Commit b7d5b0a8 authored by Miao Xie's avatar Miao Xie Committed by Josef Bacik
Browse files

Btrfs: fix joining the same transaction handler more than 2 times 



If we flush inodes with pending delalloc in a transaction, we may join
the same transaction handler more than 2 times.

The reason is:
  Task						use_count of trans handle
  commit_transaction				1
    |-> btrfs_start_delalloc_inodes		1
	  |-> run_delalloc_nocow		1
		|-> join_transaction		2
		|-> cow_file_range		2
			|-> join_transaction	3

In fact, cow_file_range needn't join the transaction again because the caller
have joined the transaction, so we fix this problem by this way.

Reported-by: default avatarLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: default avatarMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: default avatarChris Mason <chris.mason@fusionio.com>
parent 4fde183d

fs/btrfs/inode.c

+47 −30
Original line number Diff line number Diff line
@@ -804,14 +804,14 @@ static u64 get_extent_allocation_hint(struct inode *inode, u64 start, 
 * required to start IO on it.  It may be clean and already done with

 * IO when we return.

 */

static noinline int cow_file_range(struct inode *inode,

static noinline int __cow_file_range(struct btrfs_trans_handle *trans,

				     struct inode *inode,

				     struct btrfs_root *root,

				     struct page *locked_page,

				     u64 start, u64 end, int *page_started,

				     unsigned long *nr_written,

				     int unlock)

{

	struct btrfs_root *root = BTRFS_I(inode)->root;

	struct btrfs_trans_handle *trans;

	u64 alloc_hint = 0;

	u64 num_bytes;

	unsigned long ram_size;
@@ -824,25 +824,10 @@ static noinline int cow_file_range(struct inode *inode, 
	int ret = 0;



	BUG_ON(btrfs_is_free_space_inode(inode));

	trans = btrfs_join_transaction(root);

	if (IS_ERR(trans)) {

		extent_clear_unlock_delalloc(inode,

			     &BTRFS_I(inode)->io_tree,

			     start, end, locked_page,

			     EXTENT_CLEAR_UNLOCK_PAGE |

			     EXTENT_CLEAR_UNLOCK |

			     EXTENT_CLEAR_DELALLOC |

			     EXTENT_CLEAR_DIRTY |

			     EXTENT_SET_WRITEBACK |

			     EXTENT_END_WRITEBACK);

		return PTR_ERR(trans);

	}

	trans->block_rsv = &root->fs_info->delalloc_block_rsv;



	num_bytes = (end - start + blocksize) & ~(blocksize - 1);

	num_bytes = max(blocksize,  num_bytes);

	disk_num_bytes = num_bytes;

	ret = 0;



	/* if this is a small write inside eof, kick off defrag */

	if (num_bytes < 64 * 1024 &&
@@ -953,11 +938,9 @@ static noinline int cow_file_range(struct inode *inode, 
		alloc_hint = ins.objectid + ins.offset;

		start += cur_alloc_size;

	}

	ret = 0;

out:

	btrfs_end_transaction(trans, root);



	return ret;



out_unlock:

	extent_clear_unlock_delalloc(inode,

		     &BTRFS_I(inode)->io_tree,
@@ -972,6 +955,39 @@ out_unlock: 
	goto out;

}



static noinline int cow_file_range(struct inode *inode,

				   struct page *locked_page,

				   u64 start, u64 end, int *page_started,

				   unsigned long *nr_written,

				   int unlock)

{

	struct btrfs_trans_handle *trans;

	struct btrfs_root *root = BTRFS_I(inode)->root;

	int ret;



	trans = btrfs_join_transaction(root);

	if (IS_ERR(trans)) {

		extent_clear_unlock_delalloc(inode,

			     &BTRFS_I(inode)->io_tree,

			     start, end, locked_page,

			     EXTENT_CLEAR_UNLOCK_PAGE |

			     EXTENT_CLEAR_UNLOCK |

			     EXTENT_CLEAR_DELALLOC |

			     EXTENT_CLEAR_DIRTY |

			     EXTENT_SET_WRITEBACK |

			     EXTENT_END_WRITEBACK);

		return PTR_ERR(trans);

	}

	trans->block_rsv = &root->fs_info->delalloc_block_rsv;



	ret = __cow_file_range(trans, inode, root, locked_page, start, end,

			       page_started, nr_written, unlock);



	btrfs_end_transaction(trans, root);



	return ret;

}



/*

 * work queue call back to started compression on a file and pages

 */
@@ -1282,9 +1298,9 @@ out_check: 


		btrfs_release_path(path);

		if (cow_start != (u64)-1) {

			ret = cow_file_range(inode, locked_page, cow_start,

					found_key.offset - 1, page_started,

					nr_written, 1);

			ret = __cow_file_range(trans, inode, root, locked_page,

					       cow_start, found_key.offset - 1,

					       page_started, nr_written, 1);

			if (ret) {

				btrfs_abort_transaction(trans, root, ret);

				goto error;
@@ -1353,7 +1369,8 @@ out_check: 
	}



	if (cow_start != (u64)-1) {

		ret = cow_file_range(inode, locked_page, cow_start, end,

		ret = __cow_file_range(trans, inode, root, locked_page,

				       cow_start, end,

				       page_started, nr_written, 1);

		if (ret) {

			btrfs_abort_transaction(trans, root, ret);

fs/btrfs/transaction.c

+1 −0
Original line number Diff line number Diff line
@@ -312,6 +312,7 @@ start_transaction(struct btrfs_root *root, u64 num_items, int type, 
		WARN_ON(type != TRANS_JOIN && type != TRANS_JOIN_NOLOCK);

		h = current->journal_info;

		h->use_count++;

		WARN_ON(h->use_count > 2);

		h->orig_rsv = h->block_rsv;

		h->block_rsv = NULL;

		goto got_it;

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