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| author | Matthew Wilcox (Oracle) <willy@infradead.org> | 2022-03-31 08:27:09 -0400 |
|---|---|---|
| committer | Matthew Wilcox (Oracle) <willy@infradead.org> | 2022-03-31 08:52:57 -0400 |
| commit | 3ed4bb77156da0bc732847c8c9df92454c1fbeea (patch) | |
| tree | 0f74eca6af6a307a4a4ea604a759a71e82086ef2 /lib/xarray.c | |
| parent | 3e3c658055c002900982513e289398a1aad4a488 (diff) | |
| download | lwn-3ed4bb77156da0bc732847c8c9df92454c1fbeea.tar.gz lwn-3ed4bb77156da0bc732847c8c9df92454c1fbeea.zip | |
XArray: Update the LRU list in xas_split()
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>
Diffstat (limited to 'lib/xarray.c')
| -rw-r--r-- | lib/xarray.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/lib/xarray.c b/lib/xarray.c index 757644617b9b..88ca87435e3d 100644 --- a/lib/xarray.c +++ b/lib/xarray.c @@ -1081,6 +1081,7 @@ 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; @@ -1095,6 +1096,7 @@ 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 |