mm/memory-failure: unnecessary amount of unmapping

BugLink: https://bugs.launchpad.net/bugs/1929455
[ Upstream commit 4d75136be8bf3ae01b0bc3e725b2cdc921e103bd ]

It appears that unmap_mapping_range() actually takes a 'size' as its third
argument rather than a location, the current calling fashion causes
unnecessary amount of unmapping to occur.

Link: https://lkml.kernel.org/r/20210420002821.2749748-1-jane.chu@oracle.com
Fixes: 6100e34b2526e ("mm, memory_failure: Teach memory_failure() about dev_pagemap pages")
Signed-off-by: Jane Chu <jane.chu@oracle.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kelsey Skunberg <kelsey.skunberg@canonical.com>

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 4e3684d694c12408b2515750e5d853c61ece7963..39db9f84b85cc25c6ba495fbdefe4b57e5cc8de0 100644 (file)
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1364,7 +1364,7 @@ static int memory_failure_dev_pagemap(unsigned long pfn, int flags,
                 * communicated in siginfo, see kill_proc()
                 */
                start = (page->index << PAGE_SHIFT) & ~(size - 1);
-               unmap_mapping_range(page->mapping, start, start + size, 0);
+               unmap_mapping_range(page->mapping, start, size, 0);
        }
        kill_procs(&tokill, flags & MF_MUST_KILL, !unmap_success, pfn, flags);
        rc = 0;