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* md: Make flush bios explicitely syncJan Kara2017-05-311-2/+2
| | | | | | | | | | | | | | | | | | | 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 <shli@kernel.org> Fixes: b685d3d65ac791406e0dfd8779cc9b3707fea5a3 CC: stable@vger.kernel.org Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Shaohua Li <shli@fb.com>
* md/r5cache: handle sync with data in write back cacheSong Liu2017-05-111-1/+7
| | | | | | | | | | | | | | | | | | | | 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 <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com>
* md/r5cache: gracefully handle journal device errors for writeback modeSong Liu2017-05-111-2/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com>
* md/raid5-cache: in r5l_do_submit_io(), submit io->split_bio firstSong Liu2017-05-101-9/+19
| | | | | | | | | 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 <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com>
* Merge tag 'for-4.12/dm-changes' of ↵Linus Torvalds2017-05-031-28/+34
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm 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 APIHeinz Mauelshagen2017-03-271-28/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <heinzm@redhat.com> Acked-by: Shaohua Li <shli@fb.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* | md/raid5-cache: fix payload endianness problem in raid5-cacheJason Yan2017-03-251-9/+9
| | | | | | | | | | | | | | | | | | The payload->header.type and payload->size are little-endian, so just convert them to the right byte order. Signed-off-by: Jason Yan <yanaijie@huawei.com> Cc: <stable@vger.kernel.org> #v4.10+ Signed-off-by: Shaohua Li <shli@fb.com>
* | md/raid5: use bio_inc_remaining() instead of repurposing bi_phys_segments as ↵NeilBrown2017-03-221-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | a counter md/raid5 needs to keep track of how many stripe_heads are processing a bio so that it can delay calling bio_endio() until all stripe_heads have completed. It currently uses 16 bits of ->bi_phys_segments for this purpose. 16 bits is only enough for 256M requests, and it is possible for a single bio to be larger than this, which causes problems. Also, the bio struct contains a larger counter, __bi_remaining, which has a purpose very similar to the purpose of our counter. So stop using ->bi_phys_segments, and instead use __bi_remaining. This means we don't need to initialize the counter, as our caller initializes it to '1'. It also means we can call bio_endio() directly as it tests this counter internally. Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Shaohua Li <shli@fb.com>
* | md/raid5: call bio_endio() directly rather than queueing for later.NeilBrown2017-03-221-8/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We currently gather bios that need to be returned into a bio_list and call bio_endio() on them all together. The original reason for this was to avoid making the calls while holding a spinlock. Locking has changed a lot since then, and that reason is no longer valid. So discard return_io() and various return_bi lists, and just call bio_endio() directly as needed. Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Shaohua Li <shli@fb.com>
* | md/raid5: use md_write_start to count stripes, not biosNeilBrown2017-03-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We use md_write_start() to increase the count of pending writes, and md_write_end() to decrement the count. We currently count bios submitted to md/raid5. Change it count stripe_heads that a WRITE bio has been attached to. So now, raid5_make_request() calls md_write_start() and then md_write_end() to keep the count elevated during the setup of the request. add_stripe_bio() calls md_write_start() for each stripe_head, and the completion routines always call md_write_end(), instead of only calling it when raid5_dec_bi_active_stripes() returns 0. make_discard_request also calls md_write_start/end(). The parallel between md_write_{start,end} and use of bi_phys_segments can be seen in that: Whenever we set bi_phys_segments to 1, we now call md_write_start. Whenever we increment it on non-read requests with raid5_inc_bi_active_stripes(), we now call md_write_start(). Whenever we decrement bi_phys_segments on non-read requsts with raid5_dec_bi_active_stripes(), we now call md_write_end(). This reduces our dependence on keeping a per-bio count of active stripes in bi_phys_segments. md_write_inc() is added which parallels md_write_start(), but requires that a write has already been started, and is certain never to sleep. This can be used inside a spinlocked region when adding to a write request. Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Shaohua Li <shli@fb.com>
* | md/r5cache: generate R5LOG_PAYLOAD_FLUSHSong Liu2017-03-161-3/+42
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In r5c_finish_stripe_write_out(), R5LOG_PAYLOAD_FLUSH is append to log->current_io. Appending R5LOG_PAYLOAD_FLUSH in quiesce needs extra writes to journal. To simplify the logic, we just skip R5LOG_PAYLOAD_FLUSH in quiesce. Even R5LOG_PAYLOAD_FLUSH supports multiple stripes per payload. However, current implementation is one stripe per R5LOG_PAYLOAD_FLUSH, which is simpler. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com>
* | md/r5cache: handle R5LOG_PAYLOAD_FLUSH in recoverySong Liu2017-03-161-6/+41
| | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds handling of R5LOG_PAYLOAD_FLUSH in journal recovery. Next patch will add logic that generate R5LOG_PAYLOAD_FLUSH on flush finish. When R5LOG_PAYLOAD_FLUSH is seen in recovery, pending data and parity will be dropped from recovery. This will reduce the number of stripes to replay, and thus accelerate the recovery process. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com>
* | raid5: separate header for log functionsArtur Paszkiewicz2017-03-161-4/+13
| | | | | | | | | | | | | | | | | | | | | | | | Move raid5-cache declarations from raid5.h to raid5-log.h, add inline wrappers for functions which will be shared with ppl and use them in raid5 core instead of direct calls to raid5-cache. Remove unused parameter from r5c_cache_data(), move two duplicated pr_debug() calls to r5l_init_log(). Signed-off-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com> Signed-off-by: Shaohua Li <shli@fb.com>
* | md/r5cache: improve recovery with read ahead page poolSong Liu2017-03-161-46/+175
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In r5cache recovery, the journal device is scanned page by page. Currently, we use sync_page_io() to read journal device. This is not efficient when we have to recovery many stripes from the journal. To improve the speed of recovery, this patch introduces a read ahead page pool (ra_pool) to recovery_ctx. With ra_pool, multiple consecutive pages are read in one IO. Then the recovery code read the journal from ra_pool. With ra_pool, r5l_recovery_ctx has become much bigger. Therefore, r5l_recovery_log() is refactored so r5l_recovery_ctx is not using stack space. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com>
* | md/raid5-cache: bump flush stripe batch sizeShaohua Li2017-03-161-3/+3
|/ | | | | | | | | | | | | | | | | Bump the flush stripe batch size to 2048. For my 12 disks raid array, the stripes takes: 12 * 4k * 2048 = 96MB This is still quite small. A hardware raid card generally has 1GB size, which we suggest the raid5-cache has similar cache size. The advantage of a big batch size is we can dispatch a lot of IO in the same time, then we can do some scheduling to make better IO pattern. Last patch prioritizes stripes, so we don't worry about a big flush stripe batch will starve normal stripes. Signed-off-by: Shaohua Li <shli@fb.com>
* md/raid5-cache: exclude reclaiming stripes in reclaim checkShaohua Li2017-02-131-2/+12
| | | | | | | | | | | stripes which are being reclaimed are still accounted into cached stripes. The reclaim takes time. r5c_do_reclaim isn't aware of the stripes and does unnecessary stripe reclaim. In practice, I saw one stripe is reclaimed one time. This will cause bad IO pattern. Fixing this by excluding the reclaing stripes in the check. Cc: Song Liu <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com>
* md/raid5-cache: stripe reclaim only counts valid stripesShaohua Li2017-02-131-2/+2
