| /* |
| * Copyright (C) 2015 Shaohua Li <shli@fb.com> |
| * Copyright (C) 2016 Song Liu <songliubraving@fb.com> |
| * |
| * This program is free software; you can redistribute it and/or modify it |
| * under the terms and conditions of the GNU General Public License, |
| * version 2, as published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for |
| * more details. |
| * |
| */ |
| #include <linux/kernel.h> |
| #include <linux/wait.h> |
| #include <linux/blkdev.h> |
| #include <linux/slab.h> |
| #include <linux/raid/md_p.h> |
| #include <linux/crc32c.h> |
| #include <linux/random.h> |
| #include <linux/kthread.h> |
| #include <linux/types.h> |
| #include "md.h" |
| #include "raid5.h" |
| #include "md-bitmap.h" |
| #include "raid5-log.h" |
| |
| /* |
| * metadata/data stored in disk with 4k size unit (a block) regardless |
| * underneath hardware sector size. only works with PAGE_SIZE == 4096 |
| */ |
| #define BLOCK_SECTORS (8) |
| #define BLOCK_SECTOR_SHIFT (3) |
| |
| /* |
| * log->max_free_space is min(1/4 disk size, 10G reclaimable space). |
| * |
| * In write through mode, the reclaim runs every log->max_free_space. |
| * This can prevent the recovery scans for too long |
| */ |
| #define RECLAIM_MAX_FREE_SPACE (10 * 1024 * 1024 * 2) /* sector */ |
| #define RECLAIM_MAX_FREE_SPACE_SHIFT (2) |
| |
| /* wake up reclaim thread periodically */ |
| #define R5C_RECLAIM_WAKEUP_INTERVAL (30 * HZ) |
| /* start flush with these full stripes */ |
| #define R5C_FULL_STRIPE_FLUSH_BATCH(conf) (conf->max_nr_stripes / 4) |
| /* reclaim stripes in groups */ |
| #define R5C_RECLAIM_STRIPE_GROUP (NR_STRIPE_HASH_LOCKS * 2) |
| |
| /* |
| * We only need 2 bios per I/O unit to make progress, but ensure we |
| * have a few more available to not get too tight. |
| */ |
| #define R5L_POOL_SIZE 4 |
| |
| static char *r5c_journal_mode_str[] = {"write-through", |
| "write-back"}; |
| /* |
| * raid5 cache state machine |
| * |
| * With the RAID cache, each stripe works in two phases: |
| * - caching phase |
| * - writing-out phase |
| * |
| * These two phases are controlled by bit STRIPE_R5C_CACHING: |
| * if STRIPE_R5C_CACHING == 0, the stripe is in writing-out phase |
| * if STRIPE_R5C_CACHING == 1, the stripe is in caching phase |
| * |
| * When there is no journal, or the journal is in write-through mode, |
| * the stripe is always in writing-out phase. |
| * |
| * For write-back journal, the stripe is sent to caching phase on write |
| * (r5c_try_caching_write). r5c_make_stripe_write_out() kicks off |
| * the write-out phase by clearing STRIPE_R5C_CACHING. |
| * |
| * Stripes in caching phase do not write the raid disks. Instead, all |
| * writes are committed from the log device. Therefore, a stripe in |
| * caching phase handles writes as: |
| * - write to log device |
| * - return IO |
| * |
| * Stripes in writing-out phase handle writes as: |
| * - calculate parity |
| * - write pending data and parity to journal |
| * - write data and parity to raid disks |
| * - return IO for pending writes |
| */ |
| |
| struct r5l_log { |
| struct md_rdev *rdev; |
| |
| u32 uuid_checksum; |
| |
| sector_t device_size; /* log device size, round to |
| * BLOCK_SECTORS */ |
| sector_t max_free_space; /* reclaim run if free space is at |
| * this size */ |
| |
| sector_t last_checkpoint; /* log tail. where recovery scan |
| * starts from */ |
| u64 last_cp_seq; /* log tail sequence */ |
| |
| sector_t log_start; /* log head. where new data appends */ |
| u64 seq; /* log head sequence */ |
| |
| sector_t next_checkpoint; |
| |
| struct mutex io_mutex; |
| struct r5l_io_unit *current_io; /* current io_unit accepting new data */ |
| |
| spinlock_t io_list_lock; |
| struct list_head running_ios; /* io_units which are still running, |
| * and have not yet been completely |
| * written to the log */ |
| struct list_head io_end_ios; /* io_units which have been completely |
| * written to the log but not yet written |
| * to the RAID */ |
| struct list_head flushing_ios; /* io_units which are waiting for log |
| * cache flush */ |
| struct list_head finished_ios; /* io_units which settle down in log disk */ |
| struct bio flush_bio; |
| |
| struct list_head no_mem_stripes; /* pending stripes, -ENOMEM */ |
| |
| struct kmem_cache *io_kc; |
| mempool_t io_pool; |
| struct bio_set bs; |
| mempool_t meta_pool; |
| |
| struct md_thread *reclaim_thread; |
| unsigned long reclaim_target; /* number of space that need to be |
| * reclaimed. if it's 0, reclaim spaces |
| * used by io_units which are in |
| * IO_UNIT_STRIPE_END state (eg, reclaim |
| * dones't wait for specific io_unit |
| * switching to IO_UNIT_STRIPE_END |
| * state) */ |
| wait_queue_head_t iounit_wait; |
| |
| struct list_head no_space_stripes; /* pending stripes, log has no space */ |
| spinlock_t no_space_stripes_lock; |
| |
| bool need_cache_flush; |
| |
| /* for r5c_cache */ |
| enum r5c_journal_mode r5c_journal_mode; |
| |
| /* all stripes in r5cache, in the order of seq at sh->log_start */ |
| struct list_head stripe_in_journal_list; |
| |
| spinlock_t stripe_in_journal_lock; |
| atomic_t stripe_in_journal_count; |
| |
| /* to submit async io_units, to fulfill ordering of flush */ |
| struct work_struct deferred_io_work; |
| /* to disable write back during in degraded mode */ |
| struct work_struct disable_writeback_work; |
| |
| /* to for chunk_aligned_read in writeback mode, details below */ |
| spinlock_t tree_lock; |
| struct radix_tree_root big_stripe_tree; |
| }; |
| |
| /* |
| * Enable chunk_aligned_read() with write back cache. |
| * |
| * 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". |
| * For each big_stripe, we count how many stripes of this big_stripe |
| * are in the write back cache. These data are tracked in a radix tree |
| * (big_stripe_tree). We use radix_tree item pointer as the counter. |
| * 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(). |
| */ |
| |
| /* |
| * radix tree requests lowest 2 bits of data pointer to be 2b'00. |
| * So it is necessary to left shift the counter by 2 bits before using it |
| * as data pointer of the tree. |
| */ |
| #define R5C_RADIX_COUNT_SHIFT 2 |
| |
| /* |
| * calculate key for big_stripe_tree |
| * |
| * sect: align_bi->bi_iter.bi_sector or sh->sector |
| */ |
| static inline sector_t r5c_tree_index(struct r5conf *conf, |
| sector_t sect) |
| { |
| sector_t offset; |
| |
| offset = sector_div(sect, conf->chunk_sectors); |
| return sect; |
| } |
| |
| /* |
| * an IO range starts from a meta data block and end at the next meta data |
| * block. The io unit's the meta data block tracks data/parity followed it. io |
| * unit is written to log disk with normal write, as we always flush log disk |
| * first and then start move data to raid disks, there is no requirement to |
| * write io unit with FLUSH/FUA |
| */ |
| struct r5l_io_unit { |
| struct r5l_log *log; |
| |
| struct page *meta_page; /* store meta block */ |
| int meta_offset; /* current offset in meta_page */ |
| |
| struct bio *current_bio;/* current_bio accepting new data */ |
| |
| atomic_t pending_stripe;/* how many stripes not flushed to raid */ |
| u64 seq; /* seq number of the metablock */ |
| sector_t log_start; /* where the io_unit starts */ |
| sector_t log_end; /* where the io_unit ends */ |
| struct list_head log_sibling; /* log->running_ios */ |
| struct list_head stripe_list; /* stripes added to the io_unit */ |
| |
| int state; |
| bool need_split_bio; |
| struct bio *split_bio; |
| |
| unsigned int has_flush:1; /* include flush request */ |
| unsigned int has_fua:1; /* include fua request */ |
| unsigned int has_null_flush:1; /* include null flush request */ |
| unsigned int has_flush_payload:1; /* include flush payload */ |
| /* |
| * io isn't sent yet, flush/fua request can only be submitted till it's |
| * the first IO in running_ios list |
| */ |
| unsigned int io_deferred:1; |
| |
| struct bio_list flush_barriers; /* size == 0 flush bios */ |
| }; |
| |
| /* r5l_io_unit state */ |
| enum r5l_io_unit_state { |
| IO_UNIT_RUNNING = 0, /* accepting new IO */ |
| IO_UNIT_IO_START = 1, /* io_unit bio start writing to log, |
| * don't accepting new bio */ |
| IO_UNIT_IO_END = 2, /* io_unit bio finish writing to log */ |
| IO_UNIT_STRIPE_END = 3, /* stripes data finished writing to raid */ |
| }; |
| |
| bool r5c_is_writeback(struct r5l_log *log) |
| { |
| return (log != NULL && |
| log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_BACK); |
| } |
| |
| static sector_t r5l_ring_add(struct r5l_log *log, sector_t start, sector_t inc) |
| { |
| start += inc; |
| if (start >= log->device_size) |
| start = start - log->device_size; |
| return start; |
| } |
| |
| static sector_t r5l_ring_distance(struct r5l_log *log, sector_t start, |
| sector_t end) |
| { |
| if (end >= start) |
| return end - start; |
| else |
| return end + log->device_size - start; |
| } |
| |
| static bool r5l_has_free_space(struct r5l_log *log, sector_t size) |
| { |
| sector_t used_size; |
| |
| used_size = r5l_ring_distance(log, log->last_checkpoint, |
| log->log_start); |
| |
| return log->device_size > used_size + size; |
| } |
| |
| static void __r5l_set_io_unit_state(struct r5l_io_unit *io, |
| enum r5l_io_unit_state state) |
| { |
| if (WARN_ON(io->state >= state)) |
| return; |
| io->state = state; |
| } |
| |
| static void |
| r5c_return_dev_pending_writes(struct r5conf *conf, struct r5dev *dev) |
| { |
| struct bio *wbi, *wbi2; |
| |
| wbi = dev->written; |
| dev->written = NULL; |
| while (wbi && wbi->bi_iter.bi_sector < |
| dev->sector + STRIPE_SECTORS) { |
| wbi2 = r5_next_bio(wbi, dev->sector); |
| md_write_end(conf->mddev); |
| bio_endio(wbi); |
| wbi = wbi2; |
| } |
| } |
| |
| void r5c_handle_cached_data_endio(struct r5conf *conf, |
| struct stripe_head *sh, int disks) |
| { |
| int i; |
| |
| for (i = sh->disks; i--; ) { |
| if (sh->dev[i].written) { |
| set_bit(R5_UPTODATE, &sh->dev[i].flags); |
| r5c_return_dev_pending_writes(conf, &sh->dev[i]); |
| bitmap_endwrite(conf->mddev->bitmap, sh->sector, |
| STRIPE_SECTORS, |
| !test_bit(STRIPE_DEGRADED, &sh->state), |
| 0); |
| } |
| } |
| } |
| |
| void r5l_wake_reclaim(struct r5l_log *log, sector_t space); |
| |
| /* Check whether we should flush some stripes to free up stripe cache */ |
| void r5c_check_stripe_cache_usage(struct r5conf *conf) |
| { |
| int total_cached; |
| |
| if (!r5c_is_writeback(conf->log)) |
| return; |
| |
| total_cached = atomic_read(&conf->r5c_cached_partial_stripes) + |
| atomic_read(&conf->r5c_cached_full_stripes); |
| |
| /* |
| * The following condition is true for either of the following: |
| * - stripe cache pressure high: |
| * total_cached > 3/4 min_nr_stripes || |
| * empty_inactive_list_nr > 0 |
| * - stripe cache pressure moderate: |
| * total_cached > 1/2 min_nr_stripes |
| */ |
| if (total_cached > conf->min_nr_stripes * 1 / 2 || |
| atomic_read(&conf->empty_inactive_list_nr) > 0) |
| r5l_wake_reclaim(conf->log, 0); |
| } |
| |
| /* |
| * flush cache when there are R5C_FULL_STRIPE_FLUSH_BATCH or more full |
| * stripes in the cache |
| */ |
| void r5c_check_cached_full_stripe(struct r5conf *conf) |
| { |
| if (!r5c_is_writeback(conf->log)) |
| return; |
| |
| /* |
| * wake up reclaim for R5C_FULL_STRIPE_FLUSH_BATCH cached stripes |
| * or a full stripe (chunk size / 4k stripes). |
| */ |
| if (atomic_read(&conf->r5c_cached_full_stripes) >= |
| min(R5C_FULL_STRIPE_FLUSH_BATCH(conf), |
| conf->chunk_sectors >> STRIPE_SHIFT)) |
| r5l_wake_reclaim(conf->log, 0); |
| } |
| |
| /* |
| * Total log space (in sectors) needed to flush all data in cache |
| * |
| * To avoid deadlock due to log space, it is necessary to reserve log |
| * space to flush critical stripes (stripes that occupying log space near |
| * last_checkpoint). This function helps check how much log space is |
| * required to flush all cached stripes. |
| * |
| * To reduce log space requirements, two mechanisms are used to give cache |
