user/sven/linux.git/drivers/md/dm-writecache.c, branch v5.8.8

dm writecache: handle DAX to partitions on persistent memory correctly

2020-09-09T17:14:31Z

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

2020-07-08T15:06:57Z

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

dm writecache: add cond_resched to loop in persistent_memory_claim()

2020-06-19T16:32:24Z

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

dm writecache: skip writecache_wait when using pmem mode

2020-06-17T16:25:42Z

The array bio_in_progress is only used with ssd mode. So skip writecache_wait_for_ios in writecache_discard when pmem mode. Signed-off-by: Huaisheng Ye Acked-by: Mikulas Patocka Signed-off-by: Mike Snitzer

dm writecache: correct uncommitted_block when discarding uncommitted entry

2020-06-17T16:25:41Z

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

dm writecache: improve performance on DDR persistent memory (Optane)

2020-05-15T14:29:36Z

When testing the dm-writecache target on a real DDR persistent memory (Intel Optane), it turned out that explicit cache flushing using the clflushopt instruction performs better than non-temporal stores for block sizes 1k, 2k and 4k. The dm-writecache target is singlethreaded (all the copying is done while holding the writecache lock), so it benefits from clwb, see: http://lore.kernel.org/r/alpine.LRH.2.02.2004160411460.7833@file01.intranet.prod.int.rdu2.redhat.com Add a new function memcpy_flushcache_optimized() that tests if clflushopt is present - and if it is, we use it instead of memcpy_flushcache. Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer

dm writecache: remove superfluous test in persistent_memory_claim

2020-05-15T14:29:36Z

Remove superfluous test if dax_dev is NULL - dax_direct_access already does this test. Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer

dm writecache: fix data corruption when reloading the target

2020-04-16T20:04:13Z

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

dm writecache: add cond_resched to avoid CPU hangs

2020-03-27T18:36:50Z

Initializing a dm-writecache device can take a long time when the persistent memory device is large. Add cond_resched() to a few loops to avoid warnings that the CPU is stuck. Cc: stable@vger.kernel.org # v4.18+ Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer

dm writecache: optimize superblock write

2020-03-24T15:55:09Z

If we write a superblock in writecache_flush, we don't need to set bit and scan the bitmap for it - we can just write the superblock directly. Also, we can set the flag REQ_FUA on the write bio, so that we don't need to submit a flush bio afterwards. Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer