6872 Commits

Author SHA1 Message Date
Logan Gunthorpe
9e86dffd0b md/raid5: Wait for MD_SB_CHANGE_PENDING in raid5d
[ Upstream commit 5e2cf333b7bd5d3e62595a44d598a254c697cd74 ]

A complicated deadlock exists when using the journal and an elevated
group_thrtead_cnt. It was found with loop devices, but its not clear
whether it can be seen with real disks. The deadlock can occur simply
by writing data with an fio script.

When the deadlock occurs, multiple threads will hang in different ways:

 1) The group threads will hang in the blk-wbt code with bios waiting to
    be submitted to the block layer:

        io_schedule+0x70/0xb0
        rq_qos_wait+0x153/0x210
        wbt_wait+0x115/0x1b0
        io_schedule+0x70/0xb0
        rq_qos_wait+0x153/0x210
        wbt_wait+0x115/0x1b0
        __rq_qos_throttle+0x38/0x60
        blk_mq_submit_bio+0x589/0xcd0
        wbt_wait+0x115/0x1b0
        __rq_qos_throttle+0x38/0x60
        blk_mq_submit_bio+0x589/0xcd0
        __submit_bio+0xe6/0x100
        submit_bio_noacct_nocheck+0x42e/0x470
        submit_bio_noacct+0x4c2/0xbb0
        ops_run_io+0x46b/0x1a30
        handle_stripe+0xcd3/0x36b0
        handle_active_stripes.constprop.0+0x6f6/0xa60
        raid5_do_work+0x177/0x330

    Or:
        io_schedule+0x70/0xb0
        rq_qos_wait+0x153/0x210
        wbt_wait+0x115/0x1b0
        __rq_qos_throttle+0x38/0x60
        blk_mq_submit_bio+0x589/0xcd0
        __submit_bio+0xe6/0x100
        submit_bio_noacct_nocheck+0x42e/0x470
        submit_bio_noacct+0x4c2/0xbb0
        flush_deferred_bios+0x136/0x170
        raid5_do_work+0x262/0x330

 2) The r5l_reclaim thread will hang in the same way, submitting a
    bio to the block layer:

        io_schedule+0x70/0xb0
        rq_qos_wait+0x153/0x210
        wbt_wait+0x115/0x1b0
        __rq_qos_throttle+0x38/0x60
        blk_mq_submit_bio+0x589/0xcd0
        __submit_bio+0xe6/0x100
        submit_bio_noacct_nocheck+0x42e/0x470
        submit_bio_noacct+0x4c2/0xbb0
        submit_bio+0x3f/0xf0
        md_super_write+0x12f/0x1b0
        md_update_sb.part.0+0x7c6/0xff0
        md_update_sb+0x30/0x60
        r5l_do_reclaim+0x4f9/0x5e0
        r5l_reclaim_thread+0x69/0x30b

    However, before hanging, the MD_SB_CHANGE_PENDING flag will be
    set for sb_flags in r5l_write_super_and_discard_space(). This
    flag will never be cleared because the submit_bio() call never
    returns.

 3) Due to the MD_SB_CHANGE_PENDING flag being set, handle_stripe()
    will do no processing on any pending stripes and re-set
    STRIPE_HANDLE. This will cause the raid5d thread to enter an
    infinite loop, constantly trying to handle the same stripes
    stuck in the queue.

    The raid5d thread has a blk_plug that holds a number of bios
    that are also stuck waiting seeing the thread is in a loop
    that never schedules. These bios have been accounted for by
    blk-wbt thus preventing the other threads above from
    continuing when they try to submit bios. --Deadlock.

To fix this, add the same wait_event() that is used in raid5_do_work()
to raid5d() such that if MD_SB_CHANGE_PENDING is set, the thread will
schedule and wait until the flag is cleared. The schedule action will
flush the plug which will allow the r5l_reclaim thread to continue,
thus preventing the deadlock.

However, md_check_recovery() calls can also clear MD_SB_CHANGE_PENDING
from the same thread and can thus deadlock if the thread is put to
sleep. So avoid waiting if md_check_recovery() is being called in the
loop.

It's not clear when the deadlock was introduced, but the similar
wait_event() call in raid5_do_work() was added in 2017 by this
commit:

    16d997b78b15 ("md/raid5: simplfy delaying of writes while metadata
                   is updated.")

Link: https://lore.kernel.org/r/7f3b87b6-b52a-f737-51d7-a4eec5c44112@deltatee.com
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-26 12:35:49 +02:00
Coly Li
1b4ed920b2 bcache: fix set_at_max_writeback_rate() for multiple attached devices
[ Upstream commit d2d05b88035d2d51a5bb6c5afec88a0880c73df4 ]

Inside set_at_max_writeback_rate() the calculation in following if()
check is wrong,
	if (atomic_inc_return(&c->idle_counter) <
	    atomic_read(&c->attached_dev_nr) * 6)

Because each attached backing device has its own writeback thread
running and increasing c->idle_counter, the counter increates much
faster than expected. The correct calculation should be,
	(counter / dev_nr) < dev_nr * 6
which equals to,
	counter < dev_nr * dev_nr * 6

This patch fixes the above mistake with correct calculation, and helper
routine idle_counter_exceeded() is added to make code be more clear.

Reported-by: Mingzhe Zou <mingzhe.zou@easystack.cn>
Signed-off-by: Coly Li <colyli@suse.de>
Acked-by: Mingzhe Zou <mingzhe.zou@easystack.cn>
Link: https://lore.kernel.org/r/20220919161647.81238-6-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-26 12:35:48 +02:00
David Sloan
7a37c58ee7 md/raid5: Remove unnecessary bio_put() in raid5_read_one_chunk()
[ Upstream commit c66a6f41e09ad386fd2cce22b9cded837bbbc704 ]

When running chunk-sized reads on disks with badblocks duplicate bio
free/puts are observed:

   =============================================================================
   BUG bio-200 (Not tainted): Object already free
   -----------------------------------------------------------------------------
   Allocated in mempool_alloc_slab+0x17/0x20 age=3 cpu=2 pid=7504
    __slab_alloc.constprop.0+0x5a/0xb0
    kmem_cache_alloc+0x31e/0x330
    mempool_alloc_slab+0x17/0x20
    mempool_alloc+0x100/0x2b0
    bio_alloc_bioset+0x181/0x460
    do_mpage_readpage+0x776/0xd00
    mpage_readahead+0x166/0x320
    blkdev_readahead+0x15/0x20
    read_pages+0x13f/0x5f0
    page_cache_ra_unbounded+0x18d/0x220
    force_page_cache_ra+0x181/0x1c0
    page_cache_sync_ra+0x65/0xb0
    filemap_get_pages+0x1df/0xaf0
    filemap_read+0x1e1/0x700
    blkdev_read_iter+0x1e5/0x330
    vfs_read+0x42a/0x570
   Freed in mempool_free_slab+0x17/0x20 age=3 cpu=2 pid=7504
    kmem_cache_free+0x46d/0x490
    mempool_free_slab+0x17/0x20
    mempool_free+0x66/0x190
    bio_free+0x78/0x90
    bio_put+0x100/0x1a0
    raid5_make_request+0x2259/0x2450
    md_handle_request+0x402/0x600
    md_submit_bio+0xd9/0x120
    __submit_bio+0x11f/0x1b0
    submit_bio_noacct_nocheck+0x204/0x480
    submit_bio_noacct+0x32e/0xc70
    submit_bio+0x98/0x1a0
    mpage_readahead+0x250/0x320
    blkdev_readahead+0x15/0x20
    read_pages+0x13f/0x5f0
    page_cache_ra_unbounded+0x18d/0x220
   Slab 0xffffea000481b600 objects=21 used=0 fp=0xffff8881206d8940 flags=0x17ffffc0010201(locked|slab|head|node=0|zone=2|lastcpupid=0x1fffff)
   CPU: 0 PID: 34525 Comm: kworker/u24:2 Not tainted 6.0.0-rc2-localyes-265166-gf11c5343fa3f 
   Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-1ubuntu1.1 04/01/2014
   Workqueue: raid5wq raid5_do_work
   Call Trace:
    <TASK>
    dump_stack_lvl+0x5a/0x78
    dump_stack+0x10/0x16
    print_trailer+0x158/0x165
    object_err+0x35/0x50
    free_debug_processing.cold+0xb7/0xbe
    __slab_free+0x1ae/0x330
    kmem_cache_free+0x46d/0x490
    mempool_free_slab+0x17/0x20
    mempool_free+0x66/0x190
    bio_free+0x78/0x90
    bio_put+0x100/0x1a0
    mpage_end_io+0x36/0x150
    bio_endio+0x2fd/0x360
    md_end_io_acct+0x7e/0x90
    bio_endio+0x2fd/0x360
    handle_failed_stripe+0x960/0xb80
    handle_stripe+0x1348/0x3760
    handle_active_stripes.constprop.0+0x72a/0xaf0
    raid5_do_work+0x177/0x330
    process_one_work+0x616/0xb20
    worker_thread+0x2bd/0x6f0
    kthread+0x179/0x1b0
    ret_from_fork+0x22/0x30
    </TASK>

