This is a note to let you know that I've just added the patch titled
erofs: apply proper VMA alignment for memory mapped files on THP
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
erofs-apply-proper-vma-alignment-for-memory-mapped-f.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 9deea584ddedefdec509c7736550783ec87c9920
Author: Gao Xiang <xiang@xxxxxxxxxx>
Date: Wed Mar 6 13:31:38 2024 +0800
erofs: apply proper VMA alignment for memory mapped files on THP
[ Upstream commit 4127caee89612a84adedd78c9453089138cd5afe ]
There are mainly two reasons that thp_get_unmapped_area() should be
used for EROFS as other filesystems:
- It's needed to enable PMD mappings as a FSDAX filesystem, see
commit 74d2fad1334d ("thp, dax: add thp_get_unmapped_area for pmd
mappings");
- It's useful together with large folios and
CONFIG_READ_ONLY_THP_FOR_FS which enable THPs for mmapped files
(e.g. shared libraries) even without FSDAX. See commit 1854bc6e2420
("mm/readahead: Align file mappings for non-DAX").
Fixes: 06252e9ce05b ("erofs: dax support for non-tailpacking regular file")
Fixes: ce529cc25b18 ("erofs: enable large folios for iomap mode")
Fixes: e6687b89225e ("erofs: enable large folios for fscache mode")
Reviewed-by: Jingbo Xu <jefflexu@xxxxxxxxxxxxxxxxx>
Reviewed-by: Chao Yu <chao@xxxxxxxxxx>
Signed-off-by: Gao Xiang <hsiangkao@xxxxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20240306053138.2240206-1-hsiangkao@xxxxxxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/erofs/data.c b/fs/erofs/data.c
index 16a41d0db55a3..a859bf0f31df2 100644
--- a/fs/erofs/data.c
+++ b/fs/erofs/data.c
@@ -340,4 +340,5 @@ const struct file_operations erofs_file_fops = {
.read_iter = erofs_file_read_iter,
.mmap = erofs_file_mmap,
.splice_read = generic_file_splice_read,
+ .get_unmapped_area = thp_get_unmapped_area,
};
