Commit Graph

316 Commits

Author SHA1 Message Date
Qianfeng Rong
8f3e4e87b0 block, bfq: remove redundant __GFP_NOWARN
Commit 16f5dfbc85 ("gfp: include __GFP_NOWARN in GFP_NOWAIT") made
GFP_NOWAIT implicitly include __GFP_NOWARN.

Therefore, explicit __GFP_NOWARN combined with GFP_NOWAIT (e.g.,
`GFP_NOWAIT | __GFP_NOWARN`) is now redundant.  Let's clean up these
redundant flags across subsystems.

Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Qianfeng Rong <rongqianfeng@vivo.com>
Link: https://lore.kernel.org/r/20250811081135.374315-1-rongqianfeng@vivo.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-08-11 07:59:22 -06:00
Yu Kuai
42e6c6ce03 lib/sbitmap: convert shallow_depth from one word to the whole sbitmap
Currently elevators will record internal 'async_depth' to throttle
asynchronous requests, and they both calculate shallow_dpeth based on
sb->shift, with the respect that sb->shift is the available tags in one
word.

However, sb->shift is not the availbale tags in the last word, see
__map_depth:

if (index == sb->map_nr - 1)
  return sb->depth - (index << sb->shift);

For consequence, if the last word is used, more tags can be get than
expected, for example, assume nr_requests=256 and there are four words,
in the worst case if user set nr_requests=32, then the first word is
the last word, and still use bits per word, which is 64, to calculate
async_depth is wrong.

One the ohter hand, due to cgroup qos, bfq can allow only one request
to be allocated, and set shallow_dpeth=1 will still allow the number
of words request to be allocated.

Fix this problems by using shallow_depth to the whole sbitmap instead
of per word, also change kyber, mq-deadline and bfq to follow this,
a new helper __map_depth_with_shallow() is introduced to calculate
available bits in each word.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20250807032413.1469456-2-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-08-07 06:30:17 -06:00
Nilay Shroff
49811586be block: move elevator queue allocation logic into blk_mq_init_sched
In preparation for allocating sched_tags before freezing the request
queue and acquiring ->elevator_lock, move the elevator queue allocation
logic from the elevator ops ->init_sched callback into blk_mq_init_sched.
As elevator_alloc is now only invoked from block layer core, we don't
need to export it, so unexport elevator_alloc function.

This refactoring provides a centralized location for elevator queue
initialization, which makes it easier to store pre-allocated sched_tags
in the struct elevator_queue during later changes.

Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Link: https://lore.kernel.org/r/20250730074614.2537382-2-nilay@linux.ibm.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-07-30 06:20:51 -06:00
Yu Kuai
5421681bc3 blk-ioc: don't hold queue_lock for ioc_lookup_icq()
Currently issue io can grab queue_lock three times from bfq_bio_merge(),
bfq_limit_depth() and bfq_prepare_request(), the queue_lock is not
necessary if icq is already created because both queue and ioc can't be
freed before io issuing is done, hence remove the unnecessary queue_lock
and use rcu to protect radix tree lookup.

Noted this is also a prep patch to support request batch dispatching[1].

[1] https://lore.kernel.org/all/20250722072431.610354-1-yukuai1@huaweicloud.com/

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20250729023229.2944898-1-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-07-29 06:26:34 -06:00
Ming Lei
78c271344b block: move wbt_enable_default() out of queue freezing from sched ->exit()
scheduler's ->exit() is called with queue frozen and elevator lock is held, and
wbt_enable_default() can't be called with queue frozen, otherwise the
following lockdep warning is triggered:

	#6 (&q->rq_qos_mutex){+.+.}-{4:4}:
	#5 (&eq->sysfs_lock){+.+.}-{4:4}:
	#4 (&q->elevator_lock){+.+.}-{4:4}:
	#3 (&q->q_usage_counter(io)#3){++++}-{0:0}:
	#2 (fs_reclaim){+.+.}-{0:0}:
	#1 (&sb->s_type->i_mutex_key#3){+.+.}-{4:4}:
	#0 (&q->debugfs_mutex){+.+.}-{4:4}:

Fix the issue by moving wbt_enable_default() out of bfq's exit(), and
call it from elevator_change_done().

Meantime add disk->rqos_state_mutex for covering wbt state change, which
matches the purpose more than ->elevator_lock.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20250505141805.2751237-26-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06 07:43:43 -06:00
Ming Lei
56dee46ff4 block: move ELEVATOR_FLAG_DISABLE_WBT a request queue flag
ELEVATOR_FLAG_DISABLE_WBT is only used by BFQ to disallow wbt when BFQ is
in use. The flag is set in BFQ's init(), and cleared in BFQ's exit().

Making it as request queue flag, so that we can avoid to deal with elevator
switch race. Also it isn't graceful to checking one scheduler flag in
wbt_enable_default().

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250505141805.2751237-3-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-06 07:43:42 -06:00
Nam Cao
2414f15910 block, bfq: Switch to use hrtimer_setup()
hrtimer_setup() takes the callback function pointer as argument and
initializes the timer completely.

Replace hrtimer_init() and the open coded initialization of
hrtimer::function with the new setup mechanism.

Patch was created by using Coccinelle.

Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/d0d57e1dab46b617856dfb93c721d221cc31ab0b.1738746821.git.namcao@linutronix.de
2025-02-18 10:32:33 +01:00
Linus Torvalds
1cbfb828e0 for-6.14/block-20250118
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Merge tag 'for-6.14/block-20250118' of git://git.kernel.dk/linux

Pull block updates from Jens Axboe:

 - NVMe pull requests via Keith:
      - Target support for PCI-Endpoint transport (Damien)
      - TCP IO queue spreading fixes (Sagi, Chaitanya)
      - Target handling for "limited retry" flags (Guixen)
      - Poll type fix (Yongsoo)
      - Xarray storage error handling (Keisuke)
      - Host memory buffer free size fix on error (Francis)

 - MD pull requests via Song:
      - Reintroduce md-linear (Yu Kuai)
      - md-bitmap refactor and fix (Yu Kuai)
      - Replace kmap_atomic with kmap_local_page (David Reaver)

 - Quite a few queue freeze and debugfs deadlock fixes

   Ming introduced lockdep support for this in the 6.13 kernel, and it
   has (unsurprisingly) uncovered quite a few issues

 - Use const attributes for IO schedulers

 - Remove bio ioprio wrappers

 - Fixes for stacked device atomic write support

 - Refactor queue affinity helpers, in preparation for better supporting
   isolated CPUs

 - Cleanups of loop O_DIRECT handling

 - Cleanup of BLK_MQ_F_* flags

 - Add rotational support for null_blk

 - Various fixes and cleanups

* tag 'for-6.14/block-20250118' of git://git.kernel.dk/linux: (106 commits)
  block: Don't trim an atomic write
  block: Add common atomic writes enable flag
  md/md-linear: Fix a NULL vs IS_ERR() bug in linear_add()
  block: limit disk max sectors to (LLONG_MAX >> 9)
  block: Change blk_stack_atomic_writes_limits() unit_min check
  block: Ensure start sector is aligned for stacking atomic writes
  blk-mq: Move more error handling into blk_mq_submit_bio()
  block: Reorder the request allocation code in blk_mq_submit_bio()
  nvme: fix bogus kzalloc() return check in nvme_init_effects_log()
  md/md-bitmap: move bitmap_{start, end}write to md upper layer
  md/raid5: implement pers->bitmap_sector()
  md: add a new callback pers->bitmap_sector()
  md/md-bitmap: remove the last parameter for bimtap_ops->endwrite()
  md/md-bitmap: factor behind write counters out from bitmap_{start/end}write()
  md: Replace deprecated kmap_atomic() with kmap_local_page()
  md: reintroduce md-linear
  partitions: ldm: remove the initial kernel-doc notation
  blk-cgroup: rwstat: fix kernel-doc warnings in header file
  blk-cgroup: fix kernel-doc warnings in header file
  nbd: fix partial sending
  ...
2025-01-20 19:38:46 -08:00
Yu Kuai
fcede1f0a0 block, bfq: fix waker_bfqq UAF after bfq_split_bfqq()
Our syzkaller report a following UAF for v6.6:

