From 876fdc7c4f366a709ac272ef3336ae7dce58f2af Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Mon, 17 Aug 2020 09:58:02 -0700 Subject: [PATCH] xfs: explicitly define inode timestamp range Formally define the inode timestamp ranges that existing filesystems support, and switch the vfs timetamp ranges to use it. Signed-off-by: Darrick J. Wong Reviewed-by: Amir Goldstein Reviewed-by: Christoph Hellwig Reviewed-by: Allison Collins Reviewed-by: Gao Xiang Reviewed-by: Dave Chinner --- fs/xfs/libxfs/xfs_format.h | 22 ++++++++++++++++++++++ fs/xfs/xfs_super.c | 4 ++-- 2 files changed, 24 insertions(+), 2 deletions(-) diff --git a/fs/xfs/libxfs/xfs_format.h b/fs/xfs/libxfs/xfs_format.h index fe129fe16d5f..e57360a8fd16 100644 --- a/fs/xfs/libxfs/xfs_format.h +++ b/fs/xfs/libxfs/xfs_format.h @@ -848,11 +848,33 @@ struct xfs_agfl { ASSERT(xfs_daddr_to_agno(mp, d) == \ xfs_daddr_to_agno(mp, (d) + (len) - 1))) +/* + * XFS Timestamps + * ============== + * + * Traditional ondisk inode timestamps consist of signed 32-bit counters for + * seconds and nanoseconds; time zero is the Unix epoch, Jan 1 00:00:00 UTC + * 1970, which means that the timestamp epoch is the same as the Unix epoch. + * Therefore, the ondisk min and max defined here can be used directly to + * constrain the incore timestamps on a Unix system. + */ typedef struct xfs_timestamp { __be32 t_sec; /* timestamp seconds */ __be32 t_nsec; /* timestamp nanoseconds */ } xfs_timestamp_t; +/* + * Smallest possible ondisk seconds value with traditional timestamps. This + * corresponds exactly with the incore timestamp Dec 13 20:45:52 UTC 1901. + */ +#define XFS_LEGACY_TIME_MIN ((int64_t)S32_MIN) + +/* + * Largest possible ondisk seconds value with traditional timestamps. This + * corresponds exactly with the incore timestamp Jan 19 03:14:07 UTC 2038. + */ +#define XFS_LEGACY_TIME_MAX ((int64_t)S32_MAX) + /* * On-disk inode structure. * diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c index e61199a4691c..2981743def87 100644 --- a/fs/xfs/xfs_super.c +++ b/fs/xfs/xfs_super.c @@ -1484,8 +1484,8 @@ xfs_fc_fill_super( sb->s_maxbytes = MAX_LFS_FILESIZE; sb->s_max_links = XFS_MAXLINK; sb->s_time_gran = 1; - sb->s_time_min = S32_MIN; - sb->s_time_max = S32_MAX; + sb->s_time_min = XFS_LEGACY_TIME_MIN; + sb->s_time_max = XFS_LEGACY_TIME_MAX; sb->s_iflags |= SB_I_CGROUPWB; set_posix_acl_flag(sb);