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
   7 static 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
  17 static inline uint64_t  bcache_flash_devs_sectors_dirty(struct cache_set *c)
  18 {
  19         uint64_t i, ret = 0;
  20
  21         mutex_lock(&bch_register_lock);
  22
  23         for (i = 0; i < c->nr_uuids; i++) {
  24                 struct bcache_device *d = c->devices[i];
  25
  26                 if (!d || !UUID_FLASH_ONLY(&c->uuids[i]))
  27                         continue;
  28            ret += bcache_dev_sectors_dirty(d);
  29         }
  30
  31         mutex_unlock(&bch_register_lock);
  32
  33         return ret;
  34 }
  35
  36 static inline unsigned offset_to_stripe(struct bcache_device *d,
  37                                         uint64_t offset)
  38 {
  39         do_div(offset, d->stripe_size);
  40         return offset;
  41 }
  42
  43 static inline bool bcache_dev_stripe_dirty(struct cached_dev *dc,
  44                                            uint64_t offset,
  45                                            unsigned nr_sectors)
  46 {
  47         unsigned stripe = offset_to_stripe(&dc->disk, offset);
  48
  49         while (1) {
  50                 if (atomic_read(dc->disk.stripe_sectors_dirty + stripe))
  51                         return true;
  52
  53                 if (nr_sectors <= dc->disk.stripe_size)
  54                         return false;
  55
  56                 nr_sectors -= dc->disk.stripe_size;
  57                 stripe++;
  58         }
  59 }
  60
  61 static inline bool should_writeback(struct cached_dev *dc, struct bio *bio,
  62                                     unsigned cache_mode, bool would_skip)
  63 {
  64         unsigned in_use = dc->disk.c->gc_stats.in_use;
  65
  66         if (cache_mode != CACHE_MODE_WRITEBACK ||
  67             test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags) ||
  68             in_use > CUTOFF_WRITEBACK_SYNC)
  69                 return false;
  70
  71         if (bio_op(bio) == REQ_OP_DISCARD)
  72                 return false;
  73
  74         if (dc->partial_stripes_expensive &&
  75             bcache_dev_stripe_dirty(dc, bio->bi_iter.bi_sector,
  76                                     bio_sectors(bio)))
  77                 return true;
  78
  79         if (would_skip)
  80                 return false;
  81
  82         return bio->bi_opf & REQ_SYNC ||
  83                 in_use <= CUTOFF_WRITEBACK;
  84 }
  85
  86 static inline void bch_writeback_queue(struct cached_dev *dc)
  87 {
  88         if (!IS_ERR_OR_NULL(dc->writeback_thread))
  89                 wake_up_process(dc->writeback_thread);
  90 }
  91
  92 static inline void bch_writeback_add(struct cached_dev *dc)
  93 {
  94         if (!atomic_read(&dc->has_dirty) &&
  95             !atomic_xchg(&dc->has_dirty, 1)) {
  96                 atomic_inc(&dc->count);
  97
  98                 if (BDEV_STATE(&dc->sb) != BDEV_STATE_DIRTY) {
  99                         SET_BDEV_STATE(&dc->sb, BDEV_STATE_DIRTY);
 100                         /* XXX: should do this synchronously */
 101                         bch_write_bdev_super(dc, NULL);
 102                 }
 103
 104                 bch_writeback_queue(dc);
 105         }
 106 }
 107
 108 void bcache_dev_sectors_dirty_add(struct cache_set *, unsigned, uint64_t, int);
 109
 110 void bch_sectors_dirty_init(struct bcache_device *);
 111 void bch_cached_dev_writeback_init(struct cached_dev *);
 112 int bch_cached_dev_writeback_start(struct cached_dev *);
 113
 114 #endif