BUG: KASAN: slab-use-after-free in bfq_init_rq+0x175d/0x17a0 block/bfq-iosched.c:6958
Read of size 8 at addr ffff8881b57147d8 by task fsstress/232726

CPU: 2 PID: 232726 Comm: fsstress Not tainted 6.6.0-g3629d1885222 #39
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x91/0xf0 lib/dump_stack.c:106
 print_address_description.constprop.0+0x66/0x300 mm/kasan/report.c:364
 print_report+0x3e/0x70 mm/kasan/report.c:475
 kasan_report+0xb8/0xf0 mm/kasan/report.c:588
 hlist_add_head include/linux/list.h:1023 [inline]
 bfq_init_rq+0x175d/0x17a0 block/bfq-iosched.c:6958
 bfq_insert_request.isra.0+0xe8/0xa20 block/bfq-iosched.c:6271
 bfq_insert_requests+0x27f/0x390 block/bfq-iosched.c:6323
 blk_mq_insert_request+0x290/0x8f0 block/blk-mq.c:2660
 blk_mq_submit_bio+0x1021/0x15e0 block/blk-mq.c:3143
 __submit_bio+0xa0/0x6b0 block/blk-core.c:639
 __submit_bio_noacct_mq block/blk-core.c:718 [inline]
 submit_bio_noacct_nocheck+0x5b7/0x810 block/blk-core.c:747
 submit_bio_noacct+0xca0/0x1990 block/blk-core.c:847
 __ext4_read_bh fs/ext4/super.c:205 [inline]
 ext4_read_bh+0x15e/0x2e0 fs/ext4/super.c:230
 __read_extent_tree_block+0x304/0x6f0 fs/ext4/extents.c:567
 ext4_find_extent+0x479/0xd20 fs/ext4/extents.c:947
 ext4_ext_map_blocks+0x1a3/0x2680 fs/ext4/extents.c:4182
 ext4_map_blocks+0x929/0x15a0 fs/ext4/inode.c:660
 ext4_iomap_begin_report+0x298/0x480 fs/ext4/inode.c:3569
 iomap_iter+0x3dd/0x1010 fs/iomap/iter.c:91
 iomap_fiemap+0x1f4/0x360 fs/iomap/fiemap.c:80
 ext4_fiemap+0x181/0x210 fs/ext4/extents.c:5051
 ioctl_fiemap.isra.0+0x1b4/0x290 fs/ioctl.c:220
 do_vfs_ioctl+0x31c/0x11a0 fs/ioctl.c:811
 __do_sys_ioctl fs/ioctl.c:869 [inline]
 __se_sys_ioctl+0xae/0x190 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x70/0x120 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x78/0xe2

Allocated by task 232719:
 kasan_save_stack+0x22/0x50 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:768 [inline]
 slab_alloc_node mm/slub.c:3492 [inline]
 kmem_cache_alloc_node+0x1b8/0x6f0 mm/slub.c:3537
 bfq_get_queue+0x215/0x1f00 block/bfq-iosched.c:5869
 bfq_get_bfqq_handle_split+0x167/0x5f0 block/bfq-iosched.c:6776
 bfq_init_rq+0x13a4/0x17a0 block/bfq-iosched.c:6938
 bfq_insert_request.isra.0+0xe8/0xa20 block/bfq-iosched.c:6271
 bfq_insert_requests+0x27f/0x390 block/bfq-iosched.c:6323
 blk_mq_insert_request+0x290/0x8f0 block/blk-mq.c:2660
 blk_mq_submit_bio+0x1021/0x15e0 block/blk-mq.c:3143
 __submit_bio+0xa0/0x6b0 block/blk-core.c:639
 __submit_bio_noacct_mq block/blk-core.c:718 [inline]
 submit_bio_noacct_nocheck+0x5b7/0x810 block/blk-core.c:747
 submit_bio_noacct+0xca0/0x1990 block/blk-core.c:847
 __ext4_read_bh fs/ext4/super.c:205 [inline]
 ext4_read_bh_nowait+0x15a/0x240 fs/ext4/super.c:217
 ext4_read_bh_lock+0xac/0xd0 fs/ext4/super.c:242
 ext4_bread_batch+0x268/0x500 fs/ext4/inode.c:958
 __ext4_find_entry+0x448/0x10f0 fs/ext4/namei.c:1671
 ext4_lookup_entry fs/ext4/namei.c:1774 [inline]
 ext4_lookup.part.0+0x359/0x6f0 fs/ext4/namei.c:1842
 ext4_lookup+0x72/0x90 fs/ext4/namei.c:1839
 __lookup_slow+0x257/0x480 fs/namei.c:1696
 lookup_slow fs/namei.c:1713 [inline]
 walk_component+0x454/0x5c0 fs/namei.c:2004
 link_path_walk.part.0+0x773/0xda0 fs/namei.c:2331
 link_path_walk fs/namei.c:3826 [inline]
 path_openat+0x1b9/0x520 fs/namei.c:3826
 do_filp_open+0x1b7/0x400 fs/namei.c:3857
 do_sys_openat2+0x5dc/0x6e0 fs/open.c:1428
 do_sys_open fs/open.c:1443 [inline]
 __do_sys_openat fs/open.c:1459 [inline]
 __se_sys_openat fs/open.c:1454 [inline]
 __x64_sys_openat+0x148/0x200 fs/open.c:1454
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x70/0x120 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x78/0xe2

Freed by task 232726:
 kasan_save_stack+0x22/0x50 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+0x12a/0x1b0 mm/kasan/common.c:244
 kasan_slab_free include/linux/kasan.h:164 [inline]
 slab_free_hook mm/slub.c:1827 [inline]
 slab_free_freelist_hook mm/slub.c:1853 [inline]
 slab_free mm/slub.c:3820 [inline]
 kmem_cache_free+0x110/0x760 mm/slub.c:3842
 bfq_put_queue+0x6a7/0xfb0 block/bfq-iosched.c:5428
 bfq_forget_entity block/bfq-wf2q.c:634 [inline]
 bfq_put_idle_entity+0x142/0x240 block/bfq-wf2q.c:645
 bfq_forget_idle+0x189/0x1e0 block/bfq-wf2q.c:671
 bfq_update_vtime block/bfq-wf2q.c:1280 [inline]
 __bfq_lookup_next_entity block/bfq-wf2q.c:1374 [inline]
 bfq_lookup_next_entity+0x350/0x480 block/bfq-wf2q.c:1433
 bfq_update_next_in_service+0x1c0/0x4f0 block/bfq-wf2q.c:128
 bfq_deactivate_entity+0x10a/0x240 block/bfq-wf2q.c:1188
 bfq_deactivate_bfqq block/bfq-wf2q.c:1592 [inline]
 bfq_del_bfqq_busy+0x2e8/0xad0 block/bfq-wf2q.c:1659
 bfq_release_process_ref+0x1cc/0x220 block/bfq-iosched.c:3139
 bfq_split_bfqq+0x481/0xdf0 block/bfq-iosched.c:6754
 bfq_init_rq+0xf29/0x17a0 block/bfq-iosched.c:6934
 bfq_insert_request.isra.0+0xe8/0xa20 block/bfq-iosched.c:6271
 bfq_insert_requests+0x27f/0x390 block/bfq-iosched.c:6323
 blk_mq_insert_request+0x290/0x8f0 block/blk-mq.c:2660
 blk_mq_submit_bio+0x1021/0x15e0 block/blk-mq.c:3143
 __submit_bio+0xa0/0x6b0 block/blk-core.c:639
 __submit_bio_noacct_mq block/blk-core.c:718 [inline]
 submit_bio_noacct_nocheck+0x5b7/0x810 block/blk-core.c:747
 submit_bio_noacct+0xca0/0x1990 block/blk-core.c:847
 __ext4_read_bh fs/ext4/super.c:205 [inline]
 ext4_read_bh+0x15e/0x2e0 fs/ext4/super.c:230
 __read_extent_tree_block+0x304/0x6f0 fs/ext4/extents.c:567
 ext4_find_extent+0x479/0xd20 fs/ext4/extents.c:947
 ext4_ext_map_blocks+0x1a3/0x2680 fs/ext4/extents.c:4182
 ext4_map_blocks+0x929/0x15a0 fs/ext4/inode.c:660
 ext4_iomap_begin_report+0x298/0x480 fs/ext4/inode.c:3569
 iomap_iter+0x3dd/0x1010 fs/iomap/iter.c:91
 iomap_fiemap+0x1f4/0x360 fs/iomap/fiemap.c:80
 ext4_fiemap+0x181/0x210 fs/ext4/extents.c:5051
 ioctl_fiemap.isra.0+0x1b4/0x290 fs/ioctl.c:220
 do_vfs_ioctl+0x31c/0x11a0 fs/ioctl.c:811
 __do_sys_ioctl fs/ioctl.c:869 [inline]
 __se_sys_ioctl+0xae/0x190 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x70/0x120 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x78/0xe2

