---

yaml
---
r: 128862
b: refs/heads/master
c: ab78c84
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 1a3f5d0400d786aec41ede15fec5710ad1a1d18b
+refs/heads/master: ab78c84de1ce4db1b2a2cef361625ad80abbab3f

trunk/fs/btrfs/ctree.h

@@ -580,6 +580,7 @@ struct btrfs_fs_info {
 	int do_barriers;
 	int closing;
 	atomic_t throttles;
+	atomic_t throttle_gen;
 
 	u64 total_pinned;
 	struct list_head dirty_cowonly_roots;

trunk/fs/btrfs/disk-io.c

@@ -1171,8 +1171,10 @@ static int transaction_kthread(void *arg)
 		vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
 		mutex_lock(&root->fs_info->transaction_kthread_mutex);
 
-		printk("btrfs: total reference cache size %Lu\n",
-			root->fs_info->total_ref_cache_size);
+		if (root->fs_info->total_ref_cache_size > 20 * 1024 * 1024) {
+			printk("btrfs: total reference cache size %Lu\n",
+				root->fs_info->total_ref_cache_size);
+		}
 
 		mutex_lock(&root->fs_info->trans_mutex);
 		cur = root->fs_info->running_transaction;
@@ -1256,6 +1258,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 	btrfs_mapping_init(&fs_info->mapping_tree);
 	atomic_set(&fs_info->nr_async_submits, 0);
 	atomic_set(&fs_info->throttles, 0);
+	atomic_set(&fs_info->throttle_gen, 0);
 	fs_info->sb = sb;
 	fs_info->max_extent = (u64)-1;
 	fs_info->max_inline = 8192 * 1024;

trunk/fs/btrfs/extent-tree.c

@@ -2650,6 +2650,7 @@ int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
 		}
 	}
 	while(1) {
+		atomic_inc(&root->fs_info->throttle_gen);
 		wret = walk_down_tree(trans, root, path, &level);
 		if (wret > 0)
 			break;

trunk/fs/btrfs/file.c

@@ -974,6 +974,7 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
 		balance_dirty_pages_ratelimited_nr(inode->i_mapping, num_pages);
 		if (num_pages < (root->leafsize >> PAGE_CACHE_SHIFT) + 1)
 			btrfs_btree_balance_dirty(root, 1);
+		btrfs_throttle(root);
 		cond_resched();
 	}
 out:

trunk/fs/btrfs/inode.c

@@ -2482,7 +2482,7 @@ static int btrfs_create(struct inode *dir, struct dentry *dentry,
 	btrfs_update_inode_block_group(trans, dir);
 out_unlock:
 	nr = trans->blocks_used;
-	btrfs_end_transaction(trans, root);
+	btrfs_end_transaction_throttle(trans, root);
 fail:
 	if (drop_inode) {
 		inode_dec_link_count(inode);
@@ -2535,7 +2535,7 @@ static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
 		drop_inode = 1;
 
 	nr = trans->blocks_used;
-	btrfs_end_transaction(trans, root);
+	btrfs_end_transaction_throttle(trans, root);
 fail:
 	if (drop_inode) {
 		inode_dec_link_count(inode);
@@ -2609,7 +2609,7 @@ static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 
 out_fail:
 	nr = trans->blocks_used;
-	btrfs_end_transaction(trans, root);
+	btrfs_end_transaction_throttle(trans, root);
 
 out_unlock:
 	if (drop_on_err)
@@ -3434,7 +3434,7 @@ static int btrfs_rename(struct inode * old_dir, struct dentry *old_dentry,
 		goto out_fail;
 
 out_fail:
-	btrfs_end_transaction(trans, root);
+	btrfs_end_transaction_throttle(trans, root);
 out_unlock:
 	return ret;
 }
@@ -3548,7 +3548,7 @@ static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
 
 out_unlock:
 	nr = trans->blocks_used;
-	btrfs_end_transaction(trans, root);
+	btrfs_end_transaction_throttle(trans, root);
 out_fail:
 	if (drop_inode) {
 		inode_dec_link_count(inode);

trunk/fs/btrfs/transaction.c

@@ -202,35 +202,64 @@ static noinline int wait_for_commit(struct btrfs_root *root,
 	return 0;
 }
 
+void btrfs_throttle(struct btrfs_root *root)
+{
+	struct btrfs_fs_info *info = root->fs_info;
+
+harder:
+	if (atomic_read(&info->throttles)) {
+		DEFINE_WAIT(wait);
+		int thr;
+		int harder_count = 0;
+		thr = atomic_read(&info->throttle_gen);
+
+		do {
+			prepare_to_wait(&info->transaction_throttle,
+					&wait, TASK_UNINTERRUPTIBLE);
+			if (!atomic_read(&info->throttles)) {
+				finish_wait(&info->transaction_throttle, &wait);
+				break;
+			}
+			schedule();
+			finish_wait(&info->transaction_throttle, &wait);
+		} while (thr == atomic_read(&info->throttle_gen));
+
+		if (harder_count < 5 &&
+		    info->total_ref_cache_size > 5 * 1024 * 1024) {
+			harder_count++;
+			goto harder;
+		}
+
+		if (harder_count < 10 &&
+		    info->total_ref_cache_size > 10 * 1024 * 1024) {
+			harder_count++;
+			goto harder;
+		}
+	}
+}
+
 static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
 			  struct btrfs_root *root, int throttle)
 {
 	struct btrfs_transaction *cur_trans;
+	struct btrfs_fs_info *info = root->fs_info;
 
-	mutex_lock(&root->fs_info->trans_mutex);
-	cur_trans = root->fs_info->running_transaction;
+	mutex_lock(&info->trans_mutex);
+	cur_trans = info->running_transaction;
 	WARN_ON(cur_trans != trans->transaction);
 	WARN_ON(cur_trans->num_writers < 1);
 	cur_trans->num_writers--;
 
 	if (waitqueue_active(&cur_trans->writer_wait))
 		wake_up(&cur_trans->writer_wait);
-
-	if (throttle && atomic_read(&root->fs_info->throttles)) {
-		DEFINE_WAIT(wait);
-		mutex_unlock(&root->fs_info->trans_mutex);
-		prepare_to_wait(&root->fs_info->transaction_throttle, &wait,
-				TASK_UNINTERRUPTIBLE);
-		if (atomic_read(&root->fs_info->throttles))
-			schedule();
-		finish_wait(&root->fs_info->transaction_throttle, &wait);
-		mutex_lock(&root->fs_info->trans_mutex);
-	}
-
 	put_transaction(cur_trans);
-	mutex_unlock(&root->fs_info->trans_mutex);
+	mutex_unlock(&info->trans_mutex);
 	memset(trans, 0, sizeof(*trans));
 	kmem_cache_free(btrfs_trans_handle_cachep, trans);
+
+	if (throttle)
+		btrfs_throttle(root);
+
 	return 0;
 }
 

trunk/fs/btrfs/transaction.h

@@ -91,4 +91,5 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
 			     struct btrfs_root *root);
 int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans,
 				   struct btrfs_root *root);
+void btrfs_throttle(struct btrfs_root *root);
 #endif