| * flush higher priorities: |
| * 1. In handle_stripe_dirtying() and schedule_reconstruction(), |
| * stripes ALREADY in journal can be flushed w/o pending writes; |
| * 2. In r5l_write_stripe() and r5c_cache_data(), stripes NOT in journal |
| * can be delayed (r5l_add_no_space_stripe). |
| * |
| * In cache flush, the stripe goes through 1 and then 2. For a stripe that |
| * already passed 1, flushing it requires at most (conf->max_degraded + 1) |
| * pages of journal space. For stripes that has not passed 1, flushing it |
| * requires (conf->raid_disks + 1) pages of journal space. There are at |
| * most (conf->group_cnt + 1) stripe that passed 1. So total journal space |
| * required to flush all cached stripes (in pages) is: |
| * |
| * (stripe_in_journal_count - group_cnt - 1) * (max_degraded + 1) + |
| * (group_cnt + 1) * (raid_disks + 1) |
| * or |
| * (stripe_in_journal_count) * (max_degraded + 1) + |
| * (group_cnt + 1) * (raid_disks - max_degraded) |
| */ |
| static sector_t r5c_log_required_to_flush_cache(struct r5conf *conf) |
| { |
| struct r5l_log *log = conf->log; |
| |
| if (!r5c_is_writeback(log)) |
| return 0; |
| |
| return BLOCK_SECTORS * |
| ((conf->max_degraded + 1) * atomic_read(&log->stripe_in_journal_count) + |
| (conf->raid_disks - conf->max_degraded) * (conf->group_cnt + 1)); |
| } |
| |
| /* |
| * evaluate log space usage and update R5C_LOG_TIGHT and R5C_LOG_CRITICAL |
| * |
| * R5C_LOG_TIGHT is set when free space on the log device is less than 3x of |
| * reclaim_required_space. R5C_LOG_CRITICAL is set when free space on the log |
| * device is less than 2x of reclaim_required_space. |
| */ |
| static inline void r5c_update_log_state(struct r5l_log *log) |
| { |
| struct r5conf *conf = log->rdev->mddev->private; |
| sector_t free_space; |
| sector_t reclaim_space; |
| bool wake_reclaim = false; |
| |
| if (!r5c_is_writeback(log)) |
| return; |
| |
| free_space = r5l_ring_distance(log, log->log_start, |
| log->last_checkpoint); |
| reclaim_space = r5c_log_required_to_flush_cache(conf); |
| if (free_space < 2 * reclaim_space) |
| set_bit(R5C_LOG_CRITICAL, &conf->cache_state); |
| else { |
| if (test_bit(R5C_LOG_CRITICAL, &conf->cache_state)) |
| wake_reclaim = true; |
| clear_bit(R5C_LOG_CRITICAL, &conf->cache_state); |
| } |
| if (free_space < 3 * reclaim_space) |
| set_bit(R5C_LOG_TIGHT, &conf->cache_state); |
| else |
| clear_bit(R5C_LOG_TIGHT, &conf->cache_state); |
| |
| if (wake_reclaim) |
| r5l_wake_reclaim(log, 0); |
| } |
| |
| /* |
| * Put the stripe into writing-out phase by clearing STRIPE_R5C_CACHING. |
| * This function should only be called in write-back mode. |
| */ |
| void r5c_make_stripe_write_out(struct stripe_head *sh) |
| { |
| struct r5conf *conf = sh->raid_conf; |
| struct r5l_log *log = conf->log; |
| |
| BUG_ON(!r5c_is_writeback(log)); |
| |
| WARN_ON(!test_bit(STRIPE_R5C_CACHING, &sh->state)); |
| clear_bit(STRIPE_R5C_CACHING, &sh->state); |
| |
| if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) |
| atomic_inc(&conf->preread_active_stripes); |
| } |
| |
| static void r5c_handle_data_cached(struct stripe_head *sh) |
| { |
| int i; |
| |
| for (i = sh->disks; i--; ) |
| if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) { |
| set_bit(R5_InJournal, &sh->dev[i].flags); |
| clear_bit(R5_LOCKED, &sh->dev[i].flags); |
| } |
| clear_bit(STRIPE_LOG_TRAPPED, &sh->state); |
| } |
| |
| /* |
| * this journal write must contain full parity, |
| * it may also contain some data pages |
| */ |
| static void r5c_handle_parity_cached(struct stripe_head *sh) |
| { |
| int i; |
| |
| for (i = sh->disks; i--; ) |
| if (test_bit(R5_InJournal, &sh->dev[i].flags)) |
| set_bit(R5_Wantwrite, &sh->dev[i].flags); |
| } |
| |
| /* |
| * Setting proper flags after writing (or flushing) data and/or parity to the |
| * log device. This is called from r5l_log_endio() or r5l_log_flush_endio(). |
| */ |
| static void r5c_finish_cache_stripe(struct stripe_head *sh) |
| { |
| struct r5l_log *log = sh->raid_conf->log; |
| |
| if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH) { |
| BUG_ON(test_bit(STRIPE_R5C_CACHING, &sh->state)); |
| /* |
| * Set R5_InJournal for parity dev[pd_idx]. This means |
| * all data AND parity in the journal. For RAID 6, it is |
| * NOT necessary to set the flag for dev[qd_idx], as the |
| * two parities are written out together. |
| */ |
| set_bit(R5_InJournal, &sh->dev[sh->pd_idx].flags); |
| } else if (test_bit(STRIPE_R5C_CACHING, &sh->state)) { |
| r5c_handle_data_cached(sh); |
| } else { |
| r5c_handle_parity_cached(sh); |
| set_bit(R5_InJournal, &sh->dev[sh->pd_idx].flags); |
| } |
| } |
| |
| static void r5l_io_run_stripes(struct r5l_io_unit *io) |
| { |
| struct stripe_head *sh, *next; |
| |
| list_for_each_entry_safe(sh, next, &io->stripe_list, log_list) { |
| list_del_init(&sh->log_list); |
| |
| r5c_finish_cache_stripe(sh); |
| |
| set_bit(STRIPE_HANDLE, &sh->state); |
| raid5_release_stripe(sh); |
| } |
| } |
| |
| static void r5l_log_run_stripes(struct r5l_log *log) |
| { |
| struct r5l_io_unit *io, *next; |
| |
| lockdep_assert_held(&log->io_list_lock); |
| |
| list_for_each_entry_safe(io, next, &log->running_ios, log_sibling) { |
| /* don't change list order */ |
| if (io->state < IO_UNIT_IO_END) |
| break; |
| |
| list_move_tail(&io->log_sibling, &log->finished_ios); |
| r5l_io_run_stripes(io); |
| } |
| } |
| |
| static void r5l_move_to_end_ios(struct r5l_log *log) |
| { |
| struct r5l_io_unit *io, *next; |
| |
| lockdep_assert_held(&log->io_list_lock); |
| |
| list_for_each_entry_safe(io, next, &log->running_ios, log_sibling) { |
| /* don't change list order */ |
| if (io->state < IO_UNIT_IO_END) |
| break; |
| list_move_tail(&io->log_sibling, &log->io_end_ios); |
| } |
| } |
| |
| static void __r5l_stripe_write_finished(struct r5l_io_unit *io); |
| static void r5l_log_endio(struct bio *bio) |
| { |
| struct r5l_io_unit *io = bio->bi_private; |
| struct r5l_io_unit *io_deferred; |
| struct r5l_log *log = io->log; |
| unsigned long flags; |
| bool has_null_flush; |
| bool has_flush_payload; |
| |
| if (bio->bi_status) |
| md_error(log->rdev->mddev, log->rdev); |
| |
| bio_put(bio); |
| mempool_free(io->meta_page, &log->meta_pool); |
| |
| spin_lock_irqsave(&log->io_list_lock, flags); |
| __r5l_set_io_unit_state(io, IO_UNIT_IO_END); |
| |
| /* |
| * if the io doesn't not have null_flush or flush payload, |
| * it is not safe to access it after releasing io_list_lock. |
| * Therefore, it is necessary to check the condition with |
| * the lock held. |
| */ |
| has_null_flush = io->has_null_flush; |
| has_flush_payload = io->has_flush_payload; |
| |
| if (log->need_cache_flush && !list_empty(&io->stripe_list)) |
| r5l_move_to_end_ios(log); |
| else |
| r5l_log_run_stripes(log); |
| if (!list_empty(&log->running_ios)) { |
| /* |
| * FLUSH/FUA io_unit is deferred because of ordering, now we |
| * can dispatch it |
| */ |
| io_deferred = list_first_entry(&log->running_ios, |
| struct r5l_io_unit, log_sibling); |
| if (io_deferred->io_deferred) |
| schedule_work(&log->deferred_io_work); |
| } |
| |
| spin_unlock_irqrestore(&log->io_list_lock, flags); |
| |
| if (log->need_cache_flush) |
| md_wakeup_thread(log->rdev->mddev->thread); |
| |
| /* finish flush only io_unit and PAYLOAD_FLUSH only io_unit */ |
| if (has_null_flush) { |
| struct bio *bi; |
| |
| WARN_ON(bio_list_empty(&io->flush_barriers)); |
| while ((bi = bio_list_pop(&io->flush_barriers)) != NULL) { |
| bio_endio(bi); |
| if (atomic_dec_and_test(&io->pending_stripe)) { |
| __r5l_stripe_write_finished(io); |
| return; |
| } |
| } |
| } |
| /* decrease pending_stripe for flush payload */ |
| if (has_flush_payload) |
| if (atomic_dec_and_test(&io->pending_stripe)) |
| __r5l_stripe_write_finished(io); |
| } |
| |
| static void r5l_do_submit_io(struct r5l_log *log, struct r5l_io_unit *io) |
| { |
| unsigned long flags; |
| |
| spin_lock_irqsave(&log->io_list_lock, flags); |
| __r5l_set_io_unit_state(io, IO_UNIT_IO_START); |
| spin_unlock_irqrestore(&log->io_list_lock, flags); |
| |
| /* |
| * In case of journal device failures, submit_bio will get error |
| * and calls endio, then active stripes will continue write |
| * process. Therefore, it is not necessary to check Faulty bit |
| * of journal device here. |
| * |
| * We can't check split_bio after current_bio is submitted. If |
| * io->split_bio is null, after current_bio is submitted, current_bio |
| * might already be completed and the io_unit is freed. We submit |
| * split_bio first to avoid the issue. |
| */ |
| if (io->split_bio) { |
| if (io->has_flush) |
| io->split_bio->bi_opf |= REQ_PREFLUSH; |
| if (io->has_fua) |
| io->split_bio->bi_opf |= REQ_FUA; |
| submit_bio(io->split_bio); |
| } |
| |
| if (io->has_flush) |
| io->current_bio->bi_opf |= REQ_PREFLUSH; |
| if (io->has_fua) |
| io->current_bio->bi_opf |= REQ_FUA; |
| submit_bio(io->current_bio); |
| } |
| |
| /* deferred io_unit will be dispatched here */ |
| static void r5l_submit_io_async(struct work_struct *work) |
| { |
| struct r5l_log *log = container_of(work, struct r5l_log, |
| deferred_io_work); |
| struct r5l_io_unit *io = NULL; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&log->io_list_lock, flags); |
| if (!list_empty(&log->running_ios)) { |
| io = list_first_entry(&log->running_ios, struct r5l_io_unit, |
| log_sibling); |
| if (!io->io_deferred) |
| io = NULL; |
| else |
| io->io_deferred = 0; |
| } |
| spin_unlock_irqrestore(&log->io_list_lock, flags); |
| if (io) |
| r5l_do_submit_io(log, io); |
| } |
| |
| static void r5c_disable_writeback_async(struct work_struct *work) |
| { |
| struct r5l_log *log = container_of(work, struct r5l_log, |
| disable_writeback_work); |
| struct mddev *mddev = log->rdev->mddev; |
| struct r5conf *conf = mddev->private; |
| int locked = 0; |
| |
| if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH) |
| return; |
| pr_info("md/raid:%s: Disabling writeback cache for degraded array.\n", |
| mdname(mddev)); |
| |
| /* wait superblock change before suspend */ |
| wait_event(mddev->sb_wait, |
| conf->log == NULL || |
| (!test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags) && |
| (locked = mddev_trylock(mddev)))); |
| if (locked) { |
| mddev_suspend(mddev); |
| log->r5c_journal_mode = R5C_JOURNAL_MODE_WRITE_THROUGH; |
| mddev_resume(mddev); |
| mddev_unlock(mddev); |
| } |
| } |
| |
| static void r5l_submit_current_io(struct r5l_log *log) |
| { |
| struct r5l_io_unit *io = log->current_io; |
| struct r5l_meta_block *block; |
| unsigned long flags; |
| u32 crc; |
| bool do_submit = true; |
| |
| if (!io) |
| return; |
| |
| block = page_address(io->meta_page); |
| block->meta_size = cpu_to_le32(io->meta_offset); |
| crc = crc32c_le(log->uuid_checksum, block, PAGE_SIZE); |
| block->checksum = cpu_to_le32(crc); |
| |
| log->current_io = NULL; |
| spin_lock_irqsave(&log->io_list_lock, flags); |
| if (io->has_flush || io->has_fua) { |
| if (io != list_first_entry(&log->running_ios, |
| struct r5l_io_unit, log_sibling)) { |
| io->io_deferred = 1; |
| do_submit = false; |
| } |
| } |
| spin_unlock_irqrestore(&log->io_list_lock, flags); |
| if (do_submit) |
| r5l_do_submit_io(log, io); |
| } |
| |
| static struct bio *r5l_bio_alloc(struct r5l_log *log) |
| { |
| struct bio *bio = bio_alloc_bioset(GFP_NOIO, BIO_MAX_PAGES, &log->bs); |
| |
| bio_set_op_attrs(bio, REQ_OP_WRITE, 0); |
| bio_set_dev(bio, log->rdev->bdev); |
| bio->bi_iter.bi_sector = log->rdev->data_offset + log->log_start; |
| |
| return bio; |
| } |
| |
| static void r5_reserve_log_entry(struct r5l_log *log, struct r5l_io_unit *io) |
| { |
| log->log_start = r5l_ring_add(log, log->log_start, BLOCK_SECTORS); |
| |
| r5c_update_log_state(log); |
| /* |
| * If we filled up the log device start from the beginning again, |
| * which will require a new bio. |
| * |
| * Note: for this to work properly the log size needs to me a multiple |
| * of BLOCK_SECTORS. |
| */ |
| if (log->log_start == 0) |
| io->need_split_bio = true; |
| |
| io->log_end = log->log_start; |
| } |
| |
| static struct r5l_io_unit *r5l_new_meta(struct r5l_log *log) |
| { |
| struct r5l_io_unit *io; |
| struct r5l_meta_block *block; |
| |
| io = mempool_alloc(&log->io_pool, GFP_ATOMIC); |
| if (!io) |
| return NULL; |
| memset(io, 0, sizeof(*io)); |
| |
| io->log = log; |
| INIT_LIST_HEAD(&io->log_sibling); |
| INIT_LIST_HEAD(&io->stripe_list); |
| bio_list_init(&io->flush_barriers); |
| io->state = IO_UNIT_RUNNING; |
| |
| io->meta_page = mempool_alloc(&log->meta_pool, GFP_NOIO); |
| block = page_address(io->meta_page); |
| clear_page(block); |
| block->magic = cpu_to_le32(R5LOG_MAGIC); |
| block->version = R5LOG_VERSION; |
| block->seq = cpu_to_le64(log->seq); |
| block->position = cpu_to_le64(log->log_start); |
| |
| io->log_start = log->log_start; |
| io->meta_offset = sizeof(struct r5l_meta_block); |
| io->seq = log->seq++; |
| |
| io->current_bio = r5l_bio_alloc(log); |
| io->current_bio->bi_end_io = r5l_log_endio; |
| io->current_bio->bi_private = io; |
| bio_add_page(io->current_bio, io->meta_page, PAGE_SIZE, 0); |
| |
| r5_reserve_log_entry(log, io); |
| |
| spin_lock_irq(&log->io_list_lock); |
| list_add_tail(&io->log_sibling, &log->running_ios); |
| spin_unlock_irq(&log->io_list_lock); |
| |
| return io; |
| } |
| |
| static int r5l_get_meta(struct r5l_log *log, unsigned int payload_size) |
| { |
| if (log->current_io && |
| log->current_io->meta_offset + payload_size > PAGE_SIZE) |
| r5l_submit_current_io(log); |
| |
| if (!log->current_io) { |
| log->current_io = r5l_new_meta(log); |
| if (!log->current_io) |
| return -ENOMEM; |
| } |
| |
| return 0; |
| } |
| |
| static void r5l_append_payload_meta(struct r5l_log *log, u16 type, |
| sector_t location, |
| u32 checksum1, u32 checksum2, |
| bool checksum2_valid) |
| { |
| struct r5l_io_unit *io = log->current_io; |
| struct r5l_payload_data_parity *payload; |
| |
| payload = page_address(io->meta_page) + io->meta_offset; |
| payload->header.type = cpu_to_le16(type); |
| payload->header.flags = cpu_to_le16(0); |
| payload->size = cpu_to_le32((1 + !!checksum2_valid) << |
| (PAGE_SHIFT - 9)); |
| payload->location = cpu_to_le64(location); |
| payload->checksum[0] = cpu_to_le32(checksum1); |
| if (checksum2_valid) |
| payload->checksum[1] = cpu_to_le32(checksum2); |
| |
| io->meta_offset += sizeof(struct r5l_payload_data_parity) + |
| sizeof(__le32) * (1 + !!checksum2_valid); |
| } |
| |
| static void r5l_append_payload_page(struct r5l_log *log, struct page *page) |
| { |
| struct r5l_io_unit *io = log->current_io; |
| |
| if (io->need_split_bio) { |
| BUG_ON(io->split_bio); |
| io->split_bio = io->current_bio; |
| io->current_bio = r5l_bio_alloc(log); |
| bio_chain(io->current_bio, io->split_bio); |
| io->need_split_bio = false; |
| } |
| |
| if (!bio_add_page(io->current_bio, page, PAGE_SIZE, 0)) |
| BUG(); |
| |
| r5_reserve_log_entry(log, io); |
| } |
| |
| static void r5l_append_flush_payload(struct r5l_log *log, sector_t sect) |
| { |
| struct mddev *mddev = log->rdev->mddev; |
| struct r5conf *conf = mddev->private; |
| struct r5l_io_unit *io; |
| struct r5l_payload_flush *payload; |
| int meta_size; |
| |
| /* |
| * payload_flush requires extra writes to the journal. |
| * To avoid handling the extra IO in quiesce, just skip |
| * flush_payload |
| */ |
| if (conf->quiesce) |
| return; |
| |
| mutex_lock(&log->io_mutex); |
| meta_size = sizeof(struct r5l_payload_flush) + sizeof(__le64); |
| |
| if (r5l_get_meta(log, meta_size)) { |
| mutex_unlock(&log->io_mutex); |
| return; |
| } |
| |
| /* current implementation is one stripe per flush payload */ |
| io = log->current_io; |
| payload = page_address(io->meta_page) + io->meta_offset; |
| payload->header.type = cpu_to_le16(R5LOG_PAYLOAD_FLUSH); |
| payload->header.flags = cpu_to_le16(0); |
| payload->size = cpu_to_le32(sizeof(__le64)); |
| payload->flush_stripes[0] = cpu_to_le64(sect); |
| io->meta_offset += meta_size; |
| /* multiple flush payloads count as one pending_stripe */ |
| if (!io->has_flush_payload) { |
| io->has_flush_payload = 1; |
| atomic_inc(&io->pending_stripe); |
| } |
| mutex_unlock(&log->io_mutex); |
| } |
| |
| static int r5l_log_stripe(struct r5l_log *log, struct stripe_head *sh, |
| int data_pages, int parity_pages) |
| { |
| int i; |
| int meta_size; |
| int ret; |
| struct r5l_io_unit *io; |
| |
| meta_size = |
| ((sizeof(struct r5l_payload_data_parity) + sizeof(__le32)) |
| * data_pages) + |
| sizeof(struct r5l_payload_data_parity) + |
| sizeof(__le32) * parity_pages; |
| |
| ret = r5l_get_meta(log, meta_size); |
| if (ret) |
| return ret; |
| |
| io = log->current_io; |
| |
| if (test_and_clear_bit(STRIPE_R5C_PREFLUSH, &sh->state)) |
| io->has_flush = 1; |
| |
| for (i = 0; i < sh->disks; i++) { |
| if (!test_bit(R5_Wantwrite, &sh->dev[i].flags) || |
| test_bit(R5_InJournal, &sh->dev[i].flags)) |
| continue; |
| if (i == sh->pd_idx || i == sh->qd_idx) |
| continue; |
| if (test_bit(R5_WantFUA, &sh->dev[i].flags) && |
| log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_BACK) { |
| io->has_fua = 1; |
| /* |
| * we need to flush journal to make sure recovery can |
| * reach the data with fua flag |
| */ |
| io->has_flush = 1; |
| } |
| r5l_append_payload_meta(log, R5LOG_PAYLOAD_DATA, |
| raid5_compute_blocknr(sh, i, 0), |
| sh->dev[i].log_checksum, 0, false); |
| r5l_append_payload_page(log, sh->dev[i].page); |
| } |
| |
| if (parity_pages == 2) { |
| r5l_append_payload_meta(log, R5LOG_PAYLOAD_PARITY, |
| sh->sector, sh->dev[sh->pd_idx].log_checksum, |
| sh->dev[sh->qd_idx].log_checksum, true); |
| r5l_append_payload_page(log, sh->dev[sh->pd_idx].page); |
| r5l_append_payload_page(log, sh->dev[sh->qd_idx].page); |
| } else if (parity_pages == 1) { |
| r5l_append_payload_meta(log, R5LOG_PAYLOAD_PARITY, |
| sh->sector, sh->dev[sh->pd_idx].log_checksum, |
| 0, false); |
| r5l_append_payload_page(log, sh->dev[sh->pd_idx].page); |
| } else /* Just writing data, not parity, in caching phase */ |
| BUG_ON(parity_pages != 0); |
| |
| list_add_tail(&sh->log_list, &io->stripe_list); |
| atomic_inc(&io->pending_stripe); |
| sh->log_io = io; |
| |
| if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH) |
| return 0; |
| |
| if (sh->log_start == MaxSector) { |
| BUG_ON(!list_empty(&sh->r5c)); |
| sh->log_start = io->log_start; |
| spin_lock_irq(&log->stripe_in_journal_lock); |
| list_add_tail(&sh->r5c, |
| &log->stripe_in_journal_list); |
| spin_unlock_irq(&log->stripe_in_journal_lock); |
| atomic_inc(&log->stripe_in_journal_count); |
| } |
| return 0; |
| } |
| |
| /* add stripe to no_space_stripes, and then wake up reclaim */ |
| static inline void r5l_add_no_space_stripe(struct r5l_log *log, |
| struct stripe_head *sh) |
| { |
| spin_lock(&log->no_space_stripes_lock); |
| list_add_tail(&sh->log_list, &log->no_space_stripes); |
| spin_unlock(&log->no_space_stripes_lock); |
| } |
| |
| /* |
| * running in raid5d, where reclaim could wait for raid5d too (when it flushes |
| * data from log to raid disks), so we shouldn't wait for reclaim here |
| */ |
| int r5l_write_stripe(struct r5l_log *log, struct stripe_head *sh) |
| { |
| struct r5conf *conf = sh->raid_conf; |
| int write_disks = 0; |
| int data_pages, parity_pages; |
| int reserve; |
| int i; |
| int ret = 0; |
| bool wake_reclaim = false; |
| |
| if (!log) |
| return -EAGAIN; |
| /* Don't support stripe batch */ |
| if (sh->log_io || !test_bit(R5_Wantwrite, &sh->dev[sh->pd_idx].flags) || |
| test_bit(STRIPE_SYNCING, &sh->state)) { |
| /* the stripe is written to log, we start writing it to raid */ |
| clear_bit(STRIPE_LOG_TRAPPED, &sh->state); |
| return -EAGAIN; |
| } |
| |
| WARN_ON(test_bit(STRIPE_R5C_CACHING, &sh->state)); |
| |
| for (i = 0; i < sh->disks; i++) { |
| void *addr; |
| |
| if (!test_bit(R5_Wantwrite, &sh->dev[i].flags) || |
| test_bit(R5_InJournal, &sh->dev[i].flags)) |
| continue; |
| |
| write_disks++; |
| /* checksum is already calculated in last run */ |
| if (test_bit(STRIPE_LOG_TRAPPED, &sh->state)) |
| continue; |
| addr = kmap_atomic(sh->dev[i].page); |
| sh->dev[i].log_checksum = crc32c_le(log->uuid_checksum, |
| addr, PAGE_SIZE); |
| kunmap_atomic(addr); |
| } |
| parity_pages = 1 + !!(sh->qd_idx >= 0); |
| data_pages = write_disks - parity_pages; |
| |
| set_bit(STRIPE_LOG_TRAPPED, &sh->state); |
| /* |
| * The stripe must enter state machine again to finish the write, so |
| * don't delay. |
| */ |
| clear_bit(STRIPE_DELAYED, &sh->state); |
| atomic_inc(&sh->count); |
| |
| mutex_lock(&log->io_mutex); |
| /* meta + data */ |
| reserve = (1 + write_disks) << (PAGE_SHIFT - 9); |
| |
| if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH) { |
| if (!r5l_has_free_space(log, reserve)) { |
| r5l_add_no_space_stripe(log, sh); |
| wake_reclaim = true; |
| } else { |
| ret = r5l_log_stripe(log, sh, data_pages, parity_pages); |
| if (ret) { |
| spin_lock_irq(&log->io_list_lock); |
| list_add_tail(&sh->log_list, |
| &log->no_mem_stripes); |
| spin_unlock_irq(&log->io_list_lock); |
| } |
| } |
| } else { /* R5C_JOURNAL_MODE_WRITE_BACK */ |
| /* |
| * log space critical, do not process stripes that are |
| * not in cache yet (sh->log_start == MaxSector). |
| */ |
| if (test_bit(R5C_LOG_CRITICAL, &conf->cache_state) && |
| sh->log_start == MaxSector) { |
| r5l_add_no_space_stripe(log, sh); |
| wake_reclaim = true; |
| reserve = 0; |
| } else if (!r5l_has_free_space(log, reserve)) { |
| if (sh->log_start == log->last_checkpoint) |
| BUG(); |
| else |
| r5l_add_no_space_stripe(log, sh); |
| } else { |
| ret = r5l_log_stripe(log, sh, data_pages, parity_pages); |
| if (ret) { |
| spin_lock_irq(&log->io_list_lock); |
| list_add_tail(&sh->log_list, |
| &log->no_mem_stripes); |
| spin_unlock_irq(&log->io_list_lock); |
| } |
| } |
| } |
| |
| mutex_unlock(&log->io_mutex); |
| if (wake_reclaim) |
| r5l_wake_reclaim(log, reserve); |
| return 0; |
| } |
| |
| void r5l_write_stripe_run(struct r5l_log *log) |
| { |
| if (!log) |
| return; |
| mutex_lock(&log->io_mutex); |
| r5l_submit_current_io(log); |
| mutex_unlock(&log->io_mutex); |
| } |
| |
| int r5l_handle_flush_request(struct r5l_log *log, struct bio *bio) |
| { |
| if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH) { |
| /* |
| * in write through (journal only) |
| * we flush log disk cache first, then write stripe data to |
| * raid disks. So if bio is finished, the log disk cache is |
| * flushed already. The recovery guarantees we can recovery |
| * the bio from log disk, so we don't need to flush again |
| */ |
| if (bio->bi_iter.bi_size == 0) { |
| bio_endio(bio); |
| return 0; |
| } |
| bio->bi_opf &= ~REQ_PREFLUSH; |
| } else { |
| /* write back (with cache) */ |
| if (bio->bi_iter.bi_size == 0) { |
| mutex_lock(&log->io_mutex); |
| r5l_get_meta(log, 0); |
| bio_list_add(&log->current_io->flush_barriers, bio); |
| log->current_io->has_flush = 1; |
| log->current_io->has_null_flush = 1; |
| atomic_inc(&log->current_io->pending_stripe); |
| r5l_submit_current_io(log); |
| mutex_unlock(&log->io_mutex); |
| return 0; |
| } |
| } |
| return -EAGAIN; |
| } |
| |
| /* This will run after log space is reclaimed */ |
| static void r5l_run_no_space_stripes(struct r5l_log *log) |
| { |
| struct stripe_head *sh; |
| |
| spin_lock(&log->no_space_stripes_lock); |
| while (!list_empty(&log->no_space_stripes)) { |
| sh = list_first_entry(&log->no_space_stripes, |
| struct stripe_head, log_list); |
| list_del_init(&sh->log_list); |
| set_bit(STRIPE_HANDLE, &sh->state); |
| raid5_release_stripe(sh); |
| } |
| spin_unlock(&log->no_space_stripes_lock); |
| } |
| |
| /* |
| * calculate new last_checkpoint |
| * for write through mode, returns log->next_checkpoint |
| * for write back, returns log_start of first sh in stripe_in_journal_list |
| */ |
| static sector_t r5c_calculate_new_cp(struct r5conf *conf) |
| { |
| struct stripe_head *sh; |
| struct r5l_log *log = conf->log; |
| sector_t new_cp; |
