HWPOISON: Define a new error_remove_page address space op for async truncation

Truncating metadata pages is not safe right now before
we haven't audited all file systems.

To enable truncation only for data address space define
a new address_space callback error_remove_page.

This is used for memory_failure.c memory error handling.

This can be then set to truncate_inode_page()

This patch just defines the new operation and adds documentation.

Callers and users come in followon patches.

Signed-off-by: Andi Kleen <ak@linux.intel.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/fs.h b/include/linux/fs.h
index b21cf6b9c80b..4f47afd37647 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -595,6 +595,7 @@ struct address_space_operations {
         int (*launder_page) (struct page *);
         int (*is_partially_uptodate) (struct page *, read_descriptor_t *,
                                         unsigned long);
+        int (*error_remove_page)(struct address_space *, struct page *);
 };
 
 /*