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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /drivers/md/bcache/writeback.h
Initial import
Diffstat (limited to 'drivers/md/bcache/writeback.h')
-rw-r--r--drivers/md/bcache/writeback.h91
1 files changed, 91 insertions, 0 deletions
diff --git a/drivers/md/bcache/writeback.h b/drivers/md/bcache/writeback.h
new file mode 100644
index 000000000..0a9dab187
--- /dev/null
+++ b/drivers/md/bcache/writeback.h
@@ -0,0 +1,91 @@
+#ifndef _BCACHE_WRITEBACK_H
+#define _BCACHE_WRITEBACK_H
+
+#define CUTOFF_WRITEBACK 40
+#define CUTOFF_WRITEBACK_SYNC 70
+
+static inline uint64_t bcache_dev_sectors_dirty(struct bcache_device *d)
+{
+ uint64_t i, ret = 0;
+
+ for (i = 0; i < d->nr_stripes; i++)
+ ret += atomic_read(d->stripe_sectors_dirty + i);
+
+ return ret;
+}
+
+static inline unsigned offset_to_stripe(struct bcache_device *d,
+ uint64_t offset)
+{
+ do_div(offset, d->stripe_size);
+ return offset;
+}
+
+static inline bool bcache_dev_stripe_dirty(struct cached_dev *dc,
+ uint64_t offset,
+ unsigned nr_sectors)
+{
+ unsigned stripe = offset_to_stripe(&dc->disk, offset);
+
+ while (1) {
+ if (atomic_read(dc->disk.stripe_sectors_dirty + stripe))
+ return true;
+
+ if (nr_sectors <= dc->disk.stripe_size)
+ return false;
+
+ nr_sectors -= dc->disk.stripe_size;
+ stripe++;
+ }
+}
+
+static inline bool should_writeback(struct cached_dev *dc, struct bio *bio,
+ unsigned cache_mode, bool would_skip)
+{
+ unsigned in_use = dc->disk.c->gc_stats.in_use;
+
+ if (cache_mode != CACHE_MODE_WRITEBACK ||
+ test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags) ||
+ in_use > CUTOFF_WRITEBACK_SYNC)
+ return false;
+
+ if (dc->partial_stripes_expensive &&
+ bcache_dev_stripe_dirty(dc, bio->bi_iter.bi_sector,
+ bio_sectors(bio)))
+ return true;
+
+ if (would_skip)
+ return false;
+
+ return bio->bi_rw & REQ_SYNC ||
+ in_use <= CUTOFF_WRITEBACK;
+}
+
+static inline void bch_writeback_queue(struct cached_dev *dc)
+{
+ wake_up_process(dc->writeback_thread);
+}
+
+static inline void bch_writeback_add(struct cached_dev *dc)
+{
+ if (!atomic_read(&dc->has_dirty) &&
+ !atomic_xchg(&dc->has_dirty, 1)) {
+ atomic_inc(&dc->count);
+
+ if (BDEV_STATE(&dc->sb) != BDEV_STATE_DIRTY) {
+ SET_BDEV_STATE(&dc->sb, BDEV_STATE_DIRTY);
+ /* XXX: should do this synchronously */
+ bch_write_bdev_super(dc, NULL);
+ }
+
+ bch_writeback_queue(dc);
+ }
+}
+
+void bcache_dev_sectors_dirty_add(struct cache_set *, unsigned, uint64_t, int);
+
+void bch_sectors_dirty_init(struct cached_dev *dc);
+void bch_cached_dev_writeback_init(struct cached_dev *);
+int bch_cached_dev_writeback_start(struct cached_dev *);
+
+#endif