| | | | | | | | | | When log space is tight, we try to reclaim stripes from log head. There are stripes which can't be reclaimed right now if some conditions are met. We skip such stripes but accidentally count them, which might cause no stripes are claimed. Fixing this by only counting valid stripes. Cc: Song Liu <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com>
* md/r5cache: improve journal device efficiencySong Liu2017-02-131-11/+25
| | | | | | | | | | | | | | | | | | It is important to be able to flush all stripes in raid5-cache. Therefore, we need reserve some space on the journal device for these flushes. If flush operation includes pending writes to the stripe, we need to reserve (conf->raid_disk + 1) pages per stripe for the flush out. This reduces the efficiency of journal space. If we exclude these pending writes from flush operation, we only need (conf->max_degraded + 1) pages per stripe. With this patch, when log space is critical (R5C_LOG_CRITICAL=1), pending writes will be excluded from stripe flush out. Therefore, we can reduce reserved space for flush out and thus improve journal device efficiency. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com>
* md/r5cache: enable chunk_aligned_read with write back cacheSong Liu2017-02-131-17/+154
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Chunk aligned read significantly reduces CPU usage of raid456. However, it is not safe to fully bypass the write back cache. This patch enables chunk aligned read with write back cache. For chunk aligned read, we track stripes in write back cache at a bigger granularity, "big_stripe". Each chunk may contain more than one stripe (for example, a 256kB chunk contains 64 4kB-page, so this chunk contain 64 stripes). For chunk_aligned_read, these stripes are grouped into one big_stripe, so we only need one lookup for the whole chunk. For each big_stripe, struct big_stripe_info tracks how many stripes of this big_stripe are in the write back cache. We count how many stripes of this big_stripe are in the write back cache. These counters are tracked in a radix tree (big_stripe_tree). r5c_tree_index() is used to calculate keys for the radix tree. chunk_aligned_read() calls r5c_big_stripe_cached() to look up big_stripe of each chunk in the tree. If this big_stripe is in the tree, chunk_aligned_read() aborts. This look up is protected by rcu_read_lock(). It is necessary to remember whether a stripe is counted in big_stripe_tree. Instead of adding new flag, we reuses existing flags: STRIPE_R5C_PARTIAL_STRIPE and STRIPE_R5C_FULL_STRIPE. If either of these two flags are set, the stripe is counted in big_stripe_tree. This requires moving set_bit(STRIPE_R5C_PARTIAL_STRIPE) to r5c_try_caching_write(); and moving clear_bit of STRIPE_R5C_PARTIAL_STRIPE and STRIPE_R5C_FULL_STRIPE to r5c_finish_stripe_write_out(). Signed-off-by: Song Liu <songliubraving@fb.com> Reviewed-by: NeilBrown <neilb@suse.com> Signed-off-by: Shaohua Li <shli@fb.com>
* md/r5cache: disable write back for degraded arraySong Liu2017-01-241-0/+46
| | | | | | | | | | | | | | | | | | write-back cache in degraded mode introduces corner cases to the array. Although we try to cover all these corner cases, it is safer to just disable write-back cache when the array is in degraded mode. In this patch, we disable writeback cache for degraded mode: 1. On device failure, if the array enters degraded mode, raid5_error() will submit async job r5c_disable_writeback_async to disable writeback; 2. In r5c_journal_mode_store(), it is invalid to enable writeback in degraded mode; 3. In r5c_try_caching_write(), stripes with s->failed>0 will be handled in write-through mode. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com>
