dm-raid: fix lockdep waring in "pers->hot_add_disk"

[ Upstream commit 95009ae904b1e9dca8db6f649f2d7c18a6e42c75 ]

The lockdep assert is added by commit a448af25becf ("md/raid10: remove
rcu protectio

dm-raid: fix lockdep waring in "pers->hot_add_disk"

[ Upstream commit 95009ae904b1e9dca8db6f649f2d7c18a6e42c75 ]

The lockdep assert is added by commit a448af25becf ("md/raid10: remove
rcu protection to access rdev from conf") in print_conf(). And I didn't
notice that dm-raid is calling "pers->hot_add_disk" without holding
'reconfig_mutex'.

"pers->hot_add_disk" read and write many fields that is protected by
'reconfig_mutex', and raid_resume() already grab the lock in other
contex. Hence fix this problem by protecting "pers->host_add_disk"
with the lock.

Fixes: 9092c02d9435 ("DM RAID: Add ability to restore transiently failed devices on resume")
Fixes: a448af25becf ("md/raid10: remove rcu protection to access rdev from conf")
Cc: stable@vger.kernel.org # v6.7+
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Xiao Ni <xni@redhat.com>
Acked-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240305072306.2562024-10-yukuai1@huaweicloud.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

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dm-raid: fix lockdep waring in "pers->hot_add_disk"

[ Upstream commit 95009ae904b1e9dca8db6f649f2d7c18a6e42c75 ]

The lockdep assert is added by commit a448af25becf ("md/raid10: remove
rcu protectio

dm-raid: fix lockdep waring in "pers->hot_add_disk"

[ Upstream commit 95009ae904b1e9dca8db6f649f2d7c18a6e42c75 ]

The lockdep assert is added by commit a448af25becf ("md/raid10: remove
rcu protection to access rdev from conf") in print_conf(). And I didn't
notice that dm-raid is calling "pers->hot_add_disk" without holding
'reconfig_mutex'.

"pers->hot_add_disk" read and write many fields that is protected by
'reconfig_mutex', and raid_resume() already grab the lock in other
contex. Hence fix this problem by protecting "pers->host_add_disk"
with the lock.

Fixes: 9092c02d9435 ("DM RAID: Add ability to restore transiently failed devices on resume")
Fixes: a448af25becf ("md/raid10: remove rcu protection to access rdev from conf")
Cc: stable@vger.kernel.org # v6.7+
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Xiao Ni <xni@redhat.com>
Acked-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240305072306.2562024-10-yukuai1@huaweicloud.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

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dm raid: fix false positive for requeue needed during reshape

[ Upstream commit b25b8f4b8ecef0f48c05f0c3572daeabefe16526 ]

An empty flush doesn't have a payload, so it should never be looked at
whe

dm raid: fix false positive for requeue needed during reshape

[ Upstream commit b25b8f4b8ecef0f48c05f0c3572daeabefe16526 ]

An empty flush doesn't have a payload, so it should never be looked at
when considering to possibly requeue a bio for the case when a reshape
is in progress.

Fixes: 9dbd1aa3a81c ("dm raid: add reshaping support to the target")
Reported-by: Patrick Plenefisch <simonpatp@gmail.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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Revert "md: unlock mddev before reap sync_thread in action_store"

This reverts commit 9dfbdafda3b34e262e43e786077bab8e476a89d1.

Because it will introduce a defect that sync_thread can be running wh

Revert "md: unlock mddev before reap sync_thread in action_store"

This reverts commit 9dfbdafda3b34e262e43e786077bab8e476a89d1.

Because it will introduce a defect that sync_thread can be running while
MD_RECOVERY_RUNNING is cleared, which will cause some unexpected problems,
for example:

list_add corruption. prev->next should be next (ffff0001ac1daba0), but was ffff0000ce1a02a0. (prev=ffff0000ce1a02a0).
Call trace:
__list_add_valid+0xfc/0x140
insert_work+0x78/0x1a0
__queue_work+0x500/0xcf4
queue_work_on+0xe8/0x12c
md_check_recovery+0xa34/0xf30
raid10d+0xb8/0x900 [raid10]
md_thread+0x16c/0x2cc
kthread+0x1a4/0x1ec
ret_from_fork+0x10/0x18

This is because work is requeued while it's still inside workqueue:

t1: t2:
action_store
mddev_lock
if (mddev->sync_thread)
mddev_unlock
md_unregister_thread
// first sync_thread is done
md_check_recovery
mddev_try_lock
/*
* once MD_RECOVERY_DONE is set, new sync_thread
* can start.
*/
set_bit(MD_RECOVERY_RUNNING, &mddev->recovery)
INIT_WORK(&mddev->del_work, md_start_sync)
queue_work(md_misc_wq, &mddev->del_work)
test_and_set_bit(WORK_STRUCT_PENDING_BIT, ...)
// set pending bit
insert_work
list_add_tail
mddev_unlock
mddev_lock_nointr
md_reap_sync_thread
// MD_RECOVERY_RUNNING is cleared
mddev_unlock

t3:

