blk_execute_rq() with polling is used in kernel code paths such as
NVMe controller connect. The aggressive spinning in blk_hctx_poll()
can prevent the completion task from getting a chance to run, causing
a lockup.
The spinning with cpu_relax() doesn't yield CPU, so need_resched()
only becomes true on timer tick. This causes unnecessary spinning
while the completion task is already waiting to run.
Before commit f22ecf9c14, the loop would exit early because
task_is_running() was always true. After that commit removed the
check, the loop now spins until need_resched().
Fix this by using BLK_POLL_ONESHOT in blk_rq_poll_completion(). This
causes blk_hctx_poll() to poll once and return immediately, letting
the outer loop's cond_resched() yield CPU so the completion task can
run.
Fixes: f22ecf9c14 ("blk-mq: delete task running check in blk_hctx_poll()")
Cc: Diangang Li <lidiangang@bytedance.com>
Cc: Fengnan Chang <changfengnan@bytedance.com>
Reported-by: Yi Zhang <yi.zhang@redhat.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Yi Zhang <yi.zhang@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Any queue_limits_start_update() call must be followed either by a
queue_limits_commit_update() call or by a queue_limits_cancel_update()
call. Make sure that the error path near the start of
disk_update_zone_resources() follows this requirement. Remove the
"goto unfreeze" statement from that error path to make the code easier
to verify.
This was detected by annotating the queue_limits_*() calls with Clang
thread-safety attributes and by building the kernel with thread-safety
checking enabled. Without this patch and with thread-safety checking
enabled, the following error is reported:
block/blk-zoned.c:2020:1: error: mutex 'disk->queue->limits_lock' is not held on every path through here [-Werror,-Wthread-safety-analysis]
2020 | }
| ^
block/blk-zoned.c:1959:8: note: mutex acquired here
1959 | lim = queue_limits_start_update(q);
| ^
Cc: Damien Le Moal <dlemoal@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Fixes: bba4322e3f ("block: freeze queue when updating zone resources")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20260114192803.4171847-3-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The auto-generated integrity buffer for writes needs to be fully
initialized before being passed to the underlying block device,
otherwise the uninitialized memory can be read back by userspace or
anyone with physical access to the storage device. If protection
information is generated, that portion of the integrity buffer is
already initialized. The integrity data is also zeroed if PI generation
is disabled via sysfs or the PI tuple size is 0. However, this misses
the case where PI is generated and the PI tuple size is nonzero, but the
metadata size is larger than the PI tuple. In this case, the remainder
("opaque") of the metadata is left uninitialized.
Generalize the BLK_INTEGRITY_CSUM_NONE check to cover any case when the
metadata is larger than just the PI tuple.
Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Fixes: c546d6f438 ("block: only zero non-PI metadata tuples in bio_integrity_prep")
Reviewed-by: Anuj Gupta <anuj20.g@samsung.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
nvme_set_app_tag() uses the app_tag value from the bio_integrity_payload
of the struct request's first bio. This assumes all the request's bios
have the same app_tag. However, it is possible for bios with different
app_tag values to be merged into a single request.
Add a check in blk_integrity_merge_{bio,rq}() to prevent the merging of
bios/requests with different app_tag values if BIP_CHECK_APPTAG is set.
Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Fixes: 3d8b5a22d4 ("block: add support to pass user meta buffer")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The unlikely() annotations on QUEUE_FLAG_QOS_ENABLED checks are
counterproductive. Writeback throttling (WBT) might be enabled by
default, mainly because CONFIG_BLK_WBT_MQ defaults to 'y'.
Branch profiling on Meta servers, which have WBT enabled, confirms 100%
misprediction rates on these checks.
Remove the unlikely() annotations to let the CPU's branch predictor
learn the actual behavior, potentially improving I/O path performance.
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The function bfq_bfqq_may_idle() was renamed as bfq_better_to_idle()
in commit 277a4a9b56 ("block, bfq: give a better name to
bfq_bfqq_may_idle"). Update the comment accordingly.
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
If an hctx has no software ctx mapped, blk_mq_map_swqueue() never
allocates tags and leaves hctx->tags NULL. The CPU hotplug offline
notifier can still run for that hctx, return early since hctx cannot
hold any requests.
Signed-off-by: Cong Zhang <cong.zhang@oss.qualcomm.com>
Fixes: bf0beec060 ("blk-mq: drain I/O when all CPUs in a hctx are offline")
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Route bfqg_stats_add_aux() time accumulation into the destination
stats object instead of the source, aligning with other stat fields.
Reviewed-by: Yu Kuai <yukuai@fnnas.com>
Signed-off-by: shechenglong <shechenglong@xfusion.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Various code assumes that the integrity interval is at least 1 sector
and evenly divides the logical block size. Add these checks to
blk_validate_integrity_limits(). This guards against block drivers that
report invalid interval_exp values.
Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The PI tuple must be contained within the metadata value, so validate
that pi_offset + pi_tuple_size <= metadata_size. This guards against
block drivers that report invalid pi_offset values.
Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
blkdev_pr_read_keys() takes num_keys from userspace and uses it to
calculate the allocation size for keys_info via struct_size(). While
there is a check for SIZE_MAX (integer overflow), there is no upper
bound validation on the allocation size itself.
A malicious or buggy userspace can pass a large num_keys value that
doesn't trigger overflow but still results in an excessive allocation
attempt, causing a warning in the page allocator when the order exceeds
MAX_PAGE_ORDER.
Fix this by introducing PR_KEYS_MAX to limit the number of keys to
a sane value. This makes the SIZE_MAX check redundant, so remove it.
Also switch to kvzalloc/kvfree to handle larger allocations gracefully.
Fixes: 22a1ffea5f ("block: add IOC_PR_READ_KEYS ioctl")
Tested-by: syzbot+660d079d90f8a1baf54d@syzkaller.appspotmail.com
Reported-by: syzbot+660d079d90f8a1baf54d@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=660d079d90f8a1baf54d
Link: https://lore.kernel.org/all/20251212013510.3576091-1-kartikey406@gmail.com/T/ [v1]
Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When wbt_enable_default() is moved out of queue freezing in elevator_change(),
it can cause the wbt inflight counter to become negative (-1), leading to hung
tasks in the writeback path. Tasks get stuck in wbt_wait() because the counter
is in an inconsistent state.
