linux-stable.git/drivers/md/md.c, branch v6.0

md: call __md_stop_writes in md_stop

2022-08-24T18:19:59+00:00

From the link [1], we can see raid1d was running even after the path
raid_dtr -> md_stop -> __md_stop.

Let's stop write first in destructor to align with normal md-raid to
fix the KASAN issue.

[1]. https://lore.kernel.org/linux-raid/CAPhsuW5gc4AakdGNdF8ubpezAuDLFOYUO_sfMZcec6hQFm8nhg@mail.gmail.com/T/#m7f12bf90481c02c6d2da68c64aeed4779b7df74a

Fixes: 48df498daf62 ("md: move bitmap_destroy to the beginning of __md_stop")
Reported-by: Mikulas Patocka 
Signed-off-by: Guoqing Jiang 
Signed-off-by: Song Liu

Revert "md-raid: destroy the bitmap after destroying the thread"

2022-08-24T18:19:23+00:00

This reverts commit e151db8ecfb019b7da31d076130a794574c89f6f. Because it
obviously breaks clustered raid as noticed by Neil though it fixed KASAN
issue for dm-raid, let's revert it and fix KASAN issue in next commit.

[1]. https://lore.kernel.org/linux-raid/a6657e08-b6a7-358b-2d2a-0ac37d49d23a@linux.dev/T/#m95ac225cab7409f66c295772483d091084a6d470

Fixes: e151db8ecfb0 ("md-raid: destroy the bitmap after destroying the thread")
Signed-off-by: Guoqing Jiang 
Signed-off-by: Song Liu

md: Flush workqueue md_rdev_misc_wq in md_alloc()

2022-08-24T17:26:35+00:00

A race condition still exists when removing and re-creating md devices
in test cases. However, it is only seen on some setups.

The race condition was tracked down to a reference still being held
to the kobject by the rdev in the md_rdev_misc_wq which will be released
in rdev_delayed_delete().

md_alloc() waits for previous deletions by waiting on the md_misc_wq,
but the md_rdev_misc_wq may still be holding a reference to a recently
removed device.

To fix this, also flush the md_rdev_misc_wq in md_alloc().

Signed-off-by: David Sloan 
[logang@deltatee.com: rewrote commit message]
Signed-off-by: Logan Gunthorpe 
Signed-off-by: Song Liu

block: change the blk_queue_split calling convention

2022-08-02T23:22:53+00:00

The double indirect bio leads to somewhat suboptimal code generation.
Instead return the (original or split) bio, and make sure the
request_queue arguments to the lower level helpers is passed after the
bio to avoid constant reshuffling of the argument passing registers.

Also give it and the helpers used to implement it more descriptive names.

Signed-off-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20220727162300.3089193-2-hch@lst.de
Signed-off-by: Jens Axboe

md-raid: destroy the bitmap after destroying the thread

2022-08-02T23:22:46+00:00

When we ran the lvm test "shell/integrity-blocksize-3.sh" on a kernel with
kasan, we got failure in write_page.

The reason for the failure is that md_bitmap_destroy is called before
destroying the thread and the thread may be waiting in the function
write_page for the bio to complete. When the thread finishes waiting, it
executes "if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))", which
triggers the kasan warning.

Note that the commit 48df498daf62 that caused this bug claims that it is
neede for md-cluster, you should check md-cluster and possibly find
another bugfix for it.

BUG: KASAN: use-after-free in write_page+0x18d/0x680 [md_mod]
Read of size 8 at addr ffff889162030c78 by task mdX_raid1/5539

CPU: 10 PID: 5539 Comm: mdX_raid1 Not tainted 5.19.0-rc2 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014
Call Trace:
 
 dump_stack_lvl+0x34/0x44
 print_report.cold+0x45/0x57a
 ? __lock_text_start+0x18/0x18
 ? write_page+0x18d/0x680 [md_mod]
 kasan_report+0xa8/0xe0
 ? write_page+0x18d/0x680 [md_mod]
 kasan_check_range+0x13f/0x180
 write_page+0x18d/0x680 [md_mod]
 ? super_sync+0x4d5/0x560 [dm_raid]
 ? md_bitmap_file_kick+0xa0/0xa0 [md_mod]
 ? rs_set_dev_and_array_sectors+0x2e0/0x2e0 [dm_raid]
 ? mutex_trylock+0x120/0x120
 ? preempt_count_add+0x6b/0xc0
 ? preempt_count_sub+0xf/0xc0
 md_update_sb+0x707/0xe40 [md_mod]
 md_reap_sync_thread+0x1b2/0x4a0 [md_mod]
 md_check_recovery+0x533/0x960 [md_mod]
 raid1d+0xc8/0x2a20 [raid1]
 ? var_wake_function+0xe0/0xe0
 ? psi_group_change+0x411/0x500
 ? preempt_count_sub+0xf/0xc0
 ? _raw_spin_lock_irqsave+0x78/0xc0
 ? __lock_text_start+0x18/0x18
 ? raid1_end_read_request+0x2a0/0x2a0 [raid1]
 ? preempt_count_sub+0xf/0xc0
 ? _raw_spin_unlock_irqrestore+0x19/0x40
 ? del_timer_sync+0xa9/0x100
 ? try_to_del_timer_sync+0xc0/0xc0
 ? _raw_spin_lock_irqsave+0x78/0xc0
 ? __lock_text_start+0x18/0x18
 ? __list_del_entry_valid+0x68/0xa0
 ? finish_wait+0xa3/0x100
 md_thread+0x161/0x260 [md_mod]
 ? unregister_md_personality+0xa0/0xa0 [md_mod]
 ? _raw_spin_lock_irqsave+0x78/0xc0
 ? prepare_to_wait_event+0x2c0/0x2c0
 ? unregister_md_personality+0xa0/0xa0 [md_mod]
 kthread+0x148/0x180
 ? kthread_complete_and_exit+0x20/0x20
 ret_from_fork+0x1f/0x30
 