| unsigned long flags; |
| |
| if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH) |
| return log->next_checkpoint; |
| |
| spin_lock_irqsave(&log->stripe_in_journal_lock, flags); |
| if (list_empty(&conf->log->stripe_in_journal_list)) { |
| /* all stripes flushed */ |
| spin_unlock_irqrestore(&log->stripe_in_journal_lock, flags); |
| return log->next_checkpoint; |
| } |
| sh = list_first_entry(&conf->log->stripe_in_journal_list, |
| struct stripe_head, r5c); |
| new_cp = sh->log_start; |
| spin_unlock_irqrestore(&log->stripe_in_journal_lock, flags); |
| return new_cp; |
| } |
| |
| static sector_t r5l_reclaimable_space(struct r5l_log *log) |
| { |
| struct r5conf *conf = log->rdev->mddev->private; |
| |
| return r5l_ring_distance(log, log->last_checkpoint, |
| r5c_calculate_new_cp(conf)); |
| } |
| |
| static void r5l_run_no_mem_stripe(struct r5l_log *log) |
| { |
| struct stripe_head *sh; |
| |
| lockdep_assert_held(&log->io_list_lock); |
| |
| if (!list_empty(&log->no_mem_stripes)) { |
| sh = list_first_entry(&log->no_mem_stripes, |
| struct stripe_head, log_list); |
| list_del_init(&sh->log_list); |
| set_bit(STRIPE_HANDLE, &sh->state); |
| raid5_release_stripe(sh); |
| } |
| } |
| |
| static bool r5l_complete_finished_ios(struct r5l_log *log) |
| { |
| struct r5l_io_unit *io, *next; |
| bool found = false; |
| |
| lockdep_assert_held(&log->io_list_lock); |
| |
| list_for_each_entry_safe(io, next, &log->finished_ios, log_sibling) { |
| /* don't change list order */ |
| if (io->state < IO_UNIT_STRIPE_END) |
| break; |
| |
| log->next_checkpoint = io->log_start; |
| |
| list_del(&io->log_sibling); |
| mempool_free(io, &log->io_pool); |
| r5l_run_no_mem_stripe(log); |
| |
| found = true; |
| } |
| |
| return found; |
| } |
| |
| static void __r5l_stripe_write_finished(struct r5l_io_unit *io) |
| { |
| struct r5l_log *log = io->log; |
| struct r5conf *conf = log->rdev->mddev->private; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&log->io_list_lock, flags); |
| __r5l_set_io_unit_state(io, IO_UNIT_STRIPE_END); |
| |
| if (!r5l_complete_finished_ios(log)) { |
| spin_unlock_irqrestore(&log->io_list_lock, flags); |
| return; |
| } |
| |
| if (r5l_reclaimable_space(log) > log->max_free_space || |
| test_bit(R5C_LOG_TIGHT, &conf->cache_state)) |
| r5l_wake_reclaim(log, 0); |
| |
| spin_unlock_irqrestore(&log->io_list_lock, flags); |
| wake_up(&log->iounit_wait); |
| } |
| |
| void r5l_stripe_write_finished(struct stripe_head *sh) |
| { |
| struct r5l_io_unit *io; |
| |
| io = sh->log_io; |
| sh->log_io = NULL; |
| |
| if (io && atomic_dec_and_test(&io->pending_stripe)) |
| __r5l_stripe_write_finished(io); |
| } |
| |
| static void r5l_log_flush_endio(struct bio *bio) |
| { |
| struct r5l_log *log = container_of(bio, struct r5l_log, |
| flush_bio); |
| unsigned long flags; |
| struct r5l_io_unit *io; |
| |
| if (bio->bi_status) |
| md_error(log->rdev->mddev, log->rdev); |
| |
| spin_lock_irqsave(&log->io_list_lock, flags); |
| list_for_each_entry(io, &log->flushing_ios, log_sibling) |
| r5l_io_run_stripes(io); |
| list_splice_tail_init(&log->flushing_ios, &log->finished_ios); |
| spin_unlock_irqrestore(&log->io_list_lock, flags); |
| } |
| |
| /* |
| * Starting dispatch IO to raid. |
| * io_unit(meta) consists of a log. There is one situation we want to avoid. A |
| * broken meta in the middle of a log causes recovery can't find meta at the |
| * head of log. If operations require meta at the head persistent in log, we |
| * must make sure meta before it persistent in log too. A case is: |
| * |
| * stripe data/parity is in log, we start write stripe to raid disks. stripe |
| * data/parity must be persistent in log before we do the write to raid disks. |
| * |
| * The solution is we restrictly maintain io_unit list order. In this case, we |
| * only write stripes of an io_unit to raid disks till the io_unit is the first |
| * one whose data/parity is in log. |
| */ |
| void r5l_flush_stripe_to_raid(struct r5l_log *log) |
| { |
| bool do_flush; |
| |
| if (!log || !log->need_cache_flush) |
| return; |
| |
| spin_lock_irq(&log->io_list_lock); |
| /* flush bio is running */ |
| if (!list_empty(&log->flushing_ios)) { |
| spin_unlock_irq(&log->io_list_lock); |
| return; |
| } |
| list_splice_tail_init(&log->io_end_ios, &log->flushing_ios); |
| do_flush = !list_empty(&log->flushing_ios); |
| spin_unlock_irq(&log->io_list_lock); |
| |
| if (!do_flush) |
| return; |
| bio_reset(&log->flush_bio); |
| bio_set_dev(&log->flush_bio, log->rdev->bdev); |
| log->flush_bio.bi_end_io = r5l_log_flush_endio; |
| log->flush_bio.bi_opf = REQ_OP_WRITE | REQ_PREFLUSH; |
| submit_bio(&log->flush_bio); |
| } |
| |
| static void r5l_write_super(struct r5l_log *log, sector_t cp); |
| static void r5l_write_super_and_discard_space(struct r5l_log *log, |
| sector_t end) |
| { |
| struct block_device *bdev = log->rdev->bdev; |
| struct mddev *mddev; |
| |
| r5l_write_super(log, end); |
| |
| if (!blk_queue_discard(bdev_get_queue(bdev))) |
| return; |
| |
| mddev = log->rdev->mddev; |
| /* |
| * Discard could zero data, so before discard we must make sure |
| * superblock is updated to new log tail. Updating superblock (either |
| * directly call md_update_sb() or depend on md thread) must hold |
| * reconfig mutex. On the other hand, raid5_quiesce is called with |
| * reconfig_mutex hold. The first step of raid5_quiesce() is waitting |
| * for all IO finish, hence waitting for reclaim thread, while reclaim |
| * thread is calling this function and waitting for reconfig mutex. So |
| * there is a deadlock. We workaround this issue with a trylock. |
| * FIXME: we could miss discard if we can't take reconfig mutex |
| */ |
| set_mask_bits(&mddev->sb_flags, 0, |
| BIT(MD_SB_CHANGE_DEVS) | BIT(MD_SB_CHANGE_PENDING)); |
| if (!mddev_trylock(mddev)) |
| return; |
| md_update_sb(mddev, 1); |
| mddev_unlock(mddev); |
| |
| /* discard IO error really doesn't matter, ignore it */ |
| if (log->last_checkpoint < end) { |
| blkdev_issue_discard(bdev, |
| log->last_checkpoint + log->rdev->data_offset, |
| end - log->last_checkpoint, GFP_NOIO, 0); |
| } else { |
| blkdev_issue_discard(bdev, |
| log->last_checkpoint + log->rdev->data_offset, |
| log->device_size - log->last_checkpoint, |
| GFP_NOIO, 0); |
| blkdev_issue_discard(bdev, log->rdev->data_offset, end, |
| GFP_NOIO, 0); |
| } |
| } |
| |
| /* |
| * r5c_flush_stripe moves stripe from cached list to handle_list. When called, |
| * the stripe must be on r5c_cached_full_stripes or r5c_cached_partial_stripes. |
| * |
| * must hold conf->device_lock |
| */ |
| static void r5c_flush_stripe(struct r5conf *conf, struct stripe_head *sh) |
| { |
| BUG_ON(list_empty(&sh->lru)); |
| BUG_ON(!test_bit(STRIPE_R5C_CACHING, &sh->state)); |
| BUG_ON(test_bit(STRIPE_HANDLE, &sh->state)); |
| |
| /* |
| * The stripe is not ON_RELEASE_LIST, so it is safe to call |
| * raid5_release_stripe() while holding conf->device_lock |
| */ |
| BUG_ON(test_bit(STRIPE_ON_RELEASE_LIST, &sh->state)); |
| lockdep_assert_held(&conf->device_lock); |
| |
| list_del_init(&sh->lru); |
| atomic_inc(&sh->count); |
| |
| set_bit(STRIPE_HANDLE, &sh->state); |
| atomic_inc(&conf->active_stripes); |
| r5c_make_stripe_write_out(sh); |
| |
| if (test_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state)) |
| atomic_inc(&conf->r5c_flushing_partial_stripes); |
| else |
| atomic_inc(&conf->r5c_flushing_full_stripes); |
| raid5_release_stripe(sh); |
| } |
| |
| /* |
| * if num == 0, flush all full stripes |
| * if num > 0, flush all full stripes. If less than num full stripes are |
| * flushed, flush some partial stripes until totally num stripes are |
| * flushed or there is no more cached stripes. |
| */ |
| void r5c_flush_cache(struct r5conf *conf, int num) |
| { |
| int count; |
| struct stripe_head *sh, *next; |
| |
| lockdep_assert_held(&conf->device_lock); |
| if (!conf->log) |
| return; |
| |
| count = 0; |
| list_for_each_entry_safe(sh, next, &conf->r5c_full_stripe_list, lru) { |
| r5c_flush_stripe(conf, sh); |
| count++; |
| } |
| |
| if (count >= num) |
| return; |
| list_for_each_entry_safe(sh, next, |
| &conf->r5c_partial_stripe_list, lru) { |
| r5c_flush_stripe(conf, sh); |
| if (++count >= num) |
| break; |
| } |
| } |
| |
| static void r5c_do_reclaim(struct r5conf *conf) |
| { |
| struct r5l_log *log = conf->log; |
| struct stripe_head *sh; |
| int count = 0; |
| unsigned long flags; |
| int total_cached; |
| int stripes_to_flush; |
| int flushing_partial, flushing_full; |
| |
| if (!r5c_is_writeback(log)) |
| return; |
| |
| flushing_partial = atomic_read(&conf->r5c_flushing_partial_stripes); |
| flushing_full = atomic_read(&conf->r5c_flushing_full_stripes); |
| total_cached = atomic_read(&conf->r5c_cached_partial_stripes) + |
| atomic_read(&conf->r5c_cached_full_stripes) - |
| flushing_full - flushing_partial; |
| |
| if (total_cached > conf->min_nr_stripes * 3 / 4 || |
| atomic_read(&conf->empty_inactive_list_nr) > 0) |
| /* |
| * if stripe cache pressure high, flush all full stripes and |
| * some partial stripes |
| */ |
| stripes_to_flush = R5C_RECLAIM_STRIPE_GROUP; |
| else if (total_cached > conf->min_nr_stripes * 1 / 2 || |
| atomic_read(&conf->r5c_cached_full_stripes) - flushing_full > |
| R5C_FULL_STRIPE_FLUSH_BATCH(conf)) |
| /* |
| * if stripe cache pressure moderate, or if there is many full |
| * stripes,flush all full stripes |
| */ |
| stripes_to_flush = 0; |
| else |
| /* no need to flush */ |
| stripes_to_flush = -1; |
| |
| if (stripes_to_flush >= 0) { |
| spin_lock_irqsave(&conf->device_lock, flags); |
| r5c_flush_cache(conf, stripes_to_flush); |
| spin_unlock_irqrestore(&conf->device_lock, flags); |
| } |
| |
| /* if log space is tight, flush stripes on stripe_in_journal_list */ |
| if (test_bit(R5C_LOG_TIGHT, &conf->cache_state)) { |
| spin_lock_irqsave(&log->stripe_in_journal_lock, flags); |
| spin_lock(&conf->device_lock); |
| list_for_each_entry(sh, &log->stripe_in_journal_list, r5c) { |
| /* |
| * stripes on stripe_in_journal_list could be in any |
| * state of the stripe_cache state machine. In this |
| * case, we only want to flush stripe on |
| * r5c_cached_full/partial_stripes. The following |
| * condition makes sure the stripe is on one of the |
| * two lists. |
| */ |
| if (!list_empty(&sh->lru) && |
| !test_bit(STRIPE_HANDLE, &sh->state) && |
| atomic_read(&sh->count) == 0) { |
| r5c_flush_stripe(conf, sh); |
| if (count++ >= R5C_RECLAIM_STRIPE_GROUP) |
| break; |
| } |
| } |
| spin_unlock(&conf->device_lock); |
| spin_unlock_irqrestore(&log->stripe_in_journal_lock, flags); |
| } |
| |
| if (!test_bit(R5C_LOG_CRITICAL, &conf->cache_state)) |
| r5l_run_no_space_stripes(log); |
| |
| md_wakeup_thread(conf->mddev->thread); |
| } |
| |
| static void r5l_do_reclaim(struct r5l_log *log) |
| { |
| struct r5conf *conf = log->rdev->mddev->private; |
| sector_t reclaim_target = xchg(&log->reclaim_target, 0); |
| sector_t reclaimable; |
| sector_t next_checkpoint; |
| bool write_super; |
| |
| spin_lock_irq(&log->io_list_lock); |
| write_super = r5l_reclaimable_space(log) > log->max_free_space || |
| reclaim_target != 0 || !list_empty(&log->no_space_stripes); |
| /* |
| * move proper io_unit to reclaim list. We should not change the order. |
| * reclaimable/unreclaimable io_unit can be mixed in the list, we |
| * shouldn't reuse space of an unreclaimable io_unit |
| */ |
| while (1) { |
| reclaimable = r5l_reclaimable_space(log); |
| if (reclaimable >= reclaim_target || |
| (list_empty(&log->running_ios) && |
| list_empty(&log->io_end_ios) && |
| list_empty(&log->flushing_ios) && |
| list_empty(&log->finished_ios))) |
| break; |
| |
| md_wakeup_thread(log->rdev->mddev->thread); |
| wait_event_lock_irq(log->iounit_wait, |
| r5l_reclaimable_space(log) > reclaimable, |
| log->io_list_lock); |
| } |
| |
| next_checkpoint = r5c_calculate_new_cp(conf); |
| spin_unlock_irq(&log->io_list_lock); |
| |
| if (reclaimable == 0 || !write_super) |