The double free is caused by an unnecessary bio_put() in the
if(is_badblock(...)) error path in raid5_read_one_chunk().

The error path was moved ahead of bio_alloc_clone() in c82aa1b76787c
("md/raid5: move checking badblock before clone bio in
raid5_read_one_chunk"). The previous code checked and freed align_bio
which required a bio_put. After the move that is no longer needed as
raid_bio is returned to the control of the common io path which
performs its own endio resulting in a double free on bad device blocks.

Fixes: c82aa1b76787c ("md/raid5: move checking badblock before clone bio in raid5_read_one_chunk")
Signed-off-by: David Sloan <david.sloan@eideticom.com>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Guoqing Jiang <Guoqing.jiang@linux.dev>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-26 12:35:12 +02:00
Logan Gunthorpe
b467d9460e md/raid5: Ensure stripe_fill happens on non-read IO with journal
[ Upstream commit e2eed85bc75138a9eeb63863d20f8904ac42a577 ]

When doing degrade/recover tests using the journal a kernel BUG
is hit at drivers/md/raid5.c:4381 in handle_parity_checks5():

  BUG_ON(!test_bit(R5_UPTODATE, &dev->flags));

This was found to occur because handle_stripe_fill() was skipped
for stripes in the journal due to a condition in that function.
Thus blocks were not fetched and R5_UPTODATE was not set when
the code reached handle_parity_checks5().

To fix this, don't skip handle_stripe_fill() unless the stripe is
for read.

Fixes: 07e83364845e ("md/r5cache: shift complex rmw from read path to write path")
Link: https://lore.kernel.org/linux-raid/e05c4239-41a9-d2f7-3cfa-4aa9d2cea8c1@deltatee.com/
Suggested-by: Song Liu <song@kernel.org>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-26 12:35:12 +02:00
Saurabh Sengar
5d8259c9d1 md: Replace snprintf with scnprintf
[ Upstream commit 1727fd5015d8f93474148f94e34cda5aa6ad4a43 ]

Current code produces a warning as shown below when total characters
in the constituent block device names plus the slashes exceeds 200.
snprintf() returns the number of characters generated from the given
input, which could cause the expression “200 – len” to wrap around
to a large positive number. Fix this by using scnprintf() instead,
which returns the actual number of characters written into the buffer.

[ 1513.267938] ------------[ cut here ]------------
[ 1513.267943] WARNING: CPU: 15 PID: 37247 at <snip>/lib/vsprintf.c:2509 vsnprintf+0x2c8/0x510
[ 1513.267944] Modules linked in:  <snip>
[ 1513.267969] CPU: 15 PID: 37247 Comm: mdadm Not tainted 5.4.0-1085-azure #90~18.04.1-Ubuntu
[ 1513.267969] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.1 05/09/2022
[ 1513.267971] RIP: 0010:vsnprintf+0x2c8/0x510
<-snip->
[ 1513.267982] Call Trace:
[ 1513.267986]  snprintf+0x45/0x70
[ 1513.267990]  ? disk_name+0x71/0xa0
[ 1513.267993]  dump_zones+0x114/0x240 [raid0]
[ 1513.267996]  ? _cond_resched+0x19/0x40
[ 1513.267998]  raid0_run+0x19e/0x270 [raid0]
[ 1513.268000]  md_run+0x5e0/0xc50
[ 1513.268003]  ? security_capable+0x3f/0x60
[ 1513.268005]  do_md_run+0x19/0x110
[ 1513.268006]  md_ioctl+0x195e/0x1f90
[ 1513.268007]  blkdev_ioctl+0x91f/0x9f0
[ 1513.268010]  block_ioctl+0x3d/0x50
[ 1513.268012]  do_vfs_ioctl+0xa9/0x640
[ 1513.268014]  ? __fput+0x162/0x260
[ 1513.268016]  ksys_ioctl+0x75/0x80
[ 1513.268017]  __x64_sys_ioctl+0x1a/0x20
[ 1513.268019]  do_syscall_64+0x5e/0x200
[ 1513.268021]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: 766038846e875 ("md/raid0: replace printk() with pr_*()")
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Acked-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-26 12:35:12 +02:00
David Sloan
a7dff6f41e md: Flush workqueue md_rdev_misc_wq in md_alloc()
[ Upstream commit 5e8daf906f890560df430d30617c692a794acb73 ]

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 <david.sloan@eideticom.com>
[logang@deltatee.com: rewrote commit message]
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-09-15 11:30:01 +02:00
Guoqing Jiang
661c01b218 md: call __md_stop_writes in md_stop
commit 0dd84b319352bb8ba64752d4e45396d8b13e6018 upstream.

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 <mpatocka@redhat.com>
Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-31 17:16:50 +02:00
Guoqing Jiang
ee0c613bfe Revert "md-raid: destroy the bitmap after destroying the thread"
commit 1d258758cf06a0734482989911d184dd5837ed4e upstream.

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 <guoqing.jiang@linux.dev>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-31 17:16:49 +02:00
Wentao_Liang
d9b94c3ace drivers:md:fix a potential use-after-free bug
[ Upstream commit 104212471b1c1817b311771d817fb692af983173 ]

In line 2884, "raid5_release_stripe(sh);" drops the reference to sh and
may cause sh to be released. However, sh is subsequently used in lines
2886 "if (sh->batch_head && sh != sh->batch_head)". This may result in an
use-after-free bug.

It can be fixed by moving "raid5_release_stripe(sh);" to the bottom of
the function.

Signed-off-by: Wentao_Liang <Wentao_Liang_g@163.com>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-25 11:40:39 +02:00
Logan Gunthorpe
e59ef9b071 md: Notify sysfs sync_completed in md_reap_sync_thread()
[ Upstream commit 9973f0fa7d20269fe6fefe6333997fb5914449c1 ]

The mdadm test 07layouts randomly produces a kernel hung task deadlock.
The deadlock is caused by the suspend_lo/suspend_hi files being set by
the mdadm background process during reshape and not being cleared
because the process hangs. (Leaving aside the issue of the fragility of
freezing kernel tasks by buggy userspace processes...)