Allocated by task 5522:
 kasan_save_stack+0x1e/0x40
 __kasan_kmalloc+0x80/0xa0
 md_bitmap_create+0xa8/0xe80 [md_mod]
 md_run+0x777/0x1300 [md_mod]
 raid_ctr+0x249c/0x4a30 [dm_raid]
 dm_table_add_target+0x2b0/0x620 [dm_mod]
 table_load+0x1c8/0x400 [dm_mod]
 ctl_ioctl+0x29e/0x560 [dm_mod]
 dm_compat_ctl_ioctl+0x7/0x20 [dm_mod]
 __do_compat_sys_ioctl+0xfa/0x160
 do_syscall_64+0x90/0xc0
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

Freed by task 5680:
 kasan_save_stack+0x1e/0x40
 kasan_set_track+0x21/0x40
 kasan_set_free_info+0x20/0x40
 __kasan_slab_free+0xf7/0x140
 kfree+0x80/0x240
 md_bitmap_free+0x1c3/0x280 [md_mod]
 __md_stop+0x21/0x120 [md_mod]
 md_stop+0x9/0x40 [md_mod]
 raid_dtr+0x1b/0x40 [dm_raid]
 dm_table_destroy+0x98/0x1e0 [dm_mod]
 __dm_destroy+0x199/0x360 [dm_mod]
 dev_remove+0x10c/0x160 [dm_mod]
 ctl_ioctl+0x29e/0x560 [dm_mod]
 dm_compat_ctl_ioctl+0x7/0x20 [dm_mod]
 __do_compat_sys_ioctl+0xfa/0x160
 do_syscall_64+0x90/0xc0
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

Signed-off-by: Mikulas Patocka 
Cc: stable@vger.kernel.org
Fixes: 48df498daf62 ("md: move bitmap_destroy to the beginning of __md_stop")
Signed-off-by: Song Liu 
Signed-off-by: Jens Axboe

md: return the allocated devices from md_alloc

2022-08-02T23:22:46+00:00

Two callers of md_alloc want to use the newly allocated devices, so
return it instead of letting them find it cumbersomely after the
allocation.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Hannes Reinecke 
Reviewed-and-tested-by: Logan Gunthorpe 
Signed-off-by: Song Liu 
Signed-off-by: Jens Axboe

md: open code md_probe in autorun_devices

2022-08-02T23:22:46+00:00

autorun_devices should not be limited to the controls for the legacy
probe on open, so just call md_alloc directly.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Hannes Reinecke 
Reviewed-and-tested-by: Logan Gunthorpe 
Signed-off-by: Song Liu 
Signed-off-by: Jens Axboe

md: remove unneeded semicolon

2022-08-02T23:22:46+00:00

Eliminate the following coccicheck warning:
./drivers/md/md.c:8208:2-3: Unneeded semicolon

Reported-by: Abaci Robot 
Signed-off-by: Yang Li 
Reported-by:  kernel test robot 
Signed-off-by: Christoph Hellwig 
Signed-off-by: Song Liu 
Signed-off-by: Jens Axboe

md: fix build failure for !MODULE

2022-08-02T23:22:46+00:00

After merging the block tree, today's linux-next build (x86_64
allmodconfig) failed like this:

drivers/md/md.c:717:22: error: 'mddev_find' defined but not used [-Werror=unused-function]
  717 | static struct mddev *mddev_find(dev_t unit)
      |                      ^~~~~~~~~~
cc1: all warnings being treated as errors

Caused by commit

  4500d5c17910 ("md: simplify md_open")

Make mddev_find() available only for non-modular builds.

Signed-off-by: Stephen Rothwell 
Reviewed-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20220721131132.070be166@canb.auug.org.au
Signed-off-by: Jens Axboe

md: simplify md_open

2022-08-02T23:22:46+00:00

Now that devices are on the all_mddevs list until the gendisk is freed,
there can't be any duplicates.  Remove the global list lookup and just
grab a reference.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Hannes Reinecke 
Reviewed-by: Logan Gunthorpe 
Signed-off-by: Song Liu 
Signed-off-by: Jens Axboe