Commit Graph

6124 Commits

Author SHA1 Message Date
Arne Welzel 80d1675903 dm crypt: Avoid percpu_counter spinlock contention in crypt_page_alloc()
commit 528b16bfc3ae5f11638e71b3b63a81f9999df727 upstream.

On systems with many cores using dm-crypt, heavy spinlock contention in
percpu_counter_compare() can be observed when the page allocation limit
for a given device is reached or close to be reached. This is due
to percpu_counter_compare() taking a spinlock to compute an exact
result on potentially many CPUs at the same time.

Switch to non-exact comparison of allocated and allowed pages by using
the value returned by percpu_counter_read_positive() to avoid taking
the percpu_counter spinlock.

This may over/under estimate the actual number of allocated pages by at
most (batch-1) * num_online_cpus().

Currently, batch is bounded by 32. The system on which this issue was
first observed has 256 CPUs and 512GB of RAM. With a 4k page size, this
change may over/under estimate by 31MB. With ~10G (2%) allowed dm-crypt
allocations, this seems an acceptable error. Certainly preferred over
running into the spinlock contention.

This behavior was reproduced on an EC2 c5.24xlarge instance with 96 CPUs
and 192GB RAM as follows, but can be provoked on systems with less CPUs
as well.

 * Disable swap
 * Tune vm settings to promote regular writeback
     $ echo 50 > /proc/sys/vm/dirty_expire_centisecs
     $ echo 25 > /proc/sys/vm/dirty_writeback_centisecs
     $ echo $((128 * 1024 * 1024)) > /proc/sys/vm/dirty_background_bytes

 * Create 8 dmcrypt devices based on files on a tmpfs
 * Create and mount an ext4 filesystem on each crypt devices
 * Run stress-ng --hdd 8 within one of above filesystems

Total %system usage collected from sysstat goes to ~35%. Write throughput
on the underlying loop device is ~2GB/s. perf profiling an individual
kworker kcryptd thread shows the following profile, indicating spinlock
contention in percpu_counter_compare():

    99.98%     0.00%  kworker/u193:46  [kernel.kallsyms]  [k] ret_from_fork
      |
      --ret_from_fork
        kthread
        worker_thread
        |
         --99.92%--process_one_work
            |
            |--80.52%--kcryptd_crypt
            |    |
            |    |--62.58%--mempool_alloc
            |    |  |
            |    |   --62.24%--crypt_page_alloc
            |    |     |
            |    |      --61.51%--__percpu_counter_compare
            |    |        |
            |    |         --61.34%--__percpu_counter_sum
            |    |           |
            |    |           |--58.68%--_raw_spin_lock_irqsave
            |    |           |  |
            |    |           |   --58.30%--native_queued_spin_lock_slowpath
            |    |           |
            |    |            --0.69%--cpumask_next
            |    |                |
            |    |                 --0.51%--_find_next_bit
            |    |
            |    |--10.61%--crypt_convert
            |    |          |
            |    |          |--6.05%--xts_crypt
            ...

After applying this patch and running the same test, %system usage is
lowered to ~7% and write throughput on the loop device increases
to ~2.7GB/s. perf report shows mempool_alloc() as ~8% rather than ~62%
in the profile and not hitting the percpu_counter() spinlock anymore.

    |--8.15%--mempool_alloc
    |    |
    |    |--3.93%--crypt_page_alloc
    |    |    |
    |    |     --3.75%--__alloc_pages
    |    |         |
    |    |          --3.62%--get_page_from_freelist
    |    |              |
    |    |               --3.22%--rmqueue_bulk
    |    |                   |
    |    |                    --2.59%--_raw_spin_lock
    |    |                      |
    |    |                       --2.57%--native_queued_spin_lock_slowpath
    |    |
    |     --3.05%--_raw_spin_lock_irqsave
    |               |
    |                --2.49%--native_queued_spin_lock_slowpath

Suggested-by: DJ Gregor <dj@corelight.com>
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Arne Welzel <arne.welzel@corelight.com>
Fixes: 5059353df8 ("dm crypt: limit the number of allocated pages")
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-22 12:26:21 +02:00
Christoph Hellwig 93cf19b4d9 bcache: add proper error unwinding in bcache_device_init
[ Upstream commit 224b0683228c5f332f9cee615d85e75e9a347170 ]

Except for the IDA none of the allocations in bcache_device_init is
unwound on error, fix that.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20210809064028.1198327-7-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-15 09:47:27 +02:00
Wei Shuyu 1b7b9713a5 md/raid10: properly indicate failure when ending a failed write request
commit 5ba03936c05584b6f6f79be5ebe7e5036c1dd252 upstream.

Similar to [1], this patch fixes the same bug in raid10. Also cleanup the
comments.

[1] commit 2417b9869b81 ("md/raid1: properly indicate failure when ending
                         a failed write request")
Cc: stable@vger.kernel.org
Fixes: 7cee6d4e60 ("md/raid10: end bio when the device faulty")
Signed-off-by: Wei Shuyu <wsy@dogben.com>
Acked-by: Guoqing Jiang <jiangguoqing@kylinos.cn>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-08-12 13:21:03 +02:00
Mikulas Patocka d73c180e6a dm writecache: return the exact table values that were set
commit 054bee16163df023e2589db09fd27d81f7ad9e72 upstream.

LVM doesn't like it when the target returns different values from what
was set in the constructor. Fix dm-writecache so that the returned
table values are exactly the same as requested values.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org # v4.18+
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-25 14:35:14 +02:00
Hou Tao 964d57d196 dm btree remove: assign new_root only when removal succeeds
commit b6e58b5466b2959f83034bead2e2e1395cca8aeb upstream.

remove_raw() in dm_btree_remove() may fail due to IO read error
(e.g. read the content of origin block fails during shadowing),
and the value of shadow_spine::root is uninitialized, but
the uninitialized value is still assign to new_root in the
end of dm_btree_remove().

For dm-thin, the value of pmd->details_root or pmd->root will become
an uninitialized value, so if trying to read details_info tree again
out-of-bound memory may occur as showed below:

  general protection fault, probably for non-canonical address 0x3fdcb14c8d7520
  CPU: 4 PID: 515 Comm: dmsetup Not tainted 5.13.0-rc6
  Hardware name: QEMU Standard PC
  RIP: 0010:metadata_ll_load_ie+0x14/0x30
  Call Trace:
   sm_metadata_count_is_more_than_one+0xb9/0xe0
   dm_tm_shadow_block+0x52/0x1c0
   shadow_step+0x59/0xf0
   remove_raw+0xb2/0x170
   dm_btree_remove+0xf4/0x1c0
   dm_pool_delete_thin_device+0xc3/0x140
   pool_message+0x218/0x2b0
   target_message+0x251/0x290
   ctl_ioctl+0x1c4/0x4d0
   dm_ctl_ioctl+0xe/0x20
   __x64_sys_ioctl+0x7b/0xb0
   do_syscall_64+0x40/0xb0
   entry_SYSCALL_64_after_hwframe+0x44/0xae

Fixing it by only assign new_root when removal succeeds

Signed-off-by: Hou Tao <houtao1@huawei.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-19 08:53:17 +02:00
Joe Thornber e10062afd6 dm space maps: don't reset space map allocation cursor when committing
[ Upstream commit 5faafc77f7de69147d1e818026b9a0cbf036a7b2 ]

Current commit code resets the place where the search for free blocks
will begin back to the start of the metadata device.  There are a couple
of repercussions to this:

- The first allocation after the commit is likely to take longer than
  normal as it searches for a free block in an area that is likely to
  have very few free blocks (if any).

