dereference fix, by Erkun
- md-cluster fail to remove the faulty disk regression fix, by
Heming
- minor cleanup, by Li Nan and Jinchao
- mdadm lifetime regression fix reported by syzkaller, by Yu Kuai
- MD pull request via Christoph
- add support for getting the FDP featuee in fabrics passthru path
(Nitesh Shetty)
- add capability to connect to an administrative controller
(Kamaljit Singh)
- fix a leak on sgl setup error (Keith Busch)
- initialize discovery subsys after debugfs is initialized
(Mohamed Khalfella)
- fix various comment typos (Bjorn Helgaas)
- remove unneeded semicolons (Jiapeng Chong)
- nvmet debugfs ordering issue fix
- Fix UAF in the tag_set in zloop
- Ensure sbitmap shallow depth covers entire set
- Reduce lock roundtrips in io context lookup
- Move scheduler tags alloc/free out of elevator and freeze lock, to
fix some lockdep found issues
- Improve robustness of queue limits checking
- Fix a regression with IO priorities, if no io context exists
* tag 'block-6.17-20250808' of git://git.kernel.dk/linux: (26 commits)
lib/sbitmap: make sbitmap_get_shallow() internal
lib/sbitmap: convert shallow_depth from one word to the whole sbitmap
nvmet: exit debugfs after discovery subsystem exits
block, bfq: Reorder struct bfq_iocq_bfqq_data
md: make rdev_addable usable for rcu mode
md/raid1: remove struct pool_info and related code
md/raid1: change r1conf->r1bio_pool to a pointer type
block: ensure discard_granularity is zero when discard is not supported
zloop: fix KASAN use-after-free of tag set
block: Fix default IO priority if there is no IO context
nvme: fix various comment typos
nvme-auth: remove unneeded semicolon
nvme-pci: fix leak on sgl setup error
nvmet: initialize discovery subsys after debugfs is initialized
nvme: add capability to connect to an administrative controller
nvmet: add support for FDP in fabrics passthru path
md: rename recovery_cp to resync_offset
md/md-cluster: handle REMOVE message earlier
md: fix create on open mddev lifetime regression
block: fix potential deadlock while running nr_hw_queue update
...
