[PATCH 2/3] Btrfs: fix missing release of the space/qgroup reservation in start_transaction()

[PATCH 2/3] Btrfs: fix missing release of the space/qgroup reservation in start_transaction()

[Miao Xie]

When we fail to start a transaction, we need to release the reserved free space
and qgroup space, fix it.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
---
 fs/btrfs/transaction.c |   27 +++++++++++++++++++--------
 1 files changed, 19 insertions(+), 8 deletions(-)

diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 87fac9a..194d0b5 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -333,12 +333,14 @@ start_transaction(struct btrfs_root *root, u64 num_items, int type,
 					  &root->fs_info->trans_block_rsv,
 					  num_bytes, flush);
 		if (ret)
-			return ERR_PTR(ret);
+			goto reserve_fail;
 	}
 again:
 	h = kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS);
-	if (!h)
-		return ERR_PTR(-ENOMEM);
+	if (!h) {
+		ret = -ENOMEM;
+		goto alloc_fail;
+	}
 
 	/*
 	 * If we are JOIN_NOLOCK we're already committing a transaction and
@@ -365,11 +367,7 @@ again:
 	if (ret < 0) {
 		/* We must get the transaction if we are JOIN_NOLOCK. */
 		BUG_ON(type == TRANS_JOIN_NOLOCK);
-
-		if (type < TRANS_JOIN_NOLOCK)
-			sb_end_intwrite(root->fs_info->sb);
-		kmem_cache_free(btrfs_trans_handle_cachep, h);
-		return ERR_PTR(ret);
+		goto join_fail;
 	}
 
 	cur_trans = root->fs_info->running_transaction;
@@ -410,6 +408,19 @@ got_it:
 	if (!current->journal_info && type != TRANS_USERSPACE)
 		current->journal_info = h;
 	return h;
+
+join_fail:
+	if (type < TRANS_JOIN_NOLOCK)
+		sb_end_intwrite(root->fs_info->sb);
+	kmem_cache_free(btrfs_trans_handle_cachep, h);
+alloc_fail:
+	if (num_bytes)
+		btrfs_block_rsv_release(root, &root->fs_info->trans_block_rsv,
+					num_bytes);
+reserve_fail:
+	if (qgroup_reserved)
+		btrfs_qgroup_free(root, qgroup_reserved);
+	return ERR_PTR(ret);
 }
 
 struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
-- 
1.6.5.2

Re: [PATCH 2/3] Btrfs: fix missing release of the space/qgroup reservation in start_transaction()

[Jan Schmidt]

On 28.01.2013 13:36, Miao Xie wrote:
> When we fail to start a transaction, we need to release the reserved free space
> and qgroup space, fix it.
> 
> Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
> ---
>  fs/btrfs/transaction.c |   27 +++++++++++++++++++--------
>  1 files changed, 19 insertions(+), 8 deletions(-)
> 
> diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
> index 87fac9a..194d0b5 100644
> --- a/fs/btrfs/transaction.c
> +++ b/fs/btrfs/transaction.c
> @@ -333,12 +333,14 @@ start_transaction(struct btrfs_root *root, u64 num_items, int type,
>  					  &root->fs_info->trans_block_rsv,
>  					  num_bytes, flush);
>  		if (ret)
> -			return ERR_PTR(ret);
> +			goto reserve_fail;
>  	}
>  again:
>  	h = kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS);
> -	if (!h)
> -		return ERR_PTR(-ENOMEM);
> +	if (!h) {
> +		ret = -ENOMEM;
> +		goto alloc_fail;
> +	}
>  
>  	/*
>  	 * If we are JOIN_NOLOCK we're already committing a transaction and
> @@ -365,11 +367,7 @@ again:
>  	if (ret < 0) {
>  		/* We must get the transaction if we are JOIN_NOLOCK. */
>  		BUG_ON(type == TRANS_JOIN_NOLOCK);
> -
> -		if (type < TRANS_JOIN_NOLOCK)
> -			sb_end_intwrite(root->fs_info->sb);
> -		kmem_cache_free(btrfs_trans_handle_cachep, h);
> -		return ERR_PTR(ret);
> +		goto join_fail;
>  	}
>  
>  	cur_trans = root->fs_info->running_transaction;
> @@ -410,6 +408,19 @@ got_it:
>  	if (!current->journal_info && type != TRANS_USERSPACE)
>  		current->journal_info = h;
>  	return h;
> +
> +join_fail:
> +	if (type < TRANS_JOIN_NOLOCK)
> +		sb_end_intwrite(root->fs_info->sb);
> +	kmem_cache_free(btrfs_trans_handle_cachep, h);
> +alloc_fail:
> +	if (num_bytes)
> +		btrfs_block_rsv_release(root, &root->fs_info->trans_block_rsv,
> +					num_bytes);
> +reserve_fail:
> +	if (qgroup_reserved)
> +		btrfs_qgroup_free(root, qgroup_reserved);
> +	return ERR_PTR(ret);
>  }
>  
>  struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
> 

Reviewed-by: Jan Schmidt <list.btrfs@jan-o-sch.net>

-Jan