When the background mdadm process hangs it, is waiting (without a
timeout) on a change to the sync_completed file signalling that the
reshape has completed. The process is woken up a couple times when
the reshape finishes but it is woken up before MD_RECOVERY_RUNNING
is cleared so sync_completed_show() reports 0 instead of "none".

To fix this, notify the sysfs file in md_reap_sync_thread() after
MD_RECOVERY_RUNNING has been cleared. This wakes up mdadm and causes
it to continue and write to suspend_lo/suspend_hi to allow IO to
continue.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-25 11:40:39 +02:00
Mikulas Patocka
50235d9a1f dm raid: fix address sanitizer warning in raid_resume
[ Upstream commit 7dad24db59d2d2803576f2e3645728866a056dab ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-17 14:24:26 +02:00
Mikulas Patocka
4c233811a4 dm raid: fix address sanitizer warning in raid_status
[ Upstream commit 1fbeea217d8f297fe0e0956a1516d14ba97d0396 ]

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> 
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-17 14:24:26 +02:00
Luo Meng
f83131a307 dm thin: fix use-after-free crash in dm_sm_register_threshold_callback
[ Upstream commit 3534e5a5ed2997ca1b00f44a0378a075bd05e8a3 ]

Fault inject on pool metadata device reports:
  BUG: KASAN: use-after-free in dm_pool_register_metadata_threshold+0x40/0x80
  Read of size 8 at addr ffff8881b9d50068 by task dmsetup/950

  CPU: 7 PID: 950 Comm: dmsetup Tainted: G        W         5.19.0-rc6 
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-1.fc33 04/01/2014
  Call Trace:
   <TASK>
   dump_stack_lvl+0x34/0x44
   print_address_description.constprop.0.cold+0xeb/0x3f4
   kasan_report.cold+0xe6/0x147
   dm_pool_register_metadata_threshold+0x40/0x80
   pool_ctr+0xa0a/0x1150
   dm_table_add_target+0x2c8/0x640
   table_load+0x1fd/0x430
   ctl_ioctl+0x2c4/0x5a0
   dm_ctl_ioctl+0xa/0x10
   __x64_sys_ioctl+0xb3/0xd0
   do_syscall_64+0x35/0x80
   entry_SYSCALL_64_after_hwframe+0x46/0xb0

This can be easily reproduced using:
  echo offline > /sys/block/sda/device/state
  dd if=/dev/zero of=/dev/mapper/thin bs=4k count=10
  dmsetup load pool --table "0 20971520 thin-pool /dev/sda /dev/sdb 128 0 0"

If a metadata commit fails, the transaction will be aborted and the
metadata space maps will be destroyed. If a DM table reload then
happens for this failed thin-pool, a use-after-free will occur in
dm_sm_register_threshold_callback (called from
dm_pool_register_metadata_threshold).

Fix this by in dm_pool_register_metadata_threshold() by returning the
-EINVAL error if the thin-pool is in fail mode. Also fail pool_ctr()
with a new error message: "Error registering metadata threshold".

Fixes: ac8c3f3df65e4 ("dm thin: generate event when metadata threshold passed")
Cc: stable@vger.kernel.org
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Luo Meng <luomeng12@huawei.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-17 14:24:23 +02:00
Mikulas Patocka
9769bd964d dm writecache: set a default MAX_WRITEBACK_JOBS
[ Upstream commit ca7dc242e358e46d963b32f9d9dd829785a9e957 ]

dm-writecache has the capability to limit the number of writeback jobs
in progress. However, this feature was off by default. As such there
were some out-of-memory crashes observed when lowering the low
watermark while the cache is full.

This commit enables writeback limit by default. It is set to 256MiB or
1/16 of total system memory, whichever is smaller.

Cc: stable@vger.kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-17 14:24:23 +02:00
Mike Snitzer
87efb79c5f dm: return early from dm_pr_call() if DM device is suspended
[ Upstream commit e120a5f1e78fab6223544e425015f393d90d6f0d ]

Otherwise PR ops may be issued while the broader DM device is being
reconfigured, etc.

Fixes: 9c72bad1f31a ("dm: call PR reserve/unreserve on each underlying device")
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-17 14:23:15 +02:00
Mikulas Patocka
a638fa9745 dm writecache: count number of blocks discarded, not number of discard bios
[ Upstream commit 2ee73ef60db4d79b9f9b8cd501e8188b5179449f ]

Change dm-writecache, so that it counts the number of blocks discarded
instead of the number of discard bios. Make it consistent with the
read and write statistics counters that were changed to count the
number of blocks instead of bios.

Fixes: e3a35d03407c ("dm writecache: add event counters")
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-17 14:23:13 +02:00
Mikulas Patocka
fc988f1ca2 dm writecache: count number of blocks written, not number of write bios
[ Upstream commit b2676e1482af89714af6988ce5d31a84692e2530 ]

Change dm-writecache, so that it counts the number of blocks written
instead of the number of write bios. Bios can be split and requeued
using the dm_accept_partial_bio function, so counting bios caused
inaccurate results.

Fixes: e3a35d03407c ("dm writecache: add event counters")
Reported-by: Yu Kuai <yukuai1@huaweicloud.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-17 14:23:13 +02:00
Mikulas Patocka
3a2500b73a dm writecache: count number of blocks read, not number of read bios
[ Upstream commit 2c6e755b49d273243431f5f1184654e71221fc78 ]

Change dm-writecache, so that it counts the number of blocks read
instead of the number of read bios. Bios can be split and requeued
using the dm_accept_partial_bio function, so counting bios caused
inaccurate results.

Fixes: e3a35d03407c ("dm writecache: add event counters")
Reported-by: Yu Kuai <yukuai1@huaweicloud.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-17 14:23:13 +02:00
Mikulas Patocka
880c4513eb dm writecache: return void from functions
[ Upstream commit 9bc0c92e4b82adb017026dbb2aa816b1ac2bef31 ]

The functions writecache_map_remap_origin and writecache_bio_copy_ssd
only return a single value, thus they can be made to return void.

This helps simplify the following IO accounting changes.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-17 14:23:13 +02:00
Mikulas Patocka
0f4d18cbea md-raid10: fix KASAN warning
commit d17f744e883b2f8d13cca252d71cfe8ace346f7d upstream.

There's a KASAN warning in raid10_remove_disk when running the lvm
test lvconvert-raid-reshape.sh. We fix this warning by verifying that the
value "number" is valid.

