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-rw-r--r--drivers/md/bcache/writeback.h64
1 files changed, 64 insertions, 0 deletions
diff --git a/drivers/md/bcache/writeback.h b/drivers/md/bcache/writeback.h
new file mode 100644
index 0000000..c91f61b
--- /dev/null
+++ b/drivers/md/bcache/writeback.h
@@ -0,0 +1,64 @@
+#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 bool bcache_dev_stripe_dirty(struct bcache_device *d,
+ uint64_t offset,
+ unsigned nr_sectors)
+{
+ uint64_t stripe = offset >> d->stripe_size_bits;
+
+ while (1) {
+ if (atomic_read(d->stripe_sectors_dirty + stripe))
+ return true;
+
+ if (nr_sectors <= 1 << d->stripe_size_bits)
+ return false;
+
+ nr_sectors -= 1 << d->stripe_size_bits;
+ 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 ||
+ atomic_read(&dc->disk.detaching) ||
+ in_use > CUTOFF_WRITEBACK_SYNC)
+ return false;
+
+ if (dc->partial_stripes_expensive &&
+ bcache_dev_stripe_dirty(&dc->disk, bio->bi_sector,
+ bio_sectors(bio)))
+ return true;
+
+ if (would_skip)
+ return false;
+
+ return bio->bi_rw & REQ_SYNC ||
+ in_use <= CUTOFF_WRITEBACK;
+}
+
+void bcache_dev_sectors_dirty_add(struct cache_set *, unsigned, uint64_t, int);
+void bch_writeback_queue(struct cached_dev *);
+void bch_writeback_add(struct cached_dev *);
+
+void bch_sectors_dirty_init(struct cached_dev *dc);
+void bch_cached_dev_writeback_init(struct cached_dev *);
+
+#endif
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