dm persistent data: only commit space map if index changed

Introduce bitmap_index_changed to track whether or not the index changed
then only commit a space map if it did.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This commit is contained in:
Joe Thornber 2012-07-27 15:08:06 +01:00 committed by Alasdair G Kergon
parent 8d44c98aac
commit f4b90369d3
2 changed files with 12 additions and 1 deletions

View File

@ -224,6 +224,7 @@ static int sm_ll_init(struct ll_disk *ll, struct dm_transaction_manager *tm)
ll->nr_blocks = 0;
ll->bitmap_root = 0;
ll->ref_count_root = 0;
ll->bitmap_index_changed = false;
return 0;
}
@ -476,7 +477,15 @@ int sm_ll_dec(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)
int sm_ll_commit(struct ll_disk *ll)
{
return ll->commit(ll);
int r = 0;
if (ll->bitmap_index_changed) {
r = ll->commit(ll);
if (!r)
ll->bitmap_index_changed = false;
}
return r;
}
/*----------------------------------------------------------------*/
@ -491,6 +500,7 @@ static int metadata_ll_load_ie(struct ll_disk *ll, dm_block_t index,
static int metadata_ll_save_ie(struct ll_disk *ll, dm_block_t index,
struct disk_index_entry *ie)
{
ll->bitmap_index_changed = true;
memcpy(ll->mi_le.index + index, ie, sizeof(*ie));
return 0;
}

View File

@ -78,6 +78,7 @@ struct ll_disk {
open_index_fn open_index;
max_index_entries_fn max_entries;
commit_fn commit;
bool bitmap_index_changed:1;
};
struct disk_sm_root {