Make code cleaner, there are no functional changes.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20240909134154.954924-8-yukuai1@huaweicloud.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Now that 'bfqq_already_existing' is only used in one branch, it can be
removed. There are no functional changes.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20240909134154.954924-7-yukuai1@huaweicloud.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

The local variable is used to call bfq_bfqq_resume_state() later,
since 'bfqd->lock' is held, and bfqq status will not change between
setting 'split' and calling bfq_bfqq_resume_state(), move forward
bfq_bfqq_resume_state() so that 'split' can be removed. There are no
functional chagnes.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20240909134154.954924-6-yukuai1@huaweicloud.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

It's not used, hence can be removed.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20240909134154.954924-5-yukuai1@huaweicloud.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Because bfq_put_cooperator() is always followed by
bfq_release_process_ref().
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20240909134154.954924-4-yukuai1@huaweicloud.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Original state:

        Process 1       Process 2       Process 3       Process 4
         (BIC1)          (BIC2)          (BIC3)          (BIC4)
          Λ                |               |               |
           \--------------\ \-------------\ \-------------\|
                           V               V               V
          bfqq1--------->bfqq2---------->bfqq3----------->bfqq4
    ref    0               1               2               4

After commit 0e456dba ("block, bfq: choose the last bfqq from merge
chain in bfq_setup_cooperator()"), if P1 issues a new IO:

Without the patch:

        Process 1       Process 2       Process 3       Process 4
         (BIC1)          (BIC2)          (BIC3)          (BIC4)
          Λ                |               |               |
           \------------------------------\ \-------------\|
                                           V               V
          bfqq1--------->bfqq2---------->bfqq3----------->bfqq4
    ref    0               0               2               4

bfqq3 will be used to handle IO from P1, this is not expected, IO
should be redirected to bfqq4;

With the patch:

          -------------------------------------------
          |                                         |
        Process 1       Process 2       Process 3   |   Process 4
         (BIC1)          (BIC2)          (BIC3)     |    (BIC4)
                           |               |        |      |
                            \-------------\ \-------------\|
                                           V               V
          bfqq1--------->bfqq2---------->bfqq3----------->bfqq4
    ref    0               0               2               4

IO is redirected to bfqq4, however, procress reference of bfqq3 is still
2, while there is only P2 using it.

Fix the problem by calling bfq_merge_bfqqs() for each bfqq in the merge
chain. Also change bfqq_merge_bfqqs() to return new_bfqq to simplify
code.

Fixes: 0e456dba ("block, bfq: choose the last bfqq from merge chain in bfq_setup_cooperator()")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20240909134154.954924-3-yukuai1@huaweicloud.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

After commit 42c306ed ("block, bfq: don't break merge chain in
bfq_split_bfqq()"), if the current procress is the last holder of bfqq,
the bfqq can be freed after bfq_split_bfqq(). Hence recored the bfqq and
then access bfqq->waker_bfqq may trigger UAF. What's more, the waker_bfqq
may in the merge chain of bfqq, hence just recored waker_bfqq is still
not safe.

Fix the problem by adding a helper bfq_waker_bfqq() to check if
bfqq->waker_bfqq is in the merge chain, and current procress is the only
holder.

Fixes: 42c306ed ("block, bfq: don't break merge chain in bfq_split_bfqq()")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20240909134154.954924-2-yukuai1@huaweicloud.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Currently, blk-throttle handle all IO fifo, hence if data IO is
throttled and then meta IO is dispatched, the meta IO will have to wait
for the data IO, causing priority inversion problems.

This patch support to handle metadata first and then pay debt while
throttling data.

