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. Acked-by: David Hildenbrand (Arm) <[email protected]> Acked-by: Miaohe Lin <[email protected]> Reviewed-by: Ackerley Tng <[email protected]> Fixes: 6a46079cf57a ("HWPOISON: The high level memory error handler in the VM v7") Fixes: a7800aa80ea4 ("KVM: Add KVM_CREATE_GUEST_MEMFD ioctl() for guest-specific backing memory") Signed-off-by: Lisa Wang <[email protected]> --- mm/memory-failure.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index e698d0e9711d..37ea23489b75 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -939,10 +939,12 @@ 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 != 0) + if (err == MF_DELAYED) + ret = err; + else if (err != 0) pr_info("%#lx: Failed to punch page: %d\n", pfn, err); else if (!filemap_release_folio(folio, GFP_NOIO)) - pr_info("%#lx: failed to release buffers\n", pfn); + pr_info("%#lx: Failed to release buffers\n", pfn); else ret = MF_RECOVERED; } else { -- 2.55.0.766.g2966f0265a-goog
