git.sesse.net Git - bcachefs-tools-debian/blob - libbcache/writeback.h

   1 #ifndef _BCACHE_WRITEBACK_H
   2 #define _BCACHE_WRITEBACK_H
   3
   4 #include "blockdev.h"
   5 #include "buckets.h"
   6
   7 #define CUTOFF_WRITEBACK        60
   8 #define CUTOFF_WRITEBACK_SYNC   30
   9
  10 static inline uint64_t bcache_dev_sectors_dirty(struct bcache_device *d)
  11 {
  12         uint64_t i, ret = 0;
  13
  14         for (i = 0; i < d->nr_stripes; i++)
  15                 ret += atomic_read(d->stripe_sectors_dirty + i);
  16
  17         return ret;
  18 }
  19
  20 static inline unsigned offset_to_stripe(struct bcache_device *d,
  21                                         uint64_t offset)
  22 {
  23         do_div(offset, d->stripe_size);
  24         return offset;
  25 }
  26
  27 static inline bool bcache_dev_stripe_dirty(struct cached_dev *dc,
  28                                            uint64_t offset,
  29                                            unsigned nr_sectors)
  30 {
  31         unsigned stripe = offset_to_stripe(&dc->disk, offset);
  32
  33         while (1) {
  34                 if (atomic_read(dc->disk.stripe_sectors_dirty + stripe))
  35                         return true;
  36
  37                 if (nr_sectors <= dc->disk.stripe_size)
  38                         return false;
  39
  40                 nr_sectors -= dc->disk.stripe_size;
  41                 stripe++;
  42         }
  43 }
  44
  45 static inline bool should_writeback(struct cached_dev *dc, struct bio *bio,
  46                                     unsigned cache_mode, bool would_skip)
  47 {
  48         struct cache_set *c = dc->disk.c;
  49         u64 available = sectors_available(c);
  50
  51         if (cache_mode != CACHE_MODE_WRITEBACK ||
  52             test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags) ||
  53             available * 100 < c->capacity * CUTOFF_WRITEBACK_SYNC)
  54                 return false;
  55
  56         if (dc->partial_stripes_expensive &&
  57             bcache_dev_stripe_dirty(dc, bio->bi_iter.bi_sector,
  58                                     bio_sectors(bio)))
  59                 return true;
  60
  61         if (would_skip)
  62                 return false;
  63
  64         return bio->bi_opf & REQ_SYNC ||
  65                 available * 100 < c->capacity * CUTOFF_WRITEBACK;
  66 }
  67
  68 static inline void bch_writeback_queue(struct cached_dev *dc)
  69 {
  70         if (!IS_ERR_OR_NULL(dc->writeback_thread))
  71                 wake_up_process(dc->writeback_thread);
  72 }
  73
  74 static inline void bch_writeback_add(struct cached_dev *dc)
  75 {
  76         if (!atomic_read(&dc->has_dirty) &&
  77             !atomic_xchg(&dc->has_dirty, 1)) {
  78                 atomic_inc(&dc->count);
  79
  80                 if (BDEV_STATE(dc->disk_sb.sb) != BDEV_STATE_DIRTY) {
  81                         SET_BDEV_STATE(dc->disk_sb.sb, BDEV_STATE_DIRTY);
  82                         /* XXX: should do this synchronously */
  83                         bch_write_bdev_super(dc, NULL);
  84                 }
  85
  86                 bch_writeback_queue(dc);
  87         }
  88 }
  89
  90 void bcache_dev_sectors_dirty_add(struct cache_set *, unsigned, u64, int);
  91
  92 void bch_writeback_recalc_oldest_gens(struct cache_set *);
  93 void bch_sectors_dirty_init(struct cached_dev *, struct cache_set *c);
  94
  95 void bch_cached_dev_writeback_stop(struct cached_dev *);
  96 void bch_cached_dev_writeback_free(struct cached_dev *);
  97 int bch_cached_dev_writeback_init(struct cached_dev *);
  98 int bch_cached_dev_writeback_start(struct cached_dev *);
  99
 100 #endif