The issue occurs because wbt_enable_default() could race with IO submission,
allowing the counter to be decremented before proper initialization. This manifests
as:
rq_wait[0]:
inflight: -1
has_waiters: True
rwb_enabled() checks the state, which can be updated exactly between wbt_wait()
(rq_qos_throttle()) and wbt_track()(rq_qos_track()), then the inflight counter
will become negative.
And results in hung task warnings like:
task:kworker/u24:39 state:D stack:0 pid:14767
Call Trace:
rq_qos_wait+0xb4/0x150
wbt_wait+0xa9/0x100
__rq_qos_throttle+0x24/0x40
blk_mq_submit_bio+0x672/0x7b0
...
Fix this by:
1. Splitting wbt_enable_default() into:
- __wbt_enable_default(): Returns true if wbt_init() should be called
- wbt_enable_default(): Wrapper for existing callers (no init)
- wbt_init_enable_default(): New function that checks and inits WBT
2. Using wbt_init_enable_default() in blk_register_queue() to ensure
proper initialization during queue registration
3. Move wbt_init() out of wbt_enable_default() which is only for enabling
disabled wbt from bfq and iocost, and wbt_init() isn't needed. Then the
original lock warning can be avoided.
4. Removing the ELEVATOR_FLAG_ENABLE_WBT_ON_EXIT flag and its handling
code since it's no longer needed
This ensures WBT is properly initialized before any IO can be submitted,
preventing the counter from going negative.
Cc: Nilay Shroff <nilay@linux.ibm.com>
Cc: Yu Kuai <yukuai@fnnas.com>
Cc: Guangwu Zhang <guazhang@redhat.com>
Fixes: 78c271344b ("block: move wbt_enable_default() out of queue freezing from sched ->exit()")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Ensure the dma state is initialized when we're not using the contiguous
iova, otherwise the caller may be using a stale state from a previous
request that could use the coalesed iova allocation.
Fixes: 2f6b2565d4 ("block: accumulate memory segment gaps per bio")
Reported-by: Sebastian Ott <sebott@redhat.com>
Tested-by: Sebastian Ott <sebott@redhat.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
blk_hctx_poll() always checks if the task is running or not, and returns
1 if the task is running. This is a leftover from when polled IO was
purely for synchronous IO, and doesn't make sense anymore when polled IO
is purely asynchronous. Similarly, marking the task as TASK_RUNNING is
also superflous, as the very much has to be running to enter the
function in the first place.
It looks like there has been this judgment for historical reasons, and
in very early versions of this function the user would set the process
state to TASK_UNINTERRUPTIBLE.
Signed-off-by: Diangang Li <lidiangang@bytedance.com>
Signed-off-by: Fengnan Chang <changfengnan@bytedance.com>
[axboe: kill all remnants of task running, pointless now. massage message]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When mounting a btrfs file system on virtio-blk which supports native
Zone Append there has been a WARN triggering in btrfs' space management
code.
Further looking into btrfs' zoned statistics uncovered the filesystem
expecting the zones to be used, but the write pointers being 0:
# cat /sys/fs/btrfs/8eabd2e7-3294-4f9e-9b58-7e64135c8bf4/zoned_stats
active block-groups: 4
reclaimable: 0
unused: 0
need reclaim: false
data relocation block-group: 1342177280
active zones:
start: 1073741824, wp: 0 used: 0, reserved: 0, unusable: 0
start: 1342177280, wp: 0 used: 0, reserved: 0, unusable: 0
start: 1610612736, wp: 0 used: 16384, reserved: 0, unusable: 18446744073709535232
start: 1879048192, wp: 0 used: 131072, reserved: 0, unusable: 18446744073709420544
Looking at the blkzone report output for the zone in question
(1610612736) the write pointer on the device moved, but the filesystem
did not see a change on the write pointer:
# blkzone report -c 1 -o 0x300000 /dev/vda
start: 0x000300000, len 0x080000, cap 0x080000, wptr 0x000040 reset:0 non-seq:0, zcond: 2(oi) [type: 2(SEQ_WRITE_REQUIRED)]
The zone write pointer is 0, because btrfs is using the cached version
of blkdev_report_zones() and as virtio-blk is supporting native zone
append, but blkdev_revalidate_zones() does not initialize the zone write
plugs in this case.
Not skipping the revalidate of sequential zones in
blkdev_revalidate_zones() callchain fixes this issue.
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Fixes: a6aa36e957 ("block: Remove zone write plugs when handling native zone append writes")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
blk_mq_{add,del}_queue_tag_set() functions add and remove queues from
tagset, the functions make sure that tagset and queues are marked as
shared when two or more queues are attached to the same tagset.
Initially a tagset starts as unshared and when the number of added
queues reaches two, blk_mq_add_queue_tag_set() marks it as shared along
with all the queues attached to it. When the number of attached queues
drops to 1 blk_mq_del_queue_tag_set() need to mark both the tagset and
the remaining queues as unshared.
Both functions need to freeze current queues in tagset before setting on
unsetting BLK_MQ_F_TAG_QUEUE_SHARED flag. While doing so, both functions
hold set->tag_list_lock mutex, which makes sense as we do not want
queues to be added or deleted in the process. This used to work fine
until commit 98d81f0df7 ("nvme: use blk_mq_[un]quiesce_tagset")
made the nvme driver quiesce tagset instead of quiscing individual
queues. blk_mq_quiesce_tagset() does the job and quiesce the queues in
set->tag_list while holding set->tag_list_lock also.
