Btrfs: Make an unplug function that doesn't unplug every spindle

[linux-2.6-block.git] / fs / btrfs / disk-io.c

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index c829612c797e9460ec20a379f6c6f5edb4366467..7f5aca35494d214bc80132902dc6a4e1583f2877 100644 (file)
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -913,18 +913,22 @@ static int btrfs_congested_fn(void *congested_data, int bdi_bits)
 
 void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
 {
-       struct list_head *cur;
-       struct btrfs_device *device;
-       struct btrfs_fs_info *info;
+       struct inode *inode = page->mapping->host;
+       struct extent_map_tree *em_tree;
+       struct extent_map *em;
+       u64 offset = page_offset(page);
 
-       info = (struct btrfs_fs_info *)bdi->unplug_io_data;
-       list_for_each(cur, &info->fs_devices->devices) {
-               device = list_entry(cur, struct btrfs_device, dev_list);
-               bdi = blk_get_backing_dev_info(device->bdev);
-               if (bdi->unplug_io_fn) {
-                       bdi->unplug_io_fn(bdi, page);
-               }
-       }
+       em_tree = &BTRFS_I(inode)->extent_tree;
+       spin_lock(&em_tree->lock);
+       em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
+       spin_unlock(&em_tree->lock);
+       if (!em)
+               return;
+
+       offset = offset - em->start;
+       btrfs_unplug_page(&BTRFS_I(inode)->root->fs_info->mapping_tree,
+                         em->block_start + offset, page);
+       free_extent_map(em);
 }
 
 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)