| return; |
| |
| /* |
| * write_super will flush cache of each raid disk. We must write super |
| * here, because the log area might be reused soon and we don't want to |
| * confuse recovery |
| */ |
| r5l_write_super_and_discard_space(log, next_checkpoint); |
| |
| mutex_lock(&log->io_mutex); |
| log->last_checkpoint = next_checkpoint; |
| r5c_update_log_state(log); |
| mutex_unlock(&log->io_mutex); |
| |
| r5l_run_no_space_stripes(log); |
| } |
| |
| static void r5l_reclaim_thread(struct md_thread *thread) |
| { |
| struct mddev *mddev = thread->mddev; |
| struct r5conf *conf = mddev->private; |
| struct r5l_log *log = conf->log; |
| |
| if (!log) |
| return; |
| r5c_do_reclaim(conf); |
| r5l_do_reclaim(log); |
| } |
| |
| void r5l_wake_reclaim(struct r5l_log *log, sector_t space) |
| { |
| unsigned long target; |
| unsigned long new = (unsigned long)space; /* overflow in theory */ |
| |
| if (!log) |
| return; |
| do { |
| target = log->reclaim_target; |
| if (new < target) |
| return; |
| } while (cmpxchg(&log->reclaim_target, target, new) != target); |
| md_wakeup_thread(log->reclaim_thread); |
| } |
| |
| void r5l_quiesce(struct r5l_log *log, int quiesce) |
| { |
| struct mddev *mddev; |
| |
| if (quiesce) { |
| /* make sure r5l_write_super_and_discard_space exits */ |
| mddev = log->rdev->mddev; |
| wake_up(&mddev->sb_wait); |
| kthread_park(log->reclaim_thread->tsk); |
| r5l_wake_reclaim(log, MaxSector); |
| r5l_do_reclaim(log); |
| } else |
| kthread_unpark(log->reclaim_thread->tsk); |
| } |
| |
| bool r5l_log_disk_error(struct r5conf *conf) |
| { |
| struct r5l_log *log; |
| bool ret; |
| /* don't allow write if journal disk is missing */ |
| rcu_read_lock(); |
| log = rcu_dereference(conf->log); |
| |
| if (!log) |
| ret = test_bit(MD_HAS_JOURNAL, &conf->mddev->flags); |
| else |
| ret = test_bit(Faulty, &log->rdev->flags); |
| rcu_read_unlock(); |
| return ret; |
| } |
| |
| #define R5L_RECOVERY_PAGE_POOL_SIZE 256 |
| |
| struct r5l_recovery_ctx { |
| struct page *meta_page; /* current meta */ |
| sector_t meta_total_blocks; /* total size of current meta and data */ |
| sector_t pos; /* recovery position */ |
| u64 seq; /* recovery position seq */ |
| int data_parity_stripes; /* number of data_parity stripes */ |
| int data_only_stripes; /* number of data_only stripes */ |
| struct list_head cached_list; |
| |
| /* |
| * read ahead page pool (ra_pool) |
| * in recovery, log is read sequentially. It is not efficient to |
| * read every page with sync_page_io(). The read ahead page pool |
| * reads multiple pages with one IO, so further log read can |
| * just copy data from the pool. |
| */ |
| struct page *ra_pool[R5L_RECOVERY_PAGE_POOL_SIZE]; |
| sector_t pool_offset; /* offset of first page in the pool */ |
| int total_pages; /* total allocated pages */ |
| int valid_pages; /* pages with valid data */ |
| struct bio *ra_bio; /* bio to do the read ahead */ |
| }; |
| |
| static int r5l_recovery_allocate_ra_pool(struct r5l_log *log, |
| struct r5l_recovery_ctx *ctx) |
| { |
| struct page *page; |
| |
| ctx->ra_bio = bio_alloc_bioset(GFP_KERNEL, BIO_MAX_PAGES, &log->bs); |
| if (!ctx->ra_bio) |
| return -ENOMEM; |
| |
| ctx->valid_pages = 0; |
| ctx->total_pages = 0; |
| while (ctx->total_pages < R5L_RECOVERY_PAGE_POOL_SIZE) { |
| page = alloc_page(GFP_KERNEL); |
| |
| if (!page) |
| break; |
| ctx->ra_pool[ctx->total_pages] = page; |
| ctx->total_pages += 1; |
| } |
| |
| if (ctx->total_pages == 0) { |
| bio_put(ctx->ra_bio); |
| return -ENOMEM; |
| } |
| |
| ctx->pool_offset = 0; |
| return 0; |
| } |
| |
| static void r5l_recovery_free_ra_pool(struct r5l_log *log, |
| struct r5l_recovery_ctx *ctx) |
| { |
| int i; |
| |
| for (i = 0; i < ctx->total_pages; ++i) |
| put_page(ctx->ra_pool[i]); |
| bio_put(ctx->ra_bio); |
| } |
| |
| /* |
| * fetch ctx->valid_pages pages from offset |
| * In normal cases, ctx->valid_pages == ctx->total_pages after the call. |
| * However, if the offset is close to the end of the journal device, |
| * ctx->valid_pages could be smaller than ctx->total_pages |
| */ |
| static int r5l_recovery_fetch_ra_pool(struct r5l_log *log, |
| struct r5l_recovery_ctx *ctx, |
| sector_t offset) |
| { |
| bio_reset(ctx->ra_bio); |
| bio_set_dev(ctx->ra_bio, log->rdev->bdev); |
| bio_set_op_attrs(ctx->ra_bio, REQ_OP_READ, 0); |
| ctx->ra_bio->bi_iter.bi_sector = log->rdev->data_offset + offset; |
| |
| ctx->valid_pages = 0; |
| ctx->pool_offset = offset; |
| |
| while (ctx->valid_pages < ctx->total_pages) { |
| bio_add_page(ctx->ra_bio, |
| ctx->ra_pool[ctx->valid_pages], PAGE_SIZE, 0); |
| ctx->valid_pages += 1; |
| |
| offset = r5l_ring_add(log, offset, BLOCK_SECTORS); |
| |
| if (offset == 0) /* reached end of the device */ |
| break; |
| } |
| |
| return submit_bio_wait(ctx->ra_bio); |
| } |
| |
| /* |
| * try read a page from the read ahead page pool, if the page is not in the |
| * pool, call r5l_recovery_fetch_ra_pool |
| */ |
| static int r5l_recovery_read_page(struct r5l_log *log, |
| struct r5l_recovery_ctx *ctx, |
| struct page *page, |
| sector_t offset) |
| { |
| int ret; |
| |
| if (offset < ctx->pool_offset || |
| offset >= ctx->pool_offset + ctx->valid_pages * BLOCK_SECTORS) { |
| ret = r5l_recovery_fetch_ra_pool(log, ctx, offset); |
| if (ret) |
| return ret; |
| } |
| |
| BUG_ON(offset < ctx->pool_offset || |
| offset >= ctx->pool_offset + ctx->valid_pages * BLOCK_SECTORS); |
| |
| memcpy(page_address(page), |
| page_address(ctx->ra_pool[(offset - ctx->pool_offset) >> |
| BLOCK_SECTOR_SHIFT]), |
| PAGE_SIZE); |
| return 0; |
| } |
| |
| static int r5l_recovery_read_meta_block(struct r5l_log *log, |
| struct r5l_recovery_ctx *ctx) |
| { |
| struct page *page = ctx->meta_page; |
| struct r5l_meta_block *mb; |
| u32 crc, stored_crc; |
| int ret; |
| |
| ret = r5l_recovery_read_page(log, ctx, page, ctx->pos); |
| if (ret != 0) |
| return ret; |
| |
| mb = page_address(page); |
| stored_crc = le32_to_cpu(mb->checksum); |
| mb->checksum = 0; |
| |
| if (le32_to_cpu(mb->magic) != R5LOG_MAGIC || |
| le64_to_cpu(mb->seq) != ctx->seq || |
| mb->version != R5LOG_VERSION || |
| le64_to_cpu(mb->position) != ctx->pos) |
| return -EINVAL; |
| |
| crc = crc32c_le(log->uuid_checksum, mb, PAGE_SIZE); |
| if (stored_crc != crc) |
| return -EINVAL; |
| |
| if (le32_to_cpu(mb->meta_size) > PAGE_SIZE) |
| return -EINVAL; |
| |
| ctx->meta_total_blocks = BLOCK_SECTORS; |
| |
| return 0; |
| } |
| |
| static void |
| r5l_recovery_create_empty_meta_block(struct r5l_log *log, |
| struct page *page, |
| sector_t pos, u64 seq) |
| { |
| struct r5l_meta_block *mb; |
| |
| mb = page_address(page); |
| clear_page(mb); |
| mb->magic = cpu_to_le32(R5LOG_MAGIC); |
| mb->version = R5LOG_VERSION; |
| mb->meta_size = cpu_to_le32(sizeof(struct r5l_meta_block)); |
| mb->seq = cpu_to_le64(seq); |
| mb->position = cpu_to_le64(pos); |
| } |
| |
| static int r5l_log_write_empty_meta_block(struct r5l_log *log, sector_t pos, |
| u64 seq) |
| { |
| struct page *page; |
| struct r5l_meta_block *mb; |
| |
| page = alloc_page(GFP_KERNEL); |
| if (!page) |
| return -ENOMEM; |
| r5l_recovery_create_empty_meta_block(log, page, pos, seq); |
| mb = page_address(page); |
| mb->checksum = cpu_to_le32(crc32c_le(log->uuid_checksum, |
| mb, PAGE_SIZE)); |
| if (!sync_page_io(log->rdev, pos, PAGE_SIZE, page, REQ_OP_WRITE, |
| REQ_SYNC | REQ_FUA, false)) { |
| __free_page(page); |
| return -EIO; |
| } |
| __free_page(page); |
| return 0; |
| } |
| |
| /* |
| * r5l_recovery_load_data and r5l_recovery_load_parity uses flag R5_Wantwrite |
| * to mark valid (potentially not flushed) data in the journal. |
| * |
| * We already verified checksum in r5l_recovery_verify_data_checksum_for_mb, |
| * so there should not be any mismatch here. |
| */ |
| static void r5l_recovery_load_data(struct r5l_log *log, |
| struct stripe_head *sh, |
| struct r5l_recovery_ctx *ctx, |
| struct r5l_payload_data_parity *payload, |
| sector_t log_offset) |
| { |
| struct mddev *mddev = log->rdev->mddev; |
| struct r5conf *conf = mddev->private; |
| int dd_idx; |
| |
| raid5_compute_sector(conf, |
| le64_to_cpu(payload->location), 0, |
| &dd_idx, sh); |
| r5l_recovery_read_page(log, ctx, sh->dev[dd_idx].page, log_offset); |
| sh->dev[dd_idx].log_checksum = |
| le32_to_cpu(payload->checksum[0]); |
| ctx->meta_total_blocks += BLOCK_SECTORS; |
| |
| set_bit(R5_Wantwrite, &sh->dev[dd_idx].flags); |
| set_bit(STRIPE_R5C_CACHING, &sh->state); |
| } |
| |
| static void r5l_recovery_load_parity(struct r5l_log *log, |
| struct stripe_head *sh, |
| struct r5l_recovery_ctx *ctx, |
| struct r5l_payload_data_parity *payload, |
| sector_t log_offset) |
| { |
| struct mddev *mddev = log->rdev->mddev; |
| struct r5conf *conf = mddev->private; |
| |
| ctx->meta_total_blocks += BLOCK_SECTORS * conf->max_degraded; |
| r5l_recovery_read_page(log, ctx, sh->dev[sh->pd_idx].page, log_offset); |
| sh->dev[sh->pd_idx].log_checksum = |
| le32_to_cpu(payload->checksum[0]); |
| set_bit(R5_Wantwrite, &sh->dev[sh->pd_idx].flags); |
| |
| if (sh->qd_idx >= 0) { |
| r5l_recovery_read_page( |
| log, ctx, sh->dev[sh->qd_idx].page, |
| r5l_ring_add(log, log_offset, BLOCK_SECTORS)); |
| sh->dev[sh->qd_idx].log_checksum = |
| le32_to_cpu(payload->checksum[1]); |
| set_bit(R5_Wantwrite, &sh->dev[sh->qd_idx].flags); |
| } |
| clear_bit(STRIPE_R5C_CACHING, &sh->state); |
| } |
| |
| static void r5l_recovery_reset_stripe(struct stripe_head *sh) |
| { |
| int i; |
| |
| sh->state = 0; |
| sh->log_start = MaxSector; |
| for (i = sh->disks; i--; ) |
| sh->dev[i].flags = 0; |
| } |
| |
| static void |
| r5l_recovery_replay_one_stripe(struct r5conf *conf, |
| struct stripe_head *sh, |
| struct r5l_recovery_ctx *ctx) |
| { |
| struct md_rdev *rdev, *rrdev; |
| int disk_index; |
| int data_count = 0; |
| |
| for (disk_index = 0; disk_index < sh->disks; disk_index++) { |
| if (!test_bit(R5_Wantwrite, &sh->dev[disk_index].flags)) |
| continue; |
| if (disk_index == sh->qd_idx || disk_index == sh->pd_idx) |
| continue; |
| data_count++; |
| } |
| |
| /* |
| * stripes that only have parity must have been flushed |
| * before the crash that we are now recovering from, so |
| * there is nothing more to recovery. |
| */ |
| if (data_count == 0) |
| goto out; |
| |
| for (disk_index = 0; disk_index < sh->disks; disk_index++) { |
| if (!test_bit(R5_Wantwrite, &sh->dev[disk_index].flags)) |
| continue; |
| |
| /* in case device is broken */ |
| rcu_read_lock(); |
| rdev = rcu_dereference(conf->disks[disk_index].rdev); |
| if (rdev) { |
| atomic_inc(&rdev->nr_pending); |
| rcu_read_unlock(); |
| sync_page_io(rdev, sh->sector, PAGE_SIZE, |
| sh->dev[disk_index].page, REQ_OP_WRITE, 0, |
| false); |
| rdev_dec_pending(rdev, rdev->mddev); |
| rcu_read_lock(); |
| } |
| rrdev = rcu_dereference(conf->disks[disk_index].replacement); |
| if (rrdev) { |
| atomic_inc(&rrdev->nr_pending); |
| rcu_read_unlock(); |
| sync_page_io(rrdev, sh->sector, PAGE_SIZE, |
| sh->dev[disk_index].page, REQ_OP_WRITE, 0, |
| false); |
| rdev_dec_pending(rrdev, rrdev->mddev); |
| rcu_read_lock(); |
| } |
| rcu_read_unlock(); |
| } |
| ctx->data_parity_stripes++; |
| out: |
| r5l_recovery_reset_stripe(sh); |
| } |
| |
| static struct stripe_head * |
| r5c_recovery_alloc_stripe(struct r5conf *conf, |
| sector_t stripe_sect) |
| { |
| struct stripe_head *sh; |
| |
| sh = raid5_get_active_stripe(conf, stripe_sect, 0, 1, 0); |
| if (!sh) |
| return NULL; /* no more stripe available */ |
| |
| r5l_recovery_reset_stripe(sh); |
| |
| return sh; |
| } |
| |
| static struct stripe_head * |
| r5c_recovery_lookup_stripe(struct list_head *list, sector_t sect) |
| { |
| struct stripe_head *sh; |
| |
| list_for_each_entry(sh, list, lru) |
| if (sh->sector == sect) |
| return sh; |
| return NULL; |
| } |
| |
| static void |
| r5c_recovery_drop_stripes(struct list_head *cached_stripe_list, |
| struct r5l_recovery_ctx *ctx) |
| { |
| struct stripe_head *sh, *next; |
| |