commit 1ba0403ac6 ("block, bfq: fix uaf for accessing waker_bfqq after
splitting") fix the problem that if waker_bfqq is in the merge chain,
and current is the only procress, waker_bfqq can be freed from
bfq_split_bfqq(). However, the case that waker_bfqq is not in the merge
chain is missed, and if the procress reference of waker_bfqq is 0,
waker_bfqq can be freed as well.

Fix the problem by checking procress reference if waker_bfqq is not in
the merge_chain.

Fixes: 1ba0403ac6 ("block, bfq: fix uaf for accessing waker_bfqq after splitting")
Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20250108084148.1549973-1-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-01-09 06:52:46 -07:00
Thomas Weißschuh
c40f9f6ac5 block, bfq: constify sysfs attributes
The elevator core now allows instances of 'struct elv_fs_entry' to be
moved into read-only memory. Make use of that to protect them against
accidental or malicious modifications.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/r/20250102-sysfs-const-attr-elevator-v1-3-9837d2058c60@weissschuh.net
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-01-02 13:20:29 -07:00
Yu Kuai
e8b8344de3 block, bfq: fix bfqq uaf in bfq_limit_depth()
Set new allocated bfqq to bic or remove freed bfqq from bic are both
protected by bfqd->lock, however bfq_limit_depth() is deferencing bfqq
from bic without the lock, this can lead to UAF if the io_context is
shared by multiple tasks.

For example, test bfq with io_uring can trigger following UAF in v6.6:

==================================================================
BUG: KASAN: slab-use-after-free in bfqq_group+0x15/0x50

Call Trace:
 <TASK>
 dump_stack_lvl+0x47/0x80
 print_address_description.constprop.0+0x66/0x300
 print_report+0x3e/0x70
 kasan_report+0xb4/0xf0
 bfqq_group+0x15/0x50
 bfqq_request_over_limit+0x130/0x9a0
 bfq_limit_depth+0x1b5/0x480
 __blk_mq_alloc_requests+0x2b5/0xa00
 blk_mq_get_new_requests+0x11d/0x1d0
 blk_mq_submit_bio+0x286/0xb00
 submit_bio_noacct_nocheck+0x331/0x400
 __block_write_full_folio+0x3d0/0x640
 writepage_cb+0x3b/0xc0
 write_cache_pages+0x254/0x6c0
 write_cache_pages+0x254/0x6c0
 do_writepages+0x192/0x310
 filemap_fdatawrite_wbc+0x95/0xc0
 __filemap_fdatawrite_range+0x99/0xd0
 filemap_write_and_wait_range.part.0+0x4d/0xa0
 blkdev_read_iter+0xef/0x1e0
 io_read+0x1b6/0x8a0
 io_issue_sqe+0x87/0x300
 io_wq_submit_work+0xeb/0x390
 io_worker_handle_work+0x24d/0x550
 io_wq_worker+0x27f/0x6c0
 ret_from_fork_asm+0x1b/0x30
 </TASK>

Allocated by task 808602:
 kasan_save_stack+0x1e/0x40
 kasan_set_track+0x21/0x30
 __kasan_slab_alloc+0x83/0x90
 kmem_cache_alloc_node+0x1b1/0x6d0
 bfq_get_queue+0x138/0xfa0
 bfq_get_bfqq_handle_split+0xe3/0x2c0
 bfq_init_rq+0x196/0xbb0
 bfq_insert_request.isra.0+0xb5/0x480
 bfq_insert_requests+0x156/0x180
 blk_mq_insert_request+0x15d/0x440
 blk_mq_submit_bio+0x8a4/0xb00
 submit_bio_noacct_nocheck+0x331/0x400
 __blkdev_direct_IO_async+0x2dd/0x330
 blkdev_write_iter+0x39a/0x450
 io_write+0x22a/0x840
 io_issue_sqe+0x87/0x300
 io_wq_submit_work+0xeb/0x390
 io_worker_handle_work+0x24d/0x550
 io_wq_worker+0x27f/0x6c0
 ret_from_fork+0x2d/0x50
 ret_from_fork_asm+0x1b/0x30

Freed by task 808589:
 kasan_save_stack+0x1e/0x40
 kasan_set_track+0x21/0x30
 kasan_save_free_info+0x27/0x40
 __kasan_slab_free+0x126/0x1b0
 kmem_cache_free+0x10c/0x750
 bfq_put_queue+0x2dd/0x770
 __bfq_insert_request.isra.0+0x155/0x7a0
 bfq_insert_request.isra.0+0x122/0x480
 bfq_insert_requests+0x156/0x180
 blk_mq_dispatch_plug_list+0x528/0x7e0
 blk_mq_flush_plug_list.part.0+0xe5/0x590
 __blk_flush_plug+0x3b/0x90
 blk_finish_plug+0x40/0x60
 do_writepages+0x19d/0x310
 filemap_fdatawrite_wbc+0x95/0xc0
 __filemap_fdatawrite_range+0x99/0xd0
 filemap_write_and_wait_range.part.0+0x4d/0xa0
 blkdev_read_iter+0xef/0x1e0
 io_read+0x1b6/0x8a0
 io_issue_sqe+0x87/0x300
 io_wq_submit_work+0xeb/0x390
 io_worker_handle_work+0x24d/0x550
 io_wq_worker+0x27f/0x6c0
 ret_from_fork+0x2d/0x50
 ret_from_fork_asm+0x1b/0x30

Fix the problem by protecting bic_to_bfqq() with bfqd->lock.

CC: Jan Kara <jack@suse.cz>
Fixes: 76f1df88bb ("bfq: Limit number of requests consumed by each cgroup")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20241129091509.2227136-1-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-29 08:42:14 -07:00
Zach Wade
cf5a60d971 Revert "block, bfq: merge bfq_release_process_ref() into bfq_put_cooperator()"
This reverts commit bc3b1e9e7c.

