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Commit 17de39ac authored by Josef Bacik's avatar Josef Bacik Committed by Chris Mason
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Btrfs: fix page leak when allocing extent buffers 



If we happen to alloc a extent buffer and then alloc a page and notice that
page is already attached to an extent buffer, we will only unlock it and
free our existing eb.  Any pages currently attached to that eb will be
properly freed, but we don't do the page_cache_release() on the page where
we noticed the other extent buffer which can cause us to leak pages and I
hope cause the weird issues we've been seeing in this area.  Thanks,

Signed-off-by: default avatarJosef Bacik <josef@redhat.com>
Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent e5846fc6

fs/btrfs/extent_io.c

+2 −2
Original line number Original line Diff line number Diff line
@@ -4120,6 +4120,7 @@ struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree, 
			if (atomic_inc_not_zero(&exists->refs)) {

			if (atomic_inc_not_zero(&exists->refs)) {

				spin_unlock(&mapping->private_lock);

				spin_unlock(&mapping->private_lock);

				unlock_page(p);

				unlock_page(p);

				page_cache_release(p);

				mark_extent_buffer_accessed(exists);

				mark_extent_buffer_accessed(exists);

				goto free_eb;

				goto free_eb;

			}

			}
@@ -4199,8 +4200,7 @@ free_eb: 
			unlock_page(eb->pages[i]);

			unlock_page(eb->pages[i]);

	}

	}





	if (!atomic_dec_and_test(&eb->refs))

	WARN_ON(!atomic_dec_and_test(&eb->refs));

		return exists;

	btrfs_release_extent_buffer(eb);

	btrfs_release_extent_buffer(eb);

	return exists;

	return exists;

}

}