This results in deadlock between two threads with these stacktraces:
__schedule+0x47c/0xbb0
? timerqueue_add+0x66/0xb0
schedule+0x1c/0xa0
schedule_preempt_disabled+0xa/0x10
__mutex_lock.constprop.0+0x271/0x600
blk_mq_quiesce_tagset+0x25/0xc0
nvme_dev_disable+0x9c/0x250
nvme_timeout+0x1fc/0x520
blk_mq_handle_expired+0x5c/0x90
bt_iter+0x7e/0x90
blk_mq_queue_tag_busy_iter+0x27e/0x550
? __blk_mq_complete_request_remote+0x10/0x10
? __blk_mq_complete_request_remote+0x10/0x10
? __call_rcu_common.constprop.0+0x1c0/0x210
blk_mq_timeout_work+0x12d/0x170
process_one_work+0x12e/0x2d0
worker_thread+0x288/0x3a0
? rescuer_thread+0x480/0x480
kthread+0xb8/0xe0
? kthread_park+0x80/0x80
ret_from_fork+0x2d/0x50
? kthread_park+0x80/0x80
ret_from_fork_asm+0x11/0x20
__schedule+0x47c/0xbb0
? xas_find+0x161/0x1a0
schedule+0x1c/0xa0
blk_mq_freeze_queue_wait+0x3d/0x70
? destroy_sched_domains_rcu+0x30/0x30
blk_mq_update_tag_set_shared+0x44/0x80
blk_mq_exit_queue+0x141/0x150
del_gendisk+0x25a/0x2d0
nvme_ns_remove+0xc9/0x170
nvme_remove_namespaces+0xc7/0x100
nvme_remove+0x62/0x150
pci_device_remove+0x23/0x60
device_release_driver_internal+0x159/0x200
unbind_store+0x99/0xa0
kernfs_fop_write_iter+0x112/0x1e0
vfs_write+0x2b1/0x3d0
ksys_write+0x4e/0xb0
do_syscall_64+0x5b/0x160
entry_SYSCALL_64_after_hwframe+0x4b/0x53
The top stacktrace is showing nvme_timeout() called to handle nvme
command timeout. timeout handler is trying to disable the controller and
as a first step, it needs to blk_mq_quiesce_tagset() to tell blk-mq not
to call queue callback handlers. The thread is stuck waiting for
set->tag_list_lock as it tries to walk the queues in set->tag_list.
The lock is held by the second thread in the bottom stack which is
waiting for one of queues to be frozen. The queue usage counter will
drop to zero after nvme_timeout() finishes, and this will not happen
because the thread will wait for this mutex forever.
Given that [un]quiescing queue is an operation that does not need to
sleep, update blk_mq_[un]quiesce_tagset() to use RCU instead of taking
set->tag_list_lock, update blk_mq_{add,del}_queue_tag_set() to use RCU
safe list operations. Also, delete INIT_LIST_HEAD(&q->tag_set_list)
in blk_mq_del_queue_tag_set() because we can not re-initialize it while
the list is being traversed under RCU. The deleted queue will not be
added/deleted to/from a tagset and it will be freed in blk_free_queue()
after the end of RCU grace period.
Signed-off-by: Mohamed Khalfella <mkhalfella@purestorage.com>
Fixes: 98d81f0df7 ("nvme: use blk_mq_[un]quiesce_tagset")
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Now that all potential callers of bio_chain_endio have been
eliminated, completely prohibit any future calls to this function.
Suggested-by: Ming Lei <ming.lei@redhat.com>
Suggested-by: Andreas Gruenbacher <agruenba@redhat.com>
Suggested-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Shida Zhang <zhangshida@kylinos.cn>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Move the fatal signal check before bio_alloc() to prevent a memory
leak when BLKDEV_ZERO_KILLABLE is set and a fatal signal is pending.
Previously, the bio was allocated before checking for a fatal signal.
If a signal was pending, the code would break out of the loop without
freeing or chaining the just-allocated bio, causing a memory leak.
This matches the pattern already used in __blkdev_issue_write_zeroes()
where the signal check precedes the allocation.
Fixes: bf86bcdb40 ("blk-lib: check for kill signal in ioctl BLKZEROOUT")
Reported-by: syzbot+527a7e48a3d3d315d862@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=527a7e48a3d3d315d862
Signed-off-by: Shaurya Rane <ssrane_b23@ee.vjti.ac.in>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Tested-by: syzbot+527a7e48a3d3d315d862@syzkaller.appspotmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Commit fe0418eb9b ("block: Prevent potential deadlocks in zone write
plug error recovery") added a WARN check in disk_put_zone_wplug() to
verify that when the last reference to a zone write plug is dropped,
this zone write plug does not have the BLK_ZONE_WPLUG_PLUGGED flag set,
that is, that it is not plugged.
However, the function disk_zone_wplug_abort(), which is called for zone
reset and zone finish operations, does not clear this flag after
emptying a zone write plug BIO list. This can result in the
disk_put_zone_wplug() warning to trigger if the user (erroneously as
that is bad pratcice) issues zone reset or zone finish operations while
the target zone still has plugged BIOs.
Modify disk_put_zone_wplug() to clear the BLK_ZONE_WPLUG_PLUGGED flag.
And while at it, also add a lockdep annotation to ensure that this
function is called with the zone write plug spinlock held.
Fixes: fe0418eb9b ("block: Prevent potential deadlocks in zone write plug error recovery")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Niklas Cassel <cassel@kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
During system suspend, wakeup capable IRQs for block device can be
delayed, which can cause blk_mq_hctx_notify_offline() to hang
indefinitely while waiting for pending request to complete.
Skip the request waiting loop and abort suspend when wakeup events are
pending to prevent the deadlock.
Fixes: bf0beec060 ("blk-mq: drain I/O when all CPUs in a hctx are offline")
Signed-off-by: Cong Zhang <cong.zhang@oss.qualcomm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add a Persistent Reservations ioctl to read the current reservation.
This calls the pr_ops->read_reservation() function that was previously
added in commit c787f1baa5 ("block: Add PR callouts for read keys and
reservation") but was only used by the in-kernel SCSI target so far.
The IOC_PR_READ_RESERVATION ioctl is necessary so that userspace
applications that rely on Persistent Reservations ioctls have a way of
inspecting the current state. Cluster managers and validation tests need
this functionality.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add a Persistent Reservations ioctl to read the list of currently
registered reservation keys. This calls the pr_ops->read_keys() function
that was previously added in commit c787f1baa5 ("block: Add PR
callouts for read keys and reservation") but was only used by the
in-kernel SCSI target so far.
The IOC_PR_READ_KEYS ioctl is necessary so that userspace applications
that rely on Persistent Reservations ioctls have a way of inspecting the
current state. Cluster managers and validation tests need this
functionality.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Since after commit 12e4e8c7ab ("io_uring/rw: enable bio caches for
IRQ rw"), bio_put is safe for task and irq context, bio_alloc_bioset is
safe for task context and no one calls in irq context, so we can enable
per cpu bio cache by default.
Benchmarked with t/io_uring and ext4+nvme:
taskset -c 6 /root/fio/t/io_uring -p0 -d128 -b4096 -s1 -c1 -F1 -B1 -R1
-X1 -n1 -P1 /mnt/testfile
base IOPS is 562K, patch IOPS is 574K. The CPU usage of bio_alloc_bioset
decrease from 1.42% to 1.22%.
The worst case is allocate bio in CPU A but free in CPU B, still use
t/io_uring and ext4+nvme:
base IOPS is 648K, patch IOPS is 647K.
Also use fio test ext4/xfs with libaio/sync/io_uring on null_blk and
nvme, no obvious performance regression.
Signed-off-by: Fengnan Chang <changfengnan@bytedance.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Use bio_alloc_bioset for passthru IO by default, so that we can enable
bio cache for irq and polled passthru IO in later.
Signed-off-by: Fengnan Chang <changfengnan@bytedance.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Merge tag 'for-6.19/block-20251201' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux
Pull block updates from Jens Axboe:
- Fix head insertion for mq-deadline, a regression from when priority
support was added
- Series simplifying and improving the ublk user copy code
- Various ublk related cleanups
- Fixup REQ_NOWAIT handling in loop/zloop, clearing NOWAIT when the
request is punted to a thread for handling
- Merge and then later revert loop dio nowait support, as it ended up
causing excessive stack usage for when the inline issue code needs to
dip back into the full file system code
- Improve auto integrity code, making it less deadlock prone
- Speedup polled IO handling, but manually managing the hctx lookups
- Fixes for blk-throttle for SSD devices
- Small series with fixes for the S390 dasd driver
- Add support for caching zones, avoiding unnecessary report zone
queries
- MD pull requests via Yu:
- fix null-ptr-dereference regression for dm-raid0
- fix IO hang for raid5 when array is broken with IO inflight
- remove legacy 1s delay to speed up system shutdown
- change maintainer's email address
- data can be lost if array is created with different lbs devices,
fix this problem and record lbs of the array in metadata
- fix rcu protection for md_thread
- fix mddev kobject lifetime regression
- enable atomic writes for md-linear
- some cleanups
- bcache updates via Coly
- remove useless discard and cache device code
- improve usage of per-cpu workqueues
- Reorganize the IO scheduler switching code, fixing some lockdep
reports as well
- Improve the block layer P2P DMA support
- Add support to the block tracing code for zoned devices
- Segment calculation improves, and memory alignment flexibility
improvements
- Set of prep and cleanups patches for ublk batching support. The
actual batching hasn't been added yet, but helps shrink down the
workload of getting that patchset ready for 6.20
- Fix for how the ps3 block driver handles segments offsets
- Improve how block plugging handles batch tag allocations
- nbd fixes for use-after-free of the configuration on device clear/put
- Set of improvements and fixes for zloop
- Add Damien as maintainer of the block zoned device code handling
- Various other fixes and cleanups
* tag 'for-6.19/block-20251201' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: (162 commits)
block/rnbd: correct all kernel-doc complaints
blk-mq: use queue_hctx in blk_mq_map_queue_type
md: remove legacy 1s delay in md_notify_reboot
md/raid5: fix IO hang when array is broken with IO inflight
md: warn about updating super block failure
md/raid0: fix NULL pointer dereference in create_strip_zones() for dm-raid
sbitmap: fix all kernel-doc warnings
ublk: add helper of __ublk_fetch()
ublk: pass const pointer to ublk_queue_is_zoned()
ublk: refactor auto buffer register in ublk_dispatch_req()
ublk: add `union ublk_io_buf` with improved naming
ublk: add parameter `struct io_uring_cmd *` to ublk_prep_auto_buf_reg()
kfifo: add kfifo_alloc_node() helper for NUMA awareness
blk-mq: fix potential uaf for 'queue_hw_ctx'
blk-mq: use array manage hctx map instead of xarray
ublk: prevent invalid access with DEBUG
s390/dasd: Use scnprintf() instead of sprintf()
s390/dasd: Move device name formatting into separate function
s390/dasd: Remove unnecessary debugfs_create() return checks
s390/dasd: Fix gendisk parent after copy pair swap
...
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Merge tag 'for-6.19/io_uring-20251201' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux
Pull io_uring updates from Jens Axboe:
- Unify how task_work cancelations are detected, placing it in the
task_work running state rather than needing to check the task state
- Series cleaning up and moving the cancelation code to where it
belongs, in cancel.c
- Cleanup of waitid and futex argument handling
- Add support for mixed sized SQEs. 6.18 added support for mixed sized
CQEs, improving flexibility and efficiency of workloads that need big
CQEs. This adds similar support for SQEs, where the occasional need
for a 128b SQE doesn't necessitate having all SQEs be 128b in size
- Introduce zcrx and SQ/CQ layout queries. The former returns what zcrx
features are available. And both return the ring size information to
help with allocation size calculation for user provided rings like
IORING_SETUP_NO_MMAP and IORING_MEM_REGION_TYPE_USER
- Zcrx updates for 6.19. It includes a bunch of small patches,
IORING_REGISTER_ZCRX_CTRL and RQ flushing and David's work on sharing
zcrx b/w multiple io_uring instances
- Series cleaning up ring initializations, notable deduplicating ring
size and offset calculations. It also moves most of the checking
before doing any allocations, making the code simpler
- Add support for getsockname and getpeername, which is mostly a
trivial hookup after a bit of refactoring on the networking side
- Various fixes and cleanups
* tag 'for-6.19/io_uring-20251201' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: (68 commits)
io_uring: Introduce getsockname io_uring cmd
socket: Split out a getsockname helper for io_uring
socket: Unify getsockname and getpeername implementation
io_uring/query: drop unused io_handle_query_entry() ctx arg
io_uring/kbuf: remove obsolete buf_nr_pages and update comments
io_uring/register: use correct location for io_rings_layout
io_uring/zcrx: share an ifq between rings
io_uring/zcrx: add io_fill_zcrx_offsets()
io_uring/zcrx: export zcrx via a file
io_uring/zcrx: move io_zcrx_scrub() and dependencies up
io_uring/zcrx: count zcrx users
io_uring/zcrx: add sync refill queue flushing
io_uring/zcrx: introduce IORING_REGISTER_ZCRX_CTRL
io_uring/zcrx: elide passing msg flags
io_uring/zcrx: use folio_nr_pages() instead of shift operation
io_uring/zcrx: convert to use netmem_desc
io_uring/query: introduce rings info query
io_uring/query: introduce zcrx query
io_uring: move cq/sq user offset init around
io_uring: pre-calculate scq layout
...
