linux-stable.git/drivers/md/dm-writecache.c, branch linux-5.4.y

dm writecache: set a default MAX_WRITEBACK_JOBS

2022-08-25T09:18:14+00:00

commit ca7dc242e358e46d963b32f9d9dd829785a9e957 upstream.

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 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm writecache: return the exact table values that were set

2021-07-25T12:35:14+00:00

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 
Cc: stable@vger.kernel.org # v4.18+
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm writecache: fix writing beyond end of underlying device when shrinking

2021-03-04T09:26:51+00:00

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

dm writecache: remove BUG() and fail gracefully instead

2020-12-11T12:23:33+00:00

commit 857c4c0a8b2888d806f4308c58f59a6a81a1dee9 upstream.

Building on arch/s390/ results in this build error:

cc1: some warnings being treated as errors
../drivers/md/dm-writecache.c: In function 'persistent_memory_claim':
../drivers/md/dm-writecache.c:323:1: error: no return statement in function returning non-void [-Werror=return-type]

Fix this by replacing the BUG() with an -EOPNOTSUPP return.

Fixes: 48debafe4f2f ("dm: add writecache target")
Reported-by: Randy Dunlap 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm writecache: fix the maximum number of arguments

2020-12-11T12:23:30+00:00

commit 67aa3ec3dbc43d6e34401d9b2a40040ff7bb57af upstream.

Advance the maximum number of arguments to 16.
This fixes issue where certain operations, combined with table
configured args, exceed 10 arguments.

Signed-off-by: Mikulas Patocka 
Fixes: 48debafe4f2f ("dm: add writecache target")
Cc: stable@vger.kernel.org # v4.18+
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm writecache: handle DAX to partitions on persistent memory correctly

2020-09-09T17:12:35+00:00

commit f9e040efcc28309e5c592f7e79085a9a52e31f58 upstream.

The function dax_direct_access doesn't take partitions into account,
it always maps pages from the beginning of the device. Therefore,
persistent_memory_claim() must get the partition offset using
get_start_sect() and add it to the page offsets passed to
dax_direct_access().

Signed-off-by: Mikulas Patocka 
Fixes: 48debafe4f2f ("dm: add writecache target")
Cc: stable@vger.kernel.org # 4.18+
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm writecache: reject asynchronous pmem devices

2020-07-16T06:16:47+00:00

commit a46624580376a3a0beb218d94cbc7f258696e29f upstream.

DM writecache does not handle asynchronous pmem. Reject it when
supplied as cache.

Link: https://lore.kernel.org/linux-nvdimm/87lfk5hahc.fsf@linux.ibm.com/
Fixes: 6e84200c0a29 ("virtio-pmem: Add virtio pmem driver")
Signed-off-by: Michal Suchanek 
Acked-by: Mikulas Patocka 
Cc: stable@vger.kernel.org # 5.3+
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm writecache: add cond_resched to loop in persistent_memory_claim()

2020-06-30T19:37:12+00:00

commit d35bd764e6899a7bea71958f08d16cea5bfa1919 upstream.

Add cond_resched() to a loop that fills in the mapper memory area
because the loop can be executed many times.

Fixes: 48debafe4f2fe ("dm: add writecache target")
Cc: stable@vger.kernel.org
Signed-off-by: Mikulas Patocka 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm writecache: correct uncommitted_block when discarding uncommitted entry

2020-06-30T19:37:12+00:00

commit 39495b12ef1cf602e6abd350dce2ef4199906531 upstream.

When uncommitted entry has been discarded, correct wc->uncommitted_block
for getting the exact number.

Fixes: 48debafe4f2fe ("dm: add writecache target")
Cc: stable@vger.kernel.org
Signed-off-by: Huaisheng Ye 
Acked-by: Mikulas Patocka 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm writecache: fix data corruption when reloading the target

2020-05-06T06:15:10+00:00

commit 31b22120194b5c0d460f59e0c98504de1d3f1f14 upstream.

The dm-writecache reads metadata in the target constructor. However, when
we reload the target, there could be another active instance running on
the same device. This is the sequence of operations when doing a reload:

1. construct new target
2. suspend old target
3. resume new target
4. destroy old target

Metadata that were written by the old target between steps 1 and 2 would
not be visible by the new target.

Fix the data corruption by loading the metadata in the resume handler.

Also, validate block_size is at least as large as both the devices'
logical block size and only read 1 block from the metadata during
target constructor -- no need to read entirety of metadata now that it
is done during resume.

Fixes: 48debafe4f2f ("dm: add writecache target")
Cc: stable@vger.kernel.org # v4.18+
Signed-off-by: Mikulas Patocka 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman