lib/lafs_segment_count.c

   1
   2 /* lafs_segment_count
   3  * adjust the usage count for the segment containing a given block
   4  */
   5
   6 #include <lafs/lafs.h>
   7
   8 static void delay_update(struct lafs *fs, int dev, loff_t seg, int diff)
   9 {
  10         struct lafs_delayed *d = fs->delayed;
  11
  12         while (d && (d->dev != dev || d->seg != seg))
  13                 d = d->next;
  14         if (!d) {
  15                 d = malloc(sizeof(*d));
  16                 d->next = fs->delayed;
  17                 fs->delayed = d;
  18                 d->dev = dev;
  19                 d->seg = seg;
  20                 d->diff = 0;
  21         }
  22         d->diff += diff;
  23 }
  24
  25 void segment_count(struct lafs *fs, int dev, loff_t seg, int diff)
  26 {
  27         struct lafs_device *dv;
  28         struct lafs_dblk *db;
  29         uint32_t *p;
  30         int cnt;
  31         loff_t addr;
  32
  33         dv = dev_by_num(fs, dev);
  34         addr = dv->tablesize + seg / (fs->blocksize >> USAGE_SHIFT);
  35
  36         db = lafs_dblk(dv->segsum, addr);
  37         lafs_load_dblk(db);
  38         p = (void*)db->b.data;
  39         cnt = __le32_to_cpu(p[seg % (fs->blocksize >> USAGE_SHIFT)]);
  40         cnt += diff;
  41         p[seg % (fs->blocksize >> USAGE_SHIFT)] = __cpu_to_le32(cnt);
  42         lafs_sched_blk(&db->b);
  43 }
  44
  45
  46 void lafs_segment_count(struct lafs *fs, loff_t addr, int diff)
  47 {
  48         int dev;
  49         loff_t seg;
  50         loff_t offset;
  51
  52         virttoseg(fs, addr, &dev, &seg, &offset);
  53
  54         if (fs->flags & LAFS_DELAY_UPDATES) {
  55                 delay_update(fs, dev, seg, diff);
  56                 return;
  57         }
  58         segment_count(fs, dev, seg, diff);
  59 }
  60
  61 void lafs_segment_apply_delayed(struct lafs *fs)
  62 {
  63         struct lafs_delayed *delayed = fs->delayed;
  64
  65         if (fs->flags & LAFS_DELAY_UPDATES)
  66                 abort();
  67         fs->delayed = NULL;
  68
  69         while (delayed) {
  70                 struct lafs_delayed *d = delayed;
  71                 delayed = d->next;
  72                 segment_count(fs, d->dev, d->seg, d->diff);
  73                 free(d);
  74         }
  75 }