From: Hugh Dickins <hughd@xxxxxxxxxx> Subject: shmem: mapping_set_exiting() to help mapped resilience When I added page_mapped() resilience in __delete_from_page_cache() for the mapping_exiting() case, I missed that mapping_set_exiting() is done in truncate_inode_pages_final(), which is not actually called for shmem. (Today, it is folio_mapped() resilience in filemap_unaccount_folio().) So the fixup to avoid a memory leak in this case never worked on shmem: add a mapping_set_exiting() in shmem_evict_inode() at last. But this is hardly a candidate for stable, since it's only useful if "Bad page". Link: https://lkml.kernel.org/r/beefffda-6326-e36d-2d41-ed15b51af872@xxxxxxxxxx Fixes: 06b241f32c71 ("mm: __delete_from_page_cache show Bad page if mapped") Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/shmem.c | 1 + 1 file changed, 1 insertion(+) --- a/mm/shmem.c~shmem-mapping_set_exiting-to-help-mapped-resilience +++ a/mm/shmem.c @@ -1129,6 +1129,7 @@ static void shmem_evict_inode(struct ino if (shmem_mapping(inode->i_mapping)) { shmem_unacct_size(info->flags, inode->i_size); inode->i_size = 0; + mapping_set_exiting(inode->i_mapping); shmem_truncate_range(inode, 0, (loff_t)-1); if (!list_empty(&info->shrinklist)) { spin_lock(&sbinfo->shrinklist_lock); _