BUG: KASAN: slab-out-of-bounds in raid10_remove_disk+0x61/0x2a0 [raid10]
Read of size 8 at addr ffff889108f3d300 by task mdX_raid10/124682

CPU: 3 PID: 124682 Comm: mdX_raid10 Not tainted 5.19.0-rc6 
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x34/0x44
 print_report.cold+0x45/0x57a
 ? __lock_text_start+0x18/0x18
 ? raid10_remove_disk+0x61/0x2a0 [raid10]
 kasan_report+0xa8/0xe0
 ? raid10_remove_disk+0x61/0x2a0 [raid10]
 raid10_remove_disk+0x61/0x2a0 [raid10]
Buffer I/O error on dev dm-76, logical block 15344, async page read
 ? __mutex_unlock_slowpath.constprop.0+0x1e0/0x1e0
 remove_and_add_spares+0x367/0x8a0 [md_mod]
 ? super_written+0x1c0/0x1c0 [md_mod]
 ? mutex_trylock+0xac/0x120
 ? _raw_spin_lock+0x72/0xc0
 ? _raw_spin_lock_bh+0xc0/0xc0
 md_check_recovery+0x848/0x960 [md_mod]
 raid10d+0xcf/0x3360 [raid10]
 ? sched_clock_cpu+0x185/0x1a0
 ? rb_erase+0x4d4/0x620
 ? 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
 ? raid10_sync_request+0x36c0/0x36c0 [raid10]
 ? 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
 ? _raw_spin_unlock_irq+0x11/0x24
 ? __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
 </TASK>

Allocated by task 124495:
 kasan_save_stack+0x1e/0x40
 __kasan_kmalloc+0x80/0xa0
 setup_conf+0x140/0x5c0 [raid10]
 raid10_run+0x4cd/0x740 [raid10]
 md_run+0x6f9/0x1300 [md_mod]
 raid_ctr+0x2531/0x4ac0 [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

Last potentially related work creation:
 kasan_save_stack+0x1e/0x40
 __kasan_record_aux_stack+0x9e/0xc0
 kvfree_call_rcu+0x84/0x480
 timerfd_release+0x82/0x140
L __fput+0xfa/0x400
 task_work_run+0x80/0xc0
 exit_to_user_mode_prepare+0x155/0x160
 syscall_exit_to_user_mode+0x12/0x40
 do_syscall_64+0x42/0xc0
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

Second to last potentially related work creation:
 kasan_save_stack+0x1e/0x40
 __kasan_record_aux_stack+0x9e/0xc0
 kvfree_call_rcu+0x84/0x480
 timerfd_release+0x82/0x140
 __fput+0xfa/0x400
 task_work_run+0x80/0xc0
 exit_to_user_mode_prepare+0x155/0x160
 syscall_exit_to_user_mode+0x12/0x40
 do_syscall_64+0x42/0xc0
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

The buggy address belongs to the object at ffff889108f3d200
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 0 bytes to the right of
 256-byte region [ffff889108f3d200, ffff889108f3d300)

The buggy address belongs to the physical page:
page:000000007ef2a34c refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1108f3c
head:000000007ef2a34c order:2 compound_mapcount:0 compound_pincount:0
flags: 0x4000000000010200(slab|head|zone=2)
raw: 4000000000010200 0000000000000000 dead000000000001 ffff889100042b40
raw: 0000000000000000 0000000080200020 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff889108f3d200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff889108f3d280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff889108f3d300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                   ^
 ffff889108f3d380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff889108f3d400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-17 14:22:57 +02:00
Mikulas Patocka
c5e4cdd443 md-raid: destroy the bitmap after destroying the thread
commit e151db8ecfb019b7da31d076130a794574c89f6f upstream.

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 
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014
Call Trace:
 <TASK>
 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
 </TASK>

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 <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 48df498daf62 ("md: move bitmap_destroy to the beginning of __md_stop")
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-17 14:22:56 +02:00
Mikulas Patocka
d5b06039b1 dm raid: fix KASAN warning in raid5_add_disks
commit 617b365872a247480e9dcd50a32c8d1806b21861 upstream.

There's a KASAN warning in raid5_add_disk when running the LVM testsuite.
The warning happens in the test
lvconvert-raid-reshape-linear_to_raid6-single-type.sh. We fix the warning
by verifying that rdev->saved_raid_disk is within limits.

Cc: stable@vger.kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-07 17:53:24 +02:00
Heinz Mauelshagen
6352b2f4d8 dm raid: fix accesses beyond end of raid member array
commit 332bd0778775d0cf105c4b9e03e460b590749916 upstream.

On dm-raid table load (using raid_ctr), dm-raid allocates an array
rs->devs[rs->raid_disks] for the raid device members. rs->raid_disks
is defined by the number of raid metadata and image tupples passed
into the target's constructor.

In the case of RAID layout changes being requested, that number can be
different from the current number of members for existing raid sets as
defined in their superblocks. Example RAID layout changes include:
- raid1 legs being added/removed
- raid4/5/6/10 number of stripes changed (stripe reshaping)
- takeover to higher raid level (e.g. raid5 -> raid6)

When accessing array members, rs->raid_disks must be used in control
loops instead of the potentially larger value in rs->md.raid_disks.
Otherwise it will cause memory access beyond the end of the rs->devs
array.

Fix this by changing code that is prone to out-of-bounds access.
Also fix validate_raid_redundancy() to validate all devices that are
added. Also, use braces to help clean up raid_iterate_devices().

The out-of-bounds memory accesses was discovered using KASAN.

This commit was verified to pass all LVM2 RAID tests (with KASAN
enabled).

Cc: stable@vger.kernel.org
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-07 17:53:24 +02:00
Coly Li
1cdcd496b7 bcache: memset on stack variables in bch_btree_check() and bch_sectors_dirty_init()
commit 7d6b902ea0e02b2a25c480edf471cbaa4ebe6b3c upstream.

The local variables check_state (in bch_btree_check()) and state (in
bch_sectors_dirty_init()) should be fully filled by 0, because before
allocating them on stack, they were dynamically allocated by kzalloc().

Signed-off-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20220527152818.27545-2-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-02 16:41:12 +02:00
Mikulas Patocka
c3f51b28a8 dm mirror log: clear log bits up to BITS_PER_LONG boundary
commit 90736eb3232d208ee048493f371075e4272e0944 upstream.

Commit 85e123c27d5c ("dm mirror log: round up region bitmap size to
BITS_PER_LONG") introduced a regression on 64-bit architectures in the
lvm testsuite tests: lvcreate-mirror, mirror-names and vgsplit-operation.

If the device is shrunk, we need to clear log bits beyond the end of the
device. The code clears bits up to a 32-bit boundary and then calculates
lc->sync_count by summing set bits up to a 64-bit boundary (the commit
changed that; previously, this boundary was 32-bit too). So, it was using
some non-zeroed bits in the calculation and this caused misbehavior.

Fix this regression by clearing bits up to BITS_PER_LONG boundary.

Fixes: 85e123c27d5c ("dm mirror log: round up region bitmap size to BITS_PER_LONG")
Cc: stable@vger.kernel.org
Reported-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-29 09:03:20 +02:00
Nikos Tsironis
ac0a5f701f dm era: commit metadata in postsuspend after worker stops
commit 9ae6e8b1c9bbf6874163d1243e393137313762b7 upstream.

During postsuspend dm-era does the following:

1. Archives the current era
2. Commits the metadata, as part of the RPC call for archiving the
   current era
3. Stops the worker

Until the worker stops, it might write to the metadata again. Moreover,
these writes are not flushed to disk immediately, but are cached by the
dm-bufio client, which writes them back asynchronously.

As a result, the committed metadata of a suspended dm-era device might
not be consistent with the in-core metadata.

In some cases, this can result in the corruption of the on-disk
metadata. Suppose the following sequence of events:

1. Load a new table, e.g. a snapshot-origin table, to a device with a
   dm-era table
2. Suspend the device
3. dm-era commits its metadata, but the worker does a few more metadata
   writes until it stops, as part of digesting an archived writeset
4. These writes are cached by the dm-bufio client
5. Load the dm-era table to another device.
6. The new instance of the dm-era target loads the committed, on-disk
   metadata, which don't include the extra writes done by the worker
   after the metadata commit.
7. Resume the new device
8. The new dm-era target instance starts using the metadata
9. Resume the original device
10. The destructor of the old dm-era target instance is called and
    destroys the dm-bufio client, which results in flushing the cached
    writes to disk
11. These writes might overwrite the writes done by the new dm-era
    instance, hence corrupting its metadata.

Fix this by committing the metadata after the worker stops running.

stop_worker uses flush_workqueue to flush the current work. However, the
work item may re-queue itself and flush_workqueue doesn't wait for
re-queued works to finish.

This could result in the worker changing the metadata after they have
been committed, or writing to the metadata concurrently with the commit
in the postsuspend thread.

Use drain_workqueue instead, which waits until the work and all
re-queued works finish.

Fixes: eec40579d8487 ("dm: add era target")
Cc: stable@vger.kernel.org # v3.15+
Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-29 09:03:20 +02:00
Mikulas Patocka
0d2209b54f dm mirror log: round up region bitmap size to BITS_PER_LONG
commit 85e123c27d5cbc22cfdc01de1e2ca1d9003a02d0 upstream.

The code in dm-log rounds up bitset_size to 32 bits. It then uses
find_next_zero_bit_le on the allocated region. find_next_zero_bit_le
accesses the bitmap using unsigned long pointers. So, on 64-bit
architectures, it may access 4 bytes beyond the allocated size.

Fix this bug by rounding up bitset_size to BITS_PER_LONG.

This bug was found by running the lvm2 testsuite with kasan.

Fixes: 29121bd0b00e ("[PATCH] dm mirror log: bitset_size fix")
Cc: stable@vger.kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-22 14:22:04 +02:00
Pascal Hambourg
4c106eb895 md/raid0: Ignore RAID0 layout if the second zone has only one device
commit ea23994edc4169bd90d7a9b5908c6ccefd82fa40 upstream.

The RAID0 layout is irrelevant if all members have the same size so the
array has only one zone. It is *also* irrelevant if the array has two
zones and the second zone has only one device, for example if the array
has two members of different sizes.

So in that case it makes sense to allow assembly even when the layout is
undefined, like what is done when the array has only one zone.

Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Pascal Hambourg <pascal@plouf.fr.eu.org>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-14 18:36:28 +02:00
Guoqing Jiang
b5a0f17b03 md: protect md_unregister_thread from reentrancy
[ Upstream commit 1e267742283a4b5a8ca65755c44166be27e9aa0f ]

Generally, the md_unregister_thread is called with reconfig_mutex, but
raid_message in dm-raid doesn't hold reconfig_mutex to unregister thread,
so md_unregister_thread can be called simulitaneously from two call sites
in theory.

Then after previous commit which remove the protection of reconfig_mutex
for md_unregister_thread completely, the potential issue could be worse
than before.

Let's take pers_lock at the beginning of function to ensure reentrancy.

Reported-by: Donald Buczek <buczek@molgen.mpg.de>
Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-14 18:36:22 +02:00
Jia-Ju Bai
2027647245 md: bcache: check the return value of kzalloc() in detached_dev_do_request()
commit 40f567bbb3b0639d2ec7d1c6ad4b1b018f80cf19 upstream.

The function kzalloc() in detached_dev_do_request() can fail, so its
return value should be checked.

Fixes: bc082a55d25c ("bcache: fix inaccurate io state for detached bcache devices")
Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20220527152818.27545-4-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-09 10:23:32 +02:00
Xiao Ni
36a2fc44c5 md: fix double free of io_acct_set bioset
commit 42b805af102471f53e3c7867b8c2b502ea4eef7e upstream.

Now io_acct_set is alloc and free in personality. Remove the codes that
free io_acct_set in md_free and md_stop.

Fixes: 0c031fd37f69 (md: Move alloc/free acct bioset in to personality)
Signed-off-by: Xiao Ni <xni@redhat.com>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-09 10:23:32 +02:00
Xiao Ni
f63fd1e0e0 md: Don't set mddev private to NULL in raid0 pers->free
commit 0f2571ad7a30ff6b33cde142439f9378669f8b4f upstream.

In normal stop process, it does like this:
   do_md_stop
      |
   __md_stop (pers->free(); mddev->private=NULL)
      |
   md_free (free mddev)
__md_stop sets mddev->private to NULL after pers->free. The raid device
will be stopped and mddev memory is free. But in reshape, it doesn't
free the mddev and mddev will still be used in new raid.

In reshape, it first sets mddev->private to new_pers and then runs
old_pers->free(). Now raid0 sets mddev->private to NULL in raid0_free.
The new raid can't work anymore. It will panic when dereference
mddev->private because of NULL pointer dereference.

It can panic like this:
[63010.814972] kernel BUG at drivers/md/raid10.c:928!
[63010.819778] invalid opcode: 0000 [] PREEMPT SMP NOPTI
[63010.825011] CPU: 3 PID: 44437 Comm: md0_resync Kdump: loaded Not tainted 5.14.0-86.el9.x86_64 
[63010.833789] Hardware name: Dell Inc. PowerEdge R6415/07YXFK, BIOS 1.15.0 09/11/2020
[63010.841440] RIP: 0010:raise_barrier+0x161/0x170 [raid10]
[63010.865508] RSP: 0018:ffffc312408bbc10 EFLAGS: 00010246
[63010.870734] RAX: 0000000000000000 RBX: ffffa00bf7d39800 RCX: 0000000000000000
[63010.877866] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffa00bf7d39800
[63010.884999] RBP: 0000000000000000 R08: fffffa4945e74400 R09: 0000000000000000
[63010.892132] R10: ffffa00eed02f798 R11: 0000000000000000 R12: ffffa00bbc435200
[63010.899266] R13: ffffa00bf7d39800 R14: 0000000000000400 R15: 0000000000000003
[63010.906399] FS:  0000000000000000(0000) GS:ffffa00eed000000(0000) knlGS:0000000000000000
[63010.914485] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[63010.920229] CR2: 00007f5cfbe99828 CR3: 0000000105efe000 CR4: 00000000003506e0
[63010.927363] Call Trace:
[63010.929822]  ? bio_reset+0xe/0x40
[63010.933144]  ? raid10_alloc_init_r10buf+0x60/0xa0 [raid10]
[63010.938629]  raid10_sync_request+0x756/0x1610 [raid10]
[63010.943770]  md_do_sync.cold+0x3e4/0x94c
[63010.947698]  md_thread+0xab/0x160
[63010.951024]  ? md_write_inc+0x50/0x50
[63010.954688]  kthread+0x149/0x170
[63010.957923]  ? set_kthread_struct+0x40/0x40
[63010.962107]  ret_from_fork+0x22/0x30

Removing the code that sets mddev->private to NULL in raid0 can fix
problem.

Fixes: 0c031fd37f69 (md: Move alloc/free acct bioset in to personality)
Reported-by: Fine Fan <ffan@redhat.com>
Signed-off-by: Xiao Ni <xni@redhat.com>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-09 10:23:32 +02:00
Coly Li
5607652823 bcache: avoid journal no-space deadlock by reserving 1 journal bucket
commit 32feee36c30ea06e38ccb8ae6e5c44c6eec790a6 upstream.

The journal no-space deadlock was reported time to time. Such deadlock
can happen in the following situation.

When all journal buckets are fully filled by active jset with heavy
write I/O load, the cache set registration (after a reboot) will load
all active jsets and inserting them into the btree again (which is
called journal replay). If a journaled bkey is inserted into a btree
node and results btree node split, new journal request might be
triggered. For example, the btree grows one more level after the node
split, then the root node record in cache device super block will be
upgrade by bch_journal_meta() from bch_btree_set_root(). But there is no
space in journal buckets, the journal replay has to wait for new journal
bucket to be reclaimed after at least one journal bucket replayed. This
is one example that how the journal no-space deadlock happens.