Test script: use cgroup v1 to throttle root cgroup, then create new
dir and file while write back is throttled

test() {
  mkdir /mnt/test/xxx
  touch /mnt/test/xxx/1
  sync /mnt/test/xxx
  sync /mnt/test/xxx
}

mkfs.ext4 -F /dev/nvme0n1 -E lazy_itable_init=0,lazy_journal_init=0
mount /dev/nvme0n1 /mnt/test

echo "259:0 $((1024*1024))" > /sys/fs/cgroup/blkio/blkio.throttle.write_bps_device
dd if=/dev/zero of=/mnt/test/foo1 bs=16M count=1 conv=fdatasync status=none &
sleep 4

time test
echo "259:0 0" > /sys/fs/cgroup/blkio/blkio.throttle.write_bps_device

sleep 1
umount /dev/nvme0n1

Test result: time cost for creating new dir and file
before this patch:  14s
after this patch:   0.1s
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20240903135149.271857-3-yukuai1@huaweicloud.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

last_low_overflow_time is not used anymore after commit bf20ab53
("blk-throttle: remove CONFIG_BLK_DEV_THROTTLING_LOW").
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20240903135149.271857-2-yukuai1@huaweicloud.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

If the net_conf pointer is NULL and the code attempts to access its
fields without a check, it will lead to a null pointer dereference.
Add a NULL check before dereferencing the pointer.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 44ed167d ("drbd: rcu_read_lock() and rcu_dereference() for tconn->net_conf")
Cc: stable@vger.kernel.org
Signed-off-by: Mikhail Lobanov <m.lobanov@rosalinux.ru>
Link: https://lore.kernel.org/r/20240909133740.84297-1-m.lobanov@rosalinux.ruSigned-off-by: Jens Axboe <axboe@kernel.dk>

The single-queue optimized list flush doesn't have an unplug trace event
to pair with the plug event. Add one.

In the unlikely event an error occurs and falls back to the less
optimized plug flush path, it's possible a 2nd unplug trace event will
be logged, but it will show the remainig count that weren't previously
handled.
Signed-off-by: Keith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/r/20240906194540.3719642-1-kbusch@meta.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Since the debugfs_create_dir() never returns a null pointer, checking
the return value for a null pointer is redundant. Since
debugfs_create_file() can deal with a ERR_PTR() style pointer, drop
the check.  Since mtip_hw_debugfs_init does not pay attention to the
return value, its return type can be changed to void.
Signed-off-by: Li Zetao <lizetao1@huawei.com>
Link: https://lore.kernel.org/r/20240907034046.3595268-1-lizetao1@huawei.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Merge tag 'md-6.12-20240906' of https://git.kernel.org/pub/scm/linux/kernel/git/song/md into for-6.12/block

Pull MD updates from Song:

"This patch, by Xiao Ni, adds a sysfs entry 'new_level'."

* tag 'md-6.12-20240906' of https://git.kernel.org/pub/scm/linux/kernel/git/song/md:
  md: Add new_level sysfs interface

Pull NVMe updates from Keith:

"nvme updates for Linux 6.12

 - Asynchronous namespace scanning (Stuart)
 - TCP TLS updates (Hannes)
 - RDMA queue controller validation (Niklas)
 - Align field names to the spec (Anuj)
 - Metadata support validation (Puranjay)"

* tag 'nvme-6.12-2024-09-06' of git://git.infradead.org/nvme:
  nvme: fix metadata handling in nvme-passthrough
  nvme: rename apptag and appmask to lbat and lbatm
  nvme-rdma: send cntlid in the RDMA_CM_REQUEST Private Data
  nvme-target: do not check authentication status for admin commands twice
  nvmet-auth: allow to clear DH-HMAC-CHAP keys
  nvme-sysfs: add 'tls_keyring' attribute
  nvme-sysfs: add 'tls_configured_key' sysfs attribute
  nvme: split off TLS sysfs attributes into a separate group
  nvme: add a newline to the 'tls_key' sysfs attribute
  nvme-tcp: check for invalidated or revoked key
  nvme-tcp: sanitize TLS key handling
  nvme-keyring: restrict match length for version '1' identifiers
  nvme_core: scan namespaces asynchronously

Now reshape supports two ways: with backup file or without backup file.
For the situation without backup file, it needs to change data offset.
It doesn't need systemd service mdadm-grow-continue. So it can finish
the reshape job in one process environment. It can know the new level
from mdadm --grow command and can change to new level after reshape
finishes.

For the situation with backup file, it needs systemd service
mdadm-grow-continue to monitor reshape progress. So there are two process
envolved. One is mdadm --grow command whick kicks off reshape and wakes
up mdadm-grow-continue service. The second process is the service, which
doesn't know the new level from the first process.