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Merge tag 'vfs-6.19-rc1.inode' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs inode updates from Christian Brauner:
"Features:
- Hide inode->i_state behind accessors. Open-coded accesses prevent
asserting they are done correctly. One obvious aspect is locking,
but significantly more can be checked. For example it can be
detected when the code is clearing flags which are already missing,
or is setting flags when it is illegal (e.g., I_FREEING when
->i_count > 0)
- Provide accessors for ->i_state, converts all filesystems using
coccinelle and manual conversions (btrfs, ceph, smb, f2fs, gfs2,
overlayfs, nilfs2, xfs), and makes plain ->i_state access fail to
compile
- Rework I_NEW handling to operate without fences, simplifying the
code after the accessor infrastructure is in place
Cleanups:
- Move wait_on_inode() from writeback.h to fs.h
- Spell out fenced ->i_state accesses with explicit smp_wmb/smp_rmb
for clarity
- Cosmetic fixes to LRU handling
- Push list presence check into inode_io_list_del()
- Touch up predicts in __d_lookup_rcu()
- ocfs2: retire ocfs2_drop_inode() and I_WILL_FREE usage
- Assert on ->i_count in iput_final()
- Assert ->i_lock held in __iget()
Fixes:
- Add missing fences to I_NEW handling"
* tag 'vfs-6.19-rc1.inode' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (22 commits)
dcache: touch up predicts in __d_lookup_rcu()
fs: push list presence check into inode_io_list_del()
fs: cosmetic fixes to lru handling
fs: rework I_NEW handling to operate without fences
fs: make plain ->i_state access fail to compile
xfs: use the new ->i_state accessors
nilfs2: use the new ->i_state accessors
overlayfs: use the new ->i_state accessors
gfs2: use the new ->i_state accessors
f2fs: use the new ->i_state accessors
smb: use the new ->i_state accessors
ceph: use the new ->i_state accessors
btrfs: use the new ->i_state accessors
Manual conversion to use ->i_state accessors of all places not covered by coccinelle
Coccinelle-based conversion to use ->i_state accessors
fs: provide accessors for ->i_state
fs: spell out fenced ->i_state accesses with explicit smp_wmb/smp_rmb
fs: move wait_on_inode() from writeback.h to fs.h
fs: add missing fences to I_NEW handling
ocfs2: retire ocfs2_drop_inode() and I_WILL_FREE usage
...
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Merge tag 'vfs-6.19-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull misc vfs updates from Christian Brauner:
"Features:
- Cheaper MAY_EXEC handling for path lookup. This elides MAY_WRITE
permission checks during path lookup and adds the
IOP_FASTPERM_MAY_EXEC flag so filesystems like btrfs can avoid
expensive permission work.
- Hide dentry_cache behind runtime const machinery.
- Add German Maglione as virtiofs co-maintainer.
Cleanups:
- Tidy up and inline step_into() and walk_component() for improved
code generation.
- Re-enable IOCB_NOWAIT writes to files. This refactors file
timestamp update logic, fixing a layering bypass in btrfs when
updating timestamps on device files and improving FMODE_NOCMTIME
handling in VFS now that nfsd started using it.
- Path lookup optimizations extracting slowpaths into dedicated
routines and adding branch prediction hints for mntput_no_expire(),
fd_install(), lookup_slow(), and various other hot paths.
- Enable clang's -fms-extensions flag, requiring a JFS rename to
avoid conflicts.
- Remove spurious exports in fs/file_attr.c.
- Stop duplicating union pipe_index declaration. This depends on the
shared kbuild branch that brings in -fms-extensions support which
is merged into this branch.
- Use MD5 library instead of crypto_shash in ecryptfs.
- Use largest_zero_folio() in iomap_dio_zero().
- Replace simple_strtol/strtoul with kstrtoint/kstrtouint in init and
initrd code.
- Various typo fixes.
Fixes:
- Fix emergency sync for btrfs. Btrfs requires an explicit sync_fs()
call with wait == 1 to commit super blocks. The emergency sync path
never passed this, leaving btrfs data uncommitted during emergency
sync.
- Use local kmap in watch_queue's post_one_notification().
- Add hint prints in sb_set_blocksize() for LBS dependency on THP"
* tag 'vfs-6.19-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (35 commits)
MAINTAINERS: add German Maglione as virtiofs co-maintainer
fs: inline step_into() and walk_component()
fs: tidy up step_into() & friends before inlining
orangefs: use inode_update_timestamps directly
btrfs: fix the comment on btrfs_update_time
btrfs: use vfs_utimes to update file timestamps
fs: export vfs_utimes
fs: lift the FMODE_NOCMTIME check into file_update_time_flags
fs: refactor file timestamp update logic
include/linux/fs.h: trivial fix: regualr -> regular
fs/splice.c: trivial fix: pipes -> pipe's
fs: mark lookup_slow() as noinline
fs: add predicts based on nd->depth
fs: move mntput_no_expire() slowpath into a dedicated routine
fs: remove spurious exports in fs/file_attr.c
watch_queue: Use local kmap in post_one_notification()
fs: touch up predicts in path lookup
fs: move fd_install() slowpath into a dedicated routine and provide commentary
fs: hide dentry_cache behind runtime const machinery
fs: touch predicts in do_dentry_open()
...
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Merge tag 'vfs-6.19-rc1.iomap' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull iomap updates from Christian Brauner:
"FUSE iomap Support for Buffered Reads:
This adds iomap support for FUSE buffered reads and readahead. This
enables granular uptodate tracking with large folios so only
non-uptodate portions need to be read. Also fixes a race condition
with large folios + writeback cache that could cause data corruption
on partial writes followed by reads.
- Refactored iomap read/readahead bio logic into helpers
- Added caller-provided callbacks for read operations
- Moved buffered IO bio logic into new file
- FUSE now uses iomap for read_folio and readahead
Zero Range Folio Batch Support:
Add folio batch support for iomap_zero_range() to handle dirty
folios over unwritten mappings. Fix raciness issues where dirty data
could be lost during zero range operations.
- filemap_get_folios_tag_range() helper for dirty folio lookup
- Optional zero range dirty folio processing
- XFS fills dirty folios on zero range of unwritten mappings
- Removed old partial EOF zeroing optimization
DIO Write Completions from Interrupt Context:
Restore pre-iomap behavior where pure overwrite completions run
inline rather than being deferred to workqueue. Reduces context
switches for high-performance workloads like ScyllaDB.
- Removed unused IOCB_DIO_CALLER_COMP code
- Error completions always run in user context (fixes zonefs)
- Reworked REQ_FUA selection logic
- Inverted IOMAP_DIO_INLINE_COMP to IOMAP_DIO_OFFLOAD_COMP
Buffered IO Cleanups:
Some performance and code clarity improvements:
- Replace manual bitmap scanning with find_next_bit()
- Simplify read skip logic for writes
- Optimize pending async writeback accounting
- Better variable naming
- Documentation for iomap_finish_folio_write() requirements
Misaligned Vectors for Zoned XFS:
Enables sub-block aligned vectors in XFS always-COW mode for zoned
devices via new IOMAP_DIO_FSBLOCK_ALIGNED flag.
Bug Fixes:
- Allocate s_dio_done_wq for async reads (fixes syzbot report after
error completion changes)
- Fix iomap_read_end() for already uptodate folios (regression fix)"
* tag 'vfs-6.19-rc1.iomap' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (40 commits)
iomap: allocate s_dio_done_wq for async reads as well
iomap: fix iomap_read_end() for already uptodate folios
iomap: invert the polarity of IOMAP_DIO_INLINE_COMP
iomap: support write completions from interrupt context
iomap: rework REQ_FUA selection
iomap: always run error completions in user context
fs, iomap: remove IOCB_DIO_CALLER_COMP
iomap: use find_next_bit() for uptodate bitmap scanning
iomap: use find_next_bit() for dirty bitmap scanning
iomap: simplify when reads can be skipped for writes
iomap: simplify ->read_folio_range() error handling for reads
iomap: optimize pending async writeback accounting
docs: document iomap writeback's iomap_finish_folio_write() requirement
iomap: account for unaligned end offsets when truncating read range
iomap: rename bytes_pending/bytes_accounted to bytes_submitted/bytes_not_submitted
xfs: support sub-block aligned vectors in always COW mode
iomap: add IOMAP_DIO_FSBLOCK_ALIGNED flag
xfs: error tag to force zeroing on debug kernels
iomap: remove old partial eof zeroing optimization
xfs: fill dirty folios on zero range of unwritten mappings
...
Some caller of blk_mq_map_queue_type now didn't grab
'q_usage_counter', such as blk_mq_cpu_mapped_to_hctx, so we need
protect 'queue_hw_ctx' through rcu.
Also checked all other functions, no more missed cases.
Fixes: 89e1fb7cef ("blk-mq: fix potential uaf for 'queue_hw_ctx'")
Reported-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Fengnan Chang <changfengnan@bytedance.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This is just apply Kuai's patch in [1] with mirror changes.
blk_mq_realloc_hw_ctxs() will free the 'queue_hw_ctx'(e.g. undate
submit_queues through configfs for null_blk), while it might still be
used from other context(e.g. switch elevator to none):
t1 t2
elevator_switch
blk_mq_unquiesce_queue
blk_mq_run_hw_queues
queue_for_each_hw_ctx
// assembly code for hctx = (q)->queue_hw_ctx[i]
mov 0x48(%rbp),%rdx -> read old queue_hw_ctx
__blk_mq_update_nr_hw_queues
blk_mq_realloc_hw_ctxs
hctxs = q->queue_hw_ctx
q->queue_hw_ctx = new_hctxs
kfree(hctxs)
movslq %ebx,%rax
mov (%rdx,%rax,8),%rdi ->uaf
This problem was found by code review, and I comfirmed that the concurrent
scenario do exist(specifically 'q->queue_hw_ctx' can be changed during
blk_mq_run_hw_queues()), however, the uaf problem hasn't been repoduced yet
without hacking the kernel.
Sicne the queue is freezed in __blk_mq_update_nr_hw_queues(), fix the
problem by protecting 'queue_hw_ctx' through rcu where it can be accessed
without grabbing 'q_usage_counter'.
[1] https://lore.kernel.org/all/20220225072053.2472431-1-yukuai3@huawei.com/
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Fengnan Chang <changfengnan@bytedance.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
After commit 4e5cc99e1e ("blk-mq: manage hctx map via xarray"), we use
an xarray instead of array to store hctx, but in poll mode, each time
in blk_mq_poll, we need use xa_load to find corresponding hctx, this
introduce some costs. In my test, xa_load may cost 3.8% cpu.
This patch revert previous change, eliminates the overhead of xa_load
and can result in a 3% performance improvement.
Signed-off-by: Fengnan Chang <changfengnan@bytedance.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
__blkdev_issue_discard() always returns 0, making the error check
in blkdev_issue_discard() dead code.
