[PATCH 2/3] HWPOISON: report sticky EIO for poisoned file

Naoya Horiguchi
2012-08-22T15:18:09Z

From: Wu Fengguang <fengguang.wu@intel.com>

This makes the EIO reports on write(), fsync(), or the NFS close()
sticky enough. The only way to get rid of it may be

echo 3 > /proc/sys/vm/drop_caches

Note that the impacted process will only be killed if it mapped the page.
XXX
via read()/write()/fsync() instead of memory mapped reads/writes, simply
because it's very hard to find them.

Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
---
include/linux/pagemap.h | 13 +++++++++++++
mm/filemap.c | 11 +++++++++++
mm/memory-failure.c | 2 +-
3 files changed, 25 insertions(+), 1 deletion(-)

diff --git v3.6-rc1.orig/include/linux/pagemap.h v3.6-rc1/include/linux/pagemap.h
index e42c762..4d8d821 100644
--- v3.6-rc1.orig/include/linux/pagemap.h
+++ v3.6-rc1/include/linux/pagemap.h
@@ -24,6 +24,7 @@ enum mapping_flags {
AS_ENOSPC = __GFP_BITS_SHIFT + 1, /* ENOSPC on async write */
AS_MM_ALL_LOCKS = __GFP_BITS_SHIFT + 2, /* under mm_take_all_locks() */
AS_UNEVICTABLE = __GFP_BITS_SHIFT + 3, /* e.g., ramdisk, SHM_LOCK */
+ AS_HWPOISON = __GFP_BITS_SHIFT + 4, /* hardware memory corruption */
};

static inline void mapping_set_error(struct address_space *mapping, int error)
@@ -53,6 +54,18 @@ static inline int mapping_unevictable(struct address_space *mapping)
return !!mapping;
}

+#ifdef CONFIG_MEMORY_FAILURE
+static inline int mapping_hwpoison(struct address_space *mapping)
+{
+ return test_bit(AS_HWPOISON, &mapping->flags);
+}
+#else
+static inline int mapping_hwpoison(struct address_space *mapping)
+{
+ return 0;
+}
+#endif
+
static inline gfp_t mapping_gfp_mask(struct address_space * mapping)
{
return (__force gfp_t)mapping->flags & __GFP_BITS_MASK;
diff --git v3.6-rc1.orig/mm/filemap.c v3.6-rc1/mm/filemap.c
index fa5ca30..8bdaf57 100644
--- v3.6-rc1.orig/mm/filemap.c
+++ v3.6-rc1/mm/filemap.c
@@ -297,6 +297,8 @@ int filemap_fdatawait_range(struct address_space *mapping, loff_t start_byte,
ret = -ENOSPC;
if (test_and_clear_bit(AS_EIO, &mapping->flags))
ret = -EIO;
+ if (mapping_hwpoison(mapping))
+ ret = -EIO;

return ret;
}
@@ -447,6 +449,15 @@ int add_to_page_cache_locked(struct page *page, struct address_space *mapping,
VM_BUG_ON(!PageLocked(page));
VM_BUG_ON(PageSwapBacked(page));

+ /*
+ * Hardware corrupted page will be removed from mapping,
+ * so we want to deny (possibly) reloading the old data.
+ */
+ if (unlikely(mapping_hwpoison(mapping))) {
+ error = -EIO;
+ goto out;
+ }
+
error = mem_cgroup_cache_charge(page, current->mm,
gfp_mask & GFP_RECLAIM_MASK);
if (error)
diff --git v3.6-rc1.orig/mm/memory-failure.c v3.6-rc1/mm/memory-failure.c
index 79dfb2f..a1e7e00 100644
--- v3.6-rc1.orig/mm/memory-failure.c
+++ v3.6-rc1/mm/memory-failure.c
@@ -652,7 +652,7 @@ static int me_pagecache_dirty(struct page *p, unsigned long pfn)
* the first EIO, but we're not worse than other parts
* of the kernel.
*/
- mapping_set_error(mapping, EIO);
+ set_bit(AS_HWPOISON, &mapping->flags);
}

return me_pagecache_clean(p, pfn);
--
1.7.11.4