The patch titled
Subject: swap: fix swapfile read/write offset
has been added to the -mm tree. Its filename is
swap-fix-swapfile-read-write-offset.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/swap-fix-swapfile-read-write-offset.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/swap-fix-swapfile-read-write-offset.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Jens Axboe <axboe@xxxxxxxxx>
Subject: swap: fix swapfile read/write offset
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...
Link: https://lkml.kernel.org/r/6f9da9c6-c6c5-08fe-95ea-940954456c40@xxxxxxxxx
Fixes: 48d15436fde6 ("mm: remove get_swap_bio")
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/swap.h | 1 +
mm/page_io.c | 5 -----
mm/swapfile.c | 17 +++++++++++++++--
3 files changed, 16 insertions(+), 7 deletions(-)
--- a/include/linux/swap.h~swap-fix-swapfile-read-write-offset
+++ a/include/linux/swap.h
@@ -485,6 +485,7 @@ 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~swap-fix-swapfile-read-write-offset
+++ a/mm/page_io.c
@@ -254,11 +254,6 @@ 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~swap-fix-swapfile-read-write-offset
+++ a/mm/swapfile.c
@@ -199,8 +199,8 @@ static int discard_swap(struct swap_info
return err; /* That will often be -EOPNOTSUPP */
}
-static struct swap_extent *
-offset_to_swap_extent(struct swap_info_struct *sis, unsigned long offset)
+struct swap_extent *offset_to_swap_extent(struct swap_info_struct *sis,
+ unsigned long offset)
{
struct swap_extent *se;
struct rb_node *rb;
@@ -1858,6 +1858,19 @@ sector_t swapdev_block(int type, pgoff_t
return se->start_block + (offset - se->start_page);
}
+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);
+}
+
/*
* Return either the total number of swap pages of given type, or the number
* of free pages of that type (depending on @free)
_
Patches currently in -mm which might be from axboe@xxxxxxxxx are
swap-fix-swapfile-read-write-offset.patch