- Any free blocks it finds will have been recently freed.  Reusing them
  means we have fewer old copies of the metadata to aid recovery from
  hardware error.

Fix these issues by leaving the cursor alone, only resetting when the
search hits the end of the metadata device.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-19 08:53:09 +02:00
John Keeping ece8ad75e3 dm verity: fix require_signatures module_param permissions
[ Upstream commit 0c1f3193b1cdd21e7182f97dc9bca7d284d18a15 ]

The third parameter of module_param() is permissions for the sysfs node
but it looks like it is being used as the initial value of the parameter
here.  In fact, false here equates to omitting the file from sysfs and
does not affect the value of require_signatures.

Making the parameter writable is not simple because going from
false->true is fine but it should not be possible to remove the
requirement to verify a signature.  But it can be useful to inspect the
value of this parameter from userspace, so change the permissions to
make a read-only file in sysfs.

Signed-off-by: John Keeping <john@metanate.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-16 11:59:37 +02:00
Mikulas Patocka d65ec240b3 dm snapshot: properly fix a crash when an origin has no snapshots
commit 7e768532b2396bcb7fbf6f82384b85c0f1d2f197 upstream.

If an origin target has no snapshots, o->split_boundary is set to 0.
This causes BUG_ON(sectors <= 0) in block/bio.c:bio_split().

Fix this by initializing chunk_size, and in turn split_boundary, to
rounddown_pow_of_two(UINT_MAX) -- the largest power of two that fits
into "unsigned" type.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-06-03 08:59:02 +02:00
Mikulas Patocka 3471a221f3 dm snapshot: fix crash with transient storage and zero chunk size
commit c699a0db2d62e3bbb7f0bf35c87edbc8d23e3062 upstream.

The following commands will crash the kernel:

modprobe brd rd_size=1048576
dmsetup create o --table "0 `blockdev --getsize /dev/ram0` snapshot-origin /dev/ram0"
dmsetup create s --table "0 `blockdev --getsize /dev/ram0` snapshot /dev/ram0 /dev/ram1 N 0"

The reason is that when we test for zero chunk size, we jump to the label
bad_read_metadata without setting the "r" variable. The function
snapshot_ctr destroys all the structures and then exits with "r == 0". The
kernel then crashes because it falsely believes that snapshot_ctr
succeeded.

In order to fix the bug, we set the variable "r" to -EINVAL.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-26 12:05:18 +02:00
Jan Glauber af7ea06b3c md: Fix missing unused status line of /proc/mdstat
commit 7abfabaf5f805f5171d133ce6af9b65ab766e76a upstream.

Reading /proc/mdstat with a read buffer size that would not
fit the unused status line in the first read will skip this
line from the output.

So 'dd if=/proc/mdstat bs=64 2>/dev/null' will not print something
like: unused devices: <none>

Don't return NULL immediately in start() for v=2 but call
show() once to print the status line also for multiple reads.

Cc: stable@vger.kernel.org
Fixes: 1f4aace60b ("fs/seq_file.c: simplify seq_file iteration code and interface")
Signed-off-by: Jan Glauber <jglauber@digitalocean.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-14 09:44:13 +02:00
Zhao Heming 79c1bfae66 md: md_open returns -EBUSY when entering racing area
commit 6a4db2a60306eb65bfb14ccc9fde035b74a4b4e7 upstream.

commit d3374825ce ("md: make devices disappear when they are no longer
needed.") introduced protection between mddev creating & removing. The
md_open shouldn't create mddev when all_mddevs list doesn't contain
mddev. With currently code logic, there will be very easy to trigger
soft lockup in non-preempt env.

This patch changes md_open returning from -ERESTARTSYS to -EBUSY, which
will break the infinitely retry when md_open enter racing area.

This patch is partly fix soft lockup issue, full fix needs mddev_find
is split into two functions: mddev_find & mddev_find_or_alloc. And
md_open should call new mddev_find (it only does searching job).

For more detail, please refer with Christoph's "split mddev_find" patch
in later commits.
2021-05-14 09:44:13 +02:00
Christoph Hellwig adb9bbf1a2 md: factor out a mddev_find_locked helper from mddev_find
commit 8b57251f9a91f5e5a599de7549915d2d226cc3af upstream.

Factor out a self-contained helper to just lookup a mddev by the dev_t
"unit".

Cc: stable@vger.kernel.org
Reviewed-by: Heming Zhao <heming.zhao@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-14 09:44:13 +02:00
Christoph Hellwig afa4de0926 md: split mddev_find
commit 65aa97c4d2bfd76677c211b9d03ef05a98c6d68e upstream.

Split mddev_find into a simple mddev_find that just finds an existing
mddev by the unit number, and a more complicated mddev_find that deals
with find or allocating a mddev.

This turns out to fix this bug reported by Zhao Heming.

----------------------------- snip ------------------------------
commit d3374825ce ("md: make devices disappear when they are no longer
needed.") introduced protection between mddev creating & removing. The
md_open shouldn't create mddev when all_mddevs list doesn't contain
mddev. With currently code logic, there will be very easy to trigger
soft lockup in non-preempt env.
2021-05-14 09:44:12 +02:00
Heming Zhao acdf531e77 md-cluster: fix use-after-free issue when removing rdev
commit f7c7a2f9a23e5b6e0f5251f29648d0238bb7757e upstream.

md_kick_rdev_from_array will remove rdev, so we should
use rdev_for_each_safe to search list.