The bic is associated with sync_bfqq, and bfq_release_process_ref cannot
be put into bfq_put_cooperator.

kasan report:
[  400.347277] ==================================================================
[  400.347287] BUG: KASAN: slab-use-after-free in bic_set_bfqq+0x200/0x230
[  400.347420] Read of size 8 at addr ffff88881cab7d60 by task dockerd/5800
[  400.347430]
[  400.347436] CPU: 24 UID: 0 PID: 5800 Comm: dockerd Kdump: loaded Tainted: G E 6.12.0 #32
[  400.347450] Tainted: [E]=UNSIGNED_MODULE
[  400.347454] Hardware name: VMware, Inc. VMware20,1/440BX Desktop Reference Platform, BIOS VMW201.00V.20192059.B64.2207280713 07/28/2022
[  400.347460] Call Trace:
[  400.347464]  <TASK>
[  400.347468]  dump_stack_lvl+0x5d/0x80
[  400.347490]  print_report+0x174/0x505
[  400.347521]  kasan_report+0xe0/0x160
[  400.347541]  bic_set_bfqq+0x200/0x230
[  400.347549]  bfq_bic_update_cgroup+0x419/0x740
[  400.347560]  bfq_bio_merge+0x133/0x320
[  400.347584]  blk_mq_submit_bio+0x1761/0x1e20
[  400.347625]  __submit_bio+0x28b/0x7b0
[  400.347664]  submit_bio_noacct_nocheck+0x6b2/0xd30
[  400.347690]  iomap_readahead+0x50c/0x680
[  400.347731]  read_pages+0x17f/0x9c0
[  400.347785]  page_cache_ra_unbounded+0x366/0x4a0
[  400.347795]  filemap_fault+0x83d/0x2340
[  400.347819]  __xfs_filemap_fault+0x11a/0x7d0 [xfs]
[  400.349256]  __do_fault+0xf1/0x610
[  400.349270]  do_fault+0x977/0x11a0
[  400.349281]  __handle_mm_fault+0x5d1/0x850
[  400.349314]  handle_mm_fault+0x1f8/0x560
[  400.349324]  do_user_addr_fault+0x324/0x970
[  400.349337]  exc_page_fault+0x76/0xf0
[  400.349350]  asm_exc_page_fault+0x26/0x30
[  400.349360] RIP: 0033:0x55a480d77375
[  400.349384] Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 49 3b 66 10 0f 86 ae 02 00 00 55 48 89 e5 48 83 ec 58 48 8b 10 <83> 7a 10 00 0f 84 27 02 00 00 44 0f b6 42 28 44 0f b6 4a 29 41 80
[  400.349392] RSP: 002b:00007f18c37fd8b8 EFLAGS: 00010216
[  400.349401] RAX: 00007f18c37fd9d0 RBX: 0000000000000000 RCX: 0000000000000000
[  400.349407] RDX: 000055a484407d38 RSI: 000000c000e8b0c0 RDI: 0000000000000000
[  400.349412] RBP: 00007f18c37fd910 R08: 000055a484017f60 R09: 000055a484066f80
[  400.349417] R10: 0000000000194000 R11: 0000000000000005 R12: 0000000000000008
[  400.349422] R13: 0000000000000000 R14: 000000c000476a80 R15: 0000000000000000
[  400.349430]  </TASK>
[  400.349452]
[  400.349454] Allocated by task 5800:
[  400.349459]  kasan_save_stack+0x30/0x50
[  400.349469]  kasan_save_track+0x14/0x30
[  400.349475]  __kasan_slab_alloc+0x89/0x90
[  400.349482]  kmem_cache_alloc_node_noprof+0xdc/0x2a0
[  400.349492]  bfq_get_queue+0x1ef/0x1100
[  400.349502]  __bfq_get_bfqq_handle_split+0x11a/0x510
[  400.349511]  bfq_insert_requests+0xf55/0x9030
[  400.349519]  blk_mq_flush_plug_list+0x446/0x14c0
[  400.349527]  __blk_flush_plug+0x27c/0x4e0
[  400.349534]  blk_finish_plug+0x52/0xa0
[  400.349540]  _xfs_buf_ioapply+0x739/0xc30 [xfs]
[  400.350246]  __xfs_buf_submit+0x1b2/0x640 [xfs]
[  400.350967]  xfs_buf_read_map+0x306/0xa20 [xfs]
[  400.351672]  xfs_trans_read_buf_map+0x285/0x7d0 [xfs]
[  400.352386]  xfs_imap_to_bp+0x107/0x270 [xfs]
[  400.353077]  xfs_iget+0x70d/0x1eb0 [xfs]
[  400.353786]  xfs_lookup+0x2ca/0x3a0 [xfs]
[  400.354506]  xfs_vn_lookup+0x14e/0x1a0 [xfs]
[  400.355197]  __lookup_slow+0x19c/0x340
[  400.355204]  lookup_one_unlocked+0xfc/0x120
[  400.355211]  ovl_lookup_single+0x1b3/0xcf0 [overlay]
[  400.355255]  ovl_lookup_layer+0x316/0x490 [overlay]
[  400.355295]  ovl_lookup+0x844/0x1fd0 [overlay]
[  400.355351]  lookup_one_qstr_excl+0xef/0x150
[  400.355357]  do_unlinkat+0x22a/0x620
[  400.355366]  __x64_sys_unlinkat+0x109/0x1e0
[  400.355375]  do_syscall_64+0x82/0x160
[  400.355384]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[  400.355393]
[  400.355395] Freed by task 5800:
[  400.355400]  kasan_save_stack+0x30/0x50
[  400.355407]  kasan_save_track+0x14/0x30
[  400.355413]  kasan_save_free_info+0x3b/0x70
[  400.355422]  __kasan_slab_free+0x4f/0x70
[  400.355429]  kmem_cache_free+0x176/0x520
[  400.355438]  bfq_put_queue+0x67e/0x980
[  400.355447]  bfq_bic_update_cgroup+0x407/0x740
[  400.355454]  bfq_bio_merge+0x133/0x320
[  400.355460]  blk_mq_submit_bio+0x1761/0x1e20
[  400.355467]  __submit_bio+0x28b/0x7b0
[  400.355473]  submit_bio_noacct_nocheck+0x6b2/0xd30
[  400.355480]  iomap_readahead+0x50c/0x680
[  400.355490]  read_pages+0x17f/0x9c0
[  400.355498]  page_cache_ra_unbounded+0x366/0x4a0
[  400.355505]  filemap_fault+0x83d/0x2340
[  400.355514]  __xfs_filemap_fault+0x11a/0x7d0 [xfs]
[  400.356204]  __do_fault+0xf1/0x610
[  400.356213]  do_fault+0x977/0x11a0
[  400.356221]  __handle_mm_fault+0x5d1/0x850
[  400.356230]  handle_mm_fault+0x1f8/0x560
[  400.356238]  do_user_addr_fault+0x324/0x970
[  400.356248]  exc_page_fault+0x76/0xf0
[  400.356258]  asm_exc_page_fault+0x26/0x30
[  400.356266]
[  400.356269] The buggy address belongs to the object at ffff88881cab7bc0
                which belongs to the cache bfq_queue of size 576
[  400.356276] The buggy address is located 416 bytes inside of
                freed 576-byte region [ffff88881cab7bc0, ffff88881cab7e00)
[  400.356285]
[  400.356287] The buggy address belongs to the physical page:
[  400.356292] page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88881cab0b00 pfn:0x81cab0
[  400.356300] head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
[  400.356323] flags: 0x50000000000040(head|node=1|zone=2)
[  400.356331] page_type: f5(slab)
[  400.356340] raw: 0050000000000040 ffff88880a00c280 dead000000000122 0000000000000000
[  400.356347] raw: ffff88881cab0b00 00000000802e0025 00000001f5000000 0000000000000000
[  400.356354] head: 0050000000000040 ffff88880a00c280 dead000000000122 0000000000000000
[  400.356359] head: ffff88881cab0b00 00000000802e0025 00000001f5000000 0000000000000000
[  400.356365] head: 0050000000000003 ffffea002072ac01 ffffffffffffffff 0000000000000000
[  400.356370] head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
[  400.356378] page dumped because: kasan: bad access detected
[  400.356381]
[  400.356383] Memory state around the buggy address:
[  400.356387]  ffff88881cab7c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  400.356392]  ffff88881cab7c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  400.356397] >ffff88881cab7d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  400.356400]                                                        ^
[  400.356405]  ffff88881cab7d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  400.356409]  ffff88881cab7e00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  400.356413] ==================================================================