In kernel space mddev->new_level is used to record the new level when
doing reshape. This patch adds a new interface to help mdadm update
new_level and sync it to metadata. Then mdadm-grow-continue can read the
right new_level.

Commit log revised by Song Liu. Please refer to the link for more details.
Signed-off-by: Xiao Ni <xni@redhat.com>
Link: https://lore.kernel.org/r/20240904235453.99120-1-xni@redhat.comSigned-off-by: Song Liu <song@kernel.org>

The zram_table_entry::flags member is of type long and uses 8 bytes on a
64bit architecture. With a PAGE_SIZE of 256KiB we have PAGE_SHIFT of 18
which in turn leads to __NR_ZRAM_PAGEFLAGS = 27. This still fits in an
ordinary integer.
By reducing the size of `flags' to four bytes, the size of the struct
goes back to 16 bytes. The padding between the lock and ac_time (if
enabled) is also gone.

Make zram_table_entry::flags an unsigned int and update the build test
to reflect the change.
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Link: https://lore.kernel.org/r/20240906141520.730009-4-bigeasy@linutronix.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

The ZRAM_LOCK was used for locking and after the addition of spinlock_t
the bit set and cleared but there no reader of it.

Remove the ZRAM_LOCK bit.
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Link: https://lore.kernel.org/r/20240906141520.730009-3-bigeasy@linutronix.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

The bit spinlock disables preemption. The spinlock_t lock becomes a sleeping
lock on PREEMPT_RT and it can not be acquired in this context. In this locked
section, zs_free() acquires a zs_pool::lock, and there is access to
zram::wb_limit_lock.

Add a spinlock_t for locking. Keep the set/ clear ZRAM_LOCK bit after
the lock has been acquired/ dropped. The size of struct zram_table_entry
increases by 4 bytes due to lock and additional 4 bytes padding with
CONFIG_ZRAM_TRACK_ENTRY_ACTIME enabled.
Signed-off-by: Mike Galbraith <umgwanakikbuti@gmail.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Link: https://lore.kernel.org/r/20240906141520.730009-2-bigeasy@linutronix.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

The version of the NBD protocol implemented by the kernel driver
currently has a 32 bit field for length values. As the NBD protocol uses
bytes as a unit of length, length values larger than 2^32 bytes cannot
be expressed.

Update the max_hw_discard_sectors field to match that.
Signed-off-by: Wouter Verhelst <w@uter.be>
Fixes: 26828324 ("nbd: use the atomic queue limits API in nbd_set_size")
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Cc: Eric Blake <eblake@redhat.Com>
Link: https://lore.kernel.org/r/20240812133032.115134-8-w@uter.beSigned-off-by: Jens Axboe <axboe@kernel.dk>

Also handle NBD_FLAG_ROTATIONAL in our debug helper function
Signed-off-by: Wouter Verhelst <w@uter.be>
Cc: Eric Blake <eblake@redhat.Com>
Link: https://lore.kernel.org/r/20240812133032.115134-6-w@uter.beSigned-off-by: Jens Axboe <axboe@kernel.dk>

The NBD protocol defines a message for zeroing out a region of an export

Add support to the kernel driver for that message.
Signed-off-by: Wouter Verhelst <w@uter.be>
Cc: Eric Blake <eblake@redhat.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20240812133032.115134-3-w@uter.beSigned-off-by: Jens Axboe <axboe@kernel.dk>

BFQ has been lacking active maintenance for approximately two years, and it
was recently transitioned to the Orphan state. However, there are still
many users, I have decided to step forward and assume the role of
maintainer to ensure continued support and development.

While I may not be the one with the most extensive knowledge of BFQ's
internals, I have been actively involved in its development since 2021.
Moreover, our team continues to rigorously test BFQ in downstream kernels,
ensuring it's stability and performance. Despite my confidence to maintain
BFQ, I believe it is prudent to classify its state as "Odd Fixes" to
accurately reflect my relatively new position as the maintainer.

By assuming this responsibility, I am committed to providing the necessary
support and addressing any issues that may arise with BFQ. As time
progresses, we will reassess the situation and determine the appropriate
state.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20240906102153.612997-1-yukuai1@huaweicloud.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Merge tag 'md-6.12-20240905' of https://git.kernel.org/pub/scm/linux/kernel/git/song/md into for-6.12/block

Pull MD fix from Song:

"This patch, from Mateusz Kusiak, improves the information reported in
/proc/mdstat."