How to trigger:

env: Two nodes on kvm-qemu x86_64 VMs (2C2G with 2 iscsi luns).

```
node2=192.168.0.3

for i in {1..20}; do
    echo ==== $i `date` ====;

    mdadm -Ss && ssh ${node2} "mdadm -Ss"
    wipefs -a /dev/sda /dev/sdb

    mdadm -CR /dev/md0 -b clustered -e 1.2 -n 2 -l 1 /dev/sda \
       /dev/sdb --assume-clean
    ssh ${node2} "mdadm -A /dev/md0 /dev/sda /dev/sdb"
    mdadm --wait /dev/md0
    ssh ${node2} "mdadm --wait /dev/md0"

    mdadm --manage /dev/md0 --fail /dev/sda --remove /dev/sda
    sleep 1
done
```

Crash stack:

```
stack segment: 0000 [#1] SMP
... ...
RIP: 0010:md_check_recovery+0x1e8/0x570 [md_mod]
... ...
RSP: 0018:ffffb149807a7d68 EFLAGS: 00010207
RAX: 0000000000000000 RBX: ffff9d494c180800 RCX: ffff9d490fc01e50
RDX: fffff047c0ed8308 RSI: 0000000000000246 RDI: 0000000000000246
RBP: 6b6b6b6b6b6b6b6b R08: ffff9d490fc01e40 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000000
R13: ffff9d494c180818 R14: ffff9d493399ef38 R15: ffff9d4933a1d800
FS:  0000000000000000(0000) GS:ffff9d494f700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe68cab9010 CR3: 000000004c6be001 CR4: 00000000003706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 raid1d+0x5c/0xd40 [raid1]
 ? finish_task_switch+0x75/0x2a0
 ? lock_timer_base+0x67/0x80
 ? try_to_del_timer_sync+0x4d/0x80
 ? del_timer_sync+0x41/0x50
 ? schedule_timeout+0x254/0x2d0
 ? md_start_sync+0xe0/0xe0 [md_mod]
 ? md_thread+0x127/0x160 [md_mod]
 md_thread+0x127/0x160 [md_mod]
 ? wait_woken+0x80/0x80
 kthread+0x10d/0x130
 ? kthread_park+0xa0/0xa0
 ret_from_fork+0x1f/0x40
```

Fixes: dbb64f8635 ("md-cluster: Fix adding of new disk with new reload code")
Fixes: 659b254fa7 ("md-cluster: remove a disk asynchronously from cluster environment")
Cc: stable@vger.kernel.org
Reviewed-by: Gang He <ghe@suse.com>
Signed-off-by: Heming Zhao <heming.zhao@suse.com>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-14 09:44:12 +02:00
Sudhakar Panneerselvam a72373588c md/bitmap: wait for external bitmap writes to complete during tear down
commit 404a8ef512587b2460107d3272c17a89aef75edf upstream.

NULL pointer dereference was observed in super_written() when it tries
to access the mddev structure.

[The below stack trace is from an older kernel, but the problem described
in this patch applies to the mainline kernel.]

[ 1194.474861] task: ffff8fdd20858000 task.stack: ffffb99d40790000
[ 1194.488000] RIP: 0010:super_written+0x29/0xe1
[ 1194.499688] RSP: 0018:ffff8ffb7fcc3c78 EFLAGS: 00010046
[ 1194.512477] RAX: 0000000000000000 RBX: ffff8ffb7bf4a000 RCX: ffff8ffb78991048
[ 1194.527325] RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff8ffb56b8a200
[ 1194.542576] RBP: ffff8ffb7fcc3c90 R08: 000000000000000b R09: 0000000000000000
[ 1194.558001] R10: ffff8ffb56b8a298 R11: 0000000000000000 R12: ffff8ffb56b8a200
[ 1194.573070] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[ 1194.588117] FS:  0000000000000000(0000) GS:ffff8ffb7fcc0000(0000) knlGS:0000000000000000
[ 1194.604264] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1194.617375] CR2: 00000000000002b8 CR3: 00000021e040a002 CR4: 00000000007606e0
[ 1194.632327] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 1194.647865] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 1194.663316] PKRU: 55555554
[ 1194.674090] Call Trace:
[ 1194.683735]  <IRQ>
[ 1194.692948]  bio_endio+0xae/0x135
[ 1194.703580]  blk_update_request+0xad/0x2fa
[ 1194.714990]  blk_update_bidi_request+0x20/0x72
[ 1194.726578]  __blk_end_bidi_request+0x2c/0x4d
[ 1194.738373]  __blk_end_request_all+0x31/0x49
[ 1194.749344]  blk_flush_complete_seq+0x377/0x383
[ 1194.761550]  flush_end_io+0x1dd/0x2a7
[ 1194.772910]  blk_finish_request+0x9f/0x13c
[ 1194.784544]  scsi_end_request+0x180/0x25c
[ 1194.796149]  scsi_io_completion+0xc8/0x610
[ 1194.807503]  scsi_finish_command+0xdc/0x125
[ 1194.818897]  scsi_softirq_done+0x81/0xde
[ 1194.830062]  blk_done_softirq+0xa4/0xcc
[ 1194.841008]  __do_softirq+0xd9/0x29f
[ 1194.851257]  irq_exit+0xe6/0xeb
[ 1194.861290]  do_IRQ+0x59/0xe3
[ 1194.871060]  common_interrupt+0x1c6/0x382
[ 1194.881988]  </IRQ>
[ 1194.890646] RIP: 0010:cpuidle_enter_state+0xdd/0x2a5
[ 1194.902532] RSP: 0018:ffffb99d40793e68 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff43
[ 1194.917317] RAX: ffff8ffb7fce27c0 RBX: ffff8ffb7fced800 RCX: 000000000000001f
[ 1194.932056] RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000000
[ 1194.946428] RBP: ffffb99d40793ea0 R08: 0000000000000004 R09: 0000000000002ed2
[ 1194.960508] R10: 0000000000002664 R11: 0000000000000018 R12: 0000000000000003
[ 1194.974454] R13: 000000000000000b R14: ffffffff925715a0 R15: 0000011610120d5a
[ 1194.988607]  ? cpuidle_enter_state+0xcc/0x2a5
[ 1194.999077]  cpuidle_enter+0x17/0x19
[ 1195.008395]  call_cpuidle+0x23/0x3a
[ 1195.017718]  do_idle+0x172/0x1d5
[ 1195.026358]  cpu_startup_entry+0x73/0x75
[ 1195.035769]  start_secondary+0x1b9/0x20b
[ 1195.044894]  secondary_startup_64+0xa5/0xa5
[ 1195.084921] RIP: super_written+0x29/0xe1 RSP: ffff8ffb7fcc3c78
[ 1195.096354] CR2: 00000000000002b8

bio in the above stack is a bitmap write whose completion is invoked after
the tear down sequence sets the mddev structure to NULL in rdev.

During tear down, there is an attempt to flush the bitmap writes, but for
external bitmaps, there is no explicit wait for all the bitmap writes to
complete. For instance, md_bitmap_flush() is called to flush the bitmap
writes, but the last call to md_bitmap_daemon_work() in md_bitmap_flush()
could generate new bitmap writes for which there is no explicit wait to
complete those writes. The call to md_bitmap_update_sb() will return
simply for external bitmaps and the follow-up call to md_update_sb() is
conditional and may not get called for external bitmaps. This results in a
kernel panic when the completion routine, super_written() is called which
tries to reference mddev in the rdev that has been set to
NULL(in unbind_rdev_from_array() by tear down sequence).