Cc: stable@vger.kernel.org
Fixes: bc3b1e9e7c ("block, bfq: merge bfq_release_process_ref() into bfq_put_cooperator()")
Signed-off-by: Zach Wade <zachwade.k@gmail.com>
Cc: Ding Hui <dinghui@sangfor.com.cn>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20241119153410.2546-1-zachwade.k@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-19 19:05:32 -07:00
Yu Kuai
a7609d2aec block, bfq: factor out a helper to split bfqq in bfq_init_rq()
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.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-09-10 16:32:09 -06:00
Yu Kuai
3c61429c29 block, bfq: remove local variable 'bfqq_already_existing' in bfq_init_rq()
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.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-09-10 16:32:09 -06:00
Yu Kuai
e61e002a67 block, bfq: remove local variable 'split' in bfq_init_rq()
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.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-09-10 16:32:09 -06:00
Yu Kuai
bc3b1e9e7c block, bfq: merge bfq_release_process_ref() into bfq_put_cooperator()
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.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-09-10 16:32:09 -06:00
Yu Kuai
73aeab3735 block, bfq: fix procress reference leakage for bfqq in merge chain
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 0e456dba86 ("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: 0e456dba86 ("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.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-09-10 16:32:09 -06:00
Yu Kuai
1ba0403ac6 block, bfq: fix uaf for accessing waker_bfqq after splitting
After commit 42c306ed72 ("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: 42c306ed72 ("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.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-09-10 16:32:09 -06:00
Yu Kuai
f45916ae60 block, bfq: use bfq_reassign_last_bfqq() in bfq_bfqq_move()
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.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-09-03 09:51:54 -06:00
Yu Kuai
42c306ed72 block, bfq: don't break merge chain in bfq_split_bfqq()
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: 36eca89483 ("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.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-09-03 09:51:54 -06:00
Yu Kuai
0e456dba86 block, bfq: choose the last bfqq from merge chain in bfq_setup_cooperator()
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: 36eca89483 ("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.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-09-03 09:51:54 -06:00
Yu Kuai
18ad4df091 block, bfq: fix possible UAF for bfqq->bic with merge chain
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: 36eca89483 ("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.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-09-03 09:51:54 -06:00
John Garry
66088084fd block: BFQ: Refactor bfq_exit_icq() to silence sparse warning
Currently building for C=1 generates the following warning:
block/bfq-iosched.c:5498:9: warning: context imbalance in 'bfq_exit_icq' - different lock contexts for basic block

Refactor bfq_exit_icq() into a core part which loops for the actuators,
and only lock calling this routine when necessary.

Signed-off-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240614090345.655716-4-john.g.garry@oracle.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-16 15:30:32 -06:00
Jens Axboe
08420cf70c block: add blk_time_get_ns() and blk_time_get() helpers
Convert any user of ktime_get_ns() to use blk_time_get_ns(), and
ktime_get() to blk_time_get(), so we have a unified API for querying the
current time in nanoseconds or as ktime.

No functional changes intended, this patch just wraps ktime_get_ns()
and ktime_get() with a block helper.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-05 10:07:22 -07:00
Linus Torvalds
ca7ce08d6a SCSI misc on 20230629
Updates to the usual drivers (ufs, pm80xx, libata-scsi, smartpqi,
 lpfc, qla2xxx).  We have a couple of major core changes impacting
 other systems: Command Duration Limits, which spills into block and
 ATA and block level Persistent Reservation Operations, which touches
 block, nvme, target and dm (both of which are added with merge commits
 containing a cover letter explaining what's going on).
 
 Signed-off-by: James E.J. Bottomley <jejb@linux.ibm.com>
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Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

Pull SCSI updates from James Bottomley:
 "Updates to the usual drivers (ufs, pm80xx, libata-scsi, smartpqi,
  lpfc, qla2xxx).

  We have a couple of major core changes impacting other systems:

   - Command Duration Limits, which spills into block and ATA

   - block level Persistent Reservation Operations, which touches block,
     nvme, target and dm

  Both of these are added with merge commits containing a cover letter
  explaining what's going on"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (187 commits)
  scsi: core: Improve warning message in scsi_device_block()
  scsi: core: Replace scsi_target_block() with scsi_block_targets()
  scsi: core: Don't wait for quiesce in scsi_device_block()
  scsi: core: Don't wait for quiesce in scsi_stop_queue()
  scsi: core: Merge scsi_internal_device_block() and device_block()
  scsi: sg: Increase number of devices
  scsi: bsg: Increase number of devices
  scsi: qla2xxx: Remove unused nvme_ls_waitq wait queue
  scsi: ufs: ufs-pci: Add support for Intel Arrow Lake
  scsi: sd: sd_zbc: Use PAGE_SECTORS_SHIFT
  scsi: ufs: wb: Add explicit flush_threshold sysfs attribute
  scsi: ufs: ufs-qcom: Switch to the new ICE API
  scsi: ufs: dt-bindings: qcom: Add ICE phandle
  scsi: ufs: ufs-mediatek: Set UFSHCD_QUIRK_MCQ_BROKEN_RTC quirk
  scsi: ufs: ufs-mediatek: Set UFSHCD_QUIRK_MCQ_BROKEN_INTR quirk
  scsi: ufs: core: Add host quirk UFSHCD_QUIRK_MCQ_BROKEN_RTC
  scsi: ufs: core: Add host quirk UFSHCD_QUIRK_MCQ_BROKEN_INTR
  scsi: ufs: core: Remove dedicated hwq for dev command
  scsi: ufs: core: mcq: Fix the incorrect OCS value for the device command
  scsi: ufs: dt-bindings: samsung,exynos: Drop unneeded quotes
  ...
2023-06-30 11:57:07 -07:00
Damien Le Moal
eca2040972 scsi: block: ioprio: Clean up interface definition
The I/O priority user interface defines the 16-bits ioprio values as the
combination of the upper 3-bits for an I/O priority class and the lower
13-bits as priority data. However, the kernel only uses the lower 3-bits of
the priority data to define priority levels for the RT and BE priority
classes. The data part of an ioprio value is completely ignored for the
IDLE and NONE classes. This is enforced by checks done in
ioprio_check_cap(), which is called for all paths that allow defining an
I/O priority for I/Os: the per-context ioprio_set() system call, aio
interface and io_uring interface.

Clarify this fact in the uapi ioprio.h header file and introduce the
IOPRIO_PRIO_LEVEL_MASK and IOPRIO_PRIO_LEVEL() macros for users to define
and get priority levels in an ioprio value. The coarser macro
IOPRIO_PRIO_DATA() is retained for backward compatibility with old
applications already using it. There is no functional change introduced
with this.

