From e9601810beb7d5b36a5fbd03c593cf63f685bfff Mon Sep 17 00:00:00 2001
From: "Darrick J. Wong" <darrick.wong@oracle.com>
Date: Fri, 20 Nov 2020 17:03:28 -0500
Subject: [PATCH] mkfs: format bigtime filesystems

Allow formatting with large timestamps.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
---

diff --git a/man/man8/mkfs.xfs.8 b/man/man8/mkfs.xfs.8
index 45b150f..0a115cb 100644
--- a/man/man8/mkfs.xfs.8
+++ b/man/man8/mkfs.xfs.8
@@ -154,6 +154,22 @@ valid
 are:
 .RS 1.2i
 .TP
+.BI bigtime= value
+This option enables filesystems that can handle inode timestamps from December
+1901 to July 2486, and quota timer expirations from January 1970 to July 2486.
+The value is either 0 to disable the feature, or 1 to enable large timestamps.
+.IP
+If this feature is not enabled, the filesystem can only handle timestamps from
+December 1901 to January 2038, and quota timers from January 1970 to February
+2106.
+.IP
+By default,
+.B mkfs.xfs
+will not enable this feature.
+If the option
+.B \-m crc=0
+is used, the large timestamp feature is not supported and is disabled.
+.TP
 .BI crc= value
 This is used to create a filesystem which maintains and checks CRC information
 in all metadata objects on disk. The value is either 0 to disable the feature,
diff --git a/mkfs/xfs_mkfs.c b/mkfs/xfs_mkfs.c
index 87f15f4..b74a00b 100644
--- a/mkfs/xfs_mkfs.c
+++ b/mkfs/xfs_mkfs.c
@@ -118,6 +118,7 @@ enum {
 	M_RMAPBT,
 	M_REFLINK,
 	M_INOBTCNT,
+	M_BIGTIME,
 	M_MAX_OPTS,
 };
 
@@ -653,6 +654,7 @@ static struct opt_params mopts = {
 		[M_RMAPBT] = "rmapbt",
 		[M_REFLINK] = "reflink",
 		[M_INOBTCNT] = "inobtcount",
+		[M_BIGTIME] = "bigtime",
 	},
 	.subopt_params = {
 		{ .index = M_CRC,
@@ -689,6 +691,12 @@ static struct opt_params mopts = {
 		  .maxval = 1,
 		  .defaultval = 1,
 		},
+		{ .index = M_BIGTIME,
+		  .conflicts = { { NULL, LAST_CONFLICT } },
+		  .minval = 0,
+		  .maxval = 1,
+		  .defaultval = 1,
+		},
 	},
 };
 
@@ -740,6 +748,7 @@ struct sb_feat_args {
 	bool	rmapbt;			/* XFS_SB_FEAT_RO_COMPAT_RMAPBT */
 	bool	reflink;		/* XFS_SB_FEAT_RO_COMPAT_REFLINK */
 	bool	inobtcnt;		/* XFS_SB_FEAT_RO_COMPAT_INOBTCNT */
+	bool	bigtime;		/* XFS_SB_FEAT_INCOMPAT_BIGTIME */
 	bool	nodalign;
 	bool	nortalign;
 };
@@ -863,7 +872,7 @@ usage( void )
 	fprintf(stderr, _("Usage: %s\n\
 /* blocksize */		[-b size=num]\n\
 /* metadata */		[-m crc=0|1,finobt=0|1,uuid=xxx,rmapbt=0|1,reflink=0|1,\n\
-			    inobtcnt=0|1]\n\
+			    inobtcnt=0|1,bigtime=0|1]\n\
 /* data subvol */	[-d agcount=n,agsize=n,file,name=xxx,size=num,\n\
 			    (sunit=value,swidth=value|su=num,sw=num|noalign),\n\
 			    sectsize=num\n\
@@ -1620,6 +1629,9 @@ meta_opts_parser(
 	case M_INOBTCNT:
 		cli->sb_feat.inobtcnt = getnum(value, opts, subopt);
 		break;
+	case M_BIGTIME:
+		cli->sb_feat.bigtime = getnum(value, opts, subopt);
+		break;
 	default:
 		return -EINVAL;
 	}
@@ -2057,6 +2069,13 @@ _("inode btree counters not supported without CRC support\n"));
 			usage();
 		}
 		cli->sb_feat.inobtcnt = false;
+
+		if (cli->sb_feat.bigtime && cli_opt_set(&mopts, M_BIGTIME)) {
+			fprintf(stderr,
+_("timestamps later than 2038 not supported without CRC support\n"));
+			usage();
+		}
+		cli->sb_feat.bigtime = false;
 	}
 
 	if (!cli->sb_feat.finobt) {
@@ -3033,6 +3052,8 @@ sb_set_features(
 		sbp->sb_features_ro_compat |= XFS_SB_FEAT_RO_COMPAT_REFLINK;
 	if (fp->inobtcnt)
 		sbp->sb_features_ro_compat |= XFS_SB_FEAT_RO_COMPAT_INOBTCNT;
+	if (fp->bigtime)
+		sbp->sb_features_incompat |= XFS_SB_FEAT_INCOMPAT_BIGTIME;
 
 	/*
 	 * Sparse inode chunk support has two main inode alignment requirements.
@@ -3952,6 +3973,7 @@ main(
 			.parent_pointers = false,
 			.nodalign = false,
 			.nortalign = false,
+			.bigtime = false,
 		},
 	};