2018-06-20 08:33:45

by Arnd Bergmann

Subject: [PATCH] nilfs2: use 64-bit superblock timstamps

The mount time field in the superblock uses a 64-bit timestamp, but
calling get_seconds() may truncate the current time to 32 bits.

This changes it to ktime_get_real_seconds() to avoid the potential
overflow.

Signed-off-by: Arnd Bergmann <[email protected]>
---
fs/nilfs2/super.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index 6ffeca84d7c3..1b9067cf4511 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -834,7 +834,7 @@ static int nilfs_setup_super(struct super_block *sb, int is_mount)
sbp[0]->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT);

sbp[0]->s_mnt_count = cpu_to_le16(mnt_count + 1);
- sbp[0]->s_mtime = cpu_to_le64(get_seconds());
+ sbp[0]->s_mtime = cpu_to_le64(ktime_get_real_seconds());

skip_mount_setup:
sbp[0]->s_state =
--
2.9.0

2018-06-21 02:43:09

by Ryusuke Konishi

Subject: Re: [PATCH] nilfs2: use 64-bit superblock timstamps

On 2018/06/20 16:50, Arnd Bergmann wrote:
> The mount time field in the superblock uses a 64-bit timestamp, but
> calling get_seconds() may truncate the current time to 32 bits.
>
> This changes it to ktime_get_real_seconds() to avoid the potential
> overflow.
>
> Signed-off-by: Arnd Bergmann <[email protected]>

Looks good to me.

Thanks, all.

Acked-by: Ryusuke Konishi <[email protected]>


> ---
> fs/nilfs2/super.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
> index 6ffeca84d7c3..1b9067cf4511 100644
> --- a/fs/nilfs2/super.c
> +++ b/fs/nilfs2/super.c
> @@ -834,7 +834,7 @@ static int nilfs_setup_super(struct super_block *sb, int is_mount)
> sbp[0]->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT);
>
> sbp[0]->s_mnt_count = cpu_to_le16(mnt_count + 1);
> - sbp[0]->s_mtime = cpu_to_le64(get_seconds());
> + sbp[0]->s_mtime = cpu_to_le64(ktime_get_real_seconds());
>
> skip_mount_setup:
> sbp[0]->s_state =
>