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authorMatthew Wilcox (Oracle) <willy@infradead.org>2022-03-31 08:27:09 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-04-15 14:18:28 +0200
commit9a8835902eb66efa716e86aae853ae3122dc0ba5 (patch)
tree978cb289569c11544fc20d037518d2102fe21830 /lib
parentcbd110b8dd7ad763bf413f71c0484116ae9302d4 (diff)
XArray: Update the LRU list in xas_split()
commit 3ed4bb77156da0bc732847c8c9df92454c1fbeea upstream. When splitting a value entry, we may need to add the new nodes to the LRU list and remove the parent node from the LRU list. The WARN_ON checks in shadow_lru_isolate() catch this oversight. This bug was latent until we stopped splitting folios in shrink_page_list() with commit 820c4e2e6f51 ("mm/vmscan: Free non-shmem folios without splitting them"). That allows the creation of large shadow entries, and subsequently when trying to page in a small page, we will split the large shadow entry in __filemap_add_folio(). Fixes: 8fc75643c5e1 ("XArray: add xas_split") Reported-by: Hugh Dickins <hughd@google.com> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'lib')
-rw-r--r--lib/xarray.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/lib/xarray.c b/lib/xarray.c
index 6a2ad7451bdd..61464c52c20e 100644
--- a/lib/xarray.c
+++ b/lib/xarray.c
@@ -1080,6 +1080,7 @@ void xas_split(struct xa_state *xas, void *entry, unsigned int order)
xa_mk_node(child));
if (xa_is_value(curr))
values--;
+ xas_update(xas, child);
} else {
unsigned int canon = offset - xas->xa_sibs;
@@ -1094,6 +1095,7 @@ void xas_split(struct xa_state *xas, void *entry, unsigned int order)
} while (offset-- > xas->xa_offset);
node->nr_values += values;
+ xas_update(xas, node);
}
EXPORT_SYMBOL_GPL(xas_split);
#endif