Btrfs: extent_io and extent_state optimizations

The end_bio routines are changed to take a pointer to the extent state
struct, and the state tree is walked in order to set/clear appropriate
bits as IO completes.  This greatly reduces the number of rbtree searches
done by the end_bio handlers, and reduces lock contention.

The extent_io releasepage function is changed to avoid expensive searches
for locked state.

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 4c4ebea0b2a9..e29a0716f6a9 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -274,7 +274,7 @@ int btree_readpage(struct file *file, struct page *page)
         return extent_read_full_page(tree, page, btree_get_extent);
 }
 
-static int btree_releasepage(struct page *page, gfp_t unused_gfp_flags)
+static int btree_releasepage(struct page *page, gfp_t gfp_flags)
 {
         struct extent_io_tree *tree;
         struct extent_map_tree *map;
@@ -282,7 +282,7 @@ static int btree_releasepage(struct page *page, gfp_t unused_gfp_flags)
 
         tree = &BTRFS_I(page->mapping->host)->io_tree;
         map = &BTRFS_I(page->mapping->host)->extent_tree;
-        ret = try_release_extent_mapping(map, tree, page);
+        ret = try_release_extent_mapping(map, tree, page, gfp_flags);
         if (ret == 1) {
                 ClearPagePrivate(page);
                 set_page_private(page, 0);