This is a note to let you know that I've just added the patch titled
btrfs: respect the max size in the header when activating swap file
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:
btrfs-respect-the-max-size-in-the-header-when-activating-swap-file.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.
>From c2f822635df873c510bda6fb7fd1b10b7c31be2d Mon Sep 17 00:00:00 2001
From: Filipe Manana <fdmanana@xxxxxxxx>
Date: Thu, 16 Dec 2021 15:00:32 +0000
Subject: btrfs: respect the max size in the header when activating swap file
From: Filipe Manana <fdmanana@xxxxxxxx>
commit c2f822635df873c510bda6fb7fd1b10b7c31be2d upstream.
If we extended the size of a swapfile after its header was created (by the
mkswap utility) and then try to activate it, we will map the entire file
when activating the swap file, instead of limiting to the max size defined
in the swap file's header.
Currently test case generic/643 from fstests fails because we do not
respect that size limit defined in the swap file's header.
So fix this by not mapping file ranges beyond the max size defined in the
swap header.
This is the same type of bug that iomap used to have, and was fixed in
commit 36ca7943ac18ae ("mm/swap: consider max pages in
iomap_swapfile_add_extent").
Fixes: ed46ff3d423780 ("Btrfs: support swap files")
CC: stable@xxxxxxxxxxxxxxx # 5.4+
Reviewed-and-tested-by: Josef Bacik <josef@xxxxxxxxxxxxxx
Signed-off-by: Filipe Manana <fdmanana@xxxxxxxx>
Reviewed-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/btrfs/inode.c | 11 +++++++++++
1 file changed, 11 insertions(+)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -10586,9 +10586,19 @@ static int btrfs_add_swap_extent(struct
struct btrfs_swap_info *bsi)
{
unsigned long nr_pages;
+ unsigned long max_pages;
u64 first_ppage, first_ppage_reported, next_ppage;
int ret;
+ /*
+ * Our swapfile may have had its size extended after the swap header was
+ * written. In that case activating the swapfile should not go beyond
+ * the max size set in the swap header.
+ */
+ if (bsi->nr_pages >= sis->max)
+ return 0;
+
+ max_pages = sis->max - bsi->nr_pages;
first_ppage = ALIGN(bsi->block_start, PAGE_SIZE) >> PAGE_SHIFT;
next_ppage = ALIGN_DOWN(bsi->block_start + bsi->block_len,
PAGE_SIZE) >> PAGE_SHIFT;
@@ -10596,6 +10606,7 @@ static int btrfs_add_swap_extent(struct
if (first_ppage >= next_ppage)
return 0;
nr_pages = next_ppage - first_ppage;
+ nr_pages = min(nr_pages, max_pages);
first_ppage_reported = first_ppage;
if (bsi->start == 0)
Patches currently in stable-queue which might be from fdmanana@xxxxxxxx are
queue-5.15/btrfs-respect-the-max-size-in-the-header-when-activating-swap-file.patch
queue-5.15/btrfs-fix-deadlock-between-quota-enable-and-other-quota-operations.patch