* md/r5cache: flush data only stripes in r5l_recovery_log()Song Liu2017-01-241-16/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | For safer operation, all arrays start in write-through mode, which has been better tested and is more mature. And actually the write-through/write-mode isn't persistent after array restarted, so we always start array in write-through mode. However, if recovery found data-only stripes before the shutdown (from previous write-back mode), it is not safe to start the array in write-through mode, as write-through mode can not handle stripes with data in write-back cache. To solve this problem, we flush all data-only stripes in r5l_recovery_log(). When r5l_recovery_log() returns, the array starts with empty cache in write-through mode. This logic is implemented in r5c_recovery_flush_data_only_stripes(): 1. enable write back cache 2. flush all stripes 3. wake up conf->mddev->thread 4. wait for all stripes get flushed (reuse wait_for_quiescent) 5. disable write back cache The wait in 4 will be waked up in release_inactive_stripe_list() when conf->active_stripes reaches 0. It is safe to wake up mddev->thread here because all the resource required for the thread has been initialized. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com>
* md/r5cache: read data into orig_page for prexor of cached dataSong Liu2017-01-241-0/+2
| | | | | | | | | | | | | | With write back cache, we use orig_page to do prexor. This patch makes sure we read data into orig_page for it. Flag R5_OrigPageUPTDODATE is added to show whether orig_page has the latest data from raid disk. We introduce a helper function uptodate_for_rmw() to simplify the a couple conditions in handle_stripe_dirtying(). Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com>
* md/raid5-cache: delete meaningless codeShaohua Li2017-01-241-2/+0
| | | | | | | sector_t is unsigned long, it's never < 0 Reported-by: Julia Lawall <julia.lawall@lip6.fr> Signed-off-by: Shaohua Li <shli@fb.com>
* md/r5cache: fix spelling mistake on "recoverying"Colin Ian King2017-01-051-1/+1
| | | | | | | | Trivial fix to spelling mistake "recoverying" to "recovering" in pr_dbg message. Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Shaohua Li <shli@fb.com>
* md/r5cache: assign conf->log before r5l_load_log()Song Liu2017-01-051-1/+3
| | | | | | | | | | r5l_load_log() calls functions that requires a proper conf->log, for example, r5c_is_writeback(). Therefore, we should set conf->log before calling r5l_load_log(). If r5l_load_log() fails, conf->log is set back to NULL. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com>
* md/r5cache: simplify handling of sh->log_start in recoverySong Liu2017-01-051-15/+12
| | | | | | | | | | | | | We only need to update sh->log_start at the end of recovery, which is r5c_recovery_rewrite_data_only_stripes(), so it is not necessary to set it before that. In this patch, log_start is removed from r5c_recovery_alloc_stripe(). After updating all sh->log_start, rewrite_data_only_stripes() also updates log->next_checkpoints to the last sh->log_start. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com>
* md/raid5-cache: removes unnecessary write-through mode judgmentsJackieLiu2017-01-051-3/+0
| | | | | | | | | The write-through mode has been returned in front of the function, do not need to do it again. Signed-off-by: JackieLiu <liuyun01@kylinos.cn> Reviewed-by: Song Liu <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com>
* Merge branch 'md-next' into md-linusShaohua Li2016-12-131-214/+1619
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| * md: separate flags for superblock changesShaohua Li2016-12-081-3/+3
| | | | | | | | | | | | | | | | | | | | | | The mddev->flags are used for different purposes. There are a lot of places we check/change the flags without masking unrelated flags, we could check/change unrelated flags. These usage are most for superblock write, so spearate superblock related flags. This should make the code clearer and also fix real bugs. Reviewed-by: NeilBrown <neilb@suse.com> Signed-off-by: Shaohua Li <shli@fb.com>
| * md/r5cache: after recovery, increase journal seq by 10000Song Liu2016-12-081-7/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, we increase journal entry seq by 10 after recovery. However, this is not sufficient in the following case. After crash the journal looks like | seq+0 | +1 | +2 | +3 | +4 | +5 | +6 | +7 | ... | +11 | +12 | If +1 is not valid, we dropped all entries from +1 to +12; and write seq+10: | seq+0 | +10 | +2 | +3 | +4 | +5 | +6 | +7 | ... | +11 | +12 | However, if we write a big journal entry with seq+11, it will connect with some stale journal entry: | seq+0 | +10 | +11 | +12 | To reduce the risk of this issue, we increase seq by 10000 instead. Shaohua: use 10000 instead of 1000. The risk should be very unlikely. The total stripe cache size is less than 2k typically, and several stripes can fit into one meta data block. So the total inflight meta data blocks would be quite small, which means the the total sequence number used should be quite small. The 10000 sequence number increase should be far more than safe. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com>
| * md/raid5-cache: fix crc in rewrite_data_only_stripes()Song Liu2016-12-081-4/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | r5l_recovery_create_empty_meta_block() creates crc for the empty metablock. After the metablock is updated, we need clear the checksum before recalculate it. Shaohua: moved checksum calculation out of r5l_recovery_create_empty_meta_block. We should calculate it after all fields are updated. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com>
| * md/raid5-cache: no recovery is required when create super-blockJackieLiu2016-12-081-2/+8
| | | | | | | | | | | | | | | | | | When create the super-block information, We do not need to do this recovery stage, only need to initialize some variables. Signed-off-by: JackieLiu <liuyun01@kylinos.cn> Reviewed-by: Song Liu <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com>
| * md/r5cache: do r5c_update_log_state after log recoveryZhengyuan Liu2016-12-051-5/+3
| | | | | | | | | | | | | | | | | | | | | | | | We should update log state after we did a log recovery, current completion may get wrong log state since log->log_start wasn't initalized until we called r5l_recovery_log. At log recovery stage, no lock needed as there is no race conditon. next_checkpoint field will be initialized in r5l_recovery_log too. Signed-off-by: Zhengyuan Liu <liuzhengyuan@kylinos.cn> Signed-off-by: Shaohua Li <shli@fb.com>
| * md/raid5-cache: adjust the write position of the empty block if no data blocksJackieLiu2016-12-051-4/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When recovery is complete, we write an empty block and record his position first, then make the data-only stripes rewritten done, the location of the empty block as the last checkpoint position to write into the super block. And we should update last_checkpoint to this empty block position. ------------------------------------------------------------------ | old log | empty block | data only stripes | invalid log | ------------------------------------------------------------------ ^ ^ ^ | |- log->last_checkpoint |- log->log_start | |- log->last_cp_seq |- log->next_checkpoint |- log->seq=n |- log->seq=10+n At the same time, if there is no data-only stripes, this scene may appear, | meta1 | meta2 | meta3 | meta 1 is valid, meta 2 is invalid. meta 3 could be valid. so we should The solution is we create a new meta in meta2 with its seq == meta1's seq + 10 and let superblock points to meta2. Signed-off-by: JackieLiu <liuyun01@kylinos.cn> Reviewed-by: Zhengyuan Liu <liuzhengyuan@kylinos.cn> Reviewed-by: Song Liu <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com>
| * md/r5cache: run_no_space_stripes() when R5C_LOG_CRITICAL == 0Song Liu2016-12-021-1/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With writeback cache, we define log space critical as free_space < 2 * reclaim_required_space So the deassert of R5C_LOG_CRITICAL could happen when 1. free_space increases 2. reclaim_required_space decreases Currently, run_no_space_stripes() is called when 1 happens, but not (always) when 2 happens. With this patch, run_no_space_stripes() is call when R5C_LOG_CRITICAL is cleared. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com>
| * md/raid5-cache: do not need to set STRIPE_PREREAD_ACTIVE repeatedlyJackieLiu2016-11-291-2/+0
| | | | | | | | | | | | | | R5c_make_stripe_write_out has set this flag, do not need to set again. Signed-off-by: JackieLiu <liuyun01@kylinos.cn> Signed-off-by: Shaohua Li <shli@fb.com>
| * md/raid5-cache: remove the unnecessary next_cp_seq field from the r5l_logJackieLiu2016-11-291-2/+0
| | | | | | | | | | | | | | The next_cp_seq field is useless, remove it. Signed-off-by: JackieLiu <liuyun01@kylinos.cn> Signed-off-by: Shaohua Li <shli@fb.com>
| * md/raid5-cache: release the stripe_head at the appropriate locationJackieLiu2016-11-291-6/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | If we released the 'stripe_head' in r5c_recovery_flush_log, ctx->cached_list will both release the data-parity stripes and data-only stripes, which will become empty. And we also need to use the data-only stripes in r5c_recovery_rewrite_data_only_stripes, so we should wait util rewrite data-only stripes is done before releasing them. Reviewed-by: Zhengyuan Liu <liuzhengyuan@kylinos.cn> Reviewed-by: Song Liu <songliubraving@fb.com> Signed-off-by: JackieLiu <liuyun01@kylinos.cn> Signed-off-by: Shaohua Li <shli@fb.com>
| * md/raid5-cache: use ring add to prevent overflowJackieLiu2016-11-291-1/+1
| | | | | | | | | | | | | | | | 'write_pos' must be protected with 'r5l_ring_add', or it may overflow Signed-off-by: JackieLiu <liuyun01@kylinos.cn> Reviewed-by: Song Liu <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com>
| * md/raid5-cache: remove unnecessary function parametersJackieLiu2016-11-291-8/+4
| | | | | | | | | | | | | | | | | | The function parameter 'recovery_list' is not used in body, we can delete it Signed-off-by: JackieLiu <liuyun01@kylinos.cn> Reviewed-by: Song Liu <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com>
| * raid5-cache: don't set STRIPE_R5C_PARTIAL_STRIPE flag while load stripe into ↵Zhengyuan Liu2016-11-291-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | cache r5c_recovery_load_one_stripe should not set STRIPE_R5C_PARTIAL_STRIPE flag,as the data-only stripe may be STRIPE_R5C_FULL_STRIPE stripe. The state machine would release the stripe later and add it into neither r5c_cached_full_stripes list or r5c_cached_partial_stripes list and set correct flag. Reviewed-by: JackieLiu <liuyun01@kylinos.cn> Signed-off-by: Zhengyuan Liu <liuzhengyuan@kylinos.cn> Signed-off-by: Shaohua Li <shli@fb.com>
| * raid5-cache: add another check conditon before replaying one stripeZhengyuan Liu2016-11-291-2/+2
| | | | | | | | | | | | | | | | | | | | | | New stripe that was just allocated has no STRIPE_R5C_CACHING state too, add this check condition could avoid unnecessary replaying for empty stripe. r5l_recovery_replay_one_stripe would reset stripe for any case, delete it to make code more clean. Signed-off-by: Zhengyuan Liu <liuzhengyuan@kylinos.cn> Signed-off-by: Shaohua Li <shli@fb.com>
| * md/r5cache: enable IRQs on error pathDan Carpenter2016-11-271-1/+1
| | | | | | | | | | | | | | | | We need to re-enable the IRQs here before returning. Fixes: a39f7afde358 ("md/r5cache: write-out phase and reclaim support") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Shaohua Li <shli@fb.com>
| * md/r5cache: handle alloc_page failureSong Liu2016-11-271-1/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | RMW of r5c write back cache uses an extra page to store old data for prexor. handle_stripe_dirtying() allocates this page by calling alloc_page(). However, alloc_page() may fail. To handle alloc_page() failures, this patch adds an extra page to disk_info. When alloc_page fails, handle_stripe() trys to use these pages. When these pages are used by other stripe (R5C_EXTRA_PAGE_IN_USE), the stripe is added to delayed_list. Signed-off-by: Song Liu <songliubraving@fb.com> Reviewed-by: NeilBrown <neilb@suse.com> Signed-off-by: Shaohua Li <shli@fb.com>
| * raid5-cache: suspend reclaim thread instead of shutdownShaohua Li2016-11-231-13/+5
| | | | | | | | | | | | | | | | | | There is mechanism to suspend a kernel thread. Use it instead of playing create/destroy game. Signed-off-by: Shaohua Li <shli@fb.com> Reviewed-by: NeilBrown <neilb@suse.de> Cc: Song Liu <songliubraving@fb.com>
| * md/r5cache: handle FLUSH and FUASong Liu2016-11-181-18/+144
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With raid5 cache, we committing data from journal device. When there is flush request, we need to flush journal device's cache. This was not needed in raid5 journal, because we will flush the journal before committing data to raid disks. This is similar to FUA, except that we also need flush journal for FUA. Otherwise, corruptions in earlier meta data will stop recovery from reaching FUA data. slightly changed the code by Shaohua Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com>
| * md/r5cache: r5cache recovery: part 2Song Liu2016-11-181-186/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 1. In previous patch, we: - add new data to r5l_recovery_ctx - add new functions to recovery write-back cache The new functions are not used in this patch, so this patch does not change the behavior of recovery. 2. In this patchpatch, we: - modify main recovery procedure r5l_recovery_log() to call new functions - remove old functions Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com>
| * md/r5cache: r5cache recovery: part 1Song Liu2016-11-181-0/+602
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Recovery of write-back cache has different logic to write-through only cache. Specifically, for write-back cache, the recovery need to scan through all active journal entries before flushing data out. Therefore, large portion of the recovery logic is rewritten here. To make the diffs cleaner, we split the rewrite as follows: 1. In this patch, we: - add new data to r5l_recovery_ctx - add new functions to recovery write-back cache The new functions are not used in this patch, so this patch does not change the behavior of recovery. 2. In next patch, we: - modify main recovery procedure r5l_recovery_log() to call new functions - remove old functions With cache feature, there are 2 different scenarios of recovery: 1. Data-Parity stripe: a stripe with complete parity in journal. 2. Data-Only stripe: a stripe with only data in journal (or partial parity). The code differentiate Data-Parity stripe from Data-Only stripe with flag STRIPE_R5C_CACHING. For Data-Parity stripes, we use the same procedure as raid5 journal, where all the data and parity are replayed to the RAID devices. For Data-Only strips, we need to finish complete calculate parity and finish the full reconstruct write or RMW write. For simplicity, in the recovery, we load the stripe to stripe cache. Once the array is started, the stripe cache state machine will handle these stripes through normal write path. r5c_recovery_flush_log contains the main procedure of recovery. The recovery code first scans through the journal and loads data to stripe cache. The code keeps tracks of all these stripes in a list (use sh->lru and ctx->cached_list), stripes in the list are organized in the order of its first appearance on the journal. During the scan, the recovery code assesses each stripe as Data-Parity or Data-Only. During scan, the array may run out of stripe cache. In these cases, the recovery code will also call raid5_set_cache_size to increase stripe cache size. If the array still runs out of stripe cache because there isn't enough memory, the array will not assemble. At the end of scan, the recovery code replays all Data-Parity stripes, and sets proper states for Data-Only stripes. The recovery code also increases seq number by 10 and rewrites all Data-Only stripes to journal. This is to avoid confusion after repeated crashes. More details is explained in raid5-cache.c before r5c_recovery_rewrite_data_only_stripes(). Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com>
| * md/r5cache: refactoring journal recovery codeSong Liu2016-11-181-9/+18
| | | | | | | | | | | | | | | | | | | | | | 1. rename r5l_read_meta_block() as r5l_recovery_read_meta_block(); 2. pull the code that initialize r5l_meta_block from r5l_log_write_empty_meta_block() to a separate function r5l_recovery_create_empty_meta_block(), so that we can reuse this piece of code. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com>
| * md/r5cache: sysfs entry journal_modeSong Liu2016-11-181-0/+65
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With write cache, journal_mode is the knob to switch between write-back and write-through. Below is an example: root@virt-test:~/# cat /sys/block/md0/md/journal_mode [write-through] write-back root@virt-test:~/# echo write-back > /sys/block/md0/md/journal_mode root@virt-test:~/# cat /sys/block/md0/md/journal_mode write-through [write-back] Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Shaohua Li <shli@fb.com>
generated by cgit v1.2.3 (git 2.25.1) at 2024-10-31 22:16:25 +0000