In-kernel users of the IOPRIO_PRIO_DATA() macro which are explicitly
handling I/O priority data as a priority level are modified to use the new
IOPRIO_PRIO_LEVEL() macro without any functional change. Since f2fs is the
only user of this macro not explicitly using that value as a priority
level, it is left unchanged.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Link: https://lore.kernel.org/r/20230511011356.227789-2-nks@flawful.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2023-05-22 17:05:18 -04:00
Bart Van Assche
f80dd11dd1 block: BFQ: Move an invariant check
Check bfqq->dispatched for each BFQ queue instead of checking it for an
invalid bfqq pointer.

Fixes: 3e49c1e4a6 ("block: BFQ: Add several invariant checks")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230519220347.3643295-1-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-05-19 19:59:52 -06:00
Bart Van Assche
3e49c1e4a6 block: BFQ: Add several invariant checks
If anything goes wrong with the counters that track the number of
requests, I/O locks up. Make such scenarios easier to debug by adding
invariant checks for the request counters. Additionally, check that
BFQ queues are empty before these are freed.

Cc: Jan Kara <jack@suse.cz>
Cc: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230516223853.1385255-1-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-05-18 20:20:43 -06:00
Colin Ian King
e53413f8de block, bfq: Fix division by zero error on zero wsum
When the weighted sum is zero the calculation of limit causes
a division by zero error. Fix this by continuing to the next level.

This was discovered by running as root:

stress-ng --ioprio 0

Fixes divison by error oops:

[  521.450556] divide error: 0000 [#1] SMP NOPTI
[  521.450766] CPU: 2 PID: 2684464 Comm: stress-ng-iopri Not tainted 6.2.1-1280.native #1
[  521.451117] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.1-0-g3208b098f51a-prebuilt.qemu.org 04/01/2014
[  521.451627] RIP: 0010:bfqq_request_over_limit+0x207/0x400
[  521.451875] Code: 01 48 8d 0c c8 74 0b 48 8b 82 98 00 00 00 48 8d 0c c8 8b 85 34 ff ff ff 48 89 ca 41 0f af 41 50 48 d1 ea 48 98 48 01 d0 31 d2 <48> f7 f1 41 39 41 48 89 85 34 ff ff ff 0f 8c 7b 01 00 00 49 8b 44
[  521.452699] RSP: 0018:ffffb1af84eb3948 EFLAGS: 00010046
[  521.452938] RAX: 000000000000003c RBX: 0000000000000000 RCX: 0000000000000000
[  521.453262] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffb1af84eb3978
[  521.453584] RBP: ffffb1af84eb3a30 R08: 0000000000000001 R09: ffff8f88ab8a4ba0
[  521.453905] R10: 0000000000000000 R11: 0000000000000001 R12: ffff8f88ab8a4b18
[  521.454224] R13: ffff8f8699093000 R14: 0000000000000001 R15: ffffb1af84eb3970
[  521.454549] FS:  00005640b6b0b580(0000) GS:ffff8f88b3880000(0000) knlGS:0000000000000000
[  521.454912] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  521.455170] CR2: 00007ffcbcae4e38 CR3: 00000002e46de001 CR4: 0000000000770ee0
[  521.455491] PKRU: 55555554
[  521.455619] Call Trace:
[  521.455736]  <TASK>
[  521.455837]  ? bfq_request_merge+0x3a/0xc0
[  521.456027]  ? elv_merge+0x115/0x140
[  521.456191]  bfq_limit_depth+0xc8/0x240
[  521.456366]  __blk_mq_alloc_requests+0x21a/0x2c0
[  521.456577]  blk_mq_submit_bio+0x23c/0x6c0
[  521.456766]  __submit_bio+0xb8/0x140
[  521.457236]  submit_bio_noacct_nocheck+0x212/0x300
[  521.457748]  submit_bio_noacct+0x1a6/0x580
[  521.458220]  submit_bio+0x43/0x80
[  521.458660]  ext4_io_submit+0x23/0x80
[  521.459116]  ext4_do_writepages+0x40a/0xd00
[  521.459596]  ext4_writepages+0x65/0x100
[  521.460050]  do_writepages+0xb7/0x1c0
[  521.460492]  __filemap_fdatawrite_range+0xa6/0x100
[  521.460979]  file_write_and_wait_range+0xbf/0x140
[  521.461452]  ext4_sync_file+0x105/0x340
[  521.461882]  __x64_sys_fsync+0x67/0x100
[  521.462305]  ? syscall_exit_to_user_mode+0x2c/0x1c0
[  521.462768]  do_syscall_64+0x3b/0xc0
[  521.463165]  entry_SYSCALL_64_after_hwframe+0x5a/0xc4
[  521.463621] RIP: 0033:0x5640b6c56590
[  521.464006] Code: 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 80 3d 71 70 0e 00 00 74 17 b8 4a 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 48 c3 0f 1f 80 00 00 00 00 48 83 ec 18 89 7c

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Link: https://lore.kernel.org/r/20230413133009.1605335-1-colin.i.king@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-16 13:01:43 -06:00
Christoph Hellwig
93fffe16f7 blk-mq: pass a flags argument to elevator_type->insert_requests
Instead of passing a bool at_head, pass down the full flags from the
blk_mq_insert_request interface.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20230413064057.707578-20-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-13 06:52:30 -06:00
Christoph Hellwig
bebe84ebee blk-mq: remove blk-mq-tag.h
blk-mq-tag.h is always included by blk-mq.h, and causes recursive
inclusion hell with further changes.  Just merge it into blk-mq.h
instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20230413064057.707578-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-13 06:52:29 -06:00
Yu Kuai
e2f2a39452 block, bfq: fix uaf for 'stable_merge_bfqq'
Before commit fd571df0ac ("block, bfq: turn bfqq_data into an array
in bfq_io_cq"), process reference is read before bfq_put_stable_ref(),
and it's safe if bfq_put_stable_ref() put the last reference, because
process reference will be 0 and 'stable_merge_bfqq' won't be accessed
in this case. However, the commit changed the order and  will cause
uaf for 'stable_merge_bfqq'.

In order to emphasize that bfq_put_stable_ref() can drop the last
reference, fix the problem by moving bfq_put_stable_ref() to the end of
bfq_setup_stable_merge().

Fixes: fd571df0ac ("block, bfq: turn bfqq_data into an array in bfq_io_cq")
Reported-and-tested-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Link: https://lore.kernel.org/linux-block/20230307071448.rzihxbm4jhbf5krj@shindev/
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-03-08 07:34:50 -07:00
Linus Torvalds
5b0ed59649 for-6.3/block-2023-02-16
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Merge tag 'for-6.3/block-2023-02-16' of git://git.kernel.dk/linux

Pull block updates from Jens Axboe:

 - NVMe updates via Christoph:
      - Small improvements to the logging functionality (Amit Engel)
      - Authentication cleanups (Hannes Reinecke)
      - Cleanup and optimize the DMA mapping cod in the PCIe driver
        (Keith Busch)
      - Work around the command effects for Format NVM (Keith Busch)
      - Misc cleanups (Keith Busch, Christoph Hellwig)
      - Fix and cleanup freeing single sgl (Keith Busch)

 - MD updates via Song:
      - Fix a rare crash during the takeover process
      - Don't update recovery_cp when curr_resync is ACTIVE
      - Free writes_pending in md_stop
      - Change active_io to percpu

 - Updates to drbd, inching us closer to unifying the out-of-tree driver
   with the in-tree one (Andreas, Christoph, Lars, Robert)

 - BFQ update adding support for multi-actuator drives (Paolo, Federico,
   Davide)

 - Make brd compliant with REQ_NOWAIT (me)

 - Fix for IOPOLL and queue entering, fixing stalled IO waiting on
   timeouts (me)

 - Fix for REQ_NOWAIT with multiple bios (me)

 - Fix memory leak in blktrace cleanup (Greg)

 - Clean up sbitmap and fix a potential hang (Kemeng)

