linux-stable.git/drivers/md, branch v6.2.13

dm: fix improper splitting for abnormal bios

2023-04-13T15:02:34+00:00

[ Upstream commit f7b58a69fad9d2c4c90cab0247811155dd0d48e7 ]

"Abnormal" bios include discards, write zeroes and secure erase. By no
longer passing the calculated 'len' pointer, commit 7dd06a2548b2 ("dm:
allow dm_accept_partial_bio() for dm_io without duplicate bios") took a
senseless approach to disallowing dm_accept_partial_bio() from working
for duplicate bios processed using __send_duplicate_bios().

It inadvertently and incorrectly stopped the use of 'len' when
initializing a target's io (in alloc_tio). As such the resulting tio
could address more area of a device than it should.

For example, when discarding an entire DM striped device with the
following DM table:
 vg-lvol0: 0 159744 striped 2 128 7:0 2048 7:1 2048
 vg-lvol0: 159744 45056 striped 2 128 7:2 2048 7:3 2048

Before this fix:

 device-mapper: striped: target_stripe=0, bdev=7:0, start=2048 len=102400
 blkdiscard: attempt to access beyond end of device
 loop0: rw=2051, sector=2048, nr_sectors = 102400 limit=81920

 device-mapper: striped: target_stripe=1, bdev=7:1, start=2048 len=102400
 blkdiscard: attempt to access beyond end of device
 loop1: rw=2051, sector=2048, nr_sectors = 102400 limit=81920

After this fix;

 device-mapper: striped: target_stripe=0, bdev=7:0, start=2048 len=79872
 device-mapper: striped: target_stripe=1, bdev=7:1, start=2048 len=79872

Fixes: 7dd06a2548b2 ("dm: allow dm_accept_partial_bio() for dm_io without duplicate bios")
Cc: stable@vger.kernel.org
Reported-by: Orange Kao 
Signed-off-by: Mike Snitzer 
Signed-off-by: Sasha Levin

dm: change "unsigned" to "unsigned int"

2023-04-13T15:02:34+00:00

[ Upstream commit 86a3238c7b9b759cb864f4f768ab2e24687dc0e6 ]

Signed-off-by: Heinz Mauelshagen 
Signed-off-by: Mike Snitzer 
Stable-dep-of: f7b58a69fad9 ("dm: fix improper splitting for abnormal bios")
Signed-off-by: Sasha Levin

dm integrity: Remove bi_sector that's only used by commented debug code

2023-04-13T15:02:34+00:00

[ Upstream commit 5cd6d1d53a1f74222e73d8b42ab7ecf28ee2f34f ]

drivers/md/dm-integrity.c:1738:13: warning: variable 'bi_sector' set but not used.

Reported-by: Abaci Robot 
Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=3895
Signed-off-by: Jiapeng Chong 
Signed-off-by: Mike Snitzer 
Stable-dep-of: f7b58a69fad9 ("dm: fix improper splitting for abnormal bios")
Signed-off-by: Sasha Levin

dm cache: Add some documentation to dm-cache-background-tracker.h

2023-04-13T15:02:34+00:00

[ Upstream commit 22c40e134c4c7a828ac09d25a5a8597b1e45c031 ]

Signed-off-by: Joe Thornber 
Signed-off-by: Mike Snitzer 
Stable-dep-of: f7b58a69fad9 ("dm: fix improper splitting for abnormal bios")
Signed-off-by: Sasha Levin

dm: fix __send_duplicate_bios() to always allow for splitting IO

2023-04-06T10:12:42+00:00

commit 666eed46769d929c3e13636134ecfc67d75ef548 upstream.

Commit 7dd76d1feec70 ("dm: improve bio splitting and associated IO
accounting") only called setup_split_accounting() from
__send_duplicate_bios() if a single bio were being issued. But the case
where duplicate bios are issued must call it too.

Otherwise the bio won't be split and resubmitted (via recursion through
block core back to DM) to submit the later portions of a bio (which may
map to an entirely different target).

For example, when discarding an entire DM striped device with the
following DM table:
 vg-lvol0: 0 159744 striped 2 128 7:0 2048 7:1 2048
 vg-lvol0: 159744 45056 striped 2 128 7:2 2048 7:3 2048

Before (broken, discards the first striped target's devices twice):
 device-mapper: striped: target_stripe=0, bdev=7:0, start=2048 len=79872
 device-mapper: striped: target_stripe=1, bdev=7:1, start=2048 len=79872
 device-mapper: striped: target_stripe=0, bdev=7:0, start=2049 len=22528
 device-mapper: striped: target_stripe=1, bdev=7:1, start=2048 len=22528

After (works as expected):
 device-mapper: striped: target_stripe=0, bdev=7:0, start=2048 len=79872
 device-mapper: striped: target_stripe=1, bdev=7:1, start=2048 len=79872
 device-mapper: striped: target_stripe=0, bdev=7:2, start=2048 len=22528
 device-mapper: striped: target_stripe=1, bdev=7:3, start=2048 len=22528

Fixes: 7dd76d1feec70 ("dm: improve bio splitting and associated IO accounting")
Cc: stable@vger.kernel.org
Reported-by: Orange Kao 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

md: avoid signed overflow in slot_store()

2023-04-06T10:12:27+00:00

[ Upstream commit 3bc57292278a0b6ac4656cad94c14f2453344b57 ]

slot_store() uses kstrtouint() to get a slot number, but stores the
result in an "int" variable (by casting a pointer).
This can result in a negative slot number if the unsigned int value is
very large.

A negative number means that the slot is empty, but setting a negative
slot number this way will not remove the device from the array.  I don't
think this is a serious problem, but it could cause confusion and it is
best to fix it.

Reported-by: Dan Carpenter 
Signed-off-by: NeilBrown 
Signed-off-by: Song Liu 
Signed-off-by: Sasha Levin

dm crypt: avoid accessing uninitialized tasklet

2023-03-30T10:51:42+00:00

commit d9a02e016aaf5a57fb44e9a5e6da8ccd3b9e2e70 upstream.

When neither "no_read_workqueue" nor "no_write_workqueue" are enabled,
tasklet_trylock() in crypt_dec_pending() may still return false due to
an uninitialized state, and dm-crypt will unnecessarily do io completion
in io_queue workqueue instead of current context.

Fix this by adding an 'in_tasklet' flag to dm_crypt_io struct and
initialize it to false in crypt_io_init(). Set this flag to true in
kcryptd_queue_crypt() before calling tasklet_schedule(). If set
crypt_dec_pending() will punt io completion to a workqueue.

This also nicely avoids the tasklet_trylock/unlock hack when tasklets
aren't in use.

Fixes: 8e14f610159d ("dm crypt: do not call bio_endio() from the dm-crypt tasklet")
Cc: stable@vger.kernel.org
Reported-by: Hou Tao 
Suggested-by: Ignat Korchagin 
Reviewed-by: Ignat Korchagin 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm crypt: add cond_resched() to dmcrypt_write()

2023-03-30T10:51:42+00:00

commit fb294b1c0ba982144ca467a75e7d01ff26304e2b upstream.

The loop in dmcrypt_write may be running for unbounded amount of time,
thus we need cond_resched() in it.

This commit fixes the following warning:

[ 3391.153255][   C12] watchdog: BUG: soft lockup - CPU#12 stuck for 23s! [dmcrypt_write/2:2897]
...
[ 3391.387210][   C12] Call trace:
[ 3391.390338][   C12]  blk_attempt_bio_merge.part.6+0x38/0x158
[ 3391.395970][   C12]  blk_attempt_plug_merge+0xc0/0x1b0
[ 3391.401085][   C12]  blk_mq_submit_bio+0x398/0x550
[ 3391.405856][   C12]  submit_bio_noacct+0x308/0x380
[ 3391.410630][   C12]  dmcrypt_write+0x1e4/0x208 [dm_crypt]
[ 3391.416005][   C12]  kthread+0x130/0x138
[ 3391.419911][   C12]  ret_from_fork+0x10/0x18

Reported-by: yangerkun 
Fixes: dc2676210c42 ("dm crypt: offload writes to thread")
Cc: stable@vger.kernel.org
Signed-off-by: Mikulas Patocka 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm stats: check for and propagate alloc_percpu failure

2023-03-30T10:51:42+00:00

commit d3aa3e060c4a80827eb801fc448debc9daa7c46b upstream.

Check alloc_precpu()'s return value and return an error from
dm_stats_init() if it fails. Update alloc_dev() to fail if
dm_stats_init() does.

Otherwise, a NULL pointer dereference will occur in dm_stats_cleanup()
even if dm-stats isn't being actively used.

Fixes: fd2ed4d25270 ("dm: add statistics support")
Cc: stable@vger.kernel.org
Signed-off-by: Jiasheng Jiang 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm thin: fix deadlock when swapping to thin device

2023-03-30T10:51:35+00:00

commit 9bbf5feecc7eab2c370496c1c161bbfe62084028 upstream.

This is an already known issue that dm-thin volume cannot be used as
swap, otherwise a deadlock may happen when dm-thin internal memory
demand triggers swap I/O on the dm-thin volume itself.

But thanks to commit a666e5c05e7c ("dm: fix deadlock when swapping to
encrypted device"), the limit_swap_bios target flag can also be used
for dm-thin to avoid the recursive I/O when it is used as swap.

Fix is to simply set ti->limit_swap_bios to true in both pool_ctr()
and thin_ctr().

In my test, I create a dm-thin volume /dev/vg/swap and use it as swap
device. Then I run fio on another dm-thin volume /dev/vg/main and use
large --blocksize to trigger swap I/O onto /dev/vg/swap.

The following fio command line is used in my test,
  fio --name recursive-swap-io --lockmem 1 --iodepth 128 \
     --ioengine libaio --filename /dev/vg/main --rw randrw \
    --blocksize 1M --numjobs 32 --time_based --runtime=12h

Without this fix, the whole system can be locked up within 15 seconds.

With this fix, there is no any deadlock or hung task observed after
2 hours of running fio.

Furthermore, if blocksize is changed from 1M to 128M, after around 30
seconds fio has no visible I/O, and the out-of-memory killer message
shows up in kernel message. After around 20 minutes all fio processes
are killed and the whole system is back to being alive.

This is exactly what is expected when recursive I/O happens on dm-thin
volume when it is used as swap.

Depends-on: a666e5c05e7c ("dm: fix deadlock when swapping to encrypted device")
Cc: stable@vger.kernel.org
Signed-off-by: Coly Li 
Acked-by: Mikulas Patocka 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman