[PATCH 8/9] mkfs: enable the inode btree counter feature

["Darrick J. Wong" <darrick.wong@oracle.com>]

From: Darrick J. Wong <darrick.wong@oracle.com>

Teach mkfs how to enable the inode btree counter feature.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 man/man8/mkfs.xfs.8 |   15 +++++++++++++++
 mkfs/xfs_mkfs.c     |   34 +++++++++++++++++++++++++++++++++-
 2 files changed, 48 insertions(+), 1 deletion(-)


diff --git a/man/man8/mkfs.xfs.8 b/man/man8/mkfs.xfs.8
index 0a7858748457..1a6a5f93f0ea 100644
--- a/man/man8/mkfs.xfs.8
+++ b/man/man8/mkfs.xfs.8
@@ -184,6 +184,21 @@ option set. When the option
 .B \-m crc=0
 is used, the free inode btree feature is not supported and is disabled.
 .TP
+.BI inobtcount= value
+This option causes the filesystem to record the number of blocks used by
+the inode btree and the free inode btree.
+This can be used to reduce mount times when the free inode btree is enabled.
+.IP
+By default,
+.B mkfs.xfs
+will not enable this option.
+This feature is only available for filesystems created with the (default)
+.B \-m finobt=1
+option set.
+When the option
+.B \-m finobt=0
+is used, the inode btree counter feature is not supported and is disabled.
+.TP
 .BI uuid= value
 Use the given value as the filesystem UUID for the newly created filesystem.
 The default is to generate a random UUID.
diff --git a/mkfs/xfs_mkfs.c b/mkfs/xfs_mkfs.c
index 908d520df909..23e3077e0174 100644
--- a/mkfs/xfs_mkfs.c
+++ b/mkfs/xfs_mkfs.c
@@ -119,6 +119,7 @@ enum {
 	M_UUID,
 	M_RMAPBT,
 	M_REFLINK,
+	M_INOBTCNT,
 	M_MAX_OPTS,
 };
 
@@ -660,6 +661,7 @@ static struct opt_params mopts = {
 		[M_UUID] = "uuid",
 		[M_RMAPBT] = "rmapbt",
 		[M_REFLINK] = "reflink",
+		[M_INOBTCNT] = "inobtcount",
 	},
 	.subopt_params = {
 		{ .index = M_CRC,
@@ -690,6 +692,12 @@ static struct opt_params mopts = {
 		  .maxval = 1,
 		  .defaultval = 1,
 		},
+		{ .index = M_INOBTCNT,
+		  .conflicts = { { NULL, LAST_CONFLICT } },
+		  .minval = 0,
+		  .maxval = 1,
+		  .defaultval = 1,
+		},
 	},
 };
 
@@ -740,6 +748,7 @@ struct sb_feat_args {
 	bool	spinodes;		/* XFS_SB_FEAT_INCOMPAT_SPINODES */
 	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	nodalign;
 	bool	nortalign;
 };
@@ -862,7 +871,8 @@ 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\
+/* metadata */		[-m crc=0|1,finobt=0|1,uuid=xxx,rmapbt=0|1,reflink=0|1,\n\
+			    inobtcnt=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\
@@ -1565,6 +1575,9 @@ meta_opts_parser(
 	case M_REFLINK:
 		cli->sb_feat.reflink = getnum(value, opts, subopt);
 		break;
+	case M_INOBTCNT:
+		cli->sb_feat.inobtcnt = getnum(value, opts, subopt);
+		break;
 	default:
 		return -EINVAL;
 	}
@@ -1988,6 +2001,22 @@ _("reflink not supported without CRC support\n"));
 			usage();
 		}
 		cli->sb_feat.reflink = false;
+
+		if (cli->sb_feat.inobtcnt && cli_opt_set(&mopts, M_INOBTCNT)) {
+			fprintf(stderr,
+_("inode btree counters not supported without CRC support\n"));
+			usage();
+		}
+		cli->sb_feat.inobtcnt = false;
+	}
+
+	if (!cli->sb_feat.finobt) {
+		if (cli->sb_feat.inobtcnt && cli_opt_set(&mopts, M_INOBTCNT)) {
+			fprintf(stderr,
+_("inode btree counters not supported without finobt support\n"));
+			usage();
+		}
+		cli->sb_feat.inobtcnt = false;
 	}
 
 	if ((cli->fsx.fsx_xflags & FS_XFLAG_COWEXTSIZE) &&
@@ -2955,6 +2984,8 @@ sb_set_features(
 		sbp->sb_features_ro_compat |= XFS_SB_FEAT_RO_COMPAT_RMAPBT;
 	if (fp->reflink)
 		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;
 
 	/*
 	 * Sparse inode chunk support has two main inode alignment requirements.
@@ -3617,6 +3648,7 @@ main(
 			.spinodes = true,
 			.rmapbt = false,
 			.reflink = true,
+			.inobtcnt = false,
 			.parent_pointers = false,
 			.nodalign = false,
 			.nortalign = false,