diff options
| -rw-r--r-- | drivers/md/dm-cache-target.c | 94 |
1 files changed, 87 insertions, 7 deletions
diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c index 41e7cfd..2c66315 100644 --- a/drivers/md/dm-cache-target.c +++ b/drivers/md/dm-cache-target.c @@ -2817,17 +2817,86 @@ static int load_mapping(void *context, dm_oblock_t oblock, dm_cblock_t cblock, return 0; } +/* + * The discard block size in the on disk metadata is not + * neccessarily the same as we're currently using. So we have to + * be careful to only set the discarded attribute if we know it + * covers a complete block of the new size. + */ +struct discard_load_info { + struct cache *cache; + + /* + * These blocks are sized using the on disk dblock size, rather + * than the current one. + */ + dm_block_t block_size; + dm_block_t discard_begin, discard_end; +}; + +static void discard_load_info_init(struct cache *cache, + struct discard_load_info *li) +{ + li->cache = cache; + li->discard_begin = li->discard_end = 0; +} + +static void set_discard_range(struct discard_load_info *li) +{ + sector_t b, e; + + if (li->discard_begin == li->discard_end) + return; + + /* + * Convert to sectors. + */ + b = li->discard_begin * li->block_size; + e = li->discard_end * li->block_size; + + /* + * Then convert back to the current dblock size. + */ + b = dm_sector_div_up(b, li->cache->discard_block_size); + sector_div(e, li->cache->discard_block_size); + + /* + * The origin may have shrunk, so we need to check we're still in + * bounds. + */ + if (e > from_dblock(li->cache->discard_nr_blocks)) + e = from_dblock(li->cache->discard_nr_blocks); + + for (; b < e; b++) + set_discard(li->cache, to_dblock(b)); +} + static int load_discard(void *context, sector_t discard_block_size, dm_dblock_t dblock, bool discard) { - struct cache *cache = context; + struct discard_load_info *li = context; - /* FIXME: handle mis-matched block size */ + li->block_size = discard_block_size; - if (discard) - set_discard(cache, dblock); - else - clear_discard(cache, dblock); + if (discard) { + if (from_dblock(dblock) == li->discard_end) + /* + * We're already in a discard range, just extend it. + */ + li->discard_end = li->discard_end + 1ULL; + + else { + /* + * Emit the old range and start a new one. + */ + set_discard_range(li); + li->discard_begin = from_dblock(dblock); + li->discard_end = li->discard_begin + 1ULL; + } + } else { + set_discard_range(li); + li->discard_begin = li->discard_end = 0; + } return 0; } @@ -2911,11 +2980,22 @@ static int cache_preresume(struct dm_target *ti) } if (!cache->loaded_discards) { - r = dm_cache_load_discards(cache->cmd, load_discard, cache); + struct discard_load_info li; + + /* + * The discard bitset could have been resized, or the + * discard block size changed. To be safe we start by + * setting every dblock to not discarded. + */ + clear_bitset(cache->discard_bitset, from_dblock(cache->discard_nr_blocks)); + + discard_load_info_init(cache, &li); + r = dm_cache_load_discards(cache->cmd, load_discard, &li); if (r) { DMERR("could not load origin discards"); return r; } + set_discard_range(&li); cache->loaded_discards = true; } |