* tag 'md-6.12-20240905' of https://git.kernel.org/pub/scm/linux/kernel/git/song/md:
  md: Report failed arrays as broken in mdstat

Depending on if array has personality, it is either reported as active or
inactive. This patch adds third status "broken" for arrays with
personality that became inoperative. The reason is end users tend to
assume that "active" indicates array is operational.

Add "broken" state for inoperative arrays with personality and refactor
the code.
Signed-off-by: Mateusz Kusiak <mateusz.kusiak@intel.com>
Link: https://lore.kernel.org/r/20240903142949.53628-1-mateusz.kusiak@intel.comSigned-off-by: Song Liu <song@kernel.org>

I independently rediscovered

	commit 22d24a54
	block: fix overflow in blk_ioctl_discard()

but for secure erase.

Same problem:

	uint64_t r[2] = {512, 18446744073709551104ULL};
	ioctl(fd, BLKSECDISCARD, r);

will enter near infinite loop inside blkdev_issue_secure_erase():

	a.out: attempt to access beyond end of device
	loop0: rw=5, sector=3399043073, nr_sectors = 1024 limit=2048
	bio_check_eod: 3286214 callbacks suppressed
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Link: https://lore.kernel.org/r/9e64057f-650a-46d1-b9f7-34af391536ef@p183Signed-off-by: Jens Axboe <axboe@kernel.dk>

The explanatory comment used `set_task_state` instead of
`set_current_state` which is the function actually used in the code.
Signed-off-by: Alvaro Parker <alparkerdf@gmail.com>
Link: https://lore.kernel.org/r/20240903172214.520086-1-alparkerdf@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Nobody is maintaining this code, and it just falls under the umbrella
of block layer code. But at least mark it as such, in case anyone wants
to care more deeply about it and assume the responsibility of doing so.
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Instead of open coding it, there are no functional changes.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20240902130329.3787024-5-yukuai1@huaweicloud.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Consider the following scenario:

    Process 1       Process 2       Process 3       Process 4
     (BIC1)          (BIC2)          (BIC3)          (BIC4)
      Λ               |               |                |
       \-------------\ \-------------\ \--------------\|
                      V               V                V
      bfqq1--------->bfqq2---------->bfqq3----------->bfqq4
ref    0              1               2                4

If Process 1 issue a new IO and bfqq2 is found, and then bfq_init_rq()
decide to spilt bfqq2 by bfq_split_bfqq(). Howerver, procress reference
of bfqq2 is 1 and bfq_split_bfqq() just clear the coop flag, which will
break the merge chain.

Expected result: caller will allocate a new bfqq for BIC1

    Process 1       Process 2       Process 3       Process 4
     (BIC1)          (BIC2)          (BIC3)          (BIC4)
                      |               |                |
                       \-------------\ \--------------\|
                                      V                V
      bfqq1--------->bfqq2---------->bfqq3----------->bfqq4
ref    0              0               1                3

Since the condition is only used for the last bfqq4 when the previous
bfqq2 and bfqq3 are already splited. Fix the problem by checking if
bfqq is the last one in the merge chain as well.

Fixes: 36eca894 ("block, bfq: add Early Queue Merge (EQM)")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20240902130329.3787024-4-yukuai1@huaweicloud.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Consider the following merge chain:

Process 1       Process 2       Process 3	Process 4
 (BIC1)          (BIC2)          (BIC3)		 (BIC4)
  Λ                |               |               |
   \--------------\ \-------------\ \-------------\|
                   V               V		   V
  bfqq1--------->bfqq2---------->bfqq3----------->bfqq4

IO from Process 1 will get bfqf2 from BIC1 first, then
bfq_setup_cooperator() will found bfqq2 already merged to bfqq3 and then
handle this IO from bfqq3. However, the merge chain can be much deeper
and bfqq3 can be merged to other bfqq as well.

Fix this problem by iterating to the last bfqq in
bfq_setup_cooperator().

Fixes: 36eca894 ("block, bfq: add Early Queue Merge (EQM)")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20240902130329.3787024-3-yukuai1@huaweicloud.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

1) initial state, three tasks:

		Process 1       Process 2	Process 3
		 (BIC1)          (BIC2)		 (BIC3)
		  |  Λ            |  Λ		  |  Λ
		  |  |            |  |		  |  |
		  V  |            V  |		  V  |
		  bfqq1           bfqq2		  bfqq3
process ref:	   1		    1		    1

2) bfqq1 merged to bfqq2:

		Process 1       Process 2	Process 3
		 (BIC1)          (BIC2)		 (BIC3)
		  |               |		  |  Λ
		  \--------------\|		  |  |
		                  V		  V  |
		  bfqq1--------->bfqq2		  bfqq3
process ref:	   0		    2		    1

3) bfqq2 merged to bfqq3:

		Process 1       Process 2	Process 3
		 (BIC1)          (BIC2)		 (BIC3)
	 here -> Λ                |		  |
		  \--------------\ \-------------\|
		                  V		  V
		  bfqq1--------->bfqq2---------->bfqq3
process ref:	   0		    1		    3

In this case, IO from Process 1 will get bfqq2 from BIC1 first, and then
get bfqq3 through merge chain, and finially handle IO by bfqq3.
Howerver, current code will think bfqq2 is owned by BIC1, like initial
state, and set bfqq2->bic to BIC1.

bfq_insert_request
-> by Process 1
 bfqq = bfq_init_rq(rq)
  bfqq = bfq_get_bfqq_handle_split
   bfqq = bic_to_bfqq
   -> get bfqq2 from BIC1
 bfqq->ref++
 rq->elv.priv[0] = bic
 rq->elv.priv[1] = bfqq
 if (bfqq_process_refs(bfqq) == 1)
  bfqq->bic = bic
  -> record BIC1 to bfqq2

  __bfq_insert_request
   new_bfqq = bfq_setup_cooperator
   -> get bfqq3 from bfqq2->new_bfqq
   bfqq_request_freed(bfqq)
   new_bfqq->ref++
   rq->elv.priv[1] = new_bfqq
   -> handle IO by bfqq3

Fix the problem by checking bfqq is from merge chain fist. And this
might fix a following problem reported by our syzkaller(unreproducible):

==================================================================
BUG: KASAN: slab-use-after-free in bfq_do_early_stable_merge block/bfq-iosched.c:5692 [inline]
BUG: KASAN: slab-use-after-free in bfq_do_or_sched_stable_merge block/bfq-iosched.c:5805 [inline]
BUG: KASAN: slab-use-after-free in bfq_get_queue+0x25b0/0x2610 block/bfq-iosched.c:5889
Write of size 1 at addr ffff888123839eb8 by task kworker/0:1H/18595

CPU: 0 PID: 18595 Comm: kworker/0:1H Tainted: G             L     6.6.0-07439-gba2303cacfda #6
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
Workqueue: kblockd blk_mq_requeue_work
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x91/0xf0 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0x10d/0x610 mm/kasan/report.c:475
 kasan_report+0x8e/0xc0 mm/kasan/report.c:588
 bfq_do_early_stable_merge block/bfq-iosched.c:5692 [inline]
 bfq_do_or_sched_stable_merge block/bfq-iosched.c:5805 [inline]
 bfq_get_queue+0x25b0/0x2610 block/bfq-iosched.c:5889
 bfq_get_bfqq_handle_split+0x169/0x5d0 block/bfq-iosched.c:6757
 bfq_init_rq block/bfq-iosched.c:6876 [inline]
 bfq_insert_request block/bfq-iosched.c:6254 [inline]
 bfq_insert_requests+0x1112/0x5cf0 block/bfq-iosched.c:6304
 blk_mq_insert_request+0x290/0x8d0 block/blk-mq.c:2593
 blk_mq_requeue_work+0x6bc/0xa70 block/blk-mq.c:1502
 process_one_work kernel/workqueue.c:2627 [inline]
 process_scheduled_works+0x432/0x13f0 kernel/workqueue.c:2700
 worker_thread+0x6f2/0x1160 kernel/workqueue.c:2781
 kthread+0x33c/0x440 kernel/kthread.c:388
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:305
 </TASK>

