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Diffstat (limited to 'drivers/md/bcache/writeback.c')
-rw-r--r--drivers/md/bcache/writeback.c92
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);