linux-stable.git/drivers/md, branch v3.18.129

dm: remove duplicate dm_get_live_table() in __dm_destroy()

2018-11-22T06:32:45+00:00

[3.18.y only, to fix a previous patch]

__dm_destroy() takes io_barrier SRCU lock (dm_get_live_table) twice
which leads to a deadlock.  Remove taking lock before holding
suspend_lock to prevent a different potential deadlock.

Signed-off-by: Corey Wright 
Fixes: e1db66a5fdcc ("dm: fix AB-BA deadlock in __dm_destroy()")
Cc: Sasha Levin

dm ioctl: harden copy_params()'s copy_from_user() from malicious users

2018-11-22T06:32:44+00:00

commit 800a7340ab7dd667edf95e74d8e4f23a17e87076 upstream.

In copy_params(), the struct 'dm_ioctl' is first copied from the user
space buffer 'user' to 'param_kernel' and the field 'data_size' is
checked against 'minimum_data_size' (size of 'struct dm_ioctl' payload
up to its 'data' member).  If the check fails, an error code EINVAL will be
returned.  Otherwise, param_kernel->data_size is used to do a second copy,
which copies from the same user-space buffer to 'dmi'.  After the second
copy, only 'dmi->data_size' is checked against 'param_kernel->data_size'.
Given that the buffer 'user' resides in the user space, a malicious
user-space process can race to change the content in the buffer between
the two copies.  This way, the attacker can inject inconsistent data
into 'dmi' (versus previously validated 'param_kernel').

Fix redundant copying of 'minimum_data_size' from user-space buffer by
using the first copy stored in 'param_kernel'.  Also remove the
'data_size' check after the second copy because it is now unnecessary.

Cc: stable@vger.kernel.org
Signed-off-by: Wenwen Wang 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

bcache: fix miss key refill->end in writeback

2018-11-22T06:32:41+00:00

commit 2d6cb6edd2c7fb4f40998895bda45006281b1ac5 upstream.

refill->end record the last key of writeback, for example, at the first
time, keys (1,128K) to (1,1024K) are flush to the backend device, but
the end key (1,1024K) is not included, since the bellow code:
	if (bkey_cmp(k, refill->end) >= 0) {
		ret = MAP_DONE;
		goto out;
	}
And in the next time when we refill writeback keybuf again, we searched
key start from (1,1024K), and got a key bigger than it, so the key
(1,1024K) missed.
This patch modify the above code, and let the end key to be included to
the writeback key buffer.

Signed-off-by: Tang Junhui 
Cc: stable@vger.kernel.org
Signed-off-by: Coly Li 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

dm: fix AB-BA deadlock in __dm_destroy()

2018-11-10T15:39:18+00:00

[ Upstream commit 2a708cff93f1845b9239bc7d6310aef54e716c6a ]

__dm_destroy() takes io_barrier SRCU lock (dm_get_live_table) and
suspend_lock in reverse order.  Doing so can cause AB-BA deadlock:

  __dm_destroy                    dm_swap_table
  ---------------------------------------------------
                                  mutex_lock(suspend_lock)
  dm_get_live_table()
    srcu_read_lock(io_barrier)
                                  dm_sync_table()
                                    synchronize_srcu(io_barrier)
                                      .. waiting for dm_put_live_table()
  mutex_lock(suspend_lock)
    .. waiting for suspend_lock

Fix this by taking the locks in proper order.

Signed-off-by: Jun'ichi Nomura 
Fixes: ab7c7bb6f4ab ("dm: hold suspend_lock while suspending device during device deletion")
Acked-by: Mikulas Patocka 
Signed-off-by: Mike Snitzer 
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin

dm thin: restore requested 'error_if_no_space' setting on OODS to WRITE transition

2018-11-10T15:39:13+00:00

[ Upstream commit 172c238612ebf81cabccc86b788c9209af591f61 ]

A thin-pool that is in out-of-data-space (OODS) mode may transition back
to write mode -- without the admin adding more space to the thin-pool --
if/when blocks are released (either by deleting thin devices or
discarding provisioned blocks).

But as part of the thin-pool's earlier transition to out-of-data-space
mode the thin-pool may have set the 'error_if_no_space' flag to true if
the no_space_timeout expires without more space having been made
available.  That implementation detail, of changing the pool's
error_if_no_space setting, needs to be reset back to the default that
the user specified when the thin-pool's table was loaded.

Otherwise we'll drop the user requested behaviour on the floor when this
out-of-data-space to write mode transition occurs.

Reported-by: Vivek Goyal 
Signed-off-by: Mike Snitzer 
Acked-by: Joe Thornber 
Fixes: 2c43fd26e4 ("dm thin: fix missing out-of-data-space to write mode transition if blocks are released")
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin

dm thin metadata: fix __udivdi3 undefined on 32-bit

2018-10-13T07:09:30+00:00

commit 013ad043906b2befd4a9bfb06219ed9fedd92716 upstream.

sector_div() is only viable for use with sector_t.
dm_block_t is typedef'd to uint64_t -- so use div_u64() instead.

Fixes: 3ab918281 ("dm thin metadata: try to avoid ever aborting transactions")
Signed-off-by: Mike Snitzer 
Cc: Sudip Mukherjee 
Signed-off-by: Greg Kroah-Hartman

dm thin metadata: try to avoid ever aborting transactions

2018-10-13T07:09:30+00:00

[ Upstream commit 3ab91828166895600efd9cdc3a0eb32001f7204a ]

Committing a transaction can consume some metadata of it's own, we now
reserve a small amount of metadata to cover this.  Free metadata
reported by the kernel will not include this reserve.

If any of the reserve has been used after a commit we enter a new
internal state PM_OUT_OF_METADATA_SPACE.  This is reported as
PM_READ_ONLY, so no userland changes are needed.  If the metadata
device is resized the pool will move back to PM_WRITE.

These changes mean we never need to abort and rollback a transaction due
to running out of metadata space.  This is particularly important
because there have been a handful of reports of data corruption against
DM thin-provisioning that can all be attributed to the thin-pool having
ran out of metadata space.

Signed-off-by: Joe Thornber 
Signed-off-by: Mike Snitzer 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

RAID10 BUG_ON in raise_barrier when force is true and conf->barrier is 0

2018-10-13T07:09:29+00:00

[ Upstream commit 1d0ffd264204eba1861865560f1f7f7a92919384 ]

In raid10 reshape_request it gets max_sectors in read_balance. If the underlayer disks
have bad blocks, the max_sectors is less than last. It will call goto read_more many
times. It calls raise_barrier(conf, sectors_done != 0) every time. In this condition
sectors_done is not 0. So the value passed to the argument force of raise_barrier is
true.

In raise_barrier it checks conf->barrier when force is true. If force is true and
conf->barrier is 0, it panic. In this case reshape_request submits bio to under layer
disks. And in the callback function of the bio it calls lower_barrier. If the bio
finishes before calling raise_barrier again, it can trigger the BUG_ON.

Add one pair of raise_barrier/lower_barrier to fix this bug.

Signed-off-by: Xiao Ni 
Suggested-by: Neil Brown 
Signed-off-by: Shaohua Li 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

md/raid5: fix data corruption of replacements after originals dropped

2018-09-26T06:33:53+00:00

[ Upstream commit d63e2fc804c46e50eee825c5d3a7228e07048b47 ]

During raid5 replacement, the stripes can be marked with R5_NeedReplace
flag. Data can be read from being-replaced devices and written to
replacing spares without reading all other devices. (It's 'replace'
mode. s.replacing = 1) If a being-replaced device is dropped, the
replacement progress will be interrupted and resumed with pure recovery
mode. However, existing stripes before being interrupted cannot read
from the dropped device anymore. It prints lots of WARN_ON messages.
And it results in data corruption because existing stripes write
problematic data into its replacement device and update the progress.