The solution to avoid the deadlock is to reserve 1 journal bucket in
run time, and only permit the reserved journal bucket to be used during
cache set registration procedure for things like journal replay. Then
the journal space will never be fully filled, there is no chance for
journal no-space deadlock to happen anymore.

This patch adds a new member "bool do_reserve" in struct journal, it is
inititalized to 0 (false) when struct journal is allocated, and set to
1 (true) by bch_journal_space_reserve() when all initialization done in
run_cache_set(). In the run time when journal_reclaim() tries to
allocate a new journal bucket, free_journal_buckets() is called to check
whether there are enough free journal buckets to use. If there is only
1 free journal bucket and journal->do_reserve is 1 (true), the last
bucket is reserved and free_journal_buckets() will return 0 to indicate
no free journal bucket. Then journal_reclaim() will give up, and try
next time to see whetheer there is free journal bucket to allocate. By
this method, there is always 1 jouranl bucket reserved in run time.

During the cache set registration, journal->do_reserve is 0 (false), so
the reserved journal bucket can be used to avoid the no-space deadlock.

Reported-by: Nikhil Kshirsagar <nkshirsagar@gmail.com>
Signed-off-by: Coly Li <colyli@suse.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220524102336.10684-5-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-09 10:23:29 +02:00
Coly Li
cc7ff57a0a bcache: remove incremental dirty sector counting for bch_sectors_dirty_init()
commit 80db4e4707e78cb22287da7d058d7274bd4cb370 upstream.

After making bch_sectors_dirty_init() being multithreaded, the existing
incremental dirty sector counting in bch_root_node_dirty_init() doesn't
release btree occupation after iterating 500000 (INIT_KEYS_EACH_TIME)
bkeys. Because a read lock is added on btree root node to prevent the
btree to be split during the dirty sectors counting, other I/O requester
has no chance to gain the write lock even restart bcache_btree().

That is to say, the incremental dirty sectors counting is incompatible
to the multhreaded bch_sectors_dirty_init(). We have to choose one and
drop another one.

In my testing, with 512 bytes random writes, I generate 1.2T dirty data
and a btree with 400K nodes. With single thread and incremental dirty
sectors counting, it takes 30+ minites to register the backing device.
And with multithreaded dirty sectors counting, the backing device
registration can be accomplished within 2 minutes.

The 30+ minutes V.S. 2- minutes difference makes me decide to keep
multithreaded bch_sectors_dirty_init() and drop the incremental dirty
sectors counting. This is what this patch does.

But INIT_KEYS_EACH_TIME is kept, in sectors_dirty_init_fn() the CPU
will be released by cond_resched() after every INIT_KEYS_EACH_TIME keys
iterated. This is to avoid the watchdog reports a bogus soft lockup
warning.

Fixes: b144e45fc576 ("bcache: make bch_sectors_dirty_init() to be multithreaded")
Signed-off-by: Coly Li <colyli@suse.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220524102336.10684-4-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-09 10:23:28 +02:00
Coly Li
df973468f9 bcache: improve multithreaded bch_sectors_dirty_init()
commit 4dc34ae1b45fe26e772a44379f936c72623dd407 upstream.

Commit b144e45fc576 ("bcache: make bch_sectors_dirty_init() to be
multithreaded") makes bch_sectors_dirty_init() to be much faster
when counting dirty sectors by iterating all dirty keys in the btree.
But it isn't in ideal shape yet, still can be improved.

This patch does the following changes to improve current parallel dirty
keys iteration on the btree,
- Add read lock to root node when multiple threads iterating the btree,
  to prevent the root node gets split by I/Os from other registered
  bcache devices.
- Remove local variable "char name[32]" and generate kernel thread name
  string directly when calling kthread_run().
- Allocate "struct bch_dirty_init_state state" directly on stack and
  avoid the unnecessary dynamic memory allocation for it.
- Decrease BCH_DIRTY_INIT_THRD_MAX from 64 to 12 which is enough indeed.
- Increase &state->started to count created kernel thread after it
  succeeds to create.
- When wait for all dirty key counting threads to finish, use
  wait_event() to replace wait_event_interruptible().

With the above changes, the code is more clear, and some potential error
conditions are avoided.

Fixes: b144e45fc576 ("bcache: make bch_sectors_dirty_init() to be multithreaded")
Signed-off-by: Coly Li <colyli@suse.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220524102336.10684-3-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-09 10:23:28 +02:00
Coly Li
a5580b90d3 bcache: improve multithreaded bch_btree_check()
commit 622536443b6731ec82c563aae7807165adbe9178 upstream.

Commit 8e7102273f59 ("bcache: make bch_btree_check() to be
multithreaded") makes bch_btree_check() to be much faster when checking
all btree nodes during cache device registration. But it isn't in ideal
shap yet, still can be improved.

This patch does the following thing to improve current parallel btree
nodes check by multiple threads in bch_btree_check(),
- Add read lock to root node while checking all the btree nodes with
  multiple threads. Although currently it is not mandatory but it is
  good to have a read lock in code logic.
- Remove local variable 'char name[32]', and generate kernel thread name
  string directly when calling kthread_run().
- Allocate local variable "struct btree_check_state check_state" on the
  stack and avoid unnecessary dynamic memory allocation for it.
- Reduce BCH_BTR_CHKTHREAD_MAX from 64 to 12 which is enough indeed.
- Increase check_state->started to count created kernel thread after it
  succeeds to create.
- When wait for all checking kernel threads to finish, use wait_event()
  to replace wait_event_interruptible().

With this change, the code is more clear, and some potential error
conditions are avoided.

Fixes: 8e7102273f59 ("bcache: make bch_btree_check() to be multithreaded")
Signed-off-by: Coly Li <colyli@suse.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220524102336.10684-2-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-09 10:23:28 +02:00
Xiaomeng Tong
a105177c05 md: fix an incorrect NULL check in md_reload_sb
commit 64c54d9244a4efe9bc6e9c98e13c4bbb8bb39083 upstream.

The bug is here:
	if (!rdev || rdev->desc_nr != nr) {

The list iterator value 'rdev' will *always* be set and non-NULL
by rdev_for_each_rcu(), so it is incorrect to assume that the
iterator value will be NULL if the list is empty or no element
found (In fact, it will be a bogus pointer to an invalid struct
object containing the HEAD). Otherwise it will bypass the check
and lead to invalid memory access passing the check.

To fix the bug, use a new variable 'iter' as the list iterator,
while using the original variable 'pdev' as a dedicated pointer to
point to the found element.

Cc: stable@vger.kernel.org
Fixes: 70bcecdb1534 ("md-cluster: Improve md_reload_sb to be less error prone")
Signed-off-by: Xiaomeng Tong <xiam0nd.tong@gmail.com>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-09 10:23:25 +02:00
Xiaomeng Tong
7907930218 md: fix an incorrect NULL check in does_sb_need_changing
commit fc8738343eefc4ea8afb6122826dea48eacde514 upstream.

The bug is here:
	if (!rdev)

The list iterator value 'rdev' will *always* be set and non-NULL
by rdev_for_each(), so it is incorrect to assume that the iterator
value will be NULL if the list is empty or no element found.
Otherwise it will bypass the NULL check and lead to invalid memory
access passing the check.

To fix the bug, use a new variable 'iter' as the list iterator,
while using the original variable 'rdev' as a dedicated pointer to
point to the found element.

Cc: stable@vger.kernel.org
Fixes: 2aa82191ac36 ("md-cluster: Perform a lazy update")
Acked-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Signed-off-by: Xiaomeng Tong <xiam0nd.tong@gmail.com>
Acked-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-09 10:23:25 +02:00
Heming Zhao
27f672af28 md/bitmap: don't set sb values if can't pass sanity check
[ Upstream commit e68cb83a57a458b01c9739e2ad9cb70b04d1e6d2 ]

If bitmap area contains invalid data, kernel will crash then mdadm
triggers "Segmentation fault".
This is cluster-md speical bug. In non-clustered env, mdadm will
handle broken metadata case. In clustered array, only kernel space
handles bitmap slot info. But even this bug only happened in clustered
env, current sanity check is wrong, the code should be changed.

How to trigger: (faulty injection)

dd if=/dev/zero bs=1M count=1 oflag=direct of=/dev/sda
dd if=/dev/zero bs=1M count=1 oflag=direct of=/dev/sdb
mdadm -C /dev/md0 -b clustered -e 1.2 -n 2 -l mirror /dev/sda /dev/sdb
mdadm -Ss
echo aaa > magic.txt
 == below modifying slot 2 bitmap data ==
dd if=magic.txt of=/dev/sda seek=16384 bs=1 count=3 <== destroy magic
dd if=/dev/zero of=/dev/sda seek=16436 bs=1 count=4 <== ZERO chunksize
mdadm -A /dev/md0 /dev/sda /dev/sdb
 == kernel crashes. mdadm outputs "Segmentation fault" ==

Reason of kernel crash:

In md_bitmap_read_sb (called by md_bitmap_create), bad bitmap magic didn't
block chunksize assignment, and zero value made DIV_ROUND_UP_SECTOR_T()
trigger "divide error".

Crash log:

kernel: md: md0 stopped.
kernel: md/raid1:md0: not clean -- starting background reconstruction
kernel: md/raid1:md0: active with 2 out of 2 mirrors
kernel: dlm: ... ...
kernel: md-cluster: Joined cluster 44810aba-38bb-e6b8-daca-bc97a0b254aa slot 1
kernel: md0: invalid bitmap file superblock: bad magic
kernel: md_bitmap_copy_from_slot can't get bitmap from slot 2
kernel: md-cluster: Could not gather bitmaps from slot 2
kernel: divide error: 0000 [] SMP NOPTI
kernel: CPU: 0 PID: 1603 Comm: mdadm Not tainted 5.14.6-1-default
kernel: Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
kernel: RIP: 0010:md_bitmap_create+0x1d1/0x850 [md_mod]
kernel: RSP: 0018:ffffc22ac0843ba0 EFLAGS: 00010246
kernel: ... ...
kernel: Call Trace:
kernel:  ? dlm_lock_sync+0xd0/0xd0 [md_cluster 77fe..7a0]
kernel:  md_bitmap_copy_from_slot+0x2c/0x290 [md_mod 24ea..d3a]
kernel:  load_bitmaps+0xec/0x210 [md_cluster 77fe..7a0]
kernel:  md_bitmap_load+0x81/0x1e0 [md_mod 24ea..d3a]
kernel:  do_md_run+0x30/0x100 [md_mod 24ea..d3a]
kernel:  md_ioctl+0x1290/0x15a0 [md_mod 24ea....d3a]
kernel:  ? mddev_unlock+0xaa/0x130 [md_mod 24ea..d3a]
kernel:  ? blkdev_ioctl+0xb1/0x2b0
kernel:  block_ioctl+0x3b/0x40
kernel:  __x64_sys_ioctl+0x7f/0xb0
kernel:  do_syscall_64+0x59/0x80
kernel:  ? exit_to_user_mode_prepare+0x1ab/0x230
kernel:  ? syscall_exit_to_user_mode+0x18/0x40
kernel:  ? do_syscall_64+0x69/0x80
kernel:  entry_SYSCALL_64_after_hwframe+0x44/0xae
kernel: RIP: 0033:0x7f4a15fa722b
kernel: ... ...
kernel: ---[ end trace 8afa7612f559c868 ]---
kernel: RIP: 0010:md_bitmap_create+0x1d1/0x850 [md_mod]

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Signed-off-by: Heming Zhao <heming.zhao@suse.com>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-09 10:22:33 +02:00
Mariusz Tkaczyk
6e5bc6f7fe raid5: introduce MD_BROKEN
commit 57668f0a4cc4083a120cc8c517ca0055c4543b59 upstream.

Raid456 module had allowed to achieve failed state. It was fixed by
fb73b357fb9 ("raid5: block failing device if raid will be failed").
This fix introduces a bug, now if raid5 fails during IO, it may result
with a hung task without completion. Faulty flag on the device is
necessary to process all requests and is checked many times, mainly in
analyze_stripe().
Allow to set faulty on drive again and set MD_BROKEN if raid is failed.

As a result, this level is allowed to achieve failed state again, but
communication with userspace (via -EBUSY status) will be preserved.

This restores possibility to fail array via #mdadm --set-faulty command
and will be fixed by additional verification on mdadm side.

Reproduction steps:
 mdadm -CR imsm -e imsm -n 3 /dev/nvme[0-2]n1
 mdadm -CR r5 -e imsm -l5 -n3 /dev/nvme[0-2]n1 --assume-clean
 mkfs.xfs /dev/md126 -f
 mount /dev/md126 /mnt/root/

 fio --filename=/mnt/root/file --size=5GB --direct=1 --rw=randrw
--bs=64k --ioengine=libaio --iodepth=64 --runtime=240 --numjobs=4
--time_based --group_reporting --name=throughput-test-job
--eta-newline=1 &

 echo 1 > /sys/block/nvme2n1/device/device/remove
 echo 1 > /sys/block/nvme1n1/device/device/remove

 [ 1475.787779] Call Trace:
 [ 1475.793111] __schedule+0x2a6/0x700
 [ 1475.799460] schedule+0x38/0xa0
 [ 1475.805454] raid5_get_active_stripe+0x469/0x5f0 [raid456]
 [ 1475.813856] ? finish_wait+0x80/0x80
 [ 1475.820332] raid5_make_request+0x180/0xb40 [raid456]
 [ 1475.828281] ? finish_wait+0x80/0x80
 [ 1475.834727] ? finish_wait+0x80/0x80
 [ 1475.841127] ? finish_wait+0x80/0x80
 [ 1475.847480] md_handle_request+0x119/0x190
 [ 1475.854390] md_make_request+0x8a/0x190
 [ 1475.861041] generic_make_request+0xcf/0x310
 [ 1475.868145] submit_bio+0x3c/0x160
 [ 1475.874355] iomap_dio_submit_bio.isra.20+0x51/0x60
 [ 1475.882070] iomap_dio_bio_actor+0x175/0x390
 [ 1475.889149] iomap_apply+0xff/0x310
 [ 1475.895447] ? iomap_dio_bio_actor+0x390/0x390
 [ 1475.902736] ? iomap_dio_bio_actor+0x390/0x390
 [ 1475.909974] iomap_dio_rw+0x2f2/0x490
 [ 1475.916415] ? iomap_dio_bio_actor+0x390/0x390
 [ 1475.923680] ? atime_needs_update+0x77/0xe0
 [ 1475.930674] ? xfs_file_dio_aio_read+0x6b/0xe0 [xfs]
 [ 1475.938455] xfs_file_dio_aio_read+0x6b/0xe0 [xfs]
 [ 1475.946084] xfs_file_read_iter+0xba/0xd0 [xfs]
 [ 1475.953403] aio_read+0xd5/0x180
 [ 1475.959395] ? _cond_resched+0x15/0x30
 [ 1475.965907] io_submit_one+0x20b/0x3c0
 [ 1475.972398] __x64_sys_io_submit+0xa2/0x180
 [ 1475.979335] ? do_io_getevents+0x7c/0xc0
 [ 1475.986009] do_syscall_64+0x5b/0x1a0
 [ 1475.992419] entry_SYSCALL_64_after_hwframe+0x65/0xca
 [ 1476.000255] RIP: 0033:0x7f11fc27978d
 [ 1476.006631] Code: Bad RIP value.
 [ 1476.073251] INFO: task fio:3877 blocked for more than 120 seconds.

