xfs: refactor xfs_mount_zones

xfs_mount_zones has grown a bit too big and unorganized.  Split the
zone reporting loop into a separate helper, hiding the rtg variable
there.  Print the mount message last, and also keep the VFS writeback
chunk size last instead of in the middle of the logic to calculate
the free/available blocks.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hans Holmberg <hans.holmberg@wdc.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

Author: Christoph Hellwig

fs/xfs/xfs_zone_alloc.c

@@ -1230,6 +1230,29 @@ xfs_free_zone_info(
 	kfree(zi);
 }
 
+static int
+xfs_report_zones(
+	struct xfs_mount	*mp,
+	struct xfs_init_zones	*iz)
+{
+	struct xfs_rtgroup	*rtg = NULL;
+
+	while ((rtg = xfs_rtgroup_next(mp, rtg))) {
+		xfs_rgblock_t		write_pointer;
+		int			error;
+
+		error = xfs_query_write_pointer(iz, rtg, &write_pointer);
+		if (!error)
+			error = xfs_init_zone(iz, rtg, write_pointer);
+		if (error) {
+			xfs_rtgroup_rele(rtg);
+			return error;
+		}
+	}
+
+	return 0;
+}
+
 int
 xfs_mount_zones(
 	struct xfs_mount	*mp)
@@ -1238,7 +1261,6 @@ xfs_mount_zones(
 		.zone_capacity	= mp->m_groups[XG_TYPE_RTG].blocks,
 		.zone_size	= xfs_rtgroup_raw_size(mp),
 	};
-	struct xfs_rtgroup	*rtg = NULL;
 	int			error;
 
 	if (!mp->m_rtdev_targp) {
@@ -1268,9 +1290,13 @@ xfs_mount_zones(
 	if (!mp->m_zone_info)
 		return -ENOMEM;
 
-	xfs_info(mp, "%u zones of %u blocks (%u max open zones)",
-		 mp->m_sb.sb_rgcount, iz.zone_capacity, mp->m_max_open_zones);
-	trace_xfs_zones_mount(mp);
+	error = xfs_report_zones(mp, &iz);
+	if (error)
+		goto out_free_zone_info;
+
+	xfs_set_freecounter(mp, XC_FREE_RTAVAILABLE, iz.available);
+	xfs_set_freecounter(mp, XC_FREE_RTEXTENTS,
+			iz.available + iz.reclaimable);
 
 	/*
 	 * The writeback code switches between inodes regularly to provide
@@ -1296,22 +1322,6 @@ xfs_mount_zones(
 		XFS_FSB_TO_B(mp, min(iz.zone_capacity, XFS_MAX_BMBT_EXTLEN)) >>
 			PAGE_SHIFT;
 
-	while ((rtg = xfs_rtgroup_next(mp, rtg))) {
-		xfs_rgblock_t		write_pointer;
-
-		error = xfs_query_write_pointer(&iz, rtg, &write_pointer);
-		if (!error)
-			error = xfs_init_zone(&iz, rtg, write_pointer);
-		if (error) {
-			xfs_rtgroup_rele(rtg);
-			goto out_free_zone_info;
-		}
-	}
-
-	xfs_set_freecounter(mp, XC_FREE_RTAVAILABLE, iz.available);
-	xfs_set_freecounter(mp, XC_FREE_RTEXTENTS,
-			iz.available + iz.reclaimable);
-
 	/*
 	 * The user may configure GC to free up a percentage of unused blocks.
 	 * By default this is 0. GC will always trigger at the minimum level
@@ -1322,6 +1332,10 @@ xfs_mount_zones(
 	error = xfs_zone_gc_mount(mp);
 	if (error)
 		goto out_free_zone_info;
+
+	xfs_info(mp, "%u zones of %u blocks (%u max open zones)",
+		 mp->m_sb.sb_rgcount, iz.zone_capacity, mp->m_max_open_zones);
+	trace_xfs_zones_mount(mp);
 	return 0;
 
 out_free_zone_info: