mm: memory_failure: Allow truncate_error_folio to return MF_DELAYED

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.

Link: https://lore.kernel.org/20260917-memory-failure-mf-delayed-fix-v6-2-4b00856b5364@google.com
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 <wyihan@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Acked-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Ackerley Tng <ackerleytng@google.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Fuad Tabba <tabba@google.com>
Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Isaku Yamahata <isaku.yamahata@intel.com>
Cc: Jiaqi Yan <jiaqiyan@google.com>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michael Roth <michael.roth@amd.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vishal Annapurve <vannapurve@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Xiaoyao Li <xiaoyao.li@intel.com>
Cc: Yu Zhang <yu.c.zhang@linux.intel.com>

0 files changed, 0 insertions, 0 deletions