The solution is to call md_super_wait() for external bitmaps after the
last call to md_bitmap_daemon_work() in md_bitmap_flush() to ensure there
are no pending bitmap writes before proceeding with the tear down.

Cc: stable@vger.kernel.org
Signed-off-by: Sudhakar Panneerselvam <sudhakar.panneerselvam@oracle.com>
Reviewed-by: Zhao Heming <heming.zhao@suse.com>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-14 09:44:12 +02:00
Benjamin Block a992a283c0 dm rq: fix double free of blk_mq_tag_set in dev remove after table load fails
commit 8e947c8f4a5620df77e43c9c75310dc510250166 upstream.

When loading a device-mapper table for a request-based mapped device,
and the allocation/initialization of the blk_mq_tag_set for the device
fails, a following device remove will cause a double free.

E.g. (dmesg):
  device-mapper: core: Cannot initialize queue for request-based dm-mq mapped device
  device-mapper: ioctl: unable to set up device queue for new table.
  Unable to handle kernel pointer dereference in virtual kernel address space
  Failing address: 0305e098835de000 TEID: 0305e098835de803
  Fault in home space mode while using kernel ASCE.
  AS:000000025efe0007 R3:0000000000000024
  Oops: 0038 ilc:3 [#1] SMP
  Modules linked in: ... lots of modules ...
  Supported: Yes, External
  CPU: 0 PID: 7348 Comm: multipathd Kdump: loaded Tainted: G        W      X    5.3.18-53-default #1 SLE15-SP3
  Hardware name: IBM 8561 T01 7I2 (LPAR)
  Krnl PSW : 0704e00180000000 000000025e368eca (kfree+0x42/0x330)
             R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 RI:0 EA:3
  Krnl GPRS: 000000000000004a 000000025efe5230 c1773200d779968d 0000000000000000
             000000025e520270 000000025e8d1b40 0000000000000003 00000007aae10000
             000000025e5202a2 0000000000000001 c1773200d779968d 0305e098835de640
             00000007a8170000 000003ff80138650 000000025e5202a2 000003e00396faa8
  Krnl Code: 000000025e368eb8: c4180041e100       lgrl    %r1,25eba50b8
             000000025e368ebe: ecba06b93a55       risbg   %r11,%r10,6,185,58
            #000000025e368ec4: e3b010000008       ag      %r11,0(%r1)
            >000000025e368eca: e310b0080004       lg      %r1,8(%r11)
             000000025e368ed0: a7110001           tmll    %r1,1
             000000025e368ed4: a7740129           brc     7,25e369126
             000000025e368ed8: e320b0080004       lg      %r2,8(%r11)
             000000025e368ede: b904001b           lgr     %r1,%r11
  Call Trace:
   [<000000025e368eca>] kfree+0x42/0x330
   [<000000025e5202a2>] blk_mq_free_tag_set+0x72/0xb8
   [<000003ff801316a8>] dm_mq_cleanup_mapped_device+0x38/0x50 [dm_mod]
   [<000003ff80120082>] free_dev+0x52/0xd0 [dm_mod]
   [<000003ff801233f0>] __dm_destroy+0x150/0x1d0 [dm_mod]
   [<000003ff8012bb9a>] dev_remove+0x162/0x1c0 [dm_mod]
   [<000003ff8012a988>] ctl_ioctl+0x198/0x478 [dm_mod]
   [<000003ff8012ac8a>] dm_ctl_ioctl+0x22/0x38 [dm_mod]
   [<000000025e3b11ee>] ksys_ioctl+0xbe/0xe0
   [<000000025e3b127a>] __s390x_sys_ioctl+0x2a/0x40
   [<000000025e8c15ac>] system_call+0xd8/0x2c8
  Last Breaking-Event-Address:
   [<000000025e52029c>] blk_mq_free_tag_set+0x6c/0xb8
  Kernel panic - not syncing: Fatal exception: panic_on_oops

When allocation/initialization of the blk_mq_tag_set fails in
dm_mq_init_request_queue(), it is uninitialized/freed, but the pointer
is not reset to NULL; so when dev_remove() later gets into
dm_mq_cleanup_mapped_device() it sees the pointer and tries to
uninitialize and free it again.

Fix this by setting the pointer to NULL in dm_mq_init_request_queue()
error-handling. Also set it to NULL in dm_mq_cleanup_mapped_device().

Cc: <stable@vger.kernel.org> # 4.6+
Fixes: 1c357a1e86 ("dm: allocate blk_mq_tag_set rather than embed in mapped_device")
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-11 14:04:18 +02:00
Tian Tao 569bae00eb dm integrity: fix missing goto in bitmap_flush_interval error handling
commit 17e9e134a8efabbbf689a0904eee92bb5a868172 upstream.

Fixes: 468dfca38b ("dm integrity: add a bitmap mode")
Cc: stable@vger.kernel.org
Signed-off-by: Tian Tao <tiantao6@hisilicon.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-11 14:04:18 +02:00
Joe Thornber ff8fd1e3b5 dm space map common: fix division bug in sm_ll_find_free_block()
commit 5208692e80a1f3c8ce2063a22b675dd5589d1d80 upstream.

This division bug meant the search for free metadata space could skip
the final allocation bitmap's worth of entries. Fix affects DM thinp,
cache and era targets.

Cc: stable@vger.kernel.org
Signed-off-by: Joe Thornber <ejt@redhat.com>
Tested-by: Ming-Hung Tsai <mtsai@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-11 14:04:18 +02:00
Joe Thornber 6fcaa44105 dm persistent data: packed struct should have an aligned() attribute too
commit a88b2358f1da2c9f9fcc432f2e0a79617fea397c upstream.

Otherwise most non-x86 architectures (e.g. riscv, arm) will resort to
byte-by-byte access.

Cc: stable@vger.kernel.org
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-11 14:04:18 +02:00
Heinz Mauelshagen dc21b42486 dm raid: fix inconclusive reshape layout on fast raid4/5/6 table reload sequences
commit f99a8e4373eeacb279bc9696937a55adbff7a28a upstream.

If fast table reloads occur during an ongoing reshape of raid4/5/6
devices the target may race reading a superblock vs the the MD resync
thread; causing an inconclusive reshape state to be read in its
constructor.

lvm2 test lvconvert-raid-reshape-stripes-load-reload.sh can cause
BUG_ON() to trigger in md_run(), e.g.:
"kernel BUG at drivers/md/raid5.c:7567!".

Scenario triggering the bug:

1. the MD sync thread calls end_reshape() from raid5_sync_request()
   when done reshaping. However end_reshape() _only_ updates the
   reshape position to MaxSector keeping the changed layout
   configuration though (i.e. any delta disks, chunk sector or RAID
   algorithm changes). That inconclusive configuration is stored in
   the superblock.