// before queued work started from t2
md_check_recovery
// MD_RECOVERY_RUNNING is not set, a new sync_thread can be started
INIT_WORK(&mddev->del_work, md_start_sync)
work->data = 0
// work pending bit is cleared
queue_work(md_misc_wq, &mddev->del_work)
insert_work
list_add_tail
// list is corrupted

The above commit is reverted to fix the problem, the deadlock this
commit tries to fix will be fixed in following patches.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230529132037.2124527-2-yukuai1@huaweicloud.com

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dm raid: protect md_stop() with 'reconfig_mutex'

__md_stop_writes() and __md_stop() will modify many fields that are
protected by 'reconfig_mutex', and all the callers will grab
'reconfig_mutex' exc

dm raid: protect md_stop() with 'reconfig_mutex'

__md_stop_writes() and __md_stop() will modify many fields that are
protected by 'reconfig_mutex', and all the callers will grab
'reconfig_mutex' except for md_stop().

Also, update md_stop() to make certain 'reconfig_mutex' is held using
lockdep_assert_held().

Fixes: 9d09e663d550 ("dm: raid456 basic support")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

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dm raid: clean up four equivalent goto tags in raid_ctr()

There are four equivalent goto tags in raid_ctr(), clean them up to
use just one.

There is no functional change and this is preparation to

dm raid: clean up four equivalent goto tags in raid_ctr()

There are four equivalent goto tags in raid_ctr(), clean them up to
use just one.

There is no functional change and this is preparation to fix
raid_ctr()'s unprotected md_stop().

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

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dm raid: fix missing reconfig_mutex unlock in raid_ctr() error paths

In the error paths 'bad_stripe_cache' and 'bad_check_reshape',
'reconfig_mutex' is still held after raid_ctr() returns.

Fixes: 9

dm raid: fix missing reconfig_mutex unlock in raid_ctr() error paths

In the error paths 'bad_stripe_cache' and 'bad_check_reshape',
'reconfig_mutex' is still held after raid_ctr() returns.

Fixes: 9dbd1aa3a81c ("dm raid: add reshaping support to the target")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

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dm-raid: remove useless checking in raid_message()

md_wakeup_thread() handle the case that pass in md_thread is NULL, there
is no need to check this.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Sig

dm-raid: remove useless checking in raid_message()

md_wakeup_thread() handle the case that pass in md_thread is NULL, there
is no need to check this.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230523021017.3048783-3-yukuai1@huaweicloud.com

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dm: add helper macro for simple DM target module init and exit

Eliminate duplicate boilerplate code for simple modules that contain
a single DM target driver without any additional setup code.

Add

dm: add helper macro for simple DM target module init and exit

Eliminate duplicate boilerplate code for simple modules that contain
a single DM target driver without any additional setup code.

Add a new module_dm() macro, which replaces the module_init() and
module_exit() with template functions that call dm_register_target()
and dm_unregister_target() respectively.

Signed-off-by: Yangtao Li <frank.li@vivo.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

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dm raid: remove unused d variable

clang with W=1 reports
drivers/md/dm-raid.c:2212:15: error: variable
'd' set but not used [-Werror,-Wunused-but-set-variable]
unsigned int d;

dm raid: remove unused d variable

clang with W=1 reports
drivers/md/dm-raid.c:2212:15: error: variable
'd' set but not used [-Werror,-Wunused-but-set-variable]
unsigned int d;
^
This variable is not used so remove it.

Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

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dm: fix suspect indent whitespace

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

dm: add missing blank line after declarations/fix those

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

dm: correct block comments format.

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

dm: address indent/space issues

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

dm: avoid initializing static variables

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

dm: change "unsigned" to "unsigned int"

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

dm: add missing SPDX-License-Indentifiers

'GPL-2.0-only' is used instead of 'GPL-2.0' because SPDX has
deprecated its use.

Suggested-by: John Wiele <jwiele@redhat.com>
Signed-off-by: Heinz Mauelsha

dm: add missing SPDX-License-Indentifiers

'GPL-2.0-only' is used instead of 'GPL-2.0' because SPDX has
deprecated its use.

Suggested-by: John Wiele <jwiele@redhat.com>
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

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dm raid: fix some spelling mistakes in comments

Signed-off-by: Yu Zhe <yuzhe@nfschina.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

dm raid: fix typo in analyse_superblocks code comment

Reported-by: k2ci <kernel-bot@kylinos.cn>
Signed-off-by: Jiangshan Yi <yijiangshan@kylinos.cn>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

dm raid: delete the redundant word 'that' in comment

Signed-off-by: Jilin Yuan <yuanjilin@cdjrlc.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

md: unlock mddev before reap sync_thread in action_store

Since the bug which commit 8b48ec23cc51a ("md: don't unregister sync_thread
with reconfig_mutex held") fixed is related with action_store pat

md: unlock mddev before reap sync_thread in action_store

Since the bug which commit 8b48ec23cc51a ("md: don't unregister sync_thread
with reconfig_mutex held") fixed is related with action_store path, other
callers which reap sync_thread didn't need to be changed.

