5 files changed, 103 insertions, 8 deletions

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 8fd9fe4282f5..cad16566da37 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1333,6 +1333,7 @@ struct btrfs_fs_info {
         struct btrfs_workers generic_worker;
         struct btrfs_workers workers;
         struct btrfs_workers delalloc_workers;
+        struct btrfs_workers flush_workers;
         struct btrfs_workers endio_workers;
         struct btrfs_workers endio_meta_workers;
         struct btrfs_workers endio_meta_write_workers;
@@ -3277,6 +3278,19 @@ int btrfs_csum_truncate(struct btrfs_trans_handle *trans,
 int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
                              struct list_head *list, int search_commit);
 /* inode.c */
+struct btrfs_delalloc_work {
+        struct inode *inode;
+        int wait;
+        int delay_iput;
+        struct completion completion;
+        struct list_head list;
+        struct btrfs_work work;
+};
+
+struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
+                                                    int wait, int delay_iput);
+void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work);
+
 struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page,
                                            size_t pg_offset, u64 start, u64 len,
                                            int create);
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 7cda51995c1e..bd70c2852ba0 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2279,6 +2279,10 @@ int open_ctree(struct super_block *sb,
                            fs_info->thread_pool_size,
                            &fs_info->generic_worker);
 
+        btrfs_init_workers(&fs_info->flush_workers, "flush_delalloc",
+                           fs_info->thread_pool_size,
+                           &fs_info->generic_worker);
+
         btrfs_init_workers(&fs_info->submit_workers, "submit",
                            min_t(u64, fs_devices->num_devices,
                            fs_info->thread_pool_size),
@@ -2350,6 +2354,7 @@ int open_ctree(struct super_block *sb,
         ret |= btrfs_start_workers(&fs_info->delayed_workers);
         ret |= btrfs_start_workers(&fs_info->caching_workers);
         ret |= btrfs_start_workers(&fs_info->readahead_workers);
+        ret |= btrfs_start_workers(&fs_info->flush_workers);
         if (ret) {
                 err = -ENOMEM;
                 goto fail_sb_buffer;
@@ -2667,6 +2672,7 @@ fail_sb_buffer:
         btrfs_stop_workers(&fs_info->submit_workers);
         btrfs_stop_workers(&fs_info->delayed_workers);
         btrfs_stop_workers(&fs_info->caching_workers);
+        btrfs_stop_workers(&fs_info->flush_workers);
 fail_alloc:
 fail_iput:
         btrfs_mapping_tree_free(&fs_info->mapping_tree);
@@ -3339,6 +3345,7 @@ int close_ctree(struct btrfs_root *root)
         btrfs_stop_workers(&fs_info->delayed_workers);
         btrfs_stop_workers(&fs_info->caching_workers);
         btrfs_stop_workers(&fs_info->readahead_workers);
+        btrfs_stop_workers(&fs_info->flush_workers);
 
 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
         if (btrfs_test_opt(root, CHECK_INTEGRITY))
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index db3dd4ed057f..dce9e218b845 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -71,6 +71,7 @@ static const struct file_operations btrfs_dir_file_operations;
 static struct extent_io_ops btrfs_extent_io_ops;
 
 static struct kmem_cache *btrfs_inode_cachep;
+static struct kmem_cache *btrfs_delalloc_work_cachep;
 struct kmem_cache *btrfs_trans_handle_cachep;
 struct kmem_cache *btrfs_transaction_cachep;
 struct kmem_cache *btrfs_path_cachep;
@@ -7204,6 +7205,8 @@ void btrfs_destroy_cachep(void)
                 kmem_cache_destroy(btrfs_path_cachep);
         if (btrfs_free_space_cachep)
                 kmem_cache_destroy(btrfs_free_space_cachep);
+        if (btrfs_delalloc_work_cachep)
+                kmem_cache_destroy(btrfs_delalloc_work_cachep);
 }
 
 int btrfs_init_cachep(void)
@@ -7238,6 +7241,13 @@ int btrfs_init_cachep(void)
         if (!btrfs_free_space_cachep)
                 goto fail;
 
+        btrfs_delalloc_work_cachep = kmem_cache_create("btrfs_delalloc_work",
+                        sizeof(struct btrfs_delalloc_work), 0,
+                        SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
+                        NULL);
+        if (!btrfs_delalloc_work_cachep)
+                goto fail;
+
         return 0;
 fail:
         btrfs_destroy_cachep();
@@ -7448,6 +7458,49 @@ out_notrans:
         return ret;
 }
 
