The .error_remove_folio a_ops is used by different filesystems to handle folio truncation upon discovery of a memory failure in the memory associated with the given folio.
Currently, MF_DELAYED is treated as an error, causing "Failed to punch page" to be written to the console. MF_DELAYED is then relayed to the caller of truncate_error_folio() as MF_FAILED. This further causes memory_failure() to return -EBUSY, which then always causes a SIGBUS. This is also implies that regardless of whether the thread's memory corruption kill policy is PR_MCE_KILL_EARLY or PR_MCE_KILL_LATE, a memory failure with MF_DELAYED will always cause a SIGBUS. Update truncate_error_folio() to return MF_DELAYED to the caller if the .error_remove_folio() callback reports MF_DELAYED. Signed-off-by: Lisa Wang <[email protected]> --- mm/memory-failure.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 4f143334d5a1..57f7762e7418 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -941,6 +941,8 @@ static int truncate_error_folio(struct folio *folio, unsigned long pfn, if (mapping->a_ops->error_remove_folio) { int err = mapping->a_ops->error_remove_folio(mapping, folio); + if (err == MF_DELAYED) + return err; if (err != 0) pr_info("%#lx: Failed to punch page: %d\n", pfn, err); else if (!filemap_release_folio(folio, GFP_NOIO)) -- 2.53.0.959.g497ff81fa9-goog

