diff options
Diffstat (limited to 'drivers/md/dm-thin.c')
| -rw-r--r-- | drivers/md/dm-thin.c | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c index f4632f97bd7..759cffc45ca 100644 --- a/drivers/md/dm-thin.c +++ b/drivers/md/dm-thin.c @@ -1281,6 +1281,10 @@ static void process_bio_fail(struct thin_c *tc, struct bio *bio) bio_io_error(bio); } +/* + * FIXME: should we also commit due to size of transaction, measured in + * metadata blocks? + */ static int need_commit_due_to_time(struct pool *pool) { return jiffies < pool->last_commit_jiffies || @@ -1909,6 +1913,16 @@ static int parse_pool_features(struct dm_arg_set *as, struct pool_features *pf, return r; } +static void metadata_low_callback(void *context) +{ + struct pool *pool = context; + + DMWARN("%s: reached low water mark for metadata device: sending event.", + dm_device_name(pool->pool_md)); + + dm_table_event(pool->ti->table); +} + static sector_t get_metadata_dev_size(struct block_device *bdev) { sector_t metadata_dev_size = i_size_read(bdev->bd_inode) >> SECTOR_SHIFT; @@ -1933,6 +1947,23 @@ static dm_block_t get_metadata_dev_size_in_blocks(struct block_device *bdev) } /* + * When a metadata threshold is crossed a dm event is triggered, and + * userland should respond by growing the metadata device. We could let + * userland set the threshold, like we do with the data threshold, but I'm + * not sure they know enough to do this well. + */ +static dm_block_t calc_metadata_threshold(struct pool_c *pt) +{ + /* + * 4M is ample for all ops with the possible exception of thin + * device deletion which is harmless if it fails (just retry the + * delete after you've grown the device). + */ + dm_block_t quarter = get_metadata_dev_size_in_blocks(pt->metadata_dev->bdev) / 4; + return min((dm_block_t)1024ULL /* 4M */, quarter); +} + +/* * thin-pool <metadata dev> <data dev> * <data block size (sectors)> * <low water mark (blocks)> @@ -2065,6 +2096,13 @@ static int pool_ctr(struct dm_target *ti, unsigned argc, char **argv) } ti->private = pt; + r = dm_pool_register_metadata_threshold(pt->pool->pmd, + calc_metadata_threshold(pt), + metadata_low_callback, + pool); + if (r) + goto out_free_pt; + pt->callbacks.congested_fn = pool_is_congested; dm_table_add_target_callbacks(ti->table, &pt->callbacks); |