Cc: stable@vger.kernel.org
Fixes: fb73b357fb9 ("raid5: block failing device if raid will be failed")
Reviewd-by: Xiao Ni <xni@redhat.com>
Signed-off-by: Mariusz Tkaczyk <mariusz.tkaczyk@linux.intel.com>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-06 08:43:40 +02:00
Sarthak Kukreti
69712b1702 dm verity: set DM_TARGET_IMMUTABLE feature flag
commit 4caae58406f8ceb741603eee460d79bacca9b1b5 upstream.

The device-mapper framework provides a mechanism to mark targets as
immutable (and hence fail table reloads that try to change the target
type). Add the DM_TARGET_IMMUTABLE flag to the dm-verity target's
feature flags to prevent switching the verity target with a different
target type.

Fixes: a4ffc152198e ("dm: add verity target")
Cc: stable@vger.kernel.org
Signed-off-by: Sarthak Kukreti <sarthakkukreti@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-06 08:43:40 +02:00
Mikulas Patocka
40aaeb41dd dm stats: add cond_resched when looping over entries
commit bfe2b0146c4d0230b68f5c71a64380ff8d361f8b upstream.

dm-stats can be used with a very large number of entries (it is only
limited by 1/4 of total system memory), so add rescheduling points to
the loops that iterate over the entries.

Cc: stable@vger.kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-06 08:43:40 +02:00
Mikulas Patocka
fd77cb6220 dm crypt: make printing of the key constant-time
commit 567dd8f34560fa221a6343729474536aa7ede4fd upstream.

The device mapper dm-crypt target is using scnprintf("%02x", cc->key[i]) to
report the current key to userspace. However, this is not a constant-time
operation and it may leak information about the key via timing, via cache
access patterns or via the branch predictor.

Change dm-crypt's key printing to use "%c" instead of "%02x". Also
introduce hex2asc() that carefully avoids any branching or memory
accesses when converting a number in the range 0 ... 15 to an ascii
character.

Cc: stable@vger.kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Tested-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-06 08:43:40 +02:00
Dan Carpenter
ed0712361a dm integrity: fix error code in dm_integrity_ctr()
commit d3f2a14b8906df913cb04a706367b012db94a6e8 upstream.

The "r" variable shadows an earlier "r" that has function scope.  It
means that we accidentally return success instead of an error code.
Smatch has a warning for this:

	drivers/md/dm-integrity.c:4503 dm_integrity_ctr()
	warn: missing error code 'r'

Fixes: 7eada909bfd7 ("dm: add integrity target")
Cc: stable@vger.kernel.org
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-06 08:43:40 +02:00
Mikulas Patocka
6b4bf97587 dm integrity: fix memory corruption when tag_size is less than digest size
commit 08c1af8f1c13bbf210f1760132f4df24d0ed46d6 upstream.

It is possible to set up dm-integrity in such a way that the
"tag_size" parameter is less than the actual digest size. In this
situation, a part of the digest beyond tag_size is ignored.

In this case, dm-integrity would write beyond the end of the
ic->recalc_tags array and corrupt memory. The corruption happened in
integrity_recalc->integrity_sector_checksum->crypto_shash_final.

Fix this corruption by increasing the tags array so that it has enough
padding at the end to accomodate the loop in integrity_recalc() being
able to write a full digest size for the last member of the tags
array.

Cc: stable@vger.kernel.org # v4.19+
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-20 09:34:20 +02:00
Khazhismel Kumykov
5fda973f0e dm mpath: only use ktime_get_ns() in historical selector
[ Upstream commit ce40426fdc3c92acdba6b5ca74bc7277ffaa6a3d ]

Mixing sched_clock() and ktime_get_ns() usage will give bad results.

Switch hst_select_path() from using sched_clock() to ktime_get_ns().
Also rename path_service_time()'s 'sched_now' variable to 'now'.

Fixes: 2613eab11996 ("dm mpath: add Historical Service Time Path Selector")
Signed-off-by: Khazhismel Kumykov <khazhy@google.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-20 09:34:13 +02:00
Mike Snitzer
da52e8b9da dm: requeue IO if mapping table not yet available
[ Upstream commit fa247089de9936a46e290d4724cb5f0b845600f5 ]

Update both bio-based and request-based DM to requeue IO if the
mapping table not available.

This race of IO being submitted before the DM device ready is so
narrow, yet possible for initial table load given that the DM device's
request_queue is created prior, that it best to requeue IO to handle
this unlikely case.

Reported-by: Zhang Yi <yi.zhang@huawei.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-13 20:59:06 +02:00
Jordy Zomer
02cc46f397 dm ioctl: prevent potential spectre v1 gadget
[ Upstream commit cd9c88da171a62c4b0f1c70e50c75845969fbc18 ]

It appears like cmd could be a Spectre v1 gadget as it's supplied by a
user and used as an array index. Prevent the contents of kernel memory
from being leaked to userspace via speculative execution by using
array_index_nospec.

Signed-off-by: Jordy Zomer <jordy@pwning.systems>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-13 20:59:05 +02:00
Aashish Sharma
5f3856f3ba dm crypt: fix get_key_size compiler warning if !CONFIG_KEYS
[ Upstream commit 6fc51504388c1a1a53db8faafe9fff78fccc7c87 ]

Explicitly convert unsigned int in the right of the conditional
expression to int to match the left side operand and the return type,
fixing the following compiler warning:

drivers/md/dm-crypt.c:2593:43: warning: signed and unsigned
type in conditional expression [-Wsign-compare]

Fixes: c538f6ec9f56 ("dm crypt: add ability to use keys from the kernel key retention service")
Signed-off-by: Aashish Sharma <shraash@google.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-08 14:23:33 +02:00
Mingzhe Zou
74e2d61e4f bcache: fixup multiple threads crash
commit 887554ab96588de2917b6c8c73e552da082e5368 upstream.

When multiple threads to check btree nodes in parallel, the main
thread wait for all threads to stop or CACHE_SET_IO_DISABLE flag:

wait_event_interruptible(check_state->wait,
                         atomic_read(&check_state->started) == 0 ||
                         test_bit(CACHE_SET_IO_DISABLE, &c->flags));

However, the bch_btree_node_read and bch_btree_node_read_done
maybe call bch_cache_set_error, then the CACHE_SET_IO_DISABLE
will be set. If the flag already set, the main thread return
error. At the same time, maybe some threads still running and
read NULL pointer, the kernel will crash.

This patch change the event wait condition, the main thread must
wait for all threads to stop.

Fixes: 8e7102273f597 ("bcache: make bch_btree_check() to be multithreaded")
Signed-off-by: Mingzhe Zou <mingzhe.zou@easystack.cn>
Cc: stable@vger.kernel.org # v5.7+
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-08 14:23:01 +02:00