From 4d2c8f62f12a6652db67cc0c1f4a4a498b05ddbc Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Thu, 14 Jul 2011 03:18:33 +0000 Subject: Btrfs: clean up code for merging extent maps unpin_extent_cache() and add_extent_mapping() shares the same code that merges extent maps. Signed-off-by: Li Zefan Signed-off-by: Chris Mason --- fs/btrfs/extent_map.c | 59 ++++++++++++++++++--------------------------------- 1 file changed, 21 insertions(+), 38 deletions(-) (limited to 'fs/btrfs/extent_map.c') diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c index df7a803005f..7c97b330145 100644 --- a/fs/btrfs/extent_map.c +++ b/fs/btrfs/extent_map.c @@ -183,22 +183,10 @@ static int mergable_maps(struct extent_map *prev, struct extent_map *next) return 0; } -int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 len) +static void try_merge_map(struct extent_map_tree *tree, struct extent_map *em) { - int ret = 0; struct extent_map *merge = NULL; struct rb_node *rb; - struct extent_map *em; - - write_lock(&tree->lock); - em = lookup_extent_mapping(tree, start, len); - - WARN_ON(!em || em->start != start); - - if (!em) - goto out; - - clear_bit(EXTENT_FLAG_PINNED, &em->flags); if (em->start != 0) { rb = rb_prev(&em->rb_node); @@ -225,6 +213,24 @@ int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 len) merge->in_tree = 0; free_extent_map(merge); } +} + +int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 len) +{ + int ret = 0; + struct extent_map *em; + + write_lock(&tree->lock); + em = lookup_extent_mapping(tree, start, len); + + WARN_ON(!em || em->start != start); + + if (!em) + goto out; + + clear_bit(EXTENT_FLAG_PINNED, &em->flags); + + try_merge_map(tree, em); free_extent_map(em); out: @@ -247,7 +253,6 @@ int add_extent_mapping(struct extent_map_tree *tree, struct extent_map *em) { int ret = 0; - struct extent_map *merge = NULL; struct rb_node *rb; struct extent_map *exist; @@ -263,30 +268,8 @@ int add_extent_mapping(struct extent_map_tree *tree, goto out; } atomic_inc(&em->refs); - if (em->start != 0) { - rb = rb_prev(&em->rb_node); - if (rb) - merge = rb_entry(rb, struct extent_map, rb_node); - if (rb && mergable_maps(merge, em)) { - em->start = merge->start; - em->len += merge->len; - em->block_len += merge->block_len; - em->block_start = merge->block_start; - merge->in_tree = 0; - rb_erase(&merge->rb_node, &tree->map); - free_extent_map(merge); - } - } - rb = rb_next(&em->rb_node); - if (rb) - merge = rb_entry(rb, struct extent_map, rb_node); - if (rb && mergable_maps(em, merge)) { - em->len += merge->len; - em->block_len += merge->len; - rb_erase(&merge->rb_node, &tree->map); - merge->in_tree = 0; - free_extent_map(merge); - } + + try_merge_map(tree, em); out: return ret; } -- cgit v1.2.3