 - Clean up some bits in BFQ, and fix a bug in the request injection
   (Kemeng)

 - Clean up the request allocation and issue code, and fix some bugs
   related to that (Kemeng)

 - ublk updates and fixes:
      - Add support for unprivileged ublk (Ming)
      - Improve device deletion handling (Ming)
      - Misc (Liu, Ziyang)

 - s390 dasd fixes (Alexander, Qiheng)

 - Improve utility of request caching and fixes (Anuj, Xiao)

 - zoned cleanups (Pankaj)

 - More constification for kobjs (Thomas)

 - blk-iocost cleanups (Yu)

 - Remove bio splitting from drivers that don't need it (Christoph)

 - Switch blk-cgroups to use struct gendisk. Some of this is now
   incomplete as select late reverts were done. (Christoph)

 - Add bvec initialization helpers, and convert callers to use that
   rather than open-coding it (Christoph)

 - Misc fixes and cleanups (Jinke, Keith, Arnd, Bart, Li, Martin,
   Matthew, Ulf, Zhong)

* tag 'for-6.3/block-2023-02-16' of git://git.kernel.dk/linux: (169 commits)
  brd: use radix_tree_maybe_preload instead of radix_tree_preload
  block: use proper return value from bio_failfast()
  block: bio-integrity: Copy flags when bio_integrity_payload is cloned
  block: Fix io statistics for cgroup in throttle path
  brd: mark as nowait compatible
  brd: check for REQ_NOWAIT and set correct page allocation mask
  brd: return 0/-error from brd_insert_page()
  block: sync mixed merged request's failfast with 1st bio's
  Revert "blk-cgroup: pin the gendisk in struct blkcg_gq"
  Revert "blk-cgroup: pass a gendisk to blkg_lookup"
  Revert "blk-cgroup: delay blk-cgroup initialization until add_disk"
  Revert "blk-cgroup: delay calling blkcg_exit_disk until disk_release"
  Revert "blk-cgroup: move the cgroup information to struct gendisk"
  nvme-pci: remove iod use_sgls
  nvme-pci: fix freeing single sgl
  block: ublk: check IO buffer based on flag need_get_data
  s390/dasd: Fix potential memleak in dasd_eckd_init()
  s390/dasd: sort out physical vs virtual pointers usage
  block: Remove the ALLOC_CACHE_SLACK constant
  block: make kobj_type structures constant
  ...
2023-02-20 14:27:21 -08:00
Christoph Hellwig
40e4996ec0 blk-cgroup: pass a gendisk to blkcg_{de,}activate_policy
Prepare for storing the blkcg information in the gendisk instead of
the request_queue.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Andreas Herrmann <aherrmann@suse.de>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20230203150400.3199230-17-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-02-03 08:20:05 -07:00
Christoph Hellwig
04aad37be1 blk-wbt: pass a gendisk to wbt_{enable,disable}_default
Pass a gendisk to wbt_enable_default and wbt_disable_default to
prepare for phasing out usage of the request_queue in the blk-cgroup
code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Andreas Herrmann <aherrmann@suse.de>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20230203150400.3199230-9-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-02-03 08:20:05 -07:00
Kemeng Shi
323745a3aa block, bfq: remove unused bfq_wr_max_time in struct bfq_data
bfqd->bfq_wr_max_time is set to 0 in bfq_init_queue and is never changed.
It is only used in bfq_wr_duration when bfq_wr_max_time > 0 which never
meets, so bfqd->bfq_wr_max_time is not used actually. Just remove it.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230116095153.3810101-9-shikemeng@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 20:03:49 -07:00
Kemeng Shi
87c971de81 block, bfq: remove unnecessary goto tag in bfq_dispatch_rq_from_bfqq
We jump to tag only for returning current rq. Return directly to
remove this tag.

Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Link: https://lore.kernel.org/r/20230116095153.3810101-8-shikemeng@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 20:03:49 -07:00
Kemeng Shi
433d4b03e7 block, bfq: remove redundant check in bfq_put_cooperator
We have already avoided a circular list in bfq_setup_merge (see comments
in bfq_setup_merge() for details), so bfq_queue will not appear in it's
new_bfqq list. Just remove this check.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230116095153.3810101-7-shikemeng@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 20:03:49 -07:00
Kemeng Shi
86f8382e6d block, bfq: remove unnecessary dereference to get async_bfqq
The async_bfqq is assigned with bfqq->bic->bfqq[0], use it directly.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230116095153.3810101-6-shikemeng@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 20:03:49 -07:00
Kemeng Shi
8ac2e43c35 block, bfq: use helper macro RQ_BFQQ to get bfqq of request
Use helper macro RQ_BFQQ to get bfqq of request.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230116095153.3810101-5-shikemeng@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 20:03:49 -07:00
Kemeng Shi
1c970450a7 block, bfq: initialize bfqq->decrease_time_jif correctly
Inject limit is updated or reset when time_is_before_eq_jiffies(
decrease_time_jif + several msecs) or think-time state changes.
decrease_time_jif is initialized to 0 and will be set to current jiffies
when inject limit is updated or reset. If the jiffies is slightly greater
than LONG_MAX, time_is_after_eq_jiffies(0) will keep for a long time, so as
time_is_after_eq_jiffies(decrease_time_jif + several msecs). If the
think-time state never chages, then the injection will not work as expected
for long time.

To be more specific:
Function bfq_update_inject_limit maybe triggered when jiffies pasts
decrease_time_jif + msecs_to_jiffies(10) in bfq_add_request by setting
bfqd->wait_dispatch to true.
Function bfq_reset_inject_limit are called in two conditions:
1. jiffies pasts bfqq->decrease_time_jif + msecs_to_jiffies(1000) in
function bfq_add_request.
2. jiffies pasts bfqq->decrease_time_jif + msecs_to_jiffies(100) or
bfq think-time state change from short to long.

Fix this by initializing bfqq->decrease_time_jif to current jiffies
to trigger service injection soon when service injection conditions
are met.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230116095153.3810101-4-shikemeng@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 20:03:49 -07:00
Kemeng Shi
bebeb9e582 block, bfq: remove unsed parameter reason in bfq_bfqq_is_slow
Parameter reason is never used, just remove it.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230116095153.3810101-3-shikemeng@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 20:03:49 -07:00
Kemeng Shi
0c3e09e885 block, bfq: correctly raise inject limit in bfq_choose_bfqq_for_injection
Function bfq_choose_bfqq_for_injection may temporarily raise inject limit
to one request if current inject_limit is 0 before search of the source
queue for injection. However the search below will reset inject limit to
bfqd->in_service_queue which is zero for raised inject limit. Then the
temporarily raised inject limit never works as expected.
Assigment limit to bfqd->in_service_queue in search is needed as limit
maybe overwriten to min_t(unsigned int, 1, limit) for condition that
a large in-flight request is on non-rotational devices in found queue.
So we need to reset limit to bfqd->in_service_queue for normal case.

Actually, we have already make sure bfqd->rq_in_driver is < limit before
search, then
 -Limit is >= 1 as bfqd->rq_in_driver is >= 0. Then min_t(unsigned int,
1, limit) is always 1. So we can simply check bfqd->rq_in_driver with
1 instead of result of min_t(unsigned int, 1, limit) for larget request in
non-rotational device case to avoid overwritting limit and the bug is gone.
 -For normal case, we have already check bfqd->rq_in_driver is < limit,
so we can return found bfqq unconditionally to remove unncessary check.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230116095153.3810101-2-shikemeng@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 20:03:49 -07:00
Yu Kuai
b600de2d7d block, bfq: fix uaf for bfqq in bic_set_bfqq()
After commit 64dc8c732f ("block, bfq: fix possible uaf for 'bfqq->bic'"),
bic->bfqq will be accessed in bic_set_bfqq(), however, in some context
bic->bfqq will be freed, and bic_set_bfqq() is called with the freed
bic->bfqq.