| list_for_each_entry_safe(sh, next, cached_stripe_list, lru) { |
| r5l_recovery_reset_stripe(sh); |
| list_del_init(&sh->lru); |
| raid5_release_stripe(sh); |
| } |
| } |
| |
| static void |
| r5c_recovery_replay_stripes(struct list_head *cached_stripe_list, |
| struct r5l_recovery_ctx *ctx) |
| { |
| struct stripe_head *sh, *next; |
| |
| list_for_each_entry_safe(sh, next, cached_stripe_list, lru) |
| if (!test_bit(STRIPE_R5C_CACHING, &sh->state)) { |
| r5l_recovery_replay_one_stripe(sh->raid_conf, sh, ctx); |
| list_del_init(&sh->lru); |
| raid5_release_stripe(sh); |
| } |
| } |
| |
| /* if matches return 0; otherwise return -EINVAL */ |
| static int |
| r5l_recovery_verify_data_checksum(struct r5l_log *log, |
| struct r5l_recovery_ctx *ctx, |
| struct page *page, |
| sector_t log_offset, __le32 log_checksum) |
| { |
| void *addr; |
| u32 checksum; |
| |
| r5l_recovery_read_page(log, ctx, page, log_offset); |
| addr = kmap_atomic(page); |
| checksum = crc32c_le(log->uuid_checksum, addr, PAGE_SIZE); |
| kunmap_atomic(addr); |
| return (le32_to_cpu(log_checksum) == checksum) ? 0 : -EINVAL; |
| } |
| |
| /* |
| * before loading data to stripe cache, we need verify checksum for all data, |
| * if there is mismatch for any data page, we drop all data in the mata block |
| */ |
| static int |
| r5l_recovery_verify_data_checksum_for_mb(struct r5l_log *log, |
| struct r5l_recovery_ctx *ctx) |
| { |
| struct mddev *mddev = log->rdev->mddev; |
| struct r5conf *conf = mddev->private; |
| struct r5l_meta_block *mb = page_address(ctx->meta_page); |
| sector_t mb_offset = sizeof(struct r5l_meta_block); |
| sector_t log_offset = r5l_ring_add(log, ctx->pos, BLOCK_SECTORS); |
| struct page *page; |
| struct r5l_payload_data_parity *payload; |
| struct r5l_payload_flush *payload_flush; |
| |
| page = alloc_page(GFP_KERNEL); |
| if (!page) |
| return -ENOMEM; |
| |
| while (mb_offset < le32_to_cpu(mb->meta_size)) { |
| payload = (void *)mb + mb_offset; |
| payload_flush = (void *)mb + mb_offset; |
| |
| if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_DATA) { |
| if (r5l_recovery_verify_data_checksum( |
| log, ctx, page, log_offset, |
| payload->checksum[0]) < 0) |
| goto mismatch; |
| } else if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_PARITY) { |
| if (r5l_recovery_verify_data_checksum( |
| log, ctx, page, log_offset, |
| payload->checksum[0]) < 0) |
| goto mismatch; |
| if (conf->max_degraded == 2 && /* q for RAID 6 */ |
| r5l_recovery_verify_data_checksum( |
| log, ctx, page, |
| r5l_ring_add(log, log_offset, |
| BLOCK_SECTORS), |
| payload->checksum[1]) < 0) |
| goto mismatch; |
| } else if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_FLUSH) { |
| /* nothing to do for R5LOG_PAYLOAD_FLUSH here */ |
| } else /* not R5LOG_PAYLOAD_DATA/PARITY/FLUSH */ |
| goto mismatch; |
| |
| if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_FLUSH) { |
| mb_offset += sizeof(struct r5l_payload_flush) + |
| le32_to_cpu(payload_flush->size); |
| } else { |
| /* DATA or PARITY payload */ |
| log_offset = r5l_ring_add(log, log_offset, |
| le32_to_cpu(payload->size)); |
| mb_offset += sizeof(struct r5l_payload_data_parity) + |
| sizeof(__le32) * |
| (le32_to_cpu(payload->size) >> (PAGE_SHIFT - 9)); |
| } |
| |
| } |
| |
| put_page(page); |
| return 0; |
| |
| mismatch: |
| put_page(page); |
| return -EINVAL; |
| } |
| |
| /* |
| * Analyze all data/parity pages in one meta block |
| * Returns: |
| * 0 for success |
| * -EINVAL for unknown playload type |
| * -EAGAIN for checksum mismatch of data page |
| * -ENOMEM for run out of memory (alloc_page failed or run out of stripes) |
| */ |
| static int |
| r5c_recovery_analyze_meta_block(struct r5l_log *log, |
| struct r5l_recovery_ctx *ctx, |
| struct list_head *cached_stripe_list) |
| { |
| struct mddev *mddev = log->rdev->mddev; |
| struct r5conf *conf = mddev->private; |
| struct r5l_meta_block *mb; |
| struct r5l_payload_data_parity *payload; |
| struct r5l_payload_flush *payload_flush; |
| int mb_offset; |
| sector_t log_offset; |
| sector_t stripe_sect; |
| struct stripe_head *sh; |
| int ret; |
| |
| /* |
| * for mismatch in data blocks, we will drop all data in this mb, but |
| * we will still read next mb for other data with FLUSH flag, as |
| * io_unit could finish out of order. |
| */ |
| ret = r5l_recovery_verify_data_checksum_for_mb(log, ctx); |
| if (ret == -EINVAL) |
| return -EAGAIN; |
| else if (ret) |
| return ret; /* -ENOMEM duo to alloc_page() failed */ |
| |
| mb = page_address(ctx->meta_page); |
| mb_offset = sizeof(struct r5l_meta_block); |
| log_offset = r5l_ring_add(log, ctx->pos, BLOCK_SECTORS); |
| |
| while (mb_offset < le32_to_cpu(mb->meta_size)) { |
| int dd; |
| |
| payload = (void *)mb + mb_offset; |
| payload_flush = (void *)mb + mb_offset; |
| |
| if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_FLUSH) { |
| int i, count; |
| |
| count = le32_to_cpu(payload_flush->size) / sizeof(__le64); |
| for (i = 0; i < count; ++i) { |
| stripe_sect = le64_to_cpu(payload_flush->flush_stripes[i]); |
| sh = r5c_recovery_lookup_stripe(cached_stripe_list, |
| stripe_sect); |
| if (sh) { |
| WARN_ON(test_bit(STRIPE_R5C_CACHING, &sh->state)); |
| r5l_recovery_reset_stripe(sh); |
| list_del_init(&sh->lru); |
| raid5_release_stripe(sh); |
| } |
| } |
| |
| mb_offset += sizeof(struct r5l_payload_flush) + |
| le32_to_cpu(payload_flush->size); |
| continue; |
| } |
| |
| /* DATA or PARITY payload */ |
| stripe_sect = (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_DATA) ? |
| raid5_compute_sector( |
| conf, le64_to_cpu(payload->location), 0, &dd, |
| NULL) |
| : le64_to_cpu(payload->location); |
| |
| sh = r5c_recovery_lookup_stripe(cached_stripe_list, |
| stripe_sect); |
| |
| if (!sh) { |
| sh = r5c_recovery_alloc_stripe(conf, stripe_sect); |
| /* |
| * cannot get stripe from raid5_get_active_stripe |
| * try replay some stripes |
| */ |
| if (!sh) { |
| r5c_recovery_replay_stripes( |
| cached_stripe_list, ctx); |
| sh = r5c_recovery_alloc_stripe( |
| conf, stripe_sect); |
| } |
| if (!sh) { |
| pr_debug("md/raid:%s: Increasing stripe cache size to %d to recovery data on journal.\n", |
| mdname(mddev), |
| conf->min_nr_stripes * 2); |
| raid5_set_cache_size(mddev, |
| conf->min_nr_stripes * 2); |
| sh = r5c_recovery_alloc_stripe(conf, |
| stripe_sect); |
| } |
| if (!sh) { |
| pr_err("md/raid:%s: Cannot get enough stripes due to memory pressure. Recovery failed.\n", |
| mdname(mddev)); |
| return -ENOMEM; |
| } |
| list_add_tail(&sh->lru, cached_stripe_list); |
| } |
| |
| if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_DATA) { |
| if (!test_bit(STRIPE_R5C_CACHING, &sh->state) && |
| test_bit(R5_Wantwrite, &sh->dev[sh->pd_idx].flags)) { |
| r5l_recovery_replay_one_stripe(conf, sh, ctx); |
| list_move_tail(&sh->lru, cached_stripe_list); |
| } |
| r5l_recovery_load_data(log, sh, ctx, payload, |
| log_offset); |
| } else if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_PARITY) |
| r5l_recovery_load_parity(log, sh, ctx, payload, |
| log_offset); |
| else |
| return -EINVAL; |
| |
| log_offset = r5l_ring_add(log, log_offset, |
| le32_to_cpu(payload->size)); |
| |
| mb_offset += sizeof(struct r5l_payload_data_parity) + |
| sizeof(__le32) * |
| (le32_to_cpu(payload->size) >> (PAGE_SHIFT - 9)); |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * Load the stripe into cache. The stripe will be written out later by |
| * the stripe cache state machine. |
| */ |
| static void r5c_recovery_load_one_stripe(struct r5l_log *log, |
| struct stripe_head *sh) |
| { |
| struct r5dev *dev; |
| int i; |
| |
| for (i = sh->disks; i--; ) { |
| dev = sh->dev + i; |
| if (test_and_clear_bit(R5_Wantwrite, &dev->flags)) { |
| set_bit(R5_InJournal, &dev->flags); |
| set_bit(R5_UPTODATE, &dev->flags); |
| } |
| } |
| } |
| |
| /* |
| * Scan through the log for all to-be-flushed data |
| * |
| * For stripes with data and parity, namely Data-Parity stripe |
| * (STRIPE_R5C_CACHING == 0), we simply replay all the writes. |
| * |
| * For stripes with only data, namely Data-Only stripe |
| * (STRIPE_R5C_CACHING == 1), we load them to stripe cache state machine. |
| * |
| * For a stripe, if we see data after parity, we should discard all previous |
| * data and parity for this stripe, as these data are already flushed to |
| * the array. |
| * |
| * At the end of the scan, we return the new journal_tail, which points to |
| * first data-only stripe on the journal device, or next invalid meta block. |
| */ |
| static int r5c_recovery_flush_log(struct r5l_log *log, |
| struct r5l_recovery_ctx *ctx) |
| { |
| struct stripe_head *sh; |
| int ret = 0; |
| |
| /* scan through the log */ |
| while (1) { |
| if (r5l_recovery_read_meta_block(log, ctx)) |
| break; |
| |
| ret = r5c_recovery_analyze_meta_block(log, ctx, |
| &ctx->cached_list); |
| /* |
| * -EAGAIN means mismatch in data block, in this case, we still |
| * try scan the next metablock |
| */ |
| if (ret && ret != -EAGAIN) |
| break; /* ret == -EINVAL or -ENOMEM */ |
| ctx->seq++; |
| ctx->pos = r5l_ring_add(log, ctx->pos, ctx->meta_total_blocks); |
| } |
| |
| if (ret == -ENOMEM) { |
| r5c_recovery_drop_stripes(&ctx->cached_list, ctx); |
| return ret; |
| } |
| |
| /* replay data-parity stripes */ |
| r5c_recovery_replay_stripes(&ctx->cached_list, ctx); |
| |
| /* load data-only stripes to stripe cache */ |
| list_for_each_entry(sh, &ctx->cached_list, lru) { |
| WARN_ON(!test_bit(STRIPE_R5C_CACHING, &sh->state)); |
| r5c_recovery_load_one_stripe(log, sh); |
| ctx->data_only_stripes++; |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * we did a recovery. Now ctx.pos points to an invalid meta block. New |
| * log will start here. but we can't let superblock point to last valid |
| * meta block. The log might looks like: |
| * | meta 1| meta 2| meta 3| |
| * meta 1 is valid, meta 2 is invalid. meta 3 could be valid. If |
| * superblock points to meta 1, we write a new valid meta 2n. if crash |
| * happens again, new recovery will start from meta 1. Since meta 2n is |
| * valid now, recovery will think meta 3 is valid, which is wrong. |
| * The solution is we create a new meta in meta2 with its seq == meta |
| * 1's seq + 10000 and let superblock points to meta2. The same recovery |
| * will not think meta 3 is a valid meta, because its seq doesn't match |
| */ |
| |
| /* |
| * Before recovery, the log looks like the following |
| * |
| * --------------------------------------------- |
| * | valid log | invalid log | |
| * --------------------------------------------- |
| * ^ |
| * |- log->last_checkpoint |
| * |- log->last_cp_seq |
| * |
| * Now we scan through the log until we see invalid entry |
| * |
| * --------------------------------------------- |
| * | valid log | invalid log | |
| * --------------------------------------------- |
| * ^ ^ |
| * |- log->last_checkpoint |- ctx->pos |
| * |- log->last_cp_seq |- ctx->seq |
| * |
| * From this point, we need to increase seq number by 10 to avoid |
| * confusing next recovery. |
| * |
| * --------------------------------------------- |
| * | valid log | invalid log | |
| * --------------------------------------------- |
| * ^ ^ |
| * |- log->last_checkpoint |- ctx->pos+1 |
| * |- log->last_cp_seq |- ctx->seq+10001 |
| * |
| * However, it is not safe to start the state machine yet, because data only |
| * parities are not yet secured in RAID. To save these data only parities, we |
| * rewrite them from seq+11. |
| * |
| * ----------------------------------------------------------------- |
| * | valid log | data only stripes | invalid log | |
| * ----------------------------------------------------------------- |
| * ^ ^ |
| * |- log->last_checkpoint |- ctx->pos+n |
| * |- log->last_cp_seq |- ctx->seq+10000+n |
| * |
| * If failure happens again during this process, the recovery can safe start |
| * again from log->last_checkpoint. |
| * |
| * Once data only stripes are rewritten to journal, we move log_tail |
