Commit 9cfc8ba7 authored by Nikolay Borisov's avatar Nikolay Borisov Committed by David Sterba
Browse files

btrfs: Remove special handling of EXTENT_BUFFER_UNMAPPED while freeing 



Now that the whole of btrfs code has been audited for eb reference count
management it's time to remove the hunk in free_extent_buffer that
essentially considered the condition

  "eb->ref == 2 && EXTENT_BUFFER_DUMMY"

to equal "eb->ref = 1". Also remove the last location
which takes an extra reference count in alloc_test_extent_buffer.

Signed-off-by: default avatarNikolay Borisov <nborisov@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent df449714

fs/btrfs/extent_io.c

+0 −11
Original line number Diff line number Diff line
@@ -4893,13 +4893,6 @@ again: 
	check_buffer_tree_ref(eb);

	set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags);



	/*

	 * We will free dummy extent buffer's if they come into

	 * free_extent_buffer with a ref count of 2, but if we are using this we

	 * want the buffers to stay in memory until we're done with them, so

	 * bump the ref count again.

	 */

	atomic_inc(&eb->refs);

	return eb;

free_eb:

	btrfs_release_extent_buffer(eb);
@@ -5089,10 +5082,6 @@ void free_extent_buffer(struct extent_buffer *eb) 
	}



	spin_lock(&eb->refs_lock);

	if (atomic_read(&eb->refs) == 2 &&

	    test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags))

		atomic_dec(&eb->refs);



	if (atomic_read(&eb->refs) == 2 &&

	    test_bit(EXTENT_BUFFER_STALE, &eb->bflags) &&

	    !extent_buffer_under_io(eb) &&

fs/btrfs/tests/btrfs-tests.c

+5 −1
Original line number Diff line number Diff line
@@ -174,8 +174,12 @@ void btrfs_free_dummy_root(struct btrfs_root *root) 
	/* Will be freed by btrfs_free_fs_roots */

	if (WARN_ON(test_bit(BTRFS_ROOT_IN_RADIX, &root->state)))

		return;

	if (root->node)

	if (root->node) {

		/* One for allocate_extent_buffer */

		free_extent_buffer(root->node);

		/* One for get_exent_buffer */

		free_extent_buffer(root->node);

	}

	kfree(root);

}

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