diff options
Diffstat (limited to 'drivers/md/bcache/writeback.c')
| -rw-r--r-- | drivers/md/bcache/writeback.c | 92 |
1 files changed, 79 insertions, 13 deletions
diff --git a/drivers/md/bcache/writeback.c b/drivers/md/bcache/writeback.c index f1d2fc15abcc..4a9547cdcdc5 100644 --- a/drivers/md/bcache/writeback.c +++ b/drivers/md/bcache/writeback.c @@ -114,6 +114,27 @@ static void update_writeback_rate(struct work_struct *work) struct cached_dev *dc = container_of(to_delayed_work(work), struct cached_dev, writeback_rate_update); + struct cache_set *c = dc->disk.c; + + /* + * should check BCACHE_DEV_RATE_DW_RUNNING before calling + * cancel_delayed_work_sync(). + */ + set_bit(BCACHE_DEV_RATE_DW_RUNNING, &dc->disk.flags); + /* paired with where BCACHE_DEV_RATE_DW_RUNNING is tested */ + smp_mb(); + + /* + * CACHE_SET_IO_DISABLE might be set via sysfs interface, + * check it here too. + */ + if (!test_bit(BCACHE_DEV_WB_RUNNING, &dc->disk.flags) || + test_bit(CACHE_SET_IO_DISABLE, &c->flags)) { + clear_bit(BCACHE_DEV_RATE_DW_RUNNING, &dc->disk.flags); + /* paired with where BCACHE_DEV_RATE_DW_RUNNING is tested */ + smp_mb(); + return; + } down_read(&dc->writeback_lock); @@ -123,8 +144,23 @@ static void update_writeback_rate(struct work_struct *work) up_read(&dc->writeback_lock); - schedule_delayed_work(&dc->writeback_rate_update, + /* + * CACHE_SET_IO_DISABLE might be set via sysfs interface, + * check it here too. + */ + if (test_bit(BCACHE_DEV_WB_RUNNING, &dc->disk.flags) && + !test_bit(CACHE_SET_IO_DISABLE, &c->flags)) { + schedule_delayed_work(&dc->writeback_rate_update, dc->writeback_rate_update_seconds * HZ); + } + + /* + * should check BCACHE_DEV_RATE_DW_RUNNING before calling + * cancel_delayed_work_sync(). + */ + clear_bit(BCACHE_DEV_RATE_DW_RUNNING, &dc->disk.flags); + /* paired with where BCACHE_DEV_RATE_DW_RUNNING is tested */ + smp_mb(); } static unsigned writeback_delay(struct cached_dev *dc, unsigned sectors) @@ -253,7 +289,8 @@ static void write_dirty(struct closure *cl) bio_set_dev(&io->bio, io->dc->bdev); io->bio.bi_end_io = dirty_endio; - closure_bio_submit(&io->bio, cl); + /* I/O request sent to backing device */ + closure_bio_submit(io->dc->disk.c, &io->bio, cl); } atomic_set(&dc->writeback_sequence_next, next_sequence); @@ -279,7 +316,7 @@ static void read_dirty_submit(struct closure *cl) { struct dirty_io *io = container_of(cl, struct dirty_io, cl); - closure_bio_submit(&io->bio, cl); + closure_bio_submit(io->dc->disk.c, &io->bio, cl); continue_at(cl, write_dirty, io->dc->writeback_write_wq); } @@ -305,7 +342,9 @@ static void read_dirty(struct cached_dev *dc) next = bch_keybuf_next(&dc->writeback_keys); - while (!kthread_should_stop() && next) { + while (!kthread_should_stop() && + !test_bit(CACHE_SET_IO_DISABLE, &dc->disk.c->flags) && + next) { size = 0; nk = 0; @@ -402,7 +441,9 @@ static void read_dirty(struct cached_dev *dc) } } - while (!kthread_should_stop() && delay) { + while (!kthread_should_stop() && + !test_bit(CACHE_SET_IO_DISABLE, &dc->disk.c->flags) && + delay) { schedule_timeout_interruptible(delay); delay = writeback_delay(dc, 0); } @@ -558,21 +599,30 @@ static bool refill_dirty(struct cached_dev *dc) static int bch_writeback_thread(void *arg) { struct cached_dev *dc = arg; + struct cache_set *c = dc->disk.c; bool searched_full_index; bch_ratelimit_reset(&dc->writeback_rate); - while (!kthread_should_stop()) { + while (!kthread_should_stop() && + !test_bit(CACHE_SET_IO_DISABLE, &c->flags)) { down_write(&dc->writeback_lock); set_current_state(TASK_INTERRUPTIBLE); - if (!atomic_read(&dc->has_dirty) || - (!test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags) && - !dc->writeback_running)) { + /* + * If the bache device is detaching, skip here and continue + * to perform writeback. Otherwise, if no dirty data on cache, + * or there is dirty data on cache but writeback is disabled, + * the writeback thread should sleep here and wait for others + * to wake up it. + */ + if (!test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags) && + (!atomic_read(&dc->has_dirty) || !dc->writeback_running)) { up_write(&dc->writeback_lock); - if (kthread_should_stop()) { + if (kthread_should_stop() || + test_bit(CACHE_SET_IO_DISABLE, &c->flags)) { set_current_state(TASK_RUNNING); - return 0; + break; } schedule(); @@ -585,9 +635,16 @@ static int bch_writeback_thread(void *arg) if (searched_full_index && RB_EMPTY_ROOT(&dc->writeback_keys.keys)) { atomic_set(&dc->has_dirty, 0); - cached_dev_put(dc); SET_BDEV_STATE(&dc->sb, BDEV_STATE_CLEAN); bch_write_bdev_super(dc, NULL); + /* + * If bcache device is detaching via sysfs interface, + * writeback thread should stop after there is no dirty + * data on cache. BCACHE_DEV_DETACHING flag is set in + * bch_cached_dev_detach(). + */ + if (test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags)) + break; } up_write(&dc->writeback_lock); @@ -599,6 +656,7 @@ static int bch_writeback_thread(void *arg) while (delay && !kthread_should_stop() && + !test_bit(CACHE_SET_IO_DISABLE, &c->flags) && !test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags)) delay = schedule_timeout_interruptible(delay); @@ -606,6 +664,9 @@ static int bch_writeback_thread(void *arg) } } + cached_dev_put(dc); + wait_for_kthread_stop(); + return 0; } @@ -659,6 +720,7 @@ void bch_cached_dev_writeback_init(struct cached_dev *dc) dc->writeback_rate_p_term_inverse = 40; dc->writeback_rate_i_term_inverse = 10000; + WARN_ON(test_and_clear_bit(BCACHE_DEV_WB_RUNNING, &dc->disk.flags)); INIT_DELAYED_WORK(&dc->writeback_rate_update, update_writeback_rate); } @@ -669,11 +731,15 @@ int bch_cached_dev_writeback_start(struct cached_dev *dc) if (!dc->writeback_write_wq) return -ENOMEM; + cached_dev_get(dc); dc->writeback_thread = kthread_create(bch_writeback_thread, dc, "bcache_writeback"); - if (IS_ERR(dc->writeback_thread)) + if (IS_ERR(dc->writeback_thread)) { + cached_dev_put(dc); return PTR_ERR(dc->writeback_thread); + } + WARN_ON(test_and_set_bit(BCACHE_DEV_WB_RUNNING, &dc->disk.flags)); schedule_delayed_work(&dc->writeback_rate_update, dc->writeback_rate_update_seconds * HZ); |