From 4ea1ff3b49681af45a4a8c14baf7f0b3d11aa74a Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Mon, 17 Aug 2020 09:59:51 -0700 Subject: xfs: widen ondisk quota expiration timestamps to handle y2038+ Enable the bigtime feature for quota timers. We decrease the accuracy of the timers to ~4s in exchange for being able to set timers up to the bigtime maximum. Signed-off-by: Darrick J. Wong Reviewed-by: Christoph Hellwig Reviewed-by: Allison Collins Reviewed-by: Dave Chinner --- fs/xfs/libxfs/xfs_format.h | 50 +++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 49 insertions(+), 1 deletion(-) (limited to 'fs/xfs/libxfs/xfs_format.h') diff --git a/fs/xfs/libxfs/xfs_format.h b/fs/xfs/libxfs/xfs_format.h index 6aabe15786b8..394159808ffa 100644 --- a/fs/xfs/libxfs/xfs_format.h +++ b/fs/xfs/libxfs/xfs_format.h @@ -1263,13 +1263,15 @@ static inline bool xfs_dinode_has_bigtime(const struct xfs_dinode *dip) #define XFS_DQTYPE_USER 0x01 /* user dquot record */ #define XFS_DQTYPE_PROJ 0x02 /* project dquot record */ #define XFS_DQTYPE_GROUP 0x04 /* group dquot record */ +#define XFS_DQTYPE_BIGTIME 0x80 /* large expiry timestamps */ /* bitmask to determine if this is a user/group/project dquot */ #define XFS_DQTYPE_REC_MASK (XFS_DQTYPE_USER | \ XFS_DQTYPE_PROJ | \ XFS_DQTYPE_GROUP) -#define XFS_DQTYPE_ANY (XFS_DQTYPE_REC_MASK) +#define XFS_DQTYPE_ANY (XFS_DQTYPE_REC_MASK | \ + XFS_DQTYPE_BIGTIME) /* * XFS Quota Timers @@ -1282,6 +1284,10 @@ static inline bool xfs_dinode_has_bigtime(const struct xfs_dinode *dip) * ondisk min and max defined here can be used directly to constrain the incore * quota expiration timestamps on a Unix system. * + * When bigtime is enabled, we trade two bits of precision to expand the + * expiration timeout range to match that of big inode timestamps. The min and + * max recorded here are the on-disk limits, not a Unix timestamp. + * * The grace period for each quota type is stored in the root dquot (id = 0) * and is applied to a non-root dquot when it exceeds the soft or hard limits. * The length of quota grace periods are unsigned 32-bit quantities measured in @@ -1300,6 +1306,48 @@ static inline bool xfs_dinode_has_bigtime(const struct xfs_dinode *dip) */ #define XFS_DQ_LEGACY_EXPIRY_MAX ((int64_t)U32_MAX) +/* + * Smallest possible ondisk quota expiration value with bigtime timestamps. + * This corresponds (after conversion to a Unix timestamp) with the incore + * expiration of Jan 1 00:00:04 UTC 1970. + */ +#define XFS_DQ_BIGTIME_EXPIRY_MIN (XFS_DQ_LEGACY_EXPIRY_MIN) + +/* + * Largest supported ondisk quota expiration value with bigtime timestamps. + * This corresponds (after conversion to a Unix timestamp) with an incore + * expiration of Jul 2 20:20:24 UTC 2486. + * + * The ondisk field supports values up to -1U, which corresponds to an incore + * expiration in 2514. This is beyond the maximum the bigtime inode timestamp, + * so we cap the maximum bigtime quota expiration to the max inode timestamp. + */ +#define XFS_DQ_BIGTIME_EXPIRY_MAX ((int64_t)4074815106U) + +/* + * The following conversion factors assist in converting a quota expiration + * timestamp between the incore and ondisk formats. + */ +#define XFS_DQ_BIGTIME_SHIFT (2) +#define XFS_DQ_BIGTIME_SLACK ((int64_t)(1ULL << XFS_DQ_BIGTIME_SHIFT) - 1) + +/* Convert an incore quota expiration timestamp to an ondisk bigtime value. */ +static inline uint32_t xfs_dq_unix_to_bigtime(time64_t unix_seconds) +{ + /* + * Round the expiration timestamp up to the nearest bigtime timestamp + * that we can store, to give users the most time to fix problems. + */ + return ((uint64_t)unix_seconds + XFS_DQ_BIGTIME_SLACK) >> + XFS_DQ_BIGTIME_SHIFT; +} + +/* Convert an ondisk bigtime quota expiration value to an incore timestamp. */ +static inline time64_t xfs_dq_bigtime_to_unix(uint32_t ondisk_seconds) +{ + return (time64_t)ondisk_seconds << XFS_DQ_BIGTIME_SHIFT; +} + /* * Default quota grace periods, ranging from zero (use the compiled defaults) * to ~136 years. These are applied to a non-root dquot that has exceeded -- cgit v1.2.3