From: Joe Thornber <ejt@redhat.com>
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>
---
drivers/md/persistent-data/dm-space-map-common.c | 12 +++++++++++-
drivers/md/persistent-data/dm-space-map-common.h | 1 +
2 files changed, 12 insertions(+), 1 deletion(-)
Index: linux/drivers/md/persistent-data/dm-space-map-common.c
===================================================================
--- linux.orig/drivers/md/persistent-data/dm-space-map-common.c
+++ linux/drivers/md/persistent-data/dm-space-map-common.c
@@ -224,6 +224,7 @@ static int sm_ll_init(struct ll_disk *ll
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_blo
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
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;
}
Index: linux/drivers/md/persistent-data/dm-space-map-common.h
===================================================================
--- linux.orig/drivers/md/persistent-data/dm-space-map-common.h
+++ linux/drivers/md/persistent-data/dm-space-map-common.h
@@ -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 {