Btrfs: Use async helpers to deal with pages that have been improperly dirtied

Higher layers sometimes call set_page_dirty without asking the filesystem
to help.  This causes many problems for the data=ordered and cow code.
This commit detects pages that haven't been properly setup for IO and
kicks off an async helper to deal with them.

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

1 files changed, 4 insertions, 0 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 4a5ebafb935a..66466d125c05 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1329,11 +1329,13 @@ struct btrfs_root *open_ctree(struct super_block *sb,
          */
         btrfs_init_workers(&fs_info->workers, fs_info->thread_pool_size);
         btrfs_init_workers(&fs_info->submit_workers, fs_info->thread_pool_size);
+        btrfs_init_workers(&fs_info->fixup_workers, 1);
         btrfs_init_workers(&fs_info->endio_workers, fs_info->thread_pool_size);
         btrfs_init_workers(&fs_info->endio_write_workers,
                            fs_info->thread_pool_size);
         btrfs_start_workers(&fs_info->workers, 1);
         btrfs_start_workers(&fs_info->submit_workers, 1);
+        btrfs_start_workers(&fs_info->fixup_workers, 1);
         btrfs_start_workers(&fs_info->endio_workers, fs_info->thread_pool_size);
         btrfs_start_workers(&fs_info->endio_write_workers,
                             fs_info->thread_pool_size);
@@ -1454,6 +1456,7 @@ fail_tree_root:
 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);
         btrfs_stop_workers(&fs_info->endio_write_workers);
@@ -1710,6 +1713,7 @@ int close_ctree(struct btrfs_root *root)
 
         truncate_inode_pages(fs_info->btree_inode->i_mapping, 0);
 
+        btrfs_stop_workers(&fs_info->fixup_workers);
         btrfs_stop_workers(&fs_info->workers);
         btrfs_stop_workers(&fs_info->endio_workers);
         btrfs_stop_workers(&fs_info->endio_write_workers);