Fix the problem by always freeing bfqq after bic_set_bfqq().

Fixes: 64dc8c732f ("block, bfq: fix possible uaf for 'bfqq->bic'")
Reported-and-tested-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230130014136.591038-1-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 18:57:01 -07:00
Davide Zini
1bd43e19de block, bfq: balance I/O injection among underutilized actuators
Upon the invocation of its dispatch function, BFQ returns the next I/O
request of the in-service bfq_queue, unless some exception holds. One
such exception is that there is some underutilized actuator, different
from the actuator for which the in-service queue contains I/O, and
that some other bfq_queue happens to contain I/O for such an
actuator. In this case, the next I/O request of the latter bfq_queue,
and not of the in-service bfq_queue, is returned (I/O is injected from
that bfq_queue). To find such an actuator, a linear scan, in
increasing index order, is performed among actuators.

Performing a linear scan entails a prioritization among actuators: an
underutilized actuator may be considered for injection only if all
actuators with a lower index are currently fully utilized, or if there
is no pending I/O for any lower-index actuator that happens to be
underutilized.

This commits breaks this prioritization and tends to distribute
injection uniformly across actuators. This is obtained by adding the
following condition to the linear scan: even if an actuator A is
underutilized, A is however skipped if its load is higher than that of
the next actuator.

Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Davide Zini <davidezini2@gmail.com>
Link: https://lore.kernel.org/r/20230103145503.71712-9-paolo.valente@linaro.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:18:33 -07:00
Davide Zini
2d31c684a0 block, bfq: inject I/O to underutilized actuators
The main service scheme of BFQ for sync I/O is serving one sync
bfq_queue at a time, for a while. In particular, BFQ enforces this
scheme when it deems the latter necessary to boost throughput or
to preserve service guarantees. Unfortunately, when BFQ enforces
this policy, only one actuator at a time gets served for a while,
because each bfq_queue contains I/O only for one actuator. The
other actuators may remain underutilized.

Actually, BFQ may serve (inject) extra I/O, taken from other
bfq_queues, in parallel with that of the in-service queue. This
injection mechanism may provide the ground for dealing also with
the above actuator-underutilization problem. Yet BFQ does not take
the actuator load into account when choosing which queue to pick
extra I/O from. In addition, BFQ may happen to inject extra I/O
only when the in-service queue is temporarily empty.

In view of these facts, this commit extends the
injection mechanism in such a way that the latter:
(1) takes into account also the actuator load;
(2) checks such a load on each dispatch, and injects I/O for an
    underutilized actuator, if there is one and there is I/O for it.

To perform the check in (2), this commit introduces a load
threshold, currently set to 4.  A linear scan of each actuator is
performed, until an actuator is found for which the following two
conditions hold: the load of the actuator is below the threshold,
and there is at least one non-in-service queue that contains I/O
for that actuator. If such a pair (actuator, queue) is found, then
the head request of that queue is returned for dispatch, instead
of the head request of the in-service queue.

We have set the threshold, empirically, to the minimum possible
value for which an actuator is fully utilized, or close to be
fully utilized. By doing so, injected I/O 'steals' as few
drive-queue slots as possibile to the in-service queue. This
reduces as much as possible the probability that the service of
I/O from the in-service bfq_queue gets delayed because of slot
exhaustion, i.e., because all the slots of the drive queue are
filled with I/O injected from other queues (NCQ provides for 32
slots).

This new mechanism also counters actuator underutilization in the
case of asymmetric configurations of bfq_queues. Namely if there
are few bfq_queues containing I/O for some actuators and many
bfq_queues containing I/O for other actuators. Or if the
bfq_queues containing I/O for some actuators have lower weights
than the other bfq_queues.

Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Davide Zini <davidezini2@gmail.com>
Link: https://lore.kernel.org/r/20230103145503.71712-8-paolo.valente@linaro.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:18:33 -07:00
Federico Gavioli
4fdb3b9f2a block, bfq: retrieve independent access ranges from request queue
This patch implements the code to gather the content of the
independent_access_ranges structure from the request_queue and copy
it into the queue's bfq_data. This copy is done at queue initialization.

We copy the access ranges into the bfq_data to avoid taking the queue
lock each time we access the ranges.

This implementation, however, puts a limit to the maximum independent
ranges supported by the scheduler. Such a limit is equal to the constant
BFQ_MAX_ACTUATORS. This limit was placed to avoid the allocation of
dynamic memory.

Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Co-developed-by: Rory Chen <rory.c.chen@seagate.com>
Signed-off-by: Rory Chen <rory.c.chen@seagate.com>
Signed-off-by: Federico Gavioli <f.gavioli97@gmail.com>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Link: https://lore.kernel.org/r/20230103145503.71712-7-paolo.valente@linaro.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:18:33 -07:00
Davide Zini
8b7fd74111 block, bfq: split also async bfq_queues on a per-actuator basis
Similarly to sync bfq_queues, also async bfq_queues need to be split
on a per-actuator basis.

Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Davide Zini <davidezini2@gmail.com>
Link: https://lore.kernel.org/r/20230103145503.71712-6-paolo.valente@linaro.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:18:33 -07:00
Paolo Valente
fd571df0ac block, bfq: turn bfqq_data into an array in bfq_io_cq
When a bfq_queue Q is merged with another queue, several pieces of
information are saved about Q. These pieces are stored in the
bfqq_data field in the bfq_io_cq data structure of the process
associated with Q.

Yet, with a multi-actuator drive, a process may get associated with
multiple bfq_queues: one queue for each of the N actuators. Each of
these queues may undergo a merge. So, the bfq_io_cq data structure
must be able to accommodate the above information for N queues.

This commit solves this problem by turning the bfqq_data scalar field
into an array of N elements (and by changing code so as to handle
this array).

This solution is written under the assumption that bfq_queues
associated with different actuators cannot be cross-merged. This
assumption holds naturally with basic queue merging: the latter is
triggered by spatial locality, and sectors for different actuators are
not close to each other (apart from the corner case of the last
sectors served by a given actuator and the first sectors served by the
next actuator). As for stable cross-merging, the assumption here is
that it is disabled.

Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Gabriele Felici <felicigb@gmail.com>
Signed-off-by: Gianmarco Lusvardi <glusvardi@posteo.net>
Signed-off-by: Giulio Barabino <giuliobarabino99@gmail.com>
Signed-off-by: Emiliano Maccaferri <inbox@emilianomaccaferri.com>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Link: https://lore.kernel.org/r/20230103145503.71712-5-paolo.valente@linaro.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:18:32 -07:00
Paolo Valente
a61230470c block, bfq: move io_cq-persistent bfqq data into a dedicated struct
With a multi-actuator drive, a process may get associated with multiple
bfq_queues: one queue for each of the N actuators. So, the bfq_io_cq
data structure must be able to accommodate its per-queue persistent
information for N queues. Currently it stores this information for
just one queue, in several scalar fields.

This is a preparatory commit for moving to accommodating persistent
information for N queues. In particular, this commit packs all the
above scalar fields into a single data structure. Then there is now
only one field, in bfq_io_cq, that stores all the above information. This
scalar field will then be turned into an array by a following commit.

Suggested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Gianmarco Lusvardi <glusvardi@posteo.net>
Signed-off-by: Giulio Barabino <giuliobarabino99@gmail.com>
Signed-off-by: Emiliano Maccaferri <inbox@emilianomaccaferri.com>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Link: https://lore.kernel.org/r/20230103145503.71712-4-paolo.valente@linaro.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:18:32 -07:00