Re: [PATCH v3 17/25] gup: Don't allow FOLL_LONGTERM pinning of FS DAX pages
From: John Hubbard <jhubbard@nvidia.com>
Date: 2024-11-22 03:23:47
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linux-arm-kernel, linux-cxl, linux-doc, linux-ext4, linux-fsdevel, linux-mm, linux-xfs, lkml, nvdimm
On 11/21/24 5:40 PM, Alistair Popple wrote:
quoted hunk ↗ jump to hunk
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> --- include/linux/mm.h | 4 ++++ 1 file changed, 4 insertions(+)diff --git a/include/linux/mm.h b/include/linux/mm.h index 22c651b..4f9ae37 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h@@ -2004,6 +2004,10 @@ 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);
Reviewed-by: John Hubbard <jhubbard@nvidia.com> thanks, -- John Hubbard