Btrfs: Index extent buffers in an rbtree

Before, extent buffers were a temporary object, meant to map a number of pages
at once and collect operations on them.

But, a few extra fields have crept in, and they are also the best place to
store a per-tree block lock field as well.  This commit puts the extent
buffers into an rbtree, and ensures a single extent buffer for each
tree block.

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

1 files changed, 9 insertions, 17 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 99bb385c2982..86e84a8579e3 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -381,7 +381,6 @@ int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
 
         end = min_t(u64, eb->len, PAGE_CACHE_SIZE);
         end = eb->start + end - 1;
-        release_extent_buffer_tail_pages(eb);
 err:
         free_extent_buffer(eb);
 out:
@@ -563,21 +562,21 @@ static int btree_releasepage(struct page *page, gfp_t gfp_flags)
         struct extent_map_tree *map;
         int ret;
 
-        if (page_count(page) > 3) {
-                /* once for page->private, once for the caller, once
-                 * once for the page cache
-                 */
-                return 0;
-        }
         tree = &BTRFS_I(page->mapping->host)->io_tree;
         map = &BTRFS_I(page->mapping->host)->extent_tree;
+
         ret = try_release_extent_state(map, tree, page, gfp_flags);
+        if (!ret) {
+                return 0;
+        }
+
+        ret = try_release_extent_buffer(tree, page);
         if (ret == 1) {
-                invalidate_extent_lru(tree, page_offset(page), PAGE_CACHE_SIZE);
                 ClearPagePrivate(page);
                 set_page_private(page, 0);
                 page_cache_release(page);
         }
+
         return ret;
 }
 
@@ -588,7 +587,8 @@ static void btree_invalidatepage(struct page *page, unsigned long offset)
         extent_invalidatepage(tree, page, offset);
         btree_releasepage(page, GFP_NOFS);
         if (PagePrivate(page)) {
-                invalidate_extent_lru(tree, page_offset(page), PAGE_CACHE_SIZE);
+                printk("warning page private not zero on page %Lu\n",
+                       page_offset(page));
                 ClearPagePrivate(page);
                 set_page_private(page, 0);
                 page_cache_release(page);
@@ -1456,7 +1456,6 @@ fail_tree_root:
         free_extent_buffer(tree_root->node);
 fail_sys_array:
 fail_sb_buffer:
-        extent_io_tree_empty_lru(&BTRFS_I(fs_info->btree_inode)->io_tree);
         btrfs_stop_workers(&fs_info->fixup_workers);
         btrfs_stop_workers(&fs_info->workers);
         btrfs_stop_workers(&fs_info->endio_workers);
@@ -1705,13 +1704,6 @@ int close_ctree(struct btrfs_root *root)
 
         filemap_write_and_wait(fs_info->btree_inode->i_mapping);
 
-        extent_io_tree_empty_lru(&fs_info->free_space_cache);
-        extent_io_tree_empty_lru(&fs_info->block_group_cache);
-        extent_io_tree_empty_lru(&fs_info->pinned_extents);
-        extent_io_tree_empty_lru(&fs_info->pending_del);
-        extent_io_tree_empty_lru(&fs_info->extent_ins);
-        extent_io_tree_empty_lru(&BTRFS_I(fs_info->btree_inode)->io_tree);
-
         truncate_inode_pages(fs_info->btree_inode->i_mapping, 0);
 
         btrfs_stop_workers(&fs_info->fixup_workers);