lwn.git/drivers/md/raid5-cache.c, branch standardize-docs

blk: replace bioset_create_nobvec() with a flags arg to bioset_create()

2017-06-18T18:40:59+00:00

"flags" arguments are often seen as good API design as they allow easy extensibility. bioset_create_nobvec() is implemented internally as a variation in flags passed to __bioset_create(). To support future extension, make the internal structure part of the API. i.e. add a 'flags' argument to bioset_create() and discard bioset_create_nobvec(). Note that the bio_split allocations in drivers/md/raid* do not need the bvec mempool - they should have used bioset_create_nobvec(). Suggested-by: Christoph Hellwig Reviewed-by: Christoph Hellwig Reviewed-by: Ming Lei Signed-off-by: NeilBrown Signed-off-by: Jens Axboe

Merge tag 'v4.12-rc5' into for-4.13/block

2017-06-12T14:30:13+00:00

We've already got a few conflicts and upcoming work depends on some of the changes that have gone into mainline as regression fixes for this series. Pull in 4.12-rc5 to resolve these conflicts and make it easier on down stream trees to continue working on 4.13 changes. Signed-off-by: Jens Axboe

block: switch bios to blk_status_t

2017-06-09T15:27:32+00:00

Replace bi_error with a new bi_status to allow for a clear conversion. Note that device mapper overloaded bi_error with a private value, which we'll have to keep arround at least for now and thus propagate to a proper blk_status_t value. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

md: Make flush bios explicitely sync

2017-05-31T16:25:53+00:00

Commit b685d3d65ac7 "block: treat REQ_FUA and REQ_PREFLUSH as synchronous" removed REQ_SYNC flag from WRITE_{FUA|PREFLUSH|...} definitions. generic_make_request_checks() however strips REQ_FUA and REQ_PREFLUSH flags from a bio when the storage doesn't report volatile write cache and thus write effectively becomes asynchronous which can lead to performance regressions Fix the problem by making sure all bios which are synchronous are properly marked with REQ_SYNC. CC: linux-raid@vger.kernel.org CC: Shaohua Li Fixes: b685d3d65ac791406e0dfd8779cc9b3707fea5a3 CC: stable@vger.kernel.org Signed-off-by: Jan Kara Signed-off-by: Shaohua Li

md/r5cache: handle sync with data in write back cache

2017-05-12T05:14:40+00:00

Currently, sync of raid456 array cannot make progress when hitting data in writeback r5cache. This patch fixes this issue by flushing cached data of the stripe before processing the sync request. This is achived by: 1. In handle_stripe(), do not set STRIPE_SYNCING if the stripe is in write back cache; 2. In r5c_try_caching_write(), handle the stripe in sync with write through; 3. In do_release_stripe(), make stripe in sync write out and send it to the state machine. Shaohua: explictly set STRIPE_HANDLE after write out completed Signed-off-by: Song Liu Signed-off-by: Shaohua Li

md/r5cache: gracefully handle journal device errors for writeback mode

2017-05-12T05:11:11+00:00

For the raid456 with writeback cache, when journal device failed during normal operation, it is still possible to persist all data, as all pending data is still in stripe cache. However, it is necessary to handle journal failure gracefully. During journal failures, the following logic handles the graceful shutdown of journal: 1. raid5_error() marks the device as Faulty and schedules async work log->disable_writeback_work; 2. In disable_writeback_work (r5c_disable_writeback_async), the mddev is suspended, set to write through, and then resumed. mddev_suspend() flushes all cached stripes; 3. All cached stripes need to be flushed carefully to the RAID array. This patch fixes issues within the process above: 1. In r5c_update_on_rdev_error() schedule disable_writeback_work for journal failures; 2. In r5c_disable_writeback_async(), wait for MD_SB_CHANGE_PENDING, since raid5_error() updates superblock. 3. In handle_stripe(), allow stripes with data in journal (s.injournal > 0) to make progress during log_failed; 4. In delay_towrite(), if log failed only process data in the cache (skip new writes in dev->towrite); 5. In __get_priority_stripe(), process loprio_list during journal device failures. 6. In raid5_remove_disk(), wait for all cached stripes are flushed before calling log_exit(). Signed-off-by: Song Liu Signed-off-by: Shaohua Li

md/raid5-cache: in r5l_do_submit_io(), submit io->split_bio first

2017-05-10T17:07:55+00:00

In r5l_do_submit_io(), it is necessary to check io->split_bio before submit io->current_bio. This is because, endio of current_bio may free the whole IO unit, and thus change io->split_bio. Signed-off-by: Song Liu Signed-off-by: Shaohua Li

