[PATCH 4/5] xfs_repair: enable inobtcount upgrade via repair

["Darrick J. Wong" <djwong@kernel.org>]

From: Darrick J. Wong <djwong@kernel.org>

Use xfs_repair to add the inode btree counter feature to a filesystem.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
---
 man/man8/xfs_admin.8 |   11 ++++++++++-
 repair/globals.c     |    1 +
 repair/globals.h     |    1 +
 repair/phase2.c      |   30 ++++++++++++++++++++++++++++++
 repair/xfs_repair.c  |   11 +++++++++++
 5 files changed, 53 insertions(+), 1 deletion(-)


diff --git a/man/man8/xfs_admin.8 b/man/man8/xfs_admin.8
index ae661648..4ba718d8 100644
--- a/man/man8/xfs_admin.8
+++ b/man/man8/xfs_admin.8
@@ -136,7 +136,16 @@ without the
 .BR -n )
 must be followed to clean the filesystem.
 .IP
-There are no feature options currently.
+Supported features are as follows:
+.RS 0.7i
+.TP 0.4i
+.B inobtcount
+Keep a count the number of blocks in each inode btree in the AGI.
+This reduces mount time by speeding up metadata space reservation calculations.
+The filesystem cannot be downgraded after this feature is enabled.
+Once enabled, the filesystem will not be writable by older kernels.
+This feature was added to Linux 5.10.
+.RE
 .TP
 .BI \-U " uuid"
 Set the UUID of the filesystem to
diff --git a/repair/globals.c b/repair/globals.c
index 537d068b..47d90bd3 100644
--- a/repair/globals.c
+++ b/repair/globals.c
@@ -48,6 +48,7 @@ char	*rt_name;		/* Name of realtime device */
 int	rt_spec;		/* Realtime dev specified as option */
 int	convert_lazy_count;	/* Convert lazy-count mode on/off */
 int	lazy_count;		/* What to set if to if converting */
+bool	add_inobtcount;		/* add inode btree counts to AGI */
 
 /* misc status variables */
 
diff --git a/repair/globals.h b/repair/globals.h
index a9287320..5b6fe4d4 100644
--- a/repair/globals.h
+++ b/repair/globals.h
@@ -89,6 +89,7 @@ extern char	*rt_name;		/* Name of realtime device */
 extern int	rt_spec;		/* Realtime dev specified as option */
 extern int	convert_lazy_count;	/* Convert lazy-count mode on/off */
 extern int	lazy_count;		/* What to set if to if converting */
+extern bool	add_inobtcount;		/* add inode btree counts to AGI */
 
 /* misc status variables */
 
diff --git a/repair/phase2.c b/repair/phase2.c
index f654edcc..96074a1d 100644
--- a/repair/phase2.c
+++ b/repair/phase2.c
@@ -131,6 +131,33 @@ zero_log(
 		libxfs_max_lsn = log->l_last_sync_lsn;
 }
 
+static bool
+set_inobtcount(
+	struct xfs_mount	*mp)
+{
+	if (!xfs_sb_version_hascrc(&mp->m_sb)) {
+		printf(
+	_("Inode btree count feature only supported on V5 filesystems.\n"));
+		exit(0);
+	}
+
+	if (!xfs_sb_version_hasfinobt(&mp->m_sb)) {
+		printf(
+	_("Inode btree count feature requires free inode btree.\n"));
+		exit(0);
+	}
+
+	if (xfs_sb_version_hasinobtcounts(&mp->m_sb)) {
+		printf(_("Filesystem already has inode btree counts.\n"));
+		exit(0);
+	}
+
+	printf(_("Adding inode btree counts to filesystem.\n"));
+	mp->m_sb.sb_features_ro_compat |= XFS_SB_FEAT_RO_COMPAT_INOBTCNT;
+	mp->m_sb.sb_features_incompat |= XFS_SB_FEAT_INCOMPAT_NEEDSREPAIR;
+	return true;
+}
+
 /* Perform the user's requested upgrades on filesystem. */
 static void
 upgrade_filesystem(
@@ -140,6 +167,9 @@ upgrade_filesystem(
 	bool			dirty = false;
 	int			error;
 
+	if (add_inobtcount)
+		dirty |= set_inobtcount(mp);
+
         if (no_modify || !dirty)
                 return;
 
diff --git a/repair/xfs_repair.c b/repair/xfs_repair.c
index 64d7607f..8a9caf15 100644
--- a/repair/xfs_repair.c
+++ b/repair/xfs_repair.c
@@ -65,11 +65,13 @@ static char *o_opts[] = {
  */
 enum c_opt_nums {
 	CONVERT_LAZY_COUNT = 0,
+	CONVERT_INOBTCOUNT,
 	C_MAX_OPTS,
 };
 
 static char *c_opts[] = {
 	[CONVERT_LAZY_COUNT]	= "lazycount",
+	[CONVERT_INOBTCOUNT]	= "inobtcount",
 	[C_MAX_OPTS]		= NULL,
 };
 
@@ -302,6 +304,15 @@ process_args(int argc, char **argv)
 					lazy_count = (int)strtol(val, NULL, 0);
 					convert_lazy_count = 1;
 					break;
+				case CONVERT_INOBTCOUNT:
+					if (!val)
+						do_abort(
+		_("-c inobtcount requires a parameter\n"));
+					if (strtol(val, NULL, 0) != 1)
+						do_abort(
+		_("-c inobtcount only supports upgrades\n"));
+					add_inobtcount = true;
+					break;
 				default:
 					unknown('c', val);
 					break;