Merge tag 'for-4.15-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux (89876f27) · Commits · 戴 / test

fs/btrfs/delayed-inode.c

+34 −11

Original line number	Diff line number	Diff line
		@@ -87,6 +87,7 @@ static struct btrfs_delayed_node *btrfs_get_delayed_node(

		spin_lock(&root->inode_lock);
		node = radix_tree_lookup(&root->delayed_nodes_tree, ino);

		if (node) {
		if (btrfs_inode->delayed_node) {
		refcount_inc(&node->refs); /* can be accessed */
		@@ -94,9 +95,30 @@ static struct btrfs_delayed_node *btrfs_get_delayed_node(
		spin_unlock(&root->inode_lock);
		return node;
		}

		/*
		* It's possible that we're racing into the middle of removing
		* this node from the radix tree. In this case, the refcount
		* was zero and it should never go back to one. Just return
		* NULL like it was never in the radix at all; our release
		* function is in the process of removing it.
		*
		* Some implementations of refcount_inc refuse to bump the
		* refcount once it has hit zero. If we don't do this dance
		* here, refcount_inc() may decide to just WARN_ONCE() instead
		* of actually bumping the refcount.
		*
		* If this node is properly in the radix, we want to bump the
		* refcount twice, once for the inode and once for this get
		* operation.
		*/
		if (refcount_inc_not_zero(&node->refs)) {
		refcount_inc(&node->refs);
		btrfs_inode->delayed_node = node;
		/* can be accessed and cached in the inode */
		refcount_add(2, &node->refs);
		} else {
		node = NULL;
		}

		spin_unlock(&root->inode_lock);
		return node;
		}
		@@ -254,16 +276,17 @@ static void __btrfs_release_delayed_node(
		mutex_unlock(&delayed_node->mutex);

		if (refcount_dec_and_test(&delayed_node->refs)) {
		bool free = false;
		struct btrfs_root *root = delayed_node->root;

		spin_lock(&root->inode_lock);
		if (refcount_read(&delayed_node->refs) == 0) {
		/*
		* Once our refcount goes to zero, nobody is allowed to bump it
		* back up. We can delete it now.
		*/
		ASSERT(refcount_read(&delayed_node->refs) == 0);
		radix_tree_delete(&root->delayed_nodes_tree,
		delayed_node->inode_id);
		free = true;
		}
		spin_unlock(&root->inode_lock);
		if (free)
		kmem_cache_free(delayed_node_cache, delayed_node);
		}
		}

fs/btrfs/volumes.c

+0 −1

Original line number	Diff line number	Diff line
		@@ -237,7 +237,6 @@ static struct btrfs_device *__alloc_device(void)
		kfree(dev);
		return ERR_PTR(-ENOMEM);
		}
		bio_get(dev->flush_bio);

		INIT_LIST_HEAD(&dev->dev_list);
		INIT_LIST_HEAD(&dev->dev_alloc_list);

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