From ca7b639e8611b3260a30b18aaa0d6db9c80a75ef Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Sun, 2 Aug 2020 14:17:21 -0400 Subject: [PATCH] XArray: Fix xas_reload for multi-index entries xas_reload() was only checking that the head entry was still at the head index. If the entry has been split, that's not enough as there may be a different entry at the specified index now. Solve this by checking the slot for the requested index instead of the head index. Signed-off-by: Matthew Wilcox (Oracle) --- include/linux/xarray.h | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) diff --git a/include/linux/xarray.h b/include/linux/xarray.h index 29db4e16eb89..4be9c57132fe 100644 --- a/include/linux/xarray.h +++ b/include/linux/xarray.h @@ -1524,10 +1524,21 @@ void xas_create_range(struct xa_state *); static inline void *xas_reload(struct xa_state *xas) { struct xa_node *node = xas->xa_node; - - if (node) - return xa_entry(xas->xa, node, xas->xa_offset); - return xa_head(xas->xa); + void *entry; + char offset; + + if (!node) + return xa_head(xas->xa); + if (IS_ENABLED(CONFIG_XARRAY_MULTI)) { + offset = (xas->xa_index >> node->shift) & XA_CHUNK_MASK; + entry = xa_entry(xas->xa, node, offset); + if (!xa_is_sibling(entry)) + return entry; + offset = xa_to_sibling(entry); + } else { + offset = xas->xa_offset; + } + return xa_entry(xas->xa, node, offset); } /** -- 2.25.1