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Commit 8ddc4734 authored by Miao Xie's avatar Miao Xie Committed by Chris Mason
Browse files

Btrfs: fix unprotected defragable inode insertion 



We forget to get the defrag lock when we re-add the defragable inode,
Fix it.

Signed-off-by: default avatarMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: default avatarChris Mason <chris.mason@fusionio.com>
parent 9247f317

fs/btrfs/file.c

+55 −15
Original line number Diff line number Diff line
@@ -91,7 +91,7 @@ static int __compare_inode_defrag(struct inode_defrag *defrag1, 
 * If an existing record is found the defrag item you

 * pass in is freed

 */

static void __btrfs_add_inode_defrag(struct inode *inode,

static int __btrfs_add_inode_defrag(struct inode *inode,

				    struct inode_defrag *defrag)

{

	struct btrfs_root *root = BTRFS_I(inode)->root;
@@ -119,18 +119,24 @@ static void __btrfs_add_inode_defrag(struct inode *inode, 
				entry->transid = defrag->transid;

			if (defrag->last_offset > entry->last_offset)

				entry->last_offset = defrag->last_offset;

			goto exists;

			return -EEXIST;

		}

	}

	set_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags);

	rb_link_node(&defrag->rb_node, parent, p);

	rb_insert_color(&defrag->rb_node, &root->fs_info->defrag_inodes);

	return;

	return 0;

}



exists:

	kmem_cache_free(btrfs_inode_defrag_cachep, defrag);

	return;

static inline int __need_auto_defrag(struct btrfs_root *root)

{

	if (!btrfs_test_opt(root, AUTO_DEFRAG))

		return 0;



	if (btrfs_fs_closing(root->fs_info))

		return 0;



	return 1;

}



/*
@@ -143,11 +149,9 @@ int btrfs_add_inode_defrag(struct btrfs_trans_handle *trans, 
	struct btrfs_root *root = BTRFS_I(inode)->root;

	struct inode_defrag *defrag;

	u64 transid;

	int ret;



	if (!btrfs_test_opt(root, AUTO_DEFRAG))

		return 0;



	if (btrfs_fs_closing(root->fs_info))

	if (!__need_auto_defrag(root))

		return 0;



	if (test_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags))
@@ -167,14 +171,50 @@ int btrfs_add_inode_defrag(struct btrfs_trans_handle *trans, 
	defrag->root = root->root_key.objectid;



	spin_lock(&root->fs_info->defrag_inodes_lock);

	if (!test_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags))

		__btrfs_add_inode_defrag(inode, defrag);

	else

	if (!test_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags)) {

		/*

		 * If we set IN_DEFRAG flag and evict the inode from memory,

		 * and then re-read this inode, this new inode doesn't have

		 * IN_DEFRAG flag. At the case, we may find the existed defrag.

		 */

		ret = __btrfs_add_inode_defrag(inode, defrag);

		if (ret)

			kmem_cache_free(btrfs_inode_defrag_cachep, defrag);

	} else {

		kmem_cache_free(btrfs_inode_defrag_cachep, defrag);

	}

	spin_unlock(&root->fs_info->defrag_inodes_lock);

	return 0;

}



/*

 * Requeue the defrag object. If there is a defrag object that points to

 * the same inode in the tree, we will merge them together (by

 * __btrfs_add_inode_defrag()) and free the one that we want to requeue.

 */

void btrfs_requeue_inode_defrag(struct inode *inode,

				struct inode_defrag *defrag)

{

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

	int ret;



	if (!__need_auto_defrag(root))

		goto out;



	/*

	 * Here we don't check the IN_DEFRAG flag, because we need merge

	 * them together.

	 */

	spin_lock(&root->fs_info->defrag_inodes_lock);

	ret = __btrfs_add_inode_defrag(inode, defrag);

	spin_unlock(&root->fs_info->defrag_inodes_lock);

	if (ret)

		goto out;

	return;

out:

	kmem_cache_free(btrfs_inode_defrag_cachep, defrag);

}



/*

 * must be called with the defrag_inodes lock held

 */
@@ -294,7 +334,7 @@ int btrfs_run_defrag_inodes(struct btrfs_fs_info *fs_info) 
		 */

		if (num_defrag == defrag_batch) {

			defrag->last_offset = range.start;

			__btrfs_add_inode_defrag(inode, defrag);

			btrfs_requeue_inode_defrag(inode, defrag);

			/*

			 * we don't want to kfree defrag, we added it back to

			 * the rbtree
@@ -308,7 +348,7 @@ int btrfs_run_defrag_inodes(struct btrfs_fs_info *fs_info) 
			 */

			defrag->last_offset = 0;

			defrag->cycled = 1;

			__btrfs_add_inode_defrag(inode, defrag);

			btrfs_requeue_inode_defrag(inode, defrag);

			defrag = NULL;

		}