btrfs: reada: Move is_need_to_readahead contition earlier

Move is_need_to_readahead contition earlier to avoid useless loop
to get relative data for readahead.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Zhao Lei 2015-12-31 22:57:52 +08:00 committed by David Sterba
parent 97d5f0e63d
commit a3f7fde243
1 changed files with 9 additions and 11 deletions

View File

@ -660,7 +660,6 @@ static int reada_start_machine_dev(struct btrfs_fs_info *fs_info,
u64 logical; u64 logical;
int ret; int ret;
int i; int i;
int need_kick = 0;
spin_lock(&fs_info->reada_lock); spin_lock(&fs_info->reada_lock);
if (dev->reada_curr_zone == NULL) { if (dev->reada_curr_zone == NULL) {
@ -696,6 +695,15 @@ static int reada_start_machine_dev(struct btrfs_fs_info *fs_info,
spin_unlock(&fs_info->reada_lock); spin_unlock(&fs_info->reada_lock);
spin_lock(&re->lock);
if (re->scheduled_for || list_empty(&re->extctl)) {
spin_unlock(&re->lock);
reada_extent_put(fs_info, re);
return 0;
}
re->scheduled_for = dev;
spin_unlock(&re->lock);
/* /*
* find mirror num * find mirror num
*/ */
@ -707,18 +715,8 @@ static int reada_start_machine_dev(struct btrfs_fs_info *fs_info,
} }
logical = re->logical; logical = re->logical;
spin_lock(&re->lock);
if (!re->scheduled_for && !list_empty(&re->extctl)) {
re->scheduled_for = dev;
need_kick = 1;
}
spin_unlock(&re->lock);
reada_extent_put(fs_info, re); reada_extent_put(fs_info, re);
if (!need_kick)
return 0;
atomic_inc(&dev->reada_in_flight); atomic_inc(&dev->reada_in_flight);
ret = reada_tree_block_flagged(fs_info->extent_root, logical, ret = reada_tree_block_flagged(fs_info->extent_root, logical,
mirror_num, &eb); mirror_num, &eb);