[PATCH v5 18/25] mm/gup: Don't allow FOLL_LONGTERM pinning of FS DAX pages
From: Alistair Popple <apopple@nvidia.com>
Date: 2025-01-07 03:44:25
Also in:
linux-cxl, linux-doc, linux-ext4, linux-fsdevel, linux-mm, linux-xfs, linuxppc-dev, lkml, nvdimm
Subsystem:
memory management - core, the rest · Maintainers:
Andrew Morton, David Hildenbrand, Linus Torvalds
Longterm pinning of FS DAX pages should already be disallowed by various pXX_devmap checks. However a future change will cause these checks to be invalid for FS DAX pages so make folio_is_longterm_pinnable() return false for FS DAX pages. Signed-off-by: Alistair Popple <apopple@nvidia.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Acked-by: David Hildenbrand <redacted> --- include/linux/mm.h | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index f267b06..01edca9 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h@@ -2078,6 +2078,10 @@ static inline bool folio_is_longterm_pinnable(struct folio *folio) if (folio_is_device_coherent(folio)) return false; + /* DAX must also always allow eviction. */ + if (folio_is_fsdax(folio)) + return false; + /* Otherwise, non-movable zone folios can be pinned. */ return !folio_is_zone_movable(folio);
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