1 files changed, 45 insertions, 5 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 228cf36ece8..22c3c958604 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1058,6 +1058,7 @@ static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
         root->name = NULL;
         root->in_sysfs = 0;
         root->inode_tree = RB_ROOT;
+        INIT_RADIX_TREE(&root->delayed_nodes_tree, GFP_ATOMIC);
         root->block_rsv = NULL;
         root->orphan_block_rsv = NULL;
 
@@ -1693,6 +1694,13 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 
         INIT_LIST_HEAD(&fs_info->ordered_extents);
         spin_lock_init(&fs_info->ordered_extent_lock);
+        fs_info->delayed_root = kmalloc(sizeof(struct btrfs_delayed_root),
+                                        GFP_NOFS);
+        if (!fs_info->delayed_root) {
+                err = -ENOMEM;
+                goto fail_iput;
+        }
+        btrfs_init_delayed_root(fs_info->delayed_root);
 
         sb->s_blocksize = 4096;
         sb->s_blocksize_bits = blksize_bits(4096);
@@ -1760,7 +1768,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
         bh = btrfs_read_dev_super(fs_devices->latest_bdev);
         if (!bh) {
                 err = -EINVAL;
-                goto fail_iput;
+                goto fail_alloc;
         }
 
         memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy));
@@ -1772,7 +1780,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 
         disk_super = &fs_info->super_copy;
         if (!btrfs_super_root(disk_super))
-                goto fail_iput;
+                goto fail_alloc;
 
         /* check FS state, whether FS is broken. */
         fs_info->fs_state |= btrfs_super_flags(disk_super);
@@ -1788,7 +1796,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
         ret = btrfs_parse_options(tree_root, options);
         if (ret) {
                 err = ret;
-                goto fail_iput;
+                goto fail_alloc;
         }
 
         features = btrfs_super_incompat_flags(disk_super) &
@@ -1798,7 +1806,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
                        "unsupported optional features (%Lx).\n",
                        (unsigned long long)features);
                 err = -EINVAL;
-                goto fail_iput;
+                goto fail_alloc;
         }
 
         features = btrfs_super_incompat_flags(disk_super);
@@ -1814,7 +1822,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
                        "unsupported option features (%Lx).\n",
                        (unsigned long long)features);
                 err = -EINVAL;
-                goto fail_iput;
+                goto fail_alloc;
         }
 
         btrfs_init_workers(&fs_info->generic_worker,
@@ -1861,6 +1869,9 @@ struct btrfs_root *open_ctree(struct super_block *sb,
                            &fs_info->generic_worker);
         btrfs_init_workers(&fs_info->endio_freespace_worker, "freespace-write",
                            1, &fs_info->generic_worker);
+        btrfs_init_workers(&fs_info->delayed_workers, "delayed-meta",
+                           fs_info->thread_pool_size,
+                           &fs_info->generic_worker);
 
         /*
          * endios are largely parallel and should have a very
@@ -1882,6 +1893,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
         btrfs_start_workers(&fs_info->endio_meta_write_workers, 1);
         btrfs_start_workers(&fs_info->endio_write_workers, 1);
         btrfs_start_workers(&fs_info->endio_freespace_worker, 1);
+        btrfs_start_workers(&fs_info->delayed_workers, 1);
 
         fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
         fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
@@ -2138,6 +2150,9 @@ fail_sb_buffer:
         btrfs_stop_workers(&fs_info->endio_write_workers);
         btrfs_stop_workers(&fs_info->endio_freespace_worker);
         btrfs_stop_workers(&fs_info->submit_workers);
+        btrfs_stop_workers(&fs_info->delayed_workers);
+fail_alloc:
+        kfree(fs_info->delayed_root);
 fail_iput:
         invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
         iput(fs_info->btree_inode);
@@ -2578,6 +2593,7 @@ int close_ctree(struct btrfs_root *root)
         del_fs_roots(fs_info);
 
         iput(fs_info->btree_inode);
+        kfree(fs_info->delayed_root);
 
         btrfs_stop_workers(&fs_info->generic_worker);
         btrfs_stop_workers(&fs_info->fixup_workers);
@@ -2589,6 +2605,7 @@ int close_ctree(struct btrfs_root *root)
         btrfs_stop_workers(&fs_info->endio_write_workers);
         btrfs_stop_workers(&fs_info->endio_freespace_worker);
         btrfs_stop_workers(&fs_info->submit_workers);
+        btrfs_stop_workers(&fs_info->delayed_workers);
 
         btrfs_close_devices(fs_info->fs_devices);
         btrfs_mapping_tree_free(&fs_info->mapping_tree);
@@ -2665,6 +2682,29 @@ void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
         if (current->flags & PF_MEMALLOC)
                 return;
 
+        btrfs_balance_delayed_items(root);
+
+        num_dirty = root->fs_info->dirty_metadata_bytes;
+
+        if (num_dirty > thresh) {
+                balance_dirty_pages_ratelimited_nr(
+                                   root->fs_info->btree_inode->i_mapping, 1);
+        }
+        return;
+}
+
+void __btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
+{
+        /*
+         * looks as though older kernels can get into trouble with
+         * this code, they end up stuck in balance_dirty_pages forever
+         */
+        u64 num_dirty;
+        unsigned long thresh = 32 * 1024 * 1024;
+
+        if (current->flags & PF_MEMALLOC)
+                return;
+
         num_dirty = root->fs_info->dirty_metadata_bytes;
 
         if (num_dirty > thresh) {