[PATCH 2/4] Btrfs: merge adjacent states as much as possible
From: Liu Bo <hidden>
Date: 2012-06-13 10:11:57
Subsystem:
btrfs file system, filesystems (vfs and infrastructure), the rest · Maintainers:
Chris Mason, David Sterba, Alexander Viro, Christian Brauner, Linus Torvalds
In order to reduce write locks, we do merge_state as much as much as possible. Signed-off-by: Liu Bo <redacted> --- fs/btrfs/extent_io.c | 47 +++++++++++++++++++++++++++-------------------- 1 files changed, 27 insertions(+), 20 deletions(-)
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 2923ede..081fe13 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c@@ -276,29 +276,36 @@ static void merge_state(struct extent_io_tree *tree, if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY)) return; - other_node = rb_prev(&state->rb_node); - if (other_node) { + while (1) { + other_node = rb_prev(&state->rb_node); + if (!other_node) + break; other = rb_entry(other_node, struct extent_state, rb_node); - if (other->end == state->start - 1 && - other->state == state->state) { - merge_cb(tree, state, other); - state->start = other->start; - other->tree = NULL; - rb_erase(&other->rb_node, &tree->state); - free_extent_state(other); - } + if (other->end != state->start - 1 || + other->state != state->state) + break; + + merge_cb(tree, state, other); + state->start = other->start; + other->tree = NULL; + rb_erase(&other->rb_node, &tree->state); + free_extent_state(other); } - other_node = rb_next(&state->rb_node); - if (other_node) { + + while (1) { + other_node = rb_next(&state->rb_node); + if (!other_node) + break; other = rb_entry(other_node, struct extent_state, rb_node); - if (other->start == state->end + 1 && - other->state == state->state) { - merge_cb(tree, state, other); - state->end = other->end; - other->tree = NULL; - rb_erase(&other->rb_node, &tree->state); - free_extent_state(other); - } + if (other->start != state->end + 1 || + other->state != state->state) + break; + + merge_cb(tree, state, other); + state->end = other->end; + other->tree = NULL; + rb_erase(&other->rb_node, &tree->state); + free_extent_state(other); } }
--
1.6.5.2