This is a note to let you know that I've just added the patch titled
swap: fix swapfile read/write offset
to the 5.4-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:
swap-fix-swapfile-read-write-offset.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From caf6912f3f4af7232340d500a4a2008f81b93f14 Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@xxxxxxxxx>
Date: Tue, 2 Mar 2021 14:53:21 -0700
Subject: swap: fix swapfile read/write offset
From: Jens Axboe <axboe@xxxxxxxxx>
commit caf6912f3f4af7232340d500a4a2008f81b93f14 upstream.
We're not factoring in the start of the file for where to write and
read the swapfile, which leads to very unfortunate side effects of
writing where we should not be...
Fixes: dd6bd0d9c7db ("swap: use bdev_read_page() / bdev_write_page()")
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Cc: Anthony Iliopoulos <ailiop@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
include/linux/swap.h | 1 +
mm/page_io.c | 5 -----
mm/swapfile.c | 13 +++++++++++++
3 files changed, 14 insertions(+), 5 deletions(-)
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -473,6 +473,7 @@ struct backing_dev_info;
extern int init_swap_address_space(unsigned int type, unsigned long nr_pages);
extern void exit_swap_address_space(unsigned int type);
extern struct swap_info_struct *get_swap_device(swp_entry_t entry);
+sector_t swap_page_sector(struct page *page);
static inline void put_swap_device(struct swap_info_struct *si)
{
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -260,11 +260,6 @@ out:
return ret;
}
-static sector_t swap_page_sector(struct page *page)
-{
- return (sector_t)__page_file_index(page) << (PAGE_SHIFT - 9);
-}
-
static inline void count_swpout_vm_event(struct page *page)
{
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -221,6 +221,19 @@ offset_to_swap_extent(struct swap_info_s
BUG();
}
+sector_t swap_page_sector(struct page *page)
+{
+ struct swap_info_struct *sis = page_swap_info(page);
+ struct swap_extent *se;
+ sector_t sector;
+ pgoff_t offset;
+
+ offset = __page_file_index(page);
+ se = offset_to_swap_extent(sis, offset);
+ sector = se->start_block + (offset - se->start_page);
+ return sector << (PAGE_SHIFT - 9);
+}
+
/*
* swap allocation tell device that a cluster of swap can now be discarded,
* to allow the swap device to optimize its wear-levelling.
Patches currently in stable-queue which might be from axboe@xxxxxxxxx are
queue-5.4/nbd-handle-device-refs-for-destroy_on_disconnect-properly.patch
queue-5.4/swap-fix-swapfile-read-write-offset.patch
