Btrfs: simpler and more efficient cleanup of a log tree's extent io tree

We currently are in a loop finding each range (corresponding to a btree
node/leaf) in a log root's extent io tree and then clean it up. This is a
waste of time since we are traversing the extent io tree's rb_tree more
times then needed (one for a range lookup and another for cleaning it up)
without any good reason.

We free the log trees when we are in the critical section of a transaction
commit (the transaction state is set to TRANS_STATE_COMMIT_DOING), so it's
of great convenience to do everything as fast as possible in order to
reduce the time we block other tasks from starting a new transaction.

So fix this by traversing the extent io tree once and cleaning up all its
records in one go while traversing it.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Filipe Manana 2018-11-09 10:43:08 +00:00 committed by David Sterba
parent 46cc775e29
commit 59b0713a8a

View file

@ -3201,8 +3201,6 @@ static void free_log_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *log)
{
int ret;
u64 start;
u64 end;
struct walk_control wc = {
.free = 1,
.process_func = process_one_buffer
@ -3216,18 +3214,8 @@ static void free_log_tree(struct btrfs_trans_handle *trans,
btrfs_handle_fs_error(log->fs_info, ret, NULL);
}
while (1) {
ret = find_first_extent_bit(&log->dirty_log_pages,
0, &start, &end,
EXTENT_DIRTY | EXTENT_NEW | EXTENT_NEED_WAIT,
NULL);
if (ret)
break;
clear_extent_bits(&log->dirty_log_pages, start, end,
EXTENT_DIRTY | EXTENT_NEW | EXTENT_NEED_WAIT);
}
clear_extent_bits(&log->dirty_log_pages, 0, (u64)-1,
EXTENT_DIRTY | EXTENT_NEW | EXTENT_NEED_WAIT);
free_extent_buffer(log->node);
kfree(log);
}