[[PATCH, RESEND]] reduce imaxpct for big filesystems,

[xaiki@sgi.com]

From: Niv Sardi <xaiki@sgi.com>

imaxpct is set to 25% for FS < 1 TB,
then 5% for FS < 50 TB,
and then 1%.

It is implemented as a step function in calc_default_imaxpct()
---
 xfsprogs/mkfs/xfs_mkfs.c |   19 +++++++++++++++++--
 1 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/xfsprogs/mkfs/xfs_mkfs.c b/xfsprogs/mkfs/xfs_mkfs.c
index 3689eb7..78c2c77 100644
--- a/xfsprogs/mkfs/xfs_mkfs.c
+++ b/xfsprogs/mkfs/xfs_mkfs.c
@@ -374,6 +374,21 @@ validate_log_size(__uint64_t logblocks, int blocklog, int min_logblocks)
 	}
 }
 
+int
+calc_default_imaxpct(
+	int		blocklog,
+	__uint64_t	dblocks)
+{
+	if (dblocks < TERABYTES(1, blocklog)) {
+		return XFS_DFL_IMAXIMUM_PCT;
+	} else if (dblocks < TERABYTES(50, blocklog)) {
+		return 5;
+	}
+
+	return 1;
+}
+
+
 void
 calc_default_ag_geometry(
 	int		blocklog,
@@ -1986,7 +2001,7 @@ an AG size that is one stripe unit smaller, for example %llu.\n"),
 			dfile, isize, (long long)agcount, (long long)agsize,
 			"", sectorsize, attrversion,
 			"", blocksize, (long long)dblocks,
-				imflag ? imaxpct : XFS_DFL_IMAXIMUM_PCT,
+			       calc_default_imaxpct(blocklog, dblocks),
 			"", dsunit, dswidth,
 			dirversion, dirversion == 1 ? blocksize : dirblocksize,
 			logfile, 1 << blocklog, (long long)logblocks,
@@ -2023,7 +2038,7 @@ an AG size that is one stripe unit smaller, for example %llu.\n"),
 		(__uint8_t)(rtextents ?
 			libxfs_highbit32((unsigned int)rtextents) : 0);
 	sbp->sb_inprogress = 1;	/* mkfs is in progress */
-	sbp->sb_imax_pct = imflag ? imaxpct : XFS_DFL_IMAXIMUM_PCT;
+	sbp->sb_imax_pct = calc_default_imaxpct(blocklog, dblocks);
 	sbp->sb_icount = 0;
 	sbp->sb_ifree = 0;
 	sbp->sb_fdblocks = dblocks - agcount * XFS_PREALLOC_BLOCKS(mp) -
-- 
1.5.3.5