LXR linux/drivers/md/bcache/writeback.h

   1#ifndef _BCACHE_WRITEBACK_H
   2#define _BCACHE_WRITEBACK_H
   3
   4#define CUTOFF_WRITEBACK        40
   5#define CUTOFF_WRITEBACK_SYNC   70
   6
   7static inline uint64_t bcache_dev_sectors_dirty(struct bcache_device *d)
   8{
   9        uint64_t i, ret = 0;
  10
  11        for (i = 0; i < d->nr_stripes; i++)
  12                ret += atomic_read(d->stripe_sectors_dirty + i);
  13
  14        return ret;
  15}
  16
  17static inline bool bcache_dev_stripe_dirty(struct bcache_device *d,
  18                                           uint64_t offset,
  19                                           unsigned nr_sectors)
  20{
  21        uint64_t stripe = offset >> d->stripe_size_bits;
  22
  23        while (1) {
  24                if (atomic_read(d->stripe_sectors_dirty + stripe))
  25                        return true;
  26
  27                if (nr_sectors <= 1 << d->stripe_size_bits)
  28                        return false;
  29
  30                nr_sectors -= 1 << d->stripe_size_bits;
  31                stripe++;
  32        }
  33}
  34
  35static inline bool should_writeback(struct cached_dev *dc, struct bio *bio,
  36                                    unsigned cache_mode, bool would_skip)
  37{
  38        unsigned in_use = dc->disk.c->gc_stats.in_use;
  39
  40        if (cache_mode != CACHE_MODE_WRITEBACK ||
  41            atomic_read(&dc->disk.detaching) ||
  42            in_use > CUTOFF_WRITEBACK_SYNC)
  43                return false;
  44
  45        if (dc->partial_stripes_expensive &&
  46            bcache_dev_stripe_dirty(&dc->disk, bio->bi_sector,
  47                                    bio_sectors(bio)))
  48                return true;
  49
  50        if (would_skip)
  51                return false;
  52
  53        return bio->bi_rw & REQ_SYNC ||
  54                in_use <= CUTOFF_WRITEBACK;
  55}
  56
  57void bcache_dev_sectors_dirty_add(struct cache_set *, unsigned, uint64_t, int);
  58void bch_writeback_queue(struct cached_dev *);
  59void bch_writeback_add(struct cached_dev *);
  60
  61void bch_sectors_dirty_init(struct cached_dev *dc);
  62void bch_cached_dev_writeback_init(struct cached_dev *);
  63
  64#endif
  65