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btrfs: reada: reduce additional fs_info->reada_lock in reada_find_zone

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We can avoid additional locking-acquirment and one pair of
kref_get/put by combine two condition.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Zhao Lei 2015-12-18 21:48:48 +08:00 committed by David Sterba
parent 503785306d
commit c37f49c7ef
1 changed files with 4 additions and 8 deletions
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12
fs/btrfs/reada.c
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@ -260,18 +260,14 @@ static struct reada_zone *reada_find_zone(struct btrfs_fs_info *fs_info,
spin_lock(&fs_info->reada_lock);
ret = radix_tree_gang_lookup(&dev->reada_zones, (void **)&zone,
logical >> PAGE_CACHE_SHIFT, 1);
if (ret == 1)
if (ret == 1 && logical >= zone->start && logical <= zone->end) {
kref_get(&zone->refcnt);
spin_unlock(&fs_info->reada_lock);
if (ret == 1) {
if (logical >= zone->start && logical <= zone->end)
return zone;
spin_lock(&fs_info->reada_lock);
kref_put(&zone->refcnt, reada_zone_release);
spin_unlock(&fs_info->reada_lock);
return zone;
}
spin_unlock(&fs_info->reada_lock);
cache = btrfs_lookup_block_group(fs_info, logical);
if (!cache)
return NULL;