Let's pull md_unregister_thread from md_reap_sync_thread, then fix previous
bug with belows.

1. unlock mddev before md_reap_sync_thread in action_store.
2. save reshape_position before unlock, then restore it to ensure position
not changed accidentally by others.

Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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dm: fix dm-raid crash if md_handle_request() splits bio

Commit ca522482e3eaf ("dm: pass NULL bdev to bio_alloc_clone")
introduced the optimization to _not_ perform bio_associate_blkg()'s
relatively

dm: fix dm-raid crash if md_handle_request() splits bio

Commit ca522482e3eaf ("dm: pass NULL bdev to bio_alloc_clone")
introduced the optimization to _not_ perform bio_associate_blkg()'s
relatively costly work when DM core clones its bio. But in doing so it
exposed the possibility for DM's cloned bio to alter DM target
behavior (e.g. crash) if a target were to issue IO without first
calling bio_set_dev().

The DM raid target can trigger an MD crash due to its need to split
the DM bio that is passed to md_handle_request(). The split will
recurse to submit_bio_noacct() using a bio with an uninitialized
->bi_blkg. This NULL bio->bi_blkg causes blk_throtl_bio() to
dereference a NULL blkg_to_tg(bio->bi_blkg).

Fix this in DM core by adding a new 'needs_bio_set_dev' target flag that
will make alloc_tio() call bio_set_dev() on behalf of the target.
dm-raid is the only target that requires this flag. bio_set_dev()
initializes the DM cloned bio's ->bi_blkg, using bio_associate_blkg,
before passing the bio to md_handle_request().

Long-term fix would be to audit and refactor MD code to rely on DM to
split its bio, using dm_accept_partial_bio(), but there are MD raid
personalities (e.g. raid1 and raid10) whose implementation are tightly
coupled to handling the bio splitting inline.

Fixes: ca522482e3eaf ("dm: pass NULL bdev to bio_alloc_clone")
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

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dm raid: fix address sanitizer warning in raid_resume

There is a KASAN warning in raid_resume when running the lvm test
lvconvert-raid.sh. The reason for the warning is that mddev->raid_disks
is gre

dm raid: fix address sanitizer warning in raid_resume

There is a KASAN warning in raid_resume when running the lvm test
lvconvert-raid.sh. The reason for the warning is that mddev->raid_disks
is greater than rs->raid_disks, so the loop touches one entry beyond
the allocated length.

Cc: stable@vger.kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

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dm raid: fix address sanitizer warning in raid_status

There is this warning when using a kernel with the address sanitizer
and running this testsuite:
https://gitlab.com/cki-project/kernel-tests/-/t

dm raid: fix address sanitizer warning in raid_status

There is this warning when using a kernel with the address sanitizer
and running this testsuite:
https://gitlab.com/cki-project/kernel-tests/-/tree/main/storage/swraid/scsi_raid

==================================================================
BUG: KASAN: slab-out-of-bounds in raid_status+0x1747/0x2820 [dm_raid]
Read of size 4 at addr ffff888079d2c7e8 by task lvcreate/13319
CPU: 0 PID: 13319 Comm: lvcreate Not tainted 5.18.0-0.rc3.<snip> #1
Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
Call Trace:
<TASK>
dump_stack_lvl+0x6a/0x9c
print_address_description.constprop.0+0x1f/0x1e0
print_report.cold+0x55/0x244
kasan_report+0xc9/0x100
raid_status+0x1747/0x2820 [dm_raid]
dm_ima_measure_on_table_load+0x4b8/0xca0 [dm_mod]
table_load+0x35c/0x630 [dm_mod]
ctl_ioctl+0x411/0x630 [dm_mod]
dm_ctl_ioctl+0xa/0x10 [dm_mod]
__x64_sys_ioctl+0x12a/0x1a0
do_syscall_64+0x5b/0x80

The warning is caused by reading conf->max_nr_stripes in raid_status. The
code in raid_status reads mddev->private, casts it to struct r5conf and
reads the entry max_nr_stripes.

However, if we have different raid type than 4/5/6, mddev->private
doesn't point to struct r5conf; it may point to struct r0conf, struct
r1conf, struct r10conf or struct mpconf. If we cast a pointer to one
of these structs to struct r5conf, we will be reading invalid memory
and KASAN warns about it.

Fix this bug by reading struct r5conf only if raid type is 4, 5 or 6.

Cc: stable@vger.kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

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md/core: Combine two sync_page_io() arguments

Improve uniformity in the kernel of handling of request operation and
flags by passing these as a single argument.

Cc: Song Liu <song@kernel.org>
Signe

md/core: Combine two sync_page_io() arguments

Improve uniformity in the kernel of handling of request operation and
flags by passing these as a single argument.

Cc: Song Liu <song@kernel.org>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220714180729.1065367-32-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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