From 18e3b8c234fac67c6c96e9ff34f0ab4598220fa1 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Tue, 10 Nov 2020 15:11:09 -0500 Subject: [PATCH] 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 --- NOTE: we hvae no xfs_compat.h so S32_MAX etc went in xfs_fs.h diff --git a/libxfs/xfs_format.h b/libxfs/xfs_format.h index 7f7b03a..5712aa0 100644 --- a/libxfs/xfs_format.h +++ b/libxfs/xfs_format.h @@ -839,11 +839,33 @@ typedef 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/libxfs/xfs_fs.h b/libxfs/xfs_fs.h index fbc9031..4fa9852 100644 --- a/libxfs/xfs_fs.h +++ b/libxfs/xfs_fs.h @@ -694,6 +694,10 @@ 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)) + #ifndef HAVE_BBMACROS /* * Block I/O parameterization. A basic block (BB) is the lowest size of