Allocated by task 20776:
 kasan_save_stack+0x20/0x40 mm/kasan/common.c:45
 kasan_set_track+0x25/0x30 mm/kasan/common.c:52
 __kasan_slab_alloc+0x87/0x90 mm/kasan/common.c:328
 kasan_slab_alloc include/linux/kasan.h:188 [inline]
 slab_post_alloc_hook mm/slab.h:763 [inline]
 slab_alloc_node mm/slub.c:3458 [inline]
 kmem_cache_alloc_node+0x1a4/0x6f0 mm/slub.c:3503
 ioc_create_icq block/blk-ioc.c:370 [inline]
 ioc_find_get_icq+0x180/0xaa0 block/blk-ioc.c:436
 bfq_prepare_request+0x39/0xf0 block/bfq-iosched.c:6812
 blk_mq_rq_ctx_init.isra.7+0x6ac/0xa00 block/blk-mq.c:403
 __blk_mq_alloc_requests+0xcc0/0x1070 block/blk-mq.c:517
 blk_mq_get_new_requests block/blk-mq.c:2940 [inline]
 blk_mq_submit_bio+0x624/0x27c0 block/blk-mq.c:3042
 __submit_bio+0x331/0x6f0 block/blk-core.c:624
 __submit_bio_noacct_mq block/blk-core.c:703 [inline]
 submit_bio_noacct_nocheck+0x816/0xb40 block/blk-core.c:732
 submit_bio_noacct+0x7a6/0x1b50 block/blk-core.c:826
 xlog_write_iclog+0x7d5/0xa00 fs/xfs/xfs_log.c:1958
 xlog_state_release_iclog+0x3b8/0x720 fs/xfs/xfs_log.c:619
 xlog_cil_push_work+0x19c5/0x2270 fs/xfs/xfs_log_cil.c:1330
 process_one_work kernel/workqueue.c:2627 [inline]
 process_scheduled_works+0x432/0x13f0 kernel/workqueue.c:2700
 worker_thread+0x6f2/0x1160 kernel/workqueue.c:2781
 kthread+0x33c/0x440 kernel/kthread.c:388
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:305

Freed by task 946:
 kasan_save_stack+0x20/0x40 mm/kasan/common.c:45
 kasan_set_track+0x25/0x30 mm/kasan/common.c:52
 kasan_save_free_info+0x2b/0x50 mm/kasan/generic.c:522
 ____kasan_slab_free mm/kasan/common.c:236 [inline]
 __kasan_slab_free+0x12c/0x1c0 mm/kasan/common.c:244
 kasan_slab_free include/linux/kasan.h:164 [inline]
 slab_free_hook mm/slub.c:1815 [inline]
 slab_free_freelist_hook mm/slub.c:1841 [inline]
 slab_free mm/slub.c:3786 [inline]
 kmem_cache_free+0x118/0x6f0 mm/slub.c:3808
 rcu_do_batch+0x35c/0xe30 kernel/rcu/tree.c:2189
 rcu_core+0x819/0xd90 kernel/rcu/tree.c:2462
 __do_softirq+0x1b0/0x7a2 kernel/softirq.c:553

Last potentially related work creation:
 kasan_save_stack+0x20/0x40 mm/kasan/common.c:45
 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492
 __call_rcu_common kernel/rcu/tree.c:2712 [inline]
 call_rcu+0xce/0x1020 kernel/rcu/tree.c:2826
 ioc_destroy_icq+0x54c/0x830 block/blk-ioc.c:105
 ioc_release_fn+0xf0/0x360 block/blk-ioc.c:124
 process_one_work kernel/workqueue.c:2627 [inline]
 process_scheduled_works+0x432/0x13f0 kernel/workqueue.c:2700
 worker_thread+0x6f2/0x1160 kernel/workqueue.c:2781
 kthread+0x33c/0x440 kernel/kthread.c:388
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:305

Second to last potentially related work creation:
 kasan_save_stack+0x20/0x40 mm/kasan/common.c:45
 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492
 __call_rcu_common kernel/rcu/tree.c:2712 [inline]
 call_rcu+0xce/0x1020 kernel/rcu/tree.c:2826
 ioc_destroy_icq+0x54c/0x830 block/blk-ioc.c:105
 ioc_release_fn+0xf0/0x360 block/blk-ioc.c:124
 process_one_work kernel/workqueue.c:2627 [inline]
 process_scheduled_works+0x432/0x13f0 kernel/workqueue.c:2700
 worker_thread+0x6f2/0x1160 kernel/workqueue.c:2781
 kthread+0x33c/0x440 kernel/kthread.c:388
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:305

The buggy address belongs to the object at ffff888123839d68
 which belongs to the cache bfq_io_cq of size 1360
The buggy address is located 336 bytes inside of
 freed 1360-byte region [ffff888123839d68, ffff88812383a2b8)

The buggy address belongs to the physical page:
page:ffffea00048e0e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88812383f588 pfn:0x123838
head:ffffea00048e0e00 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x17ffffc0000a40(workingset|slab|head|node=0|zone=2|lastcpupid=0x1fffff)
page_type: 0xffffffff()
raw: 0017ffffc0000a40 ffff88810588c200 ffffea00048ffa10 ffff888105889488
raw: ffff88812383f588 0000000000150006 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888123839d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888123839e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888123839e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                        ^
 ffff888123839f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888123839f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Fixes: 36eca894 ("block, bfq: add Early Queue Merge (EQM)")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20240902130329.3787024-2-yukuai1@huaweicloud.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

If request timetout is handled by nbd_requeue_cmd(), normal completion
has to be stopped for avoiding to complete this requeued request, other
use-after-free can be triggered.

Fix the race by clearing NBD_CMD_INFLIGHT in nbd_requeue_cmd(), meantime
make sure that cmd->lock is grabbed for clearing the flag and the
requeue.

Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Yu Kuai <yukuai3@huawei.com>
Fixes: 2895f183 ("nbd: don't clear 'NBD_CMD_INFLIGHT' flag if request is not completed")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20240830034145.1827742-1-ming.lei@redhat.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

On an NVMe namespace that does not support metadata, it is possible to
send an IO command with metadata through io-passthru. This allows issues
like [1] to trigger in the completion code path.
nvme_map_user_request() doesn't check if the namespace supports metadata
before sending it forward. It also allows admin commands with metadata to
be processed as it ignores metadata when bdev == NULL and may report
success.

Reject an IO command with metadata when the NVMe namespace doesn't
support it and reject an admin command if it has metadata.

[1] https://lore.kernel.org/all/mb61pcylvnym8.fsf@amazon.com/Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Puranjay Mohan <pjy@amazon.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Anuj Gupta <anuj20.g@samsung.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>

Merge tag 'md-6.12-20240829' of https://git.kernel.org/pub/scm/linux/kernel/git/song/md into for-6.12/block

Pull MD updates from Song:

"Major changes in this set are:

 1. md-bitmap refactoring, by Yu Kuai;
 2. raid5 performance optimization, by Artur Paszkiewicz;
 3. Other small fixes, by Yu Kuai and Chen Ni."

* tag 'md-6.12-20240829' of https://git.kernel.org/pub/scm/linux/kernel/git/song/md: (49 commits)
  md/raid5: rename wait_for_overlap to wait_for_reshape
  md/raid5: only add to wq if reshape is in progress
  md/raid5: use wait_on_bit() for R5_Overlap
  md: Remove flush handling
  md/md-bitmap: make in memory structure internal
  md/md-bitmap: merge md_bitmap_enabled() into bitmap_operations
  md/md-bitmap: merge md_bitmap_wait_behind_writes() into bitmap_operations
  md/md-bitmap: merge md_bitmap_free() into bitmap_operations
  md/md-bitmap: merge md_bitmap_set_pages() into struct bitmap_operations
  md/md-bitmap: merge md_bitmap_copy_from_slot() into struct bitmap_operation.
  md/md-bitmap: merge get_bitmap_from_slot() into bitmap_operations
  md/md-bitmap: merge md_bitmap_resize() into bitmap_operations
  md/md-bitmap: pass in mddev directly for md_bitmap_resize()
  md/md-bitmap: merge md_bitmap_daemon_work() into bitmap_operations
  md/md-bitmap: merge bitmap_unplug() into bitmap_operations
  md/md-bitmap: merge md_bitmap_unplug_async() into md_bitmap_unplug()
  md/md-bitmap: merge md_bitmap_sync_with_cluster() into bitmap_operations
  md/md-bitmap: merge md_bitmap_cond_end_sync() into bitmap_operations
  md/md-bitmap: merge md_bitmap_close_sync() into bitmap_operations
  md/md-bitmap: merge md_bitmap_end_sync() into bitmap_operations
  ...