2. dm-raid constructs a mapping, loading named inconsistent superblock
   as of step 1 before step 3 is able to finish resetting the reshape
   state completely, and calls md_run() which leads to mentioned bug
   in raid5.c.

3. the MD RAID personality's finish_reshape() is called; which resets
   the reshape information on chunk sectors, delta disks, etc. This
   explains why the bug is rarely seen on multi-core machines, as MD's
   finish_reshape() superblock update races with the dm-raid
   constructor's superblock load in step 2.

Fix identifies inconclusive superblock content in the dm-raid
constructor and resets it before calling md_run(), factoring out
identifying checks into rs_is_layout_change() to share in existing
rs_reshape_requested() and new rs_reset_inclonclusive_reshape(). Also
enhance a comment and remove an empty line.

Cc: stable@vger.kernel.org
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-11 14:04:15 +02:00
Paul Clements 6920cef604 md/raid1: properly indicate failure when ending a failed write request
commit 2417b9869b81882ab90fd5ed1081a1cb2d4db1dd upstream.

This patch addresses a data corruption bug in raid1 arrays using bitmaps.
Without this fix, the bitmap bits for the failed I/O end up being cleared.

Since we are in the failure leg of raid1_end_write_request, the request
either needs to be retried (R1BIO_WriteError) or failed (R1BIO_Degraded).

Fixes: eeba6809d8 ("md/raid1: end bio when the device faulty")
Cc: stable@vger.kernel.org # v5.2+
Signed-off-by: Paul Clements <paul.clements@us.sios.com>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-11 14:04:15 +02:00
Jaegeuk Kim ff821c7ce9 dm verity fec: fix misaligned RS roots IO
commit 8ca7cab82bda4eb0b8064befeeeaa38106cac637 upstream.

commit df7b59ba9245 ("dm verity: fix FEC for RS roots unaligned to
block size") introduced the possibility for misaligned roots IO
relative to the underlying device's logical block size. E.g. Android's
default RS roots=2 results in dm_bufio->block_size=1024, which causes
the following EIO if the logical block size of the device is 4096,
given v->data_dev_block_bits=12:

E sd 0    : 0:0:0: [sda] tag#30 request not aligned to the logical block size
E blk_update_request: I/O error, dev sda, sector 10368424 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0
E device-mapper: verity-fec: 254:8: FEC 9244672: parity read failed (block 18056): -5

Fix this by onlu using f->roots for dm_bufio blocksize IFF it is
aligned to v->data_dev_block_bits.

Fixes: df7b59ba9245 ("dm verity: fix FEC for RS roots unaligned to block size")
Cc: stable@vger.kernel.org
Signed-off-by: Jaegeuk Kim <jaegeuk@google.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-21 12:56:15 +02:00
Mikulas Patocka e6587d142d dm ioctl: fix out of bounds array access when no devices
commit 4edbe1d7bcffcd6269f3b5eb63f710393ff2ec7a upstream.

If there are not any dm devices, we need to zero the "dev" argument in
the first structure dm_name_list. However, this can cause out of
bounds write, because the "needed" variable is zero and len may be
less than eight.

Fix this bug by reporting DM_BUFFER_FULL_FLAG if the result buffer is
too small to hold the "nl->dev" value.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-30 14:35:24 +02:00
JeongHyeon Lee 7b6944f18c dm verity: fix DM_VERITY_OPTS_MAX value
commit 160f99db943224e55906dd83880da1a704c6e6b9 upstream.

Three optional parameters must be accepted at once in a DM verity table, e.g.:
  (verity_error_handling_mode) (ignore_zero_block) (check_at_most_once)
Fix this to be possible by incrementing DM_VERITY_OPTS_MAX.

Signed-off-by: JeongHyeon Lee <jhs2.lee@samsung.com>
Fixes: 843f38d382 ("dm verity: add 'check_at_most_once' option to only validate hashes once")
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-30 14:35:24 +02:00
Jeffle Xu f27765adb3 dm table: fix zoned iterate_devices based device capability checks
commit 24f6b6036c9eec21191646930ad42808e6180510 upstream.

Fix dm_table_supports_zoned_model() and invert logic of both
iterate_devices_callout_fn so that all devices' zoned capabilities are
properly checked.

Add one more parameter to dm_table_any_dev_attr(), which is actually
used as the @data parameter of iterate_devices_callout_fn, so that
dm_table_matches_zone_sectors() can be replaced by
dm_table_any_dev_attr().

Fixes: dd88d313be ("dm table: add zoned block devices validation")
Cc: stable@vger.kernel.org
Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
[jeffle: also convert partial completion check]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-11 14:06:49 +01:00
Jeffle Xu 06ef17b886 dm table: fix DAX iterate_devices based device capability checks
commit 5b0fab508992c2e120971da658ce80027acbc405 upstream.

Fix dm_table_supports_dax() and invert logic of both
iterate_devices_callout_fn so that all devices' DAX capabilities are
properly checked.

Fixes: 545ed20e6d ("dm: add infrastructure for DAX support")
Cc: stable@vger.kernel.org
Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-11 14:06:49 +01:00
Jeffle Xu b8aedc65db dm table: fix iterate_devices based device capability checks
commit a4c8dd9c2d0987cf542a2a0c42684c9c6d78a04e upstream.

According to the definition of dm_iterate_devices_fn:
 * This function must iterate through each section of device used by the
 * target until it encounters a non-zero return code, which it then returns.
 * Returns zero if no callout returned non-zero.

For some target type (e.g. dm-stripe), one call of iterate_devices() may
iterate multiple underlying devices internally, in which case a non-zero
return code returned by iterate_devices_callout_fn will stop the iteration
in advance. No iterate_devices_callout_fn should return non-zero unless
device iteration should stop.

Rename dm_table_requires_stable_pages() to dm_table_any_dev_attr() and
elevate it for reuse to stop iterating (and return non-zero) on the
first device that causes iterate_devices_callout_fn to return non-zero.
Use dm_table_any_dev_attr() to properly iterate through devices.

Rename device_is_nonrot() to device_is_rotational() and invert logic
accordingly to fix improper disposition.

Fixes: c3c4555edd ("dm table: clear add_random unless all devices have it set")
Fixes: 4693c9668f ("dm table: propagate non rotational flag")
Cc: stable@vger.kernel.org
Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-11 14:06:49 +01:00
Milan Broz b367201430 dm verity: fix FEC for RS roots unaligned to block size
commit df7b59ba9245c4a3115ebaa905e3e5719a3810da upstream.

Optional Forward Error Correction (FEC) code in dm-verity uses
Reed-Solomon code and should support roots from 2 to 24.

The error correction parity bytes (of roots lengths per RS block) are
stored on a separate device in sequence without any padding.

