kernel/linux.git/drivers/md/bcache, branch linux-5.11.y

bcache: Move journal work to new flush wq

2021-03-04T11:15:22+00:00

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 Cc: stable@vger.kernel.org # 5.4+ Signed-off-by: Kai Krakow Signed-off-by: Coly Li Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

bcache: Give btree_io_wq correct semantics again

2021-03-04T11:15:22+00:00

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 Cc: stable@vger.kernel.org # 5.4+ Signed-off-by: Kai Krakow Signed-off-by: Coly Li Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

Revert "bcache: Kill btree_io_wq"

2021-03-04T11:15:22+00:00

commit 9f233ffe02e5cef611100cd8c5bcf4de26ca7bef upstream. This reverts commit 56b30770b27d54d68ad51eccc6d888282b568cee. 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 Cc: stable@vger.kernel.org # 5.4+ Signed-off-by: Kai Krakow Signed-off-by: Coly Li Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

bcache: only check feature sets when sb->version >= BCACHE_SB_VERSION_CDEV_WITH_FEATURES

2021-01-28T14:35:07+00:00

For super block version < BCACHE_SB_VERSION_CDEV_WITH_FEATURES, it doesn't make sense to check the feature sets. This patch checks super block version in bch_has_feature_* routines, if the version doesn't have feature sets yet, returns 0 (false) to the caller. Fixes: 5342fd425502 ("bcache: set bcache device into read-only mode for BCH_FEATURE_INCOMPAT_OBSO_LARGE_BUCKET") Fixes: ffa470327572 ("bcache: add bucket_size_hi into struct cache_sb_disk for large bucket") Cc: stable@vger.kernel.org # 5.9+ Reported-and-tested-by: Bockholdt Arne Signed-off-by: Coly Li Signed-off-by: Jens Axboe

bcache: set bcache device into read-only mode for BCH_FEATURE_INCOMPAT_OBSO_LARGE_BUCKET

2021-01-09T16:21:03+00:00

If BCH_FEATURE_INCOMPAT_OBSO_LARGE_BUCKET is set in incompat feature set, it means the cache device is created with obsoleted layout with obso_bucket_site_hi. Now bcache does not support this feature bit, a new BCH_FEATURE_INCOMPAT_LOG_LARGE_BUCKET_SIZE incompat feature bit is added for a better layout to support large bucket size. For the legacy compatibility purpose, if a cache device created with obsoleted BCH_FEATURE_INCOMPAT_OBSO_LARGE_BUCKET feature bit, all bcache devices attached to this cache set should be set to read-only. Then the dirty data can be written back to backing device before re-create the cache device with BCH_FEATURE_INCOMPAT_LOG_LARGE_BUCKET_SIZE feature bit by the latest bcache-tools. This patch checks BCH_FEATURE_INCOMPAT_OBSO_LARGE_BUCKET feature bit when running a cache set and attach a bcache device to the cache set. If this bit is set, - When run a cache set, print an error kernel message to indicate all following attached bcache device will be read-only. - When attach a bcache device, print an error kernel message to indicate the attached bcache device will be read-only, and ask users to update to latest bcache-tools. Such change is only for cache device whose bucket size >= 32MB, this is for the zoned SSD and almost nobody uses such large bucket size at this moment. If you don't explicit set a large bucket size for a zoned SSD, such change is totally transparent to your bcache device. Fixes: ffa470327572 ("bcache: add bucket_size_hi into struct cache_sb_disk for large bucket") Signed-off-by: Coly Li Signed-off-by: Jens Axboe

