tree 7731d22b6309dd71bb12431be3a3c7a84d13ee1f
parent 21a449bedf3f01ea30ed657deeb2e8942ad45936
author Hugh Dickins <hughd@google.com> 1724625765 -0700
committer Andrew Morton <akpm@linux-foundation.org> 1725925142 -0700

mm: shmem: fix minor off-by-one in shrinkable calculation

There has been a long-standing and very minor off-by-one, where
shmem_get_folio_gfp() decides if a large folio extends beyond i_size far
enough to leave a page or more for freeing later under pressure.

This is not something needed for stable: but it will be proportionately
more significant as support for smaller large folios is added, and is best
fixed before duplicating the check in other places.

Link: https://lkml.kernel.org/r/d8e75079-af2d-8519-56df-6be1dccc247a@google.com
Fixes: 779750d20b93 ("shmem: split huge pages beyond i_size under memory pressure")
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>