| * |
| * ----------------------------------------------------------------- |
| * | old log | data only stripes | invalid log | |
| * ----------------------------------------------------------------- |
| * ^ ^ |
| * |- log->last_checkpoint |- ctx->pos+n |
| * |- log->last_cp_seq |- ctx->seq+10000+n |
| * |
| * Then we can safely start the state machine. If failure happens from this |
| * point on, the recovery will start from new log->last_checkpoint. |
| */ |
| static int |
| r5c_recovery_rewrite_data_only_stripes(struct r5l_log *log, |
| struct r5l_recovery_ctx *ctx) |
| { |
| struct stripe_head *sh; |
| struct mddev *mddev = log->rdev->mddev; |
| struct page *page; |
| sector_t next_checkpoint = MaxSector; |
| |
| page = alloc_page(GFP_KERNEL); |
| if (!page) { |
| pr_err("md/raid:%s: cannot allocate memory to rewrite data only stripes\n", |
| mdname(mddev)); |
| return -ENOMEM; |
| } |
| |
| WARN_ON(list_empty(&ctx->cached_list)); |
| |
| list_for_each_entry(sh, &ctx->cached_list, lru) { |
| struct r5l_meta_block *mb; |
| int i; |
| int offset; |
| sector_t write_pos; |
| |
| WARN_ON(!test_bit(STRIPE_R5C_CACHING, &sh->state)); |
| r5l_recovery_create_empty_meta_block(log, page, |
| ctx->pos, ctx->seq); |
| mb = page_address(page); |
| offset = le32_to_cpu(mb->meta_size); |
| write_pos = r5l_ring_add(log, ctx->pos, BLOCK_SECTORS); |
| |
| for (i = sh->disks; i--; ) { |
| struct r5dev *dev = &sh->dev[i]; |
| struct r5l_payload_data_parity *payload; |
| void *addr; |
| |
| if (test_bit(R5_InJournal, &dev->flags)) { |
| payload = (void *)mb + offset; |
| payload->header.type = cpu_to_le16( |
| R5LOG_PAYLOAD_DATA); |
| payload->size = cpu_to_le32(BLOCK_SECTORS); |
| payload->location = cpu_to_le64( |
| raid5_compute_blocknr(sh, i, 0)); |
| addr = kmap_atomic(dev->page); |
| payload->checksum[0] = cpu_to_le32( |
| crc32c_le(log->uuid_checksum, addr, |
| PAGE_SIZE)); |
| kunmap_atomic(addr); |
| sync_page_io(log->rdev, write_pos, PAGE_SIZE, |
| dev->page, REQ_OP_WRITE, 0, false); |
| write_pos = r5l_ring_add(log, write_pos, |
| BLOCK_SECTORS); |
| offset += sizeof(__le32) + |
| sizeof(struct r5l_payload_data_parity); |
| |
| } |
| } |
| mb->meta_size = cpu_to_le32(offset); |
| mb->checksum = cpu_to_le32(crc32c_le(log->uuid_checksum, |
| mb, PAGE_SIZE)); |
| sync_page_io(log->rdev, ctx->pos, PAGE_SIZE, page, |
| REQ_OP_WRITE, REQ_SYNC | REQ_FUA, false); |
| sh->log_start = ctx->pos; |
| list_add_tail(&sh->r5c, &log->stripe_in_journal_list); |
| atomic_inc(&log->stripe_in_journal_count); |
| ctx->pos = write_pos; |
| ctx->seq += 1; |
| next_checkpoint = sh->log_start; |
| } |
| log->next_checkpoint = next_checkpoint; |
| __free_page(page); |
| return 0; |
| } |
| |
| static void r5c_recovery_flush_data_only_stripes(struct r5l_log *log, |
| struct r5l_recovery_ctx *ctx) |
| { |
| struct mddev *mddev = log->rdev->mddev; |
| struct r5conf *conf = mddev->private; |
| struct stripe_head *sh, *next; |
| |
| if (ctx->data_only_stripes == 0) |
| return; |
| |
| log->r5c_journal_mode = R5C_JOURNAL_MODE_WRITE_BACK; |
| |
| list_for_each_entry_safe(sh, next, &ctx->cached_list, lru) { |
| r5c_make_stripe_write_out(sh); |
| set_bit(STRIPE_HANDLE, &sh->state); |
| list_del_init(&sh->lru); |
| raid5_release_stripe(sh); |
| } |
| |
| /* reuse conf->wait_for_quiescent in recovery */ |
| wait_event(conf->wait_for_quiescent, |
| atomic_read(&conf->active_stripes) == 0); |
| |
| log->r5c_journal_mode = R5C_JOURNAL_MODE_WRITE_THROUGH; |
| } |
| |
| static int r5l_recovery_log(struct r5l_log *log) |
| { |
| struct mddev *mddev = log->rdev->mddev; |
| struct r5l_recovery_ctx *ctx; |
| int ret; |
| sector_t pos; |
| |
| ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); |
| if (!ctx) |
| return -ENOMEM; |
| |
| ctx->pos = log->last_checkpoint; |
| ctx->seq = log->last_cp_seq; |
| INIT_LIST_HEAD(&ctx->cached_list); |
| ctx->meta_page = alloc_page(GFP_KERNEL); |
| |
| if (!ctx->meta_page) { |
| ret = -ENOMEM; |
| goto meta_page; |
| } |
| |
| if (r5l_recovery_allocate_ra_pool(log, ctx) != 0) { |
| ret = -ENOMEM; |
| goto ra_pool; |
| } |
| |
| ret = r5c_recovery_flush_log(log, ctx); |
| |
| if (ret) |
| goto error; |
| |
| pos = ctx->pos; |
| ctx->seq += 10000; |
| |
| if ((ctx->data_only_stripes == 0) && (ctx->data_parity_stripes == 0)) |
| pr_info("md/raid:%s: starting from clean shutdown\n", |
| mdname(mddev)); |
| else |
| pr_info("md/raid:%s: recovering %d data-only stripes and %d data-parity stripes\n", |
| mdname(mddev), ctx->data_only_stripes, |
| ctx->data_parity_stripes); |
| |
| if (ctx->data_only_stripes == 0) { |
| log->next_checkpoint = ctx->pos; |
| r5l_log_write_empty_meta_block(log, ctx->pos, ctx->seq++); |
| ctx->pos = r5l_ring_add(log, ctx->pos, BLOCK_SECTORS); |
| } else if (r5c_recovery_rewrite_data_only_stripes(log, ctx)) { |
| pr_err("md/raid:%s: failed to rewrite stripes to journal\n", |
| mdname(mddev)); |
| ret = -EIO; |
| goto error; |
| } |
| |
| log->log_start = ctx->pos; |
| log->seq = ctx->seq; |
| log->last_checkpoint = pos; |
| r5l_write_super(log, pos); |
| |
| r5c_recovery_flush_data_only_stripes(log, ctx); |
| ret = 0; |
| error: |
| r5l_recovery_free_ra_pool(log, ctx); |
| ra_pool: |
| __free_page(ctx->meta_page); |
| meta_page: |
| kfree(ctx); |
| return ret; |
| } |
| |
| static void r5l_write_super(struct r5l_log *log, sector_t cp) |
| { |
| struct mddev *mddev = log->rdev->mddev; |
| |
| log->rdev->journal_tail = cp; |
| set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags); |
| } |
| |
| static ssize_t r5c_journal_mode_show(struct mddev *mddev, char *page) |
| { |
| struct r5conf *conf; |
| int ret; |
| |
| ret = mddev_lock(mddev); |
| if (ret) |
| return ret; |
| |
| conf = mddev->private; |
| if (!conf || !conf->log) { |
| mddev_unlock(mddev); |
| return 0; |
| } |
| |
| switch (conf->log->r5c_journal_mode) { |
| case R5C_JOURNAL_MODE_WRITE_THROUGH: |
| ret = snprintf( |
| page, PAGE_SIZE, "[%s] %s\n", |
| r5c_journal_mode_str[R5C_JOURNAL_MODE_WRITE_THROUGH], |
| r5c_journal_mode_str[R5C_JOURNAL_MODE_WRITE_BACK]); |
| break; |
| case R5C_JOURNAL_MODE_WRITE_BACK: |
| ret = snprintf( |
| page, PAGE_SIZE, "%s [%s]\n", |
| r5c_journal_mode_str[R5C_JOURNAL_MODE_WRITE_THROUGH], |
| r5c_journal_mode_str[R5C_JOURNAL_MODE_WRITE_BACK]); |
| break; |
| default: |
| ret = 0; |
| } |
| mddev_unlock(mddev); |
| return ret; |
| } |
| |
| /* |
| * Set journal cache mode on @mddev (external API initially needed by dm-raid). |
| * |
| * @mode as defined in 'enum r5c_journal_mode'. |
| * |
| */ |
| int r5c_journal_mode_set(struct mddev *mddev, int mode) |
| { |
| struct r5conf *conf; |
| |
| if (mode < R5C_JOURNAL_MODE_WRITE_THROUGH || |
| mode > R5C_JOURNAL_MODE_WRITE_BACK) |
| return -EINVAL; |
| |
| conf = mddev->private; |
| if (!conf || !conf->log) |
| return -ENODEV; |
| |
| if (raid5_calc_degraded(conf) > 0 && |
| mode == R5C_JOURNAL_MODE_WRITE_BACK) |
| return -EINVAL; |
| |
| mddev_suspend(mddev); |
| conf->log->r5c_journal_mode = mode; |
| mddev_resume(mddev); |
| |
| pr_debug("md/raid:%s: setting r5c cache mode to %d: %s\n", |
| mdname(mddev), mode, r5c_journal_mode_str[mode]); |
| return 0; |
| } |
| EXPORT_SYMBOL(r5c_journal_mode_set); |
| |
| static ssize_t r5c_journal_mode_store(struct mddev *mddev, |
| const char *page, size_t length) |
| { |
| int mode = ARRAY_SIZE(r5c_journal_mode_str); |
| size_t len = length; |
| int ret; |
| |
| if (len < 2) |
| return -EINVAL; |
| |
| if (page[len - 1] == '\n') |
| len--; |
| |
| while (mode--) |
| if (strlen(r5c_journal_mode_str[mode]) == len && |
| !strncmp(page, r5c_journal_mode_str[mode], len)) |
| break; |
| ret = mddev_lock(mddev); |
| if (ret) |
| return ret; |
| ret = r5c_journal_mode_set(mddev, mode); |
| mddev_unlock(mddev); |
| return ret ?: length; |
| } |
| |
| struct md_sysfs_entry |
| r5c_journal_mode = __ATTR(journal_mode, 0644, |
| r5c_journal_mode_show, r5c_journal_mode_store); |
| |
| /* |
| * Try handle write operation in caching phase. This function should only |
| * be called in write-back mode. |
| * |
| * If all outstanding writes can be handled in caching phase, returns 0 |
| * If writes requires write-out phase, call r5c_make_stripe_write_out() |
| * and returns -EAGAIN |
| */ |
| int r5c_try_caching_write(struct r5conf *conf, |
| struct stripe_head *sh, |
| struct stripe_head_state *s, |
| int disks) |
| { |
| struct r5l_log *log = conf->log; |
| int i; |
| struct r5dev *dev; |
| int to_cache = 0; |
| void **pslot; |
| sector_t tree_index; |
| int ret; |
| uintptr_t refcount; |
| |
| BUG_ON(!r5c_is_writeback(log)); |
| |
| if (!test_bit(STRIPE_R5C_CACHING, &sh->state)) { |
| /* |
| * There are two different scenarios here: |
| * 1. The stripe has some data cached, and it is sent to |
| * write-out phase for reclaim |
| * 2. The stripe is clean, and this is the first write |
| * |
| * For 1, return -EAGAIN, so we continue with |
| * handle_stripe_dirtying(). |
| * |
| * For 2, set STRIPE_R5C_CACHING and continue with caching |
| * write. |
| */ |
| |
| /* case 1: anything injournal or anything in written */ |
| if (s->injournal > 0 || s->written > 0) |
| return -EAGAIN; |
| /* case 2 */ |
| set_bit(STRIPE_R5C_CACHING, &sh->state); |
| } |
| |
| /* |
| * When run in degraded mode, array is set to write-through mode. |
| * This check helps drain pending write safely in the transition to |
| * write-through mode. |
| * |
| * When a stripe is syncing, the write is also handled in write |
| * through mode. |
| */ |
| if (s->failed || test_bit(STRIPE_SYNCING, &sh->state)) { |
| r5c_make_stripe_write_out(sh); |
| return -EAGAIN; |
| } |
| |
| for (i = disks; i--; ) { |
| dev = &sh->dev[i]; |
| /* if non-overwrite, use writing-out phase */ |
| if (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags) && |
| !test_bit(R5_InJournal, &dev->flags)) { |
| r5c_make_stripe_write_out(sh); |
| return -EAGAIN; |
| } |
| } |
| |
| /* if the stripe is not counted in big_stripe_tree, add it now */ |
| if (!test_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state) && |
| !test_bit(STRIPE_R5C_FULL_STRIPE, &sh->state)) { |
| tree_index = r5c_tree_index(conf, sh->sector); |
| spin_lock(&log->tree_lock); |
| pslot = radix_tree_lookup_slot(&log->big_stripe_tree, |
| tree_index); |
| if (pslot) { |
| refcount = (uintptr_t)radix_tree_deref_slot_protected( |
| pslot, &log->tree_lock) >> |
| R5C_RADIX_COUNT_SHIFT; |
| radix_tree_replace_slot( |
| &log->big_stripe_tree, pslot, |
| (void *)((refcount + 1) << R5C_RADIX_COUNT_SHIFT)); |
| } else { |
| /* |
| * this radix_tree_insert can fail safely, so no |
| * need to call radix_tree_preload() |
| */ |
| ret = radix_tree_insert( |
| &log->big_stripe_tree, tree_index, |
| (void *)(1 << R5C_RADIX_COUNT_SHIFT)); |
| if (ret) { |
| spin_unlock(&log->tree_lock); |
| r5c_make_stripe_write_out(sh); |
| return -EAGAIN; |
| } |
| } |
| spin_unlock(&log->tree_lock); |
| |
| /* |
| * set STRIPE_R5C_PARTIAL_STRIPE, this shows the stripe is |
| * counted in the radix tree |
| */ |
| set_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state); |
| atomic_inc(&conf->r5c_cached_partial_stripes); |
| } |
| |
| for (i = disks; i--; ) { |
| dev = &sh->dev[i]; |
| if (dev->towrite) { |
| set_bit(R5_Wantwrite, &dev->flags); |
| set_bit(R5_Wantdrain, &dev->flags); |
| set_bit(R5_LOCKED, &dev->flags); |
| to_cache++; |
| } |
| } |
| |
| if (to_cache) { |
| set_bit(STRIPE_OP_BIODRAIN, &s->ops_request); |
| /* |
| * set STRIPE_LOG_TRAPPED, which triggers r5c_cache_data() |
| * in ops_run_io(). STRIPE_LOG_TRAPPED will be cleared in |
| * r5c_handle_data_cached() |
| */ |
| set_bit(STRIPE_LOG_TRAPPED, &sh->state); |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * free extra pages (orig_page) we allocated for prexor |
| */ |
| void r5c_release_extra_page(struct stripe_head *sh) |
| { |
| struct r5conf *conf = sh->raid_conf; |
| int i; |
| bool using_disk_info_extra_page; |
| |
| using_disk_info_extra_page = |
| sh->dev[0].orig_page == conf->disks[0].extra_page; |