Currently, to access FEC device, the dm-verity-fec code uses dm-bufio
client with block size set to verity data block (usually 4096 or 512
bytes).

Because this block size is not divisible by some (most!) of the roots
supported lengths, data repair cannot work for partially stored parity
bytes.

This fix changes FEC device dm-bufio block size to "roots << SECTOR_SHIFT"
where we can be sure that the full parity data is always available.
(There cannot be partial FEC blocks because parity must cover whole
sectors.)

Because the optional FEC starting offset could be unaligned to this
new block size, we have to use dm_bufio_set_sector_offset() to
configure it.

The problem is easily reproduced using veritysetup, e.g. for roots=13:

  # create verity device with RS FEC
  dd if=/dev/urandom of=data.img bs=4096 count=8 status=none
  veritysetup format data.img hash.img --fec-device=fec.img --fec-roots=13 | awk '/^Root hash/{ print $3 }' >roothash

  # create an erasure that should be always repairable with this roots setting
  dd if=/dev/zero of=data.img conv=notrunc bs=1 count=8 seek=4088 status=none

  # try to read it through dm-verity
  veritysetup open data.img test hash.img --fec-device=fec.img --fec-roots=13 $(cat roothash)
  dd if=/dev/mapper/test of=/dev/null bs=4096 status=noxfer
  # wait for possible recursive recovery in kernel
  udevadm settle
  veritysetup close test

With this fix, errors are properly repaired.
  device-mapper: verity-fec: 7:1: FEC 0: corrected 8 errors
  ...

Without it, FEC code usually ends on unrecoverable failure in RS decoder:
  device-mapper: verity-fec: 7:1: FEC 0: failed to correct: -74
  ...

This problem is present in all kernels since the FEC code's
introduction (kernel 4.5).

It is thought that this problem is not visible in Android ecosystem
because it always uses a default RS roots=2.

Depends-on: a14e5ec66a7a ("dm bufio: subtract the number of initial sectors in dm_bufio_get_device_size")
Signed-off-by: Milan Broz <gmazyland@gmail.com>
Tested-by: Jérôme Carretero <cJ-ko@zougloub.eu>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Cc: stable@vger.kernel.org # 4.5+
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-09 11:09:37 +01:00
Mikulas Patocka 1a41829231 dm bufio: subtract the number of initial sectors in dm_bufio_get_device_size
commit a14e5ec66a7a66e57b24e2469f9212a78460207e upstream.

dm_bufio_get_device_size returns the device size in blocks. Before
returning the value, we must subtract the nubmer of starting
sectors. The number of starting sectors may not be divisible by block
size.

Note that currently, no target is using dm_bufio_set_sector_offset and
dm_bufio_get_device_size simultaneously, so this change has no effect.
However, an upcoming dm-verity-fec fix needs this change.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Milan Broz <gmazyland@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-09 11:09:37 +01:00
Nikos Tsironis 7b518508c6 dm era: Update in-core bitset after committing the metadata
commit 2099b145d77c1d53f5711f029c37cc537897cee6 upstream.

In case of a system crash, dm-era might fail to mark blocks as written
in its metadata, although the corresponding writes to these blocks were
passed down to the origin device and completed successfully.

Consider the following sequence of events:

1. We write to a block that has not been yet written in the current era
2. era_map() checks the in-core bitmap for the current era and sees
   that the block is not marked as written.
3. The write is deferred for submission after the metadata have been
   updated and committed.
4. The worker thread processes the deferred write
   (process_deferred_bios()) and marks the block as written in the
   in-core bitmap, **before** committing the metadata.
5. The worker thread starts committing the metadata.
6. We do more writes that map to the same block as the write of step (1)
7. era_map() checks the in-core bitmap and sees that the block is marked
   as written, **although the metadata have not been committed yet**.
8. These writes are passed down to the origin device immediately and the
   device reports them as completed.
9. The system crashes, e.g., power failure, before the commit from step
   (5) finishes.

When the system recovers and we query the dm-era target for the list of
written blocks it doesn't report the aforementioned block as written,
although the writes of step (6) completed successfully.

The issue is that era_map() decides whether to defer or not a write
based on non committed information. The root cause of the bug is that we
update the in-core bitmap, **before** committing the metadata.

Fix this by updating the in-core bitmap **after** successfully
committing the metadata.

Fixes: eec40579d8 ("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@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-04 10:26:53 +01:00
Nikos Tsironis 467214ddfa dm era: only resize metadata in preresume
commit cca2c6aebe86f68103a8615074b3578e854b5016 upstream.

Metadata resize shouldn't happen in the ctr. The ctr loads a temporary
(inactive) table that will only become active upon resume. That is why
resize should always be done in terms of resume. Otherwise a load (ctr)
whose inactive table never becomes active will incorrectly resize the
metadata.

Also, perform the resize directly in preresume, instead of using the
worker to do it.

The worker might run other metadata operations, e.g., it could start
digestion, before resizing the metadata. These operations will end up
using the old size.

This could lead to errors, like:

  device-mapper: era: metadata_digest_transcribe_writeset: dm_array_set_value failed
  device-mapper: era: process_old_eras: digest step failed, stopping digestion

The reason of the above error is that the worker started the digestion
of the archived writeset using the old, larger size.

As a result, metadata_digest_transcribe_writeset tried to write beyond
the end of the era array.

Fixes: eec40579d8 ("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@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-04 10:26:52 +01:00
Nikos Tsironis fb89863630 dm era: Reinitialize bitset cache before digesting a new writeset
commit 2524933307fd0036d5c32357c693c021ab09a0b0 upstream.

In case of devices with at most 64 blocks, the digestion of consecutive
eras uses the writeset of the first era as the writeset of all eras to
digest, leading to lost writes. That is, we lose the information about
what blocks were written during the affected eras.

The digestion code uses a dm_disk_bitset object to access the archived
writesets. This structure includes a one word (64-bit) cache to reduce
the number of array lookups.

This structure is initialized only once, in metadata_digest_start(),
when we kick off digestion.

But, when we insert a new writeset into the writeset tree, before the
digestion of the previous writeset is done, or equivalently when there
are multiple writesets in the writeset tree to digest, then all these
writesets are digested using the same cache and the cache is not
re-initialized when moving from one writeset to the next.

For devices with more than 64 blocks, i.e., the size of the cache, the
cache is indirectly invalidated when we move to a next set of blocks, so
we avoid the bug.

But for devices with at most 64 blocks we end up using the same cached
data for digesting all archived writesets, i.e., the cache is loaded
when digesting the first writeset and it never gets reloaded, until the
digestion is done.

As a result, the writeset of the first era to digest is used as the
writeset of all the following archived eras, leading to lost writes.

Fix this by reinitializing the dm_disk_bitset structure, and thus
invalidating the cache, every time the digestion code starts digesting a
new writeset.

Fixes: eec40579d8 ("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@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-04 10:26:52 +01:00
Nikos Tsironis e59b9a8464 dm era: Use correct value size in equality function of writeset tree
commit 64f2d15afe7b336aafebdcd14cc835ecf856df4b upstream.

Fix the writeset tree equality test function to use the right value size
when comparing two btree values.

Fixes: eec40579d8 ("dm: add era target")
Cc: stable@vger.kernel.org # v3.15+
Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com>
Reviewed-by: Ming-Hung Tsai <mtsai@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-04 10:26:52 +01:00
Nikos Tsironis fead0c8e5c dm era: Fix bitset memory leaks
commit 904e6b266619c2da5c58b5dce14ae30629e39645 upstream.

Deallocate the memory allocated for the in-core bitsets when destroying
the target and in error paths.

Fixes: eec40579d8 ("dm: add era target")
Cc: stable@vger.kernel.org # v3.15+
Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com>
Reviewed-by: Ming-Hung Tsai <mtsai@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-04 10:26:51 +01:00
Nikos Tsironis 8ca89085fe dm era: Verify the data block size hasn't changed
commit c8e846ff93d5eaa5384f6f325a1687ac5921aade upstream.

dm-era doesn't support changing the data block size of existing devices,
so check explicitly that the requested block size for a new target
matches the one stored in the metadata.

Fixes: eec40579d8 ("dm: add era target")
Cc: stable@vger.kernel.org # v3.15+
Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com>
Reviewed-by: Ming-Hung Tsai <mtsai@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-04 10:26:51 +01:00
Nikos Tsironis e8a146ef82 dm era: Recover committed writeset after crash
commit de89afc1e40fdfa5f8b666e5d07c43d21a1d3be0 upstream.

Following a system crash, dm-era fails to recover the committed writeset
for the current era, leading to lost writes. That is, we lose the
information about what blocks were written during the affected era.

dm-era assumes that the writeset of the current era is archived when the
device is suspended. So, when resuming the device, it just moves on to
the next era, ignoring the committed writeset.

This assumption holds when the device is properly shut down. But, when
the system crashes, the code that suspends the target never runs, so the
writeset for the current era is not archived.

There are three issues that cause the committed writeset to get lost:

1. dm-era doesn't load the committed writeset when opening the metadata
2. The code that resizes the metadata wipes the information about the
   committed writeset (assuming it was loaded at step 1)
3. era_preresume() starts a new era, without taking into account that
   the current era might not have been archived, due to a system crash.

To fix this:

1. Load the committed writeset when opening the metadata
2. Fix the code that resizes the metadata to make sure it doesn't wipe
   the loaded writeset
3. Fix era_preresume() to check for a loaded writeset and archive it,
   before starting a new era.

Fixes: eec40579d8 ("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@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-04 10:26:51 +01:00
Mikulas Patocka d873884783 dm writecache: fix writing beyond end of underlying device when shrinking
commit 4134455f2aafdfeab50cabb4cccb35e916034b93 upstream.

Do not attempt to write any data beyond the end of the underlying data
device while shrinking it.

The DM writecache device must be suspended when the underlying data
device is shrunk.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-04 10:26:51 +01:00
Mikulas Patocka 5233c47c8d dm: fix deadlock when swapping to encrypted device
commit a666e5c05e7c4aaabb2c5d58117b0946803d03d2 upstream.

The system would deadlock when swapping to a dm-crypt device. The reason
is that for each incoming write bio, dm-crypt allocates memory that holds
encrypted data. These excessive allocations exhaust all the memory and the
result is either deadlock or OOM trigger.

This patch limits the number of in-flight swap bios, so that the memory
consumed by dm-crypt is limited. The limit is enforced if the target set
the "limit_swap_bios" variable and if the bio has REQ_SWAP set.

Non-swap bios are not affected becuase taking the semaphore would cause
performance degradation.

This is similar to request-based drivers - they will also block when the
number of requests is over the limit.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-04 10:26:51 +01:00
Kai Krakow 5431cb6730 bcache: Move journal work to new flush wq
commit afe78ab46f638ecdf80a35b122ffc92c20d9ae5d upstream.

This is potentially long running and not latency sensitive, let's get
it out of the way of other latency sensitive events.

As observed in the previous commit, the `system_wq` comes easily
congested by bcache, and this fixes a few more stalls I was observing
every once in a while.

Let's not make this `WQ_MEM_RECLAIM` as it showed to reduce performance
of boot and file system operations in my tests. Also, without
`WQ_MEM_RECLAIM`, I no longer see desktop stalls. This matches the
previous behavior as `system_wq` also does no memory reclaim:

> // workqueue.c:
> system_wq = alloc_workqueue("events", 0, 0);

Cc: Coly Li <colyli@suse.de>
Cc: stable@vger.kernel.org # 5.4+
Signed-off-by: Kai Krakow <kai@kaishome.de>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-04 10:26:43 +01:00
Kai Krakow a339f0998e bcache: Give btree_io_wq correct semantics again
commit d797bd9897e3559eb48d68368550d637d32e468c upstream.

Before killing `btree_io_wq`, the queue was allocated using
`create_singlethread_workqueue()` which has `WQ_MEM_RECLAIM`. After
killing it, it no longer had this property but `system_wq` is not
single threaded.

Let's combine both worlds and make it multi threaded but able to
reclaim memory.

Cc: Coly Li <colyli@suse.de>
Cc: stable@vger.kernel.org # 5.4+
Signed-off-by: Kai Krakow <kai@kaishome.de>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-04 10:26:42 +01:00
Kai Krakow de5510b982 Revert "bcache: Kill btree_io_wq"
commit 9f233ffe02e5cef611100cd8c5bcf4de26ca7bef upstream.

This reverts commit 56b30770b2.

With the btree using the `system_wq`, I seem to see a lot more desktop
latency than I should.

After some more investigation, it looks like the original assumption
of 56b3077 no longer is true, and bcache has a very high potential of
congesting the `system_wq`. In turn, this introduces laggy desktop
performance, IO stalls (at least with btrfs), and input events may be
delayed.

So let's revert this. It's important to note that the semantics of
using `system_wq` previously mean that `btree_io_wq` should be created
before and destroyed after other bcache wqs to keep the same
assumptions.

Cc: Coly Li <colyli@suse.de>
Cc: stable@vger.kernel.org # 5.4+
Signed-off-by: Kai Krakow <kai@kaishome.de>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-04 10:26:42 +01:00
Xiao Ni 7018edb19a md: Set prev_flush_start and flush_bio in an atomic way
commit dc5d17a3c39b06aef866afca19245a9cfb533a79 upstream.

One customer reports a crash problem which causes by flush request. It
triggers a warning before crash.

        /* new request after previous flush is completed */
        if (ktime_after(req_start, mddev->prev_flush_start)) {
                WARN_ON(mddev->flush_bio);
                mddev->flush_bio = bio;
                bio = NULL;
        }

The WARN_ON is triggered. We use spin lock to protect prev_flush_start and
flush_bio in md_flush_request. But there is no lock protection in
md_submit_flush_data. It can set flush_bio to NULL first because of
compiler reordering write instructions.

For example, flush bio1 sets flush bio to NULL first in
md_submit_flush_data. An interrupt or vmware causing an extended stall
happen between updating flush_bio and prev_flush_start. Because flush_bio
is NULL, flush bio2 can get the lock and submit to underlayer disks. Then
flush bio1 updates prev_flush_start after the interrupt or extended stall.

Then flush bio3 enters in md_flush_request. The start time req_start is
behind prev_flush_start. The flush_bio is not NULL(flush bio2 hasn't
finished). So it can trigger the WARN_ON now. Then it calls INIT_WORK
again. INIT_WORK() will re-initialize the list pointers in the
work_struct, which then can result in a corrupted work list and the
work_struct queued a second time. With the work list corrupted, it can
lead in invalid work items being used and cause a crash in
process_one_work.

We need to make sure only one flush bio can be handled at one same time.
So add spin lock in md_submit_flush_data to protect prev_flush_start and
flush_bio in an atomic way.

Reviewed-by: David Jeffery <djeffery@redhat.com>
Signed-off-by: Xiao Ni <xni@redhat.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-10 09:25:32 +01:00
Mikulas Patocka 2d8848edc9 dm integrity: conditionally disable "recalculate" feature
commit 5c02406428d5219c367c5f53457698c58bc5f917 upstream.

Otherwise a malicious user could (ab)use the "recalculate" feature
that makes dm-integrity calculate the checksums in the background
while the device is already usable. When the system restarts before all
checksums have been calculated, the calculation continues where it was
interrupted even if the recalculate feature is not requested the next
time the dm device is set up.

Disable recalculating if we use internal_hash or journal_hash with a
key (e.g. HMAC) and we don't have the "legacy_recalculate" flag.

This may break activation of a volume, created by an older kernel,
that is not yet fully recalculated -- if this happens, the user should
add the "legacy_recalculate" flag to constructor parameters.

Cc: stable@vger.kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reported-by: Daniel Glockner <dg@emlix.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-30 13:54:10 +01:00
Anthony Iliopoulos b477f43710 dm integrity: select CRYPTO_SKCIPHER
[ Upstream commit f7b347acb5f6c29d9229bb64893d8b6a2c7949fb ]

The integrity target relies on skcipher for encryption/decryption, but
certain kernel configurations may not enable CRYPTO_SKCIPHER, leading to
compilation errors due to unresolved symbols. Explicitly select
CRYPTO_SKCIPHER for DM_INTEGRITY, since it is unconditionally dependent
on it.

Signed-off-by: Anthony Iliopoulos <ailiop@suse.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-27 11:47:42 +01:00
Mikulas Patocka 42d855f06d dm integrity: fix a crash if "recalculate" used without "internal_hash"
commit 2d06dfecb132a1cc2e374a44eae83b5c4356b8b4 upstream.

Recalculate can only be specified with internal_hash.

Cc: stable@vger.kernel.org # v4.19+
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-27 11:47:41 +01:00
Hannes Reinecke a03ce9cc4b dm: avoid filesystem lookup in dm_get_dev_t()
commit 809b1e4945774c9ec5619a8f4e2189b7b3833c0c upstream.

This reverts commit
644bda6f34 ("dm table: fall back to getting device using name_to_dev_t()")

dm_get_dev_t() is just used to convert an arbitrary 'path' string
into a dev_t. It doesn't presume that the device is present; that
check will be done later, as the only caller is dm_get_device(),
which does a dm_get_table_device() later on, which will properly
open the device.

So if the path string already _is_ in major:minor representation
we can convert it directly, avoiding a recursion into the filesystem
to lookup the block device.

This avoids a hang in multipath_message() when the filesystem is
inaccessible.

Fixes: 644bda6f34 ("dm table: fall back to getting device using name_to_dev_t()")
Cc: stable@vger.kernel.org
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin Wilck <mwilck@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-27 11:47:41 +01:00
Mike Snitzer 2c3d03cdbd dm: eliminate potential source of excessive kernel log noise
commit 0378c625afe80eb3f212adae42cc33c9f6f31abf upstream.

There wasn't ever a real need to log an error in the kernel log for
ioctls issued with insufficient permissions. Simply return an error
and if an admin/user is sufficiently motivated they can enable DM's
dynamic debugging to see an explanation for why the ioctls were
disallowed.

Reported-by: Nir Soffer <nsoffer@redhat.com>
Fixes: e980f62353 ("dm: don't allow ioctls to targets that don't map to whole devices")
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-19 18:26:18 +01:00
Mikulas Patocka 5349b17c3d dm integrity: fix flush with external metadata device
[ Upstream commit 9b5948267adc9e689da609eb61cf7ed49cae5fa8 ]

With external metadata device, flush requests are not passed down to the
data device.

Fix this by submitting the flush request in dm_integrity_flush_buffers. In
order to not degrade performance, we overlap the data device flush with
the metadata device flush.

Reported-by: Lukas Straub <lukasstraub2@web.de>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-19 18:26:13 +01:00
Mikulas Patocka ad5f19c7e9 dm integrity: fix the maximum number of arguments
commit 17ffc193cdc6dc7a613d00d8ad47fc1f801b9bf0 upstream.

Advance the maximum number of arguments from 9 to 15 to account for
all potential feature flags that may be supplied.

Linux 4.19 added "meta_device"
(356d9d52e1) and "recalculate"
(a3fcf72531) flags.

Commit 468dfca38b added
"sectors_per_bit" and "bitmap_flush_interval".

Commit 84597a44a9d86ac949900441cea7da0af0f2f473 added
"allow_discards".

And the commit d537858ac8aaf4311b51240893add2fc62003b97 added
"fix_padding".

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org # v4.19+
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-19 18:26:13 +01:00
Akilesh Kailash 5caac6317d dm snapshot: flush merged data before committing metadata
commit fcc42338375a1e67b8568dbb558f8b784d0f3b01 upstream.

If the origin device has a volatile write-back cache and the following
events occur:

1: After finishing merge operation of one set of exceptions,
   merge_callback() is invoked.
2: Update the metadata in COW device tracking the merge completion.
   This update to COW device is flushed cleanly.
3: System crashes and the origin device's cache where the recent
   merge was completed has not been flushed.

During the next cycle when we read the metadata from the COW device,
we will skip reading those metadata whose merge was completed in
step (1). This will lead to data loss/corruption.

To address this, flush the origin device post merge IO before
updating the metadata.

Cc: stable@vger.kernel.org
Signed-off-by: Akilesh Kailash <akailash@google.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-19 18:26:13 +01:00