From: Darrick J. Wong Date: Tue, 10 Nov 2020 20:11:09 +0000 (-0500) Subject: xfs: explicitly define inode timestamp range X-Git-Tag: v5.10.0-rc0~32 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=18e3b8c234fac67c6c96e9ff34f0ab4598220fa1;p=thirdparty%2Fxfsprogs-dev.git xfs: explicitly define inode timestamp range Source kernel commit: 876fdc7c4f366a709ac272ef3336ae7dce58f2af 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 Signed-off-by: Eric Sandeen --- diff --git a/include/xfs_fs_compat.h b/include/xfs_fs_compat.h index d0ffc9775..0077f00cb 100644 --- a/include/xfs_fs_compat.h +++ b/include/xfs_fs_compat.h @@ -93,4 +93,8 @@ struct timespec64 { long tv_nsec; /* nanoseconds */ }; +#define U32_MAX ((uint32_t)~0U) +#define S32_MAX ((int32_t)(U32_MAX >> 1)) +#define S32_MIN ((int32_t)(-S32_MAX - 1)) + #endif /* __XFS_FS_COMPAT_H__ */ diff --git a/libxfs/xfs_format.h b/libxfs/xfs_format.h index 01544f9d5..568307155 100644 --- a/libxfs/xfs_format.h +++ b/libxfs/xfs_format.h @@ -847,11 +847,33 @@ 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. *