diff options
Diffstat (limited to 'mm/memory.c')
| -rw-r--r-- | mm/memory.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/mm/memory.c b/mm/memory.c index d4dba178e130..0b0727758c86 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3668,6 +3668,17 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) } /* + * PG_anon_exclusive reuses PG_mappedtodisk for anon pages. A swap pte + * must never point at an anonymous page in the swapcache that is + * PG_anon_exclusive. Sanity check that this holds and especially, that + * no filesystem set PG_mappedtodisk on a page in the swapcache. Sanity + * check after taking the PT lock and making sure that nobody + * concurrently faulted in this page and set PG_anon_exclusive. + */ + BUG_ON(!PageAnon(page) && PageMappedToDisk(page)); + BUG_ON(PageAnon(page) && PageAnonExclusive(page)); + + /* * Remove the swap entry and conditionally try to free up the swapcache. * We're already holding a reference on the page but haven't mapped it * yet. |