In function blkdev_issue_discard() initialize ret = 0, remove ret
assignment from __blkdev_issue_discard(), rely on bio == NULL check to
call submit_bio_wait(), preserve submit_bio_wait() error handling, and
preserve -EOPNOTSUPP to 0 mapping.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Chaitanya Kulkarni <ckulkarnilinux@gmail.com>
Reviewed-by: Anuj Gupta <anuj20.g@samsung.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This patch fixes multiple spelling mistakes in comments and documentation
in the file block/blk-core.c.
No functional changes intended.
Suggested-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: shechenglong <shechenglong@xfusion.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Since commit d1254a8749 ("block: remove support for delayed queue
registrations"), function __device_add_disk() has been replaced with
device_add_disk(), so fix up comments.
Signed-off-by: John Garry <john.g.garry@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
min_t(unsigned int, a, b) casts an 'unsigned long' to 'unsigned int'.
Use min(a, b) instead as it promotes any 'unsigned int' to 'unsigned long'
and so cannot discard significant bits.
In this case the 'unsigned long' value is small enough that the result
is ok.
(Similarly for max_t() and clamp_t().)
Detected by an extra check added to min_t().
Signed-off-by: David Laight <david.laight.linux@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
In commit 1e44bedbc9 ("block: unifying elevator change"), the
elevator_init_mq function was deleted, but its declaration in elevator.h
was overlooked. This patch fixes it.
Signed-off-by: Chengkaitao <chengkaitao@kylinos.cn>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Freezing the request queue from inside sysfs store callbacks may cause a
deadlock in combination with the dm-multipath driver and the
queue_if_no_path option. Additionally, freezing the request queue slows
down system boot on systems where sysfs attributes are set synchronously.
Fix this by removing the blk_mq_freeze_queue() / blk_mq_unfreeze_queue()
calls from the store callbacks that do not strictly need these callbacks.
Add the __data_racy annotation to request_queue.rq_timeout to suppress
KCSAN data race reports about the rq_timeout reads.
This patch may cause a small delay in applying the new settings.
For all the attributes affected by this patch, I/O will complete
correctly whether the old or the new value of the attribute is used.
This patch affects the following sysfs attributes:
* io_poll_delay
* io_timeout
* nomerges
* read_ahead_kb
* rq_affinity
Here is an example of a deadlock triggered by running test srp/002
if this patch is not applied:
task:multipathd
Call Trace:
<TASK>
__schedule+0x8c1/0x1bf0
schedule+0xdd/0x270
schedule_preempt_disabled+0x1c/0x30
__mutex_lock+0xb89/0x1650
mutex_lock_nested+0x1f/0x30
dm_table_set_restrictions+0x823/0xdf0
__bind+0x166/0x590
dm_swap_table+0x2a7/0x490
do_resume+0x1b1/0x610
dev_suspend+0x55/0x1a0
ctl_ioctl+0x3a5/0x7e0
dm_ctl_ioctl+0x12/0x20
__x64_sys_ioctl+0x127/0x1a0
x64_sys_call+0xe2b/0x17d0
do_syscall_64+0x96/0x3a0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
</TASK>
task:(udev-worker)
Call Trace:
<TASK>
__schedule+0x8c1/0x1bf0
schedule+0xdd/0x270
blk_mq_freeze_queue_wait+0xf2/0x140
blk_mq_freeze_queue_nomemsave+0x23/0x30
queue_ra_store+0x14e/0x290
queue_attr_store+0x23e/0x2c0
sysfs_kf_write+0xde/0x140
kernfs_fop_write_iter+0x3b2/0x630
vfs_write+0x4fd/0x1390
ksys_write+0xfd/0x230
__x64_sys_write+0x76/0xc0
x64_sys_call+0x276/0x17d0
do_syscall_64+0x96/0x3a0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
</TASK>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Nilay Shroff <nilay@linux.ibm.com>
Cc: Martin Wilck <mwilck@suse.com>
Cc: Benjamin Marzinski <bmarzins@redhat.com>
Cc: stable@vger.kernel.org
Fixes: af28141498 ("block: freeze the queue in queue_attr_store")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
loop devices under heavy stress-ng loop streessor can trigger many
capacity change events in a short time. Each event prints an info
message from set_capacity_and_notify(), flooding the console and
contributing to soft lockups on slow consoles.
Switch the printk in set_capacity_and_notify() to
pr_info_ratelimited() so frequent capacity changes do not spam
the log while still reporting occasional changes.
Cc: stable@vger.kernel.org
Signed-off-by: Li Chen <chenl311@chinatelecom.cn>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Merge tag 'vfs-6.18-rc7.fixes' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs
Pull vfs fixes from Christian Brauner:
- Fix unitialized variable in statmount_string()
- Fix hostfs mounting when passing host root during boot
- Fix dynamic lookup to fail on cell lookup failure
- Fix missing file type when reading bfs inodes from disk
- Enforce checking of sb_min_blocksize() calls and update all callers
accordingly
- Restore write access before closing files opened by open_exec() in
binfmt_misc
- Always freeze efivarfs during suspend/hibernate cycles
- Fix statmount()'s and listmount()'s grab_requested_mnt_ns() helper to
actually allow mount namespace file descriptor in addition to mount
namespace ids
- Fix tmpfs remount when noswap is specified
- Switch Landlock to iput_not_last() to remove false-positives from
might_sleep() annotations in iput()
- Remove dead node_to_mnt_ns() code
- Ensure that per-queue kobjects are successfully created
* tag 'vfs-6.18-rc7.fixes' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs:
landlock: fix splats from iput() after it started calling might_sleep()
fs: add iput_not_last()
shmem: fix tmpfs reconfiguration (remount) when noswap is set
fs/namespace: correctly handle errors returned by grab_requested_mnt_ns
power: always freeze efivarfs
binfmt_misc: restore write access before closing files opened by open_exec()
block: add __must_check attribute to sb_min_blocksize()
virtio-fs: fix incorrect check for fsvq->kobj
xfs: check the return value of sb_min_blocksize() in xfs_fs_fill_super
isofs: check the return value of sb_min_blocksize() in isofs_fill_super
exfat: check return value of sb_min_blocksize in exfat_read_boot_sector
vfat: fix missing sb_min_blocksize() return value checks
mnt: Remove dead code which might prevent from building
bfs: Reconstruct file type when loading from disk
afs: Fix dynamic lookup to fail on cell lookup failure
hostfs: Fix only passing host root in boot stage with new mount
fs: Fix uninitialized 'offp' in statmount_string()
throtl_slice is now a constant. Remove the variable and use the constant
directly where needed.
