Re: BUG_ON(!mapping_empty(&inode->i_data))
On Fri, Apr 02, 2021 at 04:13:05AM +0100, Matthew Wilcox wrote:
+ for (;;) {
+ xas_load(xas);
+ if (!xas_is_node(xas))
+ break;
+ xas_delete_node(xas);
+ xas->xa_index -= XA_CHUNK_SIZE;
+ if (xas->xa_index < index)
+ break;
That's a bug. index can be 0, so the condition would never be true.
It should be:
if (xas->xa_index <= (index | XA_CHUNK_MASK))
break;
xas->xa_index -= XA_CHUNK_SIZE;
The test doesn't notice this bug because the tree is otherwise empty,
and the !xas_is_node(xas) condition is hit first. The next test will
notice this.