Merge tag 'for-4.12/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

2017-05-03T17:31:20+00:00

Pull device mapper updates from Mike Snitzer: - A major update for DM cache that reduces the latency for deciding whether blocks should migrate to/from the cache. The bio-prison-v2 interface supports this improvement by enabling direct dispatch of work to workqueues rather than having to delay the actual work dispatch to the DM cache core. So the dm-cache policies are much more nimble by being able to drive IO as they see fit. One immediate benefit from the improved latency is a cache that should be much more adaptive to changing workloads. - Add a new DM integrity target that emulates a block device that has additional per-sector tags that can be used for storing integrity information. - Add a new authenticated encryption feature to the DM crypt target that builds on the capabilities provided by the DM integrity target. - Add MD interface for switching the raid4/5/6 journal mode and update the DM raid target to use it to enable aid4/5/6 journal write-back support. - Switch the DM verity target over to using the asynchronous hash crypto API (this helps work better with architectures that have access to off-CPU algorithm providers, which should reduce CPU utilization). - Various request-based DM and DM multipath fixes and improvements from Bart and Christoph. - A DM thinp target fix for a bio structure leak that occurs for each discard IFF discard passdown is enabled. - A fix for a possible deadlock in DM bufio and a fix to re-check the new buffer allocation watermark in the face of competing admin changes to the 'max_cache_size_bytes' tunable. - A couple DM core cleanups. * tag 'for-4.12/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (50 commits) dm bufio: check new buffer allocation watermark every 30 seconds dm bufio: avoid a possible ABBA deadlock dm mpath: make it easier to detect unintended I/O request flushes dm mpath: cleanup QUEUE_IF_NO_PATH bit manipulation by introducing assign_bit() dm mpath: micro-optimize the hot path relative to MPATHF_QUEUE_IF_NO_PATH dm: introduce enum dm_queue_mode to cleanup related code dm mpath: verify __pg_init_all_paths locking assumptions at runtime dm: verify suspend_locking assumptions at runtime dm block manager: remove an unused argument from dm_block_manager_create() dm rq: check blk_mq_register_dev() return value in dm_mq_init_request_queue() dm mpath: delay requeuing while path initialization is in progress dm mpath: avoid that path removal can trigger an infinite loop dm mpath: split and rename activate_path() to prepare for its expanded use dm ioctl: prevent stack leak in dm ioctl call dm integrity: use previously calculated log2 of sectors_per_block dm integrity: use hex2bin instead of open-coded variant dm crypt: replace custom implementation of hex2bin() dm crypt: remove obsolete references to per-CPU state dm verity: switch to using asynchronous hash crypto API dm crypt: use WQ_HIGHPRI for the IO and crypt workqueues ...

md: add raid4/5/6 journal mode switching API

2017-03-27T15:13:47+00:00

Commit 2ded370373a4 ("md/r5cache: State machine for raid5-cache write back mode") added support for "write-back" caching on the raid journal device. In order to allow the dm-raid target to switch between the available "write-through" and "write-back" modes, provide a new r5c_journal_mode_set() API. Use the new API in existing r5c_journal_mode_store() Signed-off-by: Heinz Mauelshagen Acked-by: Shaohua Li Signed-off-by: Mike Snitzer

md/raid5-cache: fix payload endianness problem in raid5-cache

2017-03-25T16:38:22+00:00

The payload->header.type and payload->size are little-endian, so just convert them to the right byte order. Signed-off-by: Jason Yan Cc: #v4.10+ Signed-off-by: Shaohua Li