| |
| for (i = sh->disks; i--; ) |
| if (sh->dev[i].page != sh->dev[i].orig_page) { |
| struct page *p = sh->dev[i].orig_page; |
| |
| sh->dev[i].orig_page = sh->dev[i].page; |
| clear_bit(R5_OrigPageUPTDODATE, &sh->dev[i].flags); |
| |
| if (!using_disk_info_extra_page) |
| put_page(p); |
| } |
| |
| if (using_disk_info_extra_page) { |
| clear_bit(R5C_EXTRA_PAGE_IN_USE, &conf->cache_state); |
| md_wakeup_thread(conf->mddev->thread); |
| } |
| } |
| |
| void r5c_use_extra_page(struct stripe_head *sh) |
| { |
| struct r5conf *conf = sh->raid_conf; |
| int i; |
| struct r5dev *dev; |
| |
| for (i = sh->disks; i--; ) { |
| dev = &sh->dev[i]; |
| if (dev->orig_page != dev->page) |
| put_page(dev->orig_page); |
| dev->orig_page = conf->disks[i].extra_page; |
| } |
| } |
| |
| /* |
| * clean up the stripe (clear R5_InJournal for dev[pd_idx] etc.) after the |
| * stripe is committed to RAID disks. |
| */ |
| void r5c_finish_stripe_write_out(struct r5conf *conf, |
| struct stripe_head *sh, |
| struct stripe_head_state *s) |
| { |
| struct r5l_log *log = conf->log; |
| int i; |
| int do_wakeup = 0; |
| sector_t tree_index; |
| void **pslot; |
| uintptr_t refcount; |
| |
| if (!log || !test_bit(R5_InJournal, &sh->dev[sh->pd_idx].flags)) |
| return; |
| |
| WARN_ON(test_bit(STRIPE_R5C_CACHING, &sh->state)); |
| clear_bit(R5_InJournal, &sh->dev[sh->pd_idx].flags); |
| |
| if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH) |
| return; |
| |
| for (i = sh->disks; i--; ) { |
| clear_bit(R5_InJournal, &sh->dev[i].flags); |
| if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) |
| do_wakeup = 1; |
| } |
| |
| /* |
| * analyse_stripe() runs before r5c_finish_stripe_write_out(), |
| * We updated R5_InJournal, so we also update s->injournal. |
| */ |
| s->injournal = 0; |
| |
| if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state)) |
| if (atomic_dec_and_test(&conf->pending_full_writes)) |
| md_wakeup_thread(conf->mddev->thread); |
| |
| if (do_wakeup) |
| wake_up(&conf->wait_for_overlap); |
| |
| spin_lock_irq(&log->stripe_in_journal_lock); |
| list_del_init(&sh->r5c); |
| spin_unlock_irq(&log->stripe_in_journal_lock); |
| sh->log_start = MaxSector; |
| |
| atomic_dec(&log->stripe_in_journal_count); |
| r5c_update_log_state(log); |
| |
| /* stop counting this stripe in big_stripe_tree */ |
| if (test_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state) || |
| test_bit(STRIPE_R5C_FULL_STRIPE, &sh->state)) { |
| tree_index = r5c_tree_index(conf, sh->sector); |
| spin_lock(&log->tree_lock); |
| pslot = radix_tree_lookup_slot(&log->big_stripe_tree, |
| tree_index); |
| BUG_ON(pslot == NULL); |
| refcount = (uintptr_t)radix_tree_deref_slot_protected( |
| pslot, &log->tree_lock) >> |
| R5C_RADIX_COUNT_SHIFT; |
| if (refcount == 1) |
| radix_tree_delete(&log->big_stripe_tree, tree_index); |
| else |
| radix_tree_replace_slot( |
| &log->big_stripe_tree, pslot, |
| (void *)((refcount - 1) << R5C_RADIX_COUNT_SHIFT)); |
| spin_unlock(&log->tree_lock); |
| } |
| |
| if (test_and_clear_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state)) { |
| BUG_ON(atomic_read(&conf->r5c_cached_partial_stripes) == 0); |
| atomic_dec(&conf->r5c_flushing_partial_stripes); |
| atomic_dec(&conf->r5c_cached_partial_stripes); |
| } |
| |
| if (test_and_clear_bit(STRIPE_R5C_FULL_STRIPE, &sh->state)) { |
| BUG_ON(atomic_read(&conf->r5c_cached_full_stripes) == 0); |
| atomic_dec(&conf->r5c_flushing_full_stripes); |
| atomic_dec(&conf->r5c_cached_full_stripes); |
| } |
| |
| r5l_append_flush_payload(log, sh->sector); |
| /* stripe is flused to raid disks, we can do resync now */ |
| if (test_bit(STRIPE_SYNC_REQUESTED, &sh->state)) |
| set_bit(STRIPE_HANDLE, &sh->state); |
| } |
| |
| int r5c_cache_data(struct r5l_log *log, struct stripe_head *sh) |
| { |
| struct r5conf *conf = sh->raid_conf; |
| int pages = 0; |
| int reserve; |
| int i; |
| int ret = 0; |
| |
| BUG_ON(!log); |
| |
| for (i = 0; i < sh->disks; i++) { |
| void *addr; |
| |
| if (!test_bit(R5_Wantwrite, &sh->dev[i].flags)) |
| continue; |
| addr = kmap_atomic(sh->dev[i].page); |
| sh->dev[i].log_checksum = crc32c_le(log->uuid_checksum, |
| addr, PAGE_SIZE); |
| kunmap_atomic(addr); |
| pages++; |
| } |
| WARN_ON(pages == 0); |
| |
| /* |
| * The stripe must enter state machine again to call endio, so |
| * don't delay. |
| */ |
| clear_bit(STRIPE_DELAYED, &sh->state); |
| atomic_inc(&sh->count); |
| |
| mutex_lock(&log->io_mutex); |
| /* meta + data */ |
| reserve = (1 + pages) << (PAGE_SHIFT - 9); |
| |
| if (test_bit(R5C_LOG_CRITICAL, &conf->cache_state) && |
| sh->log_start == MaxSector) |
| r5l_add_no_space_stripe(log, sh); |
| else if (!r5l_has_free_space(log, reserve)) { |
| if (sh->log_start == log->last_checkpoint) |
| BUG(); |
| else |
| r5l_add_no_space_stripe(log, sh); |
| } else { |
| ret = r5l_log_stripe(log, sh, pages, 0); |
| if (ret) { |
| spin_lock_irq(&log->io_list_lock); |
| list_add_tail(&sh->log_list, &log->no_mem_stripes); |
| spin_unlock_irq(&log->io_list_lock); |
| } |
| } |
| |
| mutex_unlock(&log->io_mutex); |
| return 0; |
| } |
| |
| /* check whether this big stripe is in write back cache. */ |
| bool r5c_big_stripe_cached(struct r5conf *conf, sector_t sect) |
| { |
| struct r5l_log *log = conf->log; |
| sector_t tree_index; |
| void *slot; |
| |
| if (!log) |
| return false; |
| |
| WARN_ON_ONCE(!rcu_read_lock_held()); |
| tree_index = r5c_tree_index(conf, sect); |
| slot = radix_tree_lookup(&log->big_stripe_tree, tree_index); |
| return slot != NULL; |
| } |
| |
| static int r5l_load_log(struct r5l_log *log) |
| { |
| struct md_rdev *rdev = log->rdev; |
| struct page *page; |
| struct r5l_meta_block *mb; |
| sector_t cp = log->rdev->journal_tail; |
| u32 stored_crc, expected_crc; |
| bool create_super = false; |
| int ret = 0; |
| |
| /* Make sure it's valid */ |
| if (cp >= rdev->sectors || round_down(cp, BLOCK_SECTORS) != cp) |
| cp = 0; |
| page = alloc_page(GFP_KERNEL); |
| if (!page) |
| return -ENOMEM; |
| |
| if (!sync_page_io(rdev, cp, PAGE_SIZE, page, REQ_OP_READ, 0, false)) { |
| ret = -EIO; |
| goto ioerr; |
| } |
| mb = page_address(page); |
| |
| if (le32_to_cpu(mb->magic) != R5LOG_MAGIC || |
| mb->version != R5LOG_VERSION) { |
| create_super = true; |
| goto create; |
| } |
| stored_crc = le32_to_cpu(mb->checksum); |
| mb->checksum = 0; |
| expected_crc = crc32c_le(log->uuid_checksum, mb, PAGE_SIZE); |
| if (stored_crc != expected_crc) { |
| create_super = true; |
| goto create; |
| } |
| if (le64_to_cpu(mb->position) != cp) { |
| create_super = true; |
| goto create; |
| } |
| create: |
| if (create_super) { |
| log->last_cp_seq = prandom_u32(); |
| cp = 0; |
| r5l_log_write_empty_meta_block(log, cp, log->last_cp_seq); |
| /* |
| * Make sure super points to correct address. Log might have |
| * data very soon. If super hasn't correct log tail address, |
| * recovery can't find the log |
| */ |
| r5l_write_super(log, cp); |
| } else |
| log->last_cp_seq = le64_to_cpu(mb->seq); |
| |
| log->device_size = round_down(rdev->sectors, BLOCK_SECTORS); |
| log->max_free_space = log->device_size >> RECLAIM_MAX_FREE_SPACE_SHIFT; |
| if (log->max_free_space > RECLAIM_MAX_FREE_SPACE) |
| log->max_free_space = RECLAIM_MAX_FREE_SPACE; |
| log->last_checkpoint = cp; |
| |
| __free_page(page); |
| |
| if (create_super) { |
| log->log_start = r5l_ring_add(log, cp, BLOCK_SECTORS); |
| log->seq = log->last_cp_seq + 1; |
| log->next_checkpoint = cp; |
| } else |
| ret = r5l_recovery_log(log); |
| |
| r5c_update_log_state(log); |
| return ret; |
| ioerr: |
| __free_page(page); |
| return ret; |
| } |
| |
| int r5l_start(struct r5l_log *log) |
| { |
| int ret; |
| |
| if (!log) |
| return 0; |
| |
| ret = r5l_load_log(log); |
| if (ret) { |
| struct mddev *mddev = log->rdev->mddev; |
| struct r5conf *conf = mddev->private; |
| |
| r5l_exit_log(conf); |
| } |
| return ret; |
| } |
| |
| void r5c_update_on_rdev_error(struct mddev *mddev, struct md_rdev *rdev) |
| { |
| struct r5conf *conf = mddev->private; |
| struct r5l_log *log = conf->log; |
| |
| if (!log) |
| return; |
| |
| if ((raid5_calc_degraded(conf) > 0 || |
| test_bit(Journal, &rdev->flags)) && |
| conf->log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_BACK) |
| schedule_work(&log->disable_writeback_work); |
| } |
| |
| int r5l_init_log(struct r5conf *conf, struct md_rdev *rdev) |
| { |
| struct request_queue *q = bdev_get_queue(rdev->bdev); |
| struct r5l_log *log; |
| char b[BDEVNAME_SIZE]; |
| int ret; |
| |
| pr_debug("md/raid:%s: using device %s as journal\n", |
| mdname(conf->mddev), bdevname(rdev->bdev, b)); |
| |
| if (PAGE_SIZE != 4096) |
| return -EINVAL; |
| |
| /* |
| * The PAGE_SIZE must be big enough to hold 1 r5l_meta_block and |
| * raid_disks r5l_payload_data_parity. |
| * |
| * Write journal and cache does not work for very big array |
| * (raid_disks > 203) |
| */ |
| if (sizeof(struct r5l_meta_block) + |
| ((sizeof(struct r5l_payload_data_parity) + sizeof(__le32)) * |
| conf->raid_disks) > PAGE_SIZE) { |
| pr_err("md/raid:%s: write journal/cache doesn't work for array with %d disks\n", |
| mdname(conf->mddev), conf->raid_disks); |
| return -EINVAL; |
| } |
| |
| log = kzalloc(sizeof(*log), GFP_KERNEL); |
| if (!log) |
| return -ENOMEM; |
| log->rdev = rdev; |
| |
| log->need_cache_flush = test_bit(QUEUE_FLAG_WC, &q->queue_flags) != 0; |
| |
| log->uuid_checksum = crc32c_le(~0, rdev->mddev->uuid, |
| sizeof(rdev->mddev->uuid)); |
| |
| mutex_init(&log->io_mutex); |
| |
| spin_lock_init(&log->io_list_lock); |
| INIT_LIST_HEAD(&log->running_ios); |
| INIT_LIST_HEAD(&log->io_end_ios); |
| INIT_LIST_HEAD(&log->flushing_ios); |
| INIT_LIST_HEAD(&log->finished_ios); |
| bio_init(&log->flush_bio, NULL, 0); |
| |
| log->io_kc = KMEM_CACHE(r5l_io_unit, 0); |
| if (!log->io_kc) |
| goto io_kc; |
| |
| ret = mempool_init_slab_pool(&log->io_pool, R5L_POOL_SIZE, log->io_kc); |
| if (ret) |
| goto io_pool; |
| |
| ret = bioset_init(&log->bs, R5L_POOL_SIZE, 0, BIOSET_NEED_BVECS); |
| if (ret) |
| goto io_bs; |
| |
| ret = mempool_init_page_pool(&log->meta_pool, R5L_POOL_SIZE, 0); |
| if (ret) |
| goto out_mempool; |
| |
| spin_lock_init(&log->tree_lock); |
| INIT_RADIX_TREE(&log->big_stripe_tree, GFP_NOWAIT | __GFP_NOWARN); |
| |
| log->reclaim_thread = md_register_thread(r5l_reclaim_thread, |
| log->rdev->mddev, "reclaim"); |
| if (!log->reclaim_thread) |
| goto reclaim_thread; |
| log->reclaim_thread->timeout = R5C_RECLAIM_WAKEUP_INTERVAL; |
| |
| init_waitqueue_head(&log->iounit_wait); |
| |
| INIT_LIST_HEAD(&log->no_mem_stripes); |
| |
| INIT_LIST_HEAD(&log->no_space_stripes); |
| spin_lock_init(&log->no_space_stripes_lock); |
| |
| INIT_WORK(&log->deferred_io_work, r5l_submit_io_async); |
| INIT_WORK(&log->disable_writeback_work, r5c_disable_writeback_async); |
| |
| log->r5c_journal_mode = R5C_JOURNAL_MODE_WRITE_THROUGH; |
| INIT_LIST_HEAD(&log->stripe_in_journal_list); |
| spin_lock_init(&log->stripe_in_journal_lock); |
| atomic_set(&log->stripe_in_journal_count, 0); |
| |
| rcu_assign_pointer(conf->log, log); |
| |
| set_bit(MD_HAS_JOURNAL, &conf->mddev->flags); |
| return 0; |
| |
| rcu_assign_pointer(conf->log, NULL); |
| md_unregister_thread(&log->reclaim_thread); |
| reclaim_thread: |
| mempool_exit(&log->meta_pool); |
| out_mempool: |
| bioset_exit(&log->bs); |
| io_bs: |
| mempool_exit(&log->io_pool); |
| io_pool: |
| kmem_cache_destroy(log->io_kc); |
| io_kc: |
| kfree(log); |
| return -EINVAL; |
| } |
| |
| void r5l_exit_log(struct r5conf *conf) |
| { |
| struct r5l_log *log = conf->log; |
| |
| conf->log = NULL; |
| synchronize_rcu(); |
| |
| /* Ensure disable_writeback_work wakes up and exits */ |
| wake_up(&conf->mddev->sb_wait); |
| flush_work(&log->disable_writeback_work); |
| md_unregister_thread(&log->reclaim_thread); |
| mempool_exit(&log->meta_pool); |
| bioset_exit(&log->bs); |
| mempool_exit(&log->io_pool); |
| kmem_cache_destroy(log->io_kc); |
| kfree(log); |
| } |