From Artur:

The wait_for_overlap wait queue is currently used in two cases, which
are not really related:
 - waiting for actual overlapping bios, which uses R5_Overlap bit,
 - waiting for events related to reshape.

Handling every write request in raid5_make_request() involves adding to
and removing from this wait queue, which uses a spinlock. With fast
storage and multiple submitting threads the contention on this lock is
noticeable.

This patch series aims to resolve this by separating the two cases
mentioned above and using this wait queue only when reshape is in
progress.

The results when testing 4k random writes on raid5 with null_blk
(8 jobs, qd=64, group_thread_cnt=8):
before: 463k IOPS
after:  523k IOPS

The improvement is not huge with this series alone but it is just one of
the bottlenecks. When applied onto some other changes I'm working on, it
allowed to go from 845k IOPS to 975k IOPS on the same test.

* md-6.12-raid5-opt:
  md/raid5: rename wait_for_overlap to wait_for_reshape
  md/raid5: only add to wq if reshape is in progress
  md/raid5: use wait_on_bit() for R5_Overlap
Signed-off-by: Song Liu <song@kernel.org>

The only remaining uses of wait_for_overlap are related to reshape so
rename it accordingly.
Signed-off-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
Link: https://lore.kernel.org/r/20240827153536.6743-4-artur.paszkiewicz@intel.comSigned-off-by: Song Liu <song@kernel.org>

Now that actual overlaps are not handled on the wait_for_overlap wq
anymore, the remaining cases when we wait on this wq are limited to
reshape. If reshape is not in progress, don't add to the wq in
raid5_make_request() because add_wait_queue() / remove_wait_queue()
operations take a spinlock and cause noticeable contention when multiple
threads are submitting requests to the mddev.
Signed-off-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
Link: https://lore.kernel.org/r/20240827153536.6743-3-artur.paszkiewicz@intel.comSigned-off-by: Song Liu <song@kernel.org>

Convert uses of wait_for_overlap wait queue with R5_Overlap bit to
wait_on_bit() / wake_up_bit().
Signed-off-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
Link: https://lore.kernel.org/r/20240827153536.6743-2-artur.paszkiewicz@intel.comSigned-off-by: Song Liu <song@kernel.org>

bio_split_rw is designed to split read and write bios with a payload.
Currently it is called by __bio_split_to_limits for all operations not
explicitly list, which works because bio_may_need_split explicitly checks
for bi_vcnt == 1 and thus skips the bypass if there is no payload and
bio_for_each_bvec loop will never execute it's body if bi_size is 0.

But all this is hard to understand, fragile and wasted pointless cycles.
Switch __bio_split_to_limits to only call bio_split_rw for READ and
WRITE command and don't attempt any kind split for operation that do not
require splitting.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Tested-by: Hans Holmberg <hans.holmberg@wdc.com>
Reviewed-by: Hans Holmberg <hans.holmberg@wdc.com>
Link: https://lore.kernel.org/r/20240826173820.1690925-5-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Currently REQ_OP_ZONE_APPEND is handled by the bio_split_rw case in
__bio_split_to_limits.  This is harmful because REQ_OP_ZONE_APPEND
bios do not adhere to the soft max_limits value but instead use their
own capped version of max_hw_sectors, leading to incorrect splits that
later blow up in bio_split.

We still need the bio_split_rw logic to count nr_segs for blk-mq code,
so add a new wrapper that passes in the right limit, and turns any bio
that would need a split into an error as an additional debugging aid.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Tested-by: Hans Holmberg <hans.holmberg@wdc.com>
Reviewed-by: Hans Holmberg <hans.holmberg@wdc.com>
Link: https://lore.kernel.org/r/20240826173820.1690925-4-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>