+static void btrfs_run_delalloc_work(struct btrfs_work *work)
+{
+        struct btrfs_delalloc_work *delalloc_work;
+
+        delalloc_work = container_of(work, struct btrfs_delalloc_work,
+                                     work);
+        if (delalloc_work->wait)
+                btrfs_wait_ordered_range(delalloc_work->inode, 0, (u64)-1);
+        else
+                filemap_flush(delalloc_work->inode->i_mapping);
+
+        if (delalloc_work->delay_iput)
+                btrfs_add_delayed_iput(delalloc_work->inode);
+        else
+                iput(delalloc_work->inode);
+        complete(&delalloc_work->completion);
+}
+
+struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
+                                                    int wait, int delay_iput)
+{
+        struct btrfs_delalloc_work *work;
+
+        work = kmem_cache_zalloc(btrfs_delalloc_work_cachep, GFP_NOFS);
+        if (!work)
+                return NULL;
+
+        init_completion(&work->completion);
+        INIT_LIST_HEAD(&work->list);
+        work->inode = inode;
+        work->wait = wait;
+        work->delay_iput = delay_iput;
+        work->work.func = btrfs_run_delalloc_work;
+
+        return work;
+}
+
+void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work)
+{
+        wait_for_completion(&work->completion);
+        kmem_cache_free(btrfs_delalloc_work_cachep, work);
+}
+
 /*
  * some fairly slow code that needs optimization. This walks the list
  * of all the inodes with pending delalloc and forces them to disk.
@@ -7457,10 +7510,15 @@ int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
         struct list_head *head = &root->fs_info->delalloc_inodes;
         struct btrfs_inode *binode;
         struct inode *inode;
+        struct btrfs_delalloc_work *work, *next;
+        struct list_head works;
+        int ret = 0;
 
         if (root->fs_info->sb->s_flags & MS_RDONLY)
                 return -EROFS;
 
+        INIT_LIST_HEAD(&works);
+
         spin_lock(&root->fs_info->delalloc_lock);
         while (!list_empty(head)) {
                 binode = list_entry(head->next, struct btrfs_inode,
@@ -7470,11 +7528,14 @@ int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
                         list_del_init(&binode->delalloc_inodes);
                 spin_unlock(&root->fs_info->delalloc_lock);
                 if (inode) {
-                        filemap_flush(inode->i_mapping);
-                        if (delay_iput)
-                                btrfs_add_delayed_iput(inode);
-                        else
-                                iput(inode);
+                        work = btrfs_alloc_delalloc_work(inode, 0, delay_iput);
+                        if (!work) {
+                                ret = -ENOMEM;
+                                goto out;
+                        }
+                        list_add_tail(&work->list, &works);
+                        btrfs_queue_worker(&root->fs_info->flush_workers,
+                                           &work->work);
                 }
                 cond_resched();
                 spin_lock(&root->fs_info->delalloc_lock);
@@ -7493,7 +7554,12 @@ int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
                     atomic_read(&root->fs_info->async_delalloc_pages) == 0));
         }
         atomic_dec(&root->fs_info->async_submit_draining);
-        return 0;
+out:
+        list_for_each_entry_safe(work, next, &works, list) {
+                list_del_init(&work->list);
+                btrfs_wait_and_free_delalloc_work(work);
+        }
+        return ret;
 }
 
 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 242d6de4d8eb..270f24ffe1be 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -4061,7 +4061,11 @@ int btrfs_relocate_block_group(struct btrfs_root *extent_root, u64 group_start)
                (unsigned long long)rc->block_group->key.objectid,
                (unsigned long long)rc->block_group->flags);
 
-        btrfs_start_delalloc_inodes(fs_info->tree_root, 0);
+        ret = btrfs_start_delalloc_inodes(fs_info->tree_root, 0);
+        if (ret < 0) {
+                err = ret;
+                goto out;
+        }
         btrfs_wait_ordered_extents(fs_info->tree_root, 0);
 
         while (1) {
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 4e1def4c06b1..9c466f9f8175 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -1497,7 +1497,11 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
                 WARN_ON(cur_trans != trans->transaction);
 
                 if (flush_on_commit || snap_pending) {
-                        btrfs_start_delalloc_inodes(root, 1);
+                        ret = btrfs_start_delalloc_inodes(root, 1);
+                        if (ret) {
+                                btrfs_abort_transaction(trans, root, ret);
+                                goto cleanup_transaction;
+                        }
                         btrfs_wait_ordered_extents(root, 1);
                 }