bcache: introduce BCH_FEATURE_INCOMPAT_LOG_LARGE_BUCKET_SIZE for large bucket

2021-01-09T16:21:03+00:00

When large bucket feature was added, BCH_FEATURE_INCOMPAT_LARGE_BUCKET was introduced into the incompat feature set. It used bucket_size_hi (which was added at the tail of struct cache_sb_disk) to extend current 16bit bucket size to 32bit with existing bucket_size in struct cache_sb_disk. This is not a good idea, there are two obvious problems, - Bucket size is always value power of 2, if store log2(bucket size) in existing bucket_size of struct cache_sb_disk, it is unnecessary to add bucket_size_hi. - Macro csum_set() assumes d[SB_JOURNAL_BUCKETS] is the last member in struct cache_sb_disk, bucket_size_hi was added after d[] which makes csum_set calculate an unexpected super block checksum. To fix the above problems, this patch introduces a new incompat feature bit BCH_FEATURE_INCOMPAT_LOG_LARGE_BUCKET_SIZE, when this bit is set, it means bucket_size in struct cache_sb_disk stores the order of power-of-2 bucket size value. When user specifies a bucket size larger than 32768 sectors, BCH_FEATURE_INCOMPAT_LOG_LARGE_BUCKET_SIZE will be set to incompat feature set, and bucket_size stores log2(bucket size) more than store the real bucket size value. The obsoleted BCH_FEATURE_INCOMPAT_LARGE_BUCKET won't be used anymore, it is renamed to BCH_FEATURE_INCOMPAT_OBSO_LARGE_BUCKET and still only recognized by kernel driver for legacy compatible purpose. The previous bucket_size_hi is renmaed to obso_bucket_size_hi in struct cache_sb_disk and not used in bcache-tools anymore. For cache device created with BCH_FEATURE_INCOMPAT_LARGE_BUCKET feature, bcache-tools and kernel driver still recognize the feature string and display it as "obso_large_bucket". With this change, the unnecessary extra space extend of bcache on-disk super block can be avoided, and csum_set() may generate expected check sum as well. Fixes: ffa470327572 ("bcache: add bucket_size_hi into struct cache_sb_disk for large bucket") Signed-off-by: Coly Li Cc: stable@vger.kernel.org # 5.9+ Signed-off-by: Jens Axboe

bcache: check unsupported feature sets for bcache register

2021-01-09T16:21:03+00:00

This patch adds the check for features which is incompatible for current supported feature sets. Now if the bcache device created by bcache-tools has features that current kernel doesn't support, read_super() will fail with error messoage. E.g. if an unsupported incompatible feature detected, bcache register will fail with dmesg "bcache: register_bcache() error : Unsupported incompatible feature found". Fixes: d721a43ff69c ("bcache: increase super block version for cache device and backing device") Fixes: ffa470327572 ("bcache: add bucket_size_hi into struct cache_sb_disk for large bucket") Signed-off-by: Coly Li Cc: stable@vger.kernel.org # 5.9+ Signed-off-by: Jens Axboe

bcache: fix typo from SUUP to SUPP in features.h

2021-01-09T16:21:03+00:00

This patch fixes the following typos, from BCH_FEATURE_COMPAT_SUUP to BCH_FEATURE_COMPAT_SUPP from BCH_FEATURE_INCOMPAT_SUUP to BCH_FEATURE_INCOMPAT_SUPP from BCH_FEATURE_INCOMPAT_SUUP to BCH_FEATURE_RO_COMPAT_SUPP Fixes: d721a43ff69c ("bcache: increase super block version for cache device and backing device") Fixes: ffa470327572 ("bcache: add bucket_size_hi into struct cache_sb_disk for large bucket") Signed-off-by: Coly Li Cc: stable@vger.kernel.org # 5.9+ Signed-off-by: Jens Axboe

bcache: set pdev_set_uuid before scond loop iteration

2021-01-09T16:21:03+00:00

There is no need to reassign pdev_set_uuid in the second loop iteration, so move it to the place before second loop. Signed-off-by: Yi Li Signed-off-by: Coly Li Signed-off-by: Jens Axboe

md/bcache: convert comma to semicolon

2020-12-23T16:25:15+00:00

Replace a comma between expression statements by a semicolon. Signed-off-by: Zheng Yongjun Signed-off-by: Coly Li Signed-off-by: Jens Axboe