\# Erase disks (1MB + 2GB)
dd if=/dev/zero of=/dev/sda bs=1MB count=2049
dd if=/dev/zero of=/dev/sdb bs=1MB count=2049
dd if=/dev/zero of=/dev/sdc bs=1MB count=2049
dd if=/dev/zero of=/dev/sdd bs=1MB count=2049
mdadm -C /dev/md0 -amd -R -l5 -n3 -x0 /dev/sd[abc] -z 2097152
\# Ensure array stores non-zero data
dd if=/root/data_4GB.iso of=/dev/md0 bs=1MB
\# Start replacement
mdadm /dev/md0 -a /dev/sdd
mdadm /dev/md0 --replace /dev/sda

Then, Hot-plug out /dev/sda during recovery, and wait for recovery done.
echo check > /sys/block/md0/md/sync_action
cat /sys/block/md0/md/mismatch_cnt # it will be greater than 0.

Soon after you hot-plug out /dev/sda, you will see many WARN_ON
messages. The replacement recovery will be interrupted shortly. After
the recovery finishes, it will result in data corruption.

Actually, it's just an unhandled case of replacement. In commit
 (md/raid5: fix interaction of 'replace' and 'recovery'.),
if a NeedReplace device is not UPTODATE then that is an error, the
commit just simply print WARN_ON but also mark these corrupted stripes
with R5_WantReplace. (it means it's ready for writes.)

To fix this case, we can leverage 'sync and replace' mode mentioned in
commit <9a3e1101b827> (md/raid5: detect and handle replacements during
recovery.). We can add logics to detect and use 'sync and replace' mode
for these stripes.

Reported-by: Alex Chen 
Reviewed-by: Alex Wu 
Reviewed-by: Chung-Chiang Cheng 
Signed-off-by: BingJing Chang 
Signed-off-by: Shaohua Li 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

dm kcopyd: avoid softlockup in run_complete_job

2018-09-26T06:33:51+00:00

[ Upstream commit 784c9a29e99eb40b842c29ecf1cc3a79e00fb629 ]

It was reported that softlockups occur when using dm-snapshot ontop of
slow (rbd) storage.  E.g.:

[ 4047.990647] watchdog: BUG: soft lockup - CPU#10 stuck for 22s! [kworker/10:23:26177]
...
[ 4048.034151] Workqueue: kcopyd do_work [dm_mod]
[ 4048.034156] RIP: 0010:copy_callback+0x41/0x160 [dm_snapshot]
...
[ 4048.034190] Call Trace:
[ 4048.034196]  ? __chunk_is_tracked+0x70/0x70 [dm_snapshot]
[ 4048.034200]  run_complete_job+0x5f/0xb0 [dm_mod]
[ 4048.034205]  process_jobs+0x91/0x220 [dm_mod]
[ 4048.034210]  ? kcopyd_put_pages+0x40/0x40 [dm_mod]
[ 4048.034214]  do_work+0x46/0xa0 [dm_mod]
[ 4048.034219]  process_one_work+0x171/0x370
[ 4048.034221]  worker_thread+0x1fc/0x3f0
[ 4048.034224]  kthread+0xf8/0x130
[ 4048.034226]  ? max_active_store+0x80/0x80
[ 4048.034227]  ? kthread_bind+0x10/0x10
[ 4048.034231]  ret_from_fork+0x35/0x40
[ 4048.034233] Kernel panic - not syncing: softlockup: hung tasks

Fix this by calling cond_resched() after run_complete_job()'s callout to
the dm_kcopyd_notify_fn (which is dm-snap.c:copy_callback in the above
trace).

Signed-off-by: John Pittman 
Signed-off-by: Mike Snitzer 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman