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authorJoao Martins <joao.m.martins@oracle.com>2022-01-29 13:41:01 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2022-01-30 09:56:58 +0200
commit61e28cf0543c7d8e6ef88c3c305f727c5a21ba5b (patch)
tree716d66f5994a5aebb182f1a04d1f50175995726a
parentdbecf9b8b8ce580f4e11afed9d61e8aa294cddd2 (diff)
memory-failure: fetch compound_head after pgmap_pfn_valid()
memory_failure_dev_pagemap() at the moment assumes base pages (e.g. dax_lock_page()). For devmap with compound pages fetch the compound_head in case a tail page memory failure is being handled. Currently this is a nop, but in the advent of compound pages in dev_pagemap it allows memory_failure_dev_pagemap() to keep working. Without this fix memory-failure handling (i.e. MCEs on pmem) with device-dax configured namespaces will regress (and crash). Link: https://lkml.kernel.org/r/20211202204422.26777-2-joao.m.martins@oracle.com Reported-by: Jane Chu <jane.chu@oracle.com> Signed-off-by: Joao Martins <joao.m.martins@oracle.com> Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--mm/memory-failure.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 14ae5c18e776..97a9ed8f87a9 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1596,6 +1596,12 @@ static int memory_failure_dev_pagemap(unsigned long pfn, int flags,
}
/*
+ * Pages instantiated by device-dax (not filesystem-dax)
+ * may be compound pages.
+ */
+ page = compound_head(page);
+
+ /*
* Prevent the inode from being freed while we are interrogating
* the address_space, typically this would be handled by
* lock_page(), but dax pages do not use the page lock. This