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authorDan Williams <dan.j.williams@intel.com>2021-02-25 17:17:08 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2021-02-26 09:41:00 -0800
commit34dc45be4563f344d59ba0428416d0d265aa4f4d (patch)
treecd4aad78ac82ff94569195a7509f336993f03f77 /mm
parent1f90a3477df3ff1a91e064af554cdc887c8f9e5e (diff)
downloadlinux-next-34dc45be4563f344d59ba0428416d0d265aa4f4d.tar.gz
mm: fix memory_failure() handling of dax-namespace metadata
Given 'struct dev_pagemap' spans both data pages and metadata pages be careful to consult the altmap if present to delineate metadata. In fact the pfn_first() helper already identifies the first valid data pfn, so export that helper for other code paths via pgmap_pfn_valid(). Other usage of get_dev_pagemap() are not a concern because those are operating on known data pfns having been looked up by get_user_pages(). I.e. metadata pfns are never user mapped. Link: https://lkml.kernel.org/r/161058501758.1840162.4239831989762604527.stgit@dwillia2-desk3.amr.corp.intel.com Fixes: 6100e34b2526 ("mm, memory_failure: Teach memory_failure() about dev_pagemap pages") Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reported-by: David Hildenbrand <david@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Qian Cai <cai@lca.pw> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/memory-failure.c6
-rw-r--r--mm/memremap.c15
2 files changed, 21 insertions, 0 deletions
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 55c671904aac..24210c9bd843 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1312,6 +1312,12 @@ static int memory_failure_dev_pagemap(unsigned long pfn, int flags,
*/
put_page(page);
+ /* device metadata space is not recoverable */
+ if (!pgmap_pfn_valid(pgmap, pfn)) {
+ rc = -ENXIO;
+ goto out;
+ }
+
/*
* Prevent the inode from being freed while we are interrogating
* the address_space, typically this would be handled by
diff --git a/mm/memremap.c b/mm/memremap.c
index 16b2fb482da1..2455bac89506 100644
--- a/mm/memremap.c
+++ b/mm/memremap.c
@@ -80,6 +80,21 @@ static unsigned long pfn_first(struct dev_pagemap *pgmap, int range_id)
return pfn + vmem_altmap_offset(pgmap_altmap(pgmap));
}
+bool pgmap_pfn_valid(struct dev_pagemap *pgmap, unsigned long pfn)
+{
+ int i;
+
+ for (i = 0; i < pgmap->nr_range; i++) {
+ struct range *range = &pgmap->ranges[i];
+
+ if (pfn >= PHYS_PFN(range->start) &&
+ pfn <= PHYS_PFN(range->end))
+ return pfn >= pfn_first(pgmap, i);
+ }
+
+ return false;
+}
+
static unsigned long pfn_end(struct dev_pagemap *pgmap, int range_id)
{
const struct range *range = &pgmap->ranges[range_id];