Cc: Yu Kuai <yukuai@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Khazhismel Kumykov <khazhy@google.com>
Reviewed-by: Yu Kuai <yukuai@fnnas.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
After the removal of CONFIG_BLK_DEV_THROTTLING_LOW, it is no longer
necessary to enable block accounting, so remove the call to
blk_stat_enable_accounting(). With that, the track_bio_latency variable
is no longer used and can be deleted from struct throtl_data. Also,
including blk-stat.h is no longer necessary.
Fixes: bf20ab538c ("blk-throttle: remove CONFIG_BLK_DEV_THROTTLING_LOW")
Cc: Yu Kuai <yukuai@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Khazhismel Kumykov <khazhy@google.com>
Reviewed-by: Yu Kuai <yukuai@fnnas.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Commit d61fcfa4bb ("blk-throttle: choose a small throtl_slice for SSD")
introduced device type specific throttle slices if BLK_DEV_THROTTLING_LOW
was enabled. Commit bf20ab538c ("blk-throttle: remove
CONFIG_BLK_DEV_THROTTLING_LOW") removed support for BLK_DEV_THROTTLING_LOW,
but left the device type specific throttle slices in place. This
effectively changed throttling behavior on systems with SSD which now use
a different and non-configurable slice time compared to non-SSD devices.
Practical impact is that throughput tests with low configured throttle
values (65536 bps) experience less than expected throughput on SSDs,
presumably due to rounding errors associated with the small throttle slice
time used for those devices. The same tests pass when setting the throttle
values to 65536 * 4 = 262144 bps.
The original code sets the throttle slice time to DFL_THROTL_SLICE_HD if
CONFIG_BLK_DEV_THROTTLING_LOW is disabled. Restore that code to fix the
problem. With that, DFL_THROTL_SLICE_SSD is no longer necessary. Revert to
the original code and re-introduce DFL_THROTL_SLICE to replace both
DFL_THROTL_SLICE_HD and DFL_THROTL_SLICE_SSD. This effectively reverts
commit d61fcfa4bb ("blk-throttle: choose a small throtl_slice for SSD").
While at it, also remove MAX_THROTL_SLICE since it is not used anymore.
Fixes: bf20ab538c ("blk-throttle: remove CONFIG_BLK_DEV_THROTTLING_LOW")
Cc: Yu Kuai <yukuai@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Khazhismel Kumykov <khazhy@google.com>
Reviewed-by: Yu Kuai <yukuai@fnnas.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
If the next discard range is contiguous with the current range being
considered, it's cheaper to expand the current range than to append an
additional bio.
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
In commit eadaa8b255 ("dma-mapping: introduce new DMA attribute to
indicate MMIO memory"), DMA_ATTR_MMIO attribute was added to describe
MMIO addresses, which require to avoid any memory cache flushing, as
an outcome of the discussion pointed in Link tag below.
In case of PCI_P2PDMA_MAP_THRU_HOST_BRIDGE transfer, blk-mq-dm logic
treated this as regular page and relied on "struct page" DMA flow.
That flow performs CPU cache flushing, which shouldn't be done here,
and doesn't set IOMMU_MMIO flag in DMA-IOMMU case.
As a solution, let's encode peer-to-peer transaction type in NVMe IOD
flags variable and provide it to blk-mq-dma API.
Link: https://lore.kernel.org/all/f912c446-1ae9-4390-9c11-00dce7bf0fd3@arm.com/
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
After introduction of dma_map_phys(), there is no need to convert
from physical address to struct page in order to map page. So let's
use it directly.
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Currently, the Kyber elevator allocates its private data dynamically in
->init_sched and frees it in ->exit_sched. However, since ->init_sched
is invoked during elevator switch after acquiring both ->freeze_lock and
->elevator_lock, it may trigger the lockdep splat [1] due to dependency
on pcpu_alloc_mutex.
To resolve this, move the elevator data allocation and deallocation
logic from ->init_sched and ->exit_sched into the newly introduced
->alloc_sched_data and ->free_sched_data methods. These callbacks are
invoked before acquiring ->freeze_lock and ->elevator_lock, ensuring
that memory allocation happens safely without introducing additional
locking dependencies.
This change breaks the dependency chain involving pcpu_alloc_mutex and
prevents the reported lockdep warning.
[1] https://lore.kernel.org/all/CAGVVp+VNW4M-5DZMNoADp6o2VKFhi7KxWpTDkcnVyjO0=-D5+A@mail.gmail.com/
Reported-by: Changhui Zhong <czhong@redhat.com>
Reported-by: Yi Zhang <yi.zhang@redhat.com>
Closes: https://lore.kernel.org/all/CAGVVp+VNW4M-5DZMNoADp6o2VKFhi7KxWpTDkcnVyjO0=-D5+A@mail.gmail.com/
Tested-by: Yi Zhang <yi.zhang@redhat.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Yu Kuai <yukuai@fnnas.com>
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Ming Lei
Bart Van Assche
Caleb Sander Mateos
Mikulas Patocka
Breno Leitao
Julia Lawall
Cong Zhang
shechenglong
Deepanshu Kartikey
Keith Busch
Fengnan Chang
Johannes Thumshirn
Mohamed Khalfella
Shida Zhang
Shaurya Rane
Damien Le Moal
Stefan Hajnoczi
Fengnan Chang
Linus Torvalds
Chaitanya Kulkarni
John Garry
David Laight
Chengkaitao
Jens Axboe
Xue He
Li Chen
Guenter Roeck
Leon Romanovsky
Nilay Shroff