The patch titled
Subject: fs/dax: return unmapped busy pages from dax_layout_busy_page_range()
has been added to the -mm mm-unstable branch. Its filename is
fs-dax-return-unmapped-busy-pages-from-dax_layout_busy_page_range.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/fs-dax-return-unmapped-busy-pages-from-dax_layout_busy_page_range.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Alistair Popple <apopple@xxxxxxxxxx>
Subject: fs/dax: return unmapped busy pages from dax_layout_busy_page_range()
Date: Tue, 7 Jan 2025 14:42:18 +1100
dax_layout_busy_page_range() is used by file systems to scan the DAX
page-cache to unmap mapping pages from user-space and to determine if any
pages in the given range are busy, either due to ongoing DMA or other
get_user_pages() usage.
Currently it checks to see the file mapping is mapped into user-space with
mapping_mapped() and returns early if not, skipping the check for DMA busy
pages. This is wrong as pages may still be undergoing DMA access even if
they have subsequently been unmapped from user-space. Fix this by
dropping the check for mapping_mapped().
Link: https://lkml.kernel.org/r/db02794f12a4cc8c659a1123bdc90fcb4dcb1104.1736221254.git-series.apopple@xxxxxxxxxx
Signed-off-by: Alistair Popple <apopple@xxxxxxxxxx>
Suggested-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/dax.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/fs/dax.c~fs-dax-return-unmapped-busy-pages-from-dax_layout_busy_page_range
+++ a/fs/dax.c
@@ -690,7 +690,7 @@ struct page *dax_layout_busy_page_range(
if (IS_ENABLED(CONFIG_FS_DAX_LIMITED))
return NULL;
- if (!dax_mapping(mapping) || !mapping_mapped(mapping))
+ if (!dax_mapping(mapping))
return NULL;
/* If end == LLONG_MAX, all pages from start to till end of file */
_
Patches currently in -mm which might be from apopple@xxxxxxxxxx are
fuse-fix-dax-truncate-punch_hole-fault-path.patch
fs-dax-return-unmapped-busy-pages-from-dax_layout_busy_page_range.patch
fs-dax-dont-skip-locked-entries-when-scanning-entries.patch
fs-dax-refactor-wait-for-dax-idle-page.patch
fs-dax-create-a-common-implementation-to-break-dax-layouts.patch
fs-dax-always-remove-dax-page-cache-entries-when-breaking-layouts.patch
fs-dax-ensure-all-pages-are-idle-prior-to-filesystem-unmount.patch
fs-dax-remove-page_mapping_dax_shared-mapping-flag.patch
mm-gup-remove-redundant-check-for-pci-p2pdma-page.patch
mm-mm_init-move-p2pdma-page-refcount-initialisation-to-p2pdma.patch
mm-allow-compound-zone-device-pages.patch
mm-memory-enhance-insert_page_into_pte_locked-to-create-writable-mappings.patch
mm-memory-add-vmf_insert_page_mkwrite.patch
rmap-add-support-for-pud-sized-mappings-to-rmap.patch
huge_memory-add-vmf_insert_folio_pud.patch
huge_memory-add-vmf_insert_folio_pmd.patch
memremap-add-is_devdax_page-and-is_fsdax_page-helpers.patch
mm-gup-dont-allow-foll_longterm-pinning-of-fs-dax-pages.patch
proc-task_mmu-mark-devdax-and-fsdax-pages-as-always-unpinned.patch
mm-mlock-skip-zone_device-pmds-during-mlock.patch
fs-dax-properly-refcount-fs-dax-pages.patch
device-dax-properly-refcount-device-dax-pages-when-mapping.patch
mm-remove-pxx_devmap-callers.patch
mm-remove-devmap-related-functions-and-page-table-bits.patch
revert-riscv-mm-add-support-for-zone_device.patch
