[PATCH 11/28] mkfs: sparse inode chunk support

Brian Foster
2015-06-02T18:42:07Z

Allow format of sparse inode chunk enabled filesystems via the '-i
sparse' flag. Note that sparse inode chunk support requires a v5
superblock (-m crc=1).

Signed-off-by: Brian Foster <bfoster@redhat.com>
---
man/man8/mkfs.xfs.8 | 17 +++++++++++++++++
mkfs/xfs_mkfs.c | 37 ++++++++++++++++++++++++++++++++++---
2 files changed, 51 insertions(+), 3 deletions(-)

diff --git a/man/man8/mkfs.xfs.8 b/man/man8/mkfs.xfs.8
index ad9ff3d..542dea9 100644
--- a/man/man8/mkfs.xfs.8
+++ b/man/man8/mkfs.xfs.8
@@ -409,6 +409,23 @@ This is used to enable 32bit quota project identifiers. The
is either 0 or 1, with 1 signifying that 32bit projid are to be enabled.
If the value is omitted, 1 is assumed. (This default changed
in release version 3.2.0.)
+.TP
+.BI sparse[= value ]
+Enable sparse inode chunk allocation. The
+.I value
+is either 0 or 1, with 1 signifying that sparse allocation is enabled.
+If the value is omitted, 1 is assumed. Sparse inode allocation is
+disabled by default. This feature is only available for filesystems
+formatted with
+.B \-m crc=1.
+.IP
+When enabled, sparse inode allocation allows the filesystem to allocate
+smaller than the standard 64-inode chunk when free space is severely
+limited. This feature is useful for filesystems that might fragment free
+space over time such that no free extents are large enough to
+accommodate a chunk of 64 inodes. Without this feature enabled, inode
+allocations can fail with out of space errors under severe fragmented
+free space conditions.
.RE
.TP
.BI \-l " log_section_options"
diff --git a/mkfs/xfs_mkfs.c b/mkfs/xfs_mkfs.c
index 1770666..a3f29e0 100644
--- a/mkfs/xfs_mkfs.c
+++ b/mkfs/xfs_mkfs.c
@@ -109,6 +109,8 @@ char *iopts[] = {
"attr",
#define I_PROJID32BIT 6
"projid32bit",
+#define I_SPINODES 7
+ "sparse",
NULL
};

@@ -1004,6 +1006,7 @@ main(
int lazy_sb_counters;
int crcs_enabled;
int finobt;
+ int spinodes;

progname = basename(argv[0]);
setlocale(LC_ALL, "");
@@ -1038,6 +1041,7 @@ main(
lazy_sb_counters = 1;
crcs_enabled = 0;
finobt = 0;
+ spinodes = 0;
memset(&fsx, 0, sizeof(fsx));

memset(&xi, 0, sizeof(xi));
@@ -1359,6 +1363,13 @@ main(
illegal(value, "i projid32bit");
projid16bit = c ? 0 : 1;
break;
+ case I_SPINODES:
+ if (!value || *value == '\0')
+ value = "1";
+ spinodes = atoi(value);
+ if (spinodes < 0 || spinodes > 1)
+ illegal(value, "i spinodes");
+ break;
default:
unknown('i', value);
}
@@ -1890,6 +1901,12 @@ _("warning: finobt not supported without CRC support, disabled.\n"));
finobt = 0;
}

+ if (spinodes && !crcs_enabled) {
+ fprintf(stderr,
+_("warning: sparse inodes not supported without CRC support, disabled.\n"));
+ spinodes = 0;
+ }
+
if (nsflag || nlflag) {
if (dirblocksize < blocksize ||
dirblocksize > XFS_MAX_BLOCKSIZE) {
@@ -2568,7 +2585,7 @@ _("size %s specified for log subvolume is too large, maximum is %lld blocks\n"),
printf(_(
"meta-data=%-22s isize=%-6d agcount=%lld, agsize=%lld blks\n"
" =%-22s sectsz=%-5u attr=%u, projid32bit=%u\n"
- " =%-22s crc=%-8u finobt=%u\n"
+ " =%-22s crc=%-8u finobt=%u, sparse=%u\n"
"data =%-22s bsize=%-6u blocks=%llu, imaxpct=%u\n"
" =%-22s sunit=%-6u swidth=%u blks\n"
"naming =version %-14u bsize=%-6u ascii-ci=%d ftype=%d\n"
@@ -2577,7 +2594,7 @@ _("size %s specified for log subvolume is too large, maximum is %lld blocks\n"),
"realtime =%-22s extsz=%-6d blocks=%lld, rtextents=%lld\n"),
dfile, isize, (long long)agcount, (long long)agsize,
"", sectorsize, attrversion, !projid16bit,
- "", crcs_enabled, finobt,
+ "", crcs_enabled, finobt, spinodes,
"", blocksize, (long long)dblocks, imaxpct,
"", dsunit, dswidth,
dirversion, dirblocksize, nci, dirftype,
@@ -2646,6 +2663,20 @@ _("size %s specified for log subvolume is too large, maximum is %lld blocks\n"),
sbp->sb_logsectsize = 0;
}

+ /*
+ * Sparse inode chunk support has two main inode alignment requirements.
+ * First, sparse chunk alignment must match the cluster size. Second,
+ * full chunk alignment must match the inode chunk size.
+ *
+ * Copy the already calculated/scaled inoalignmt to spino_align and
+ * update the former to the full inode chunk size.
+ */
+ if (spinodes) {
+ sbp->sb_spino_align = sbp->sb_inoalignmt;
+ sbp->sb_inoalignmt = XFS_INODES_PER_CHUNK * isize >> blocklog;
+ sbp->sb_features_incompat |= XFS_SB_FEAT_INCOMPAT_SPINODES;
+ }
+
if (force_overwrite)
zero_old_xfs_structures(&xi, sbp);

@@ -3193,7 +3224,7 @@ usage( void )
sectlog=n|sectsize=num\n\
/* force overwrite */ [-f]\n\
/* inode size */ [-i log=n|perblock=n|size=num,maxpct=n,attr=0|1|2,\n\
- projid32bit=0|1]\n\
+ projid32bit=0|1,sparse=0|1]\n\
/* no discard */ [-K]\n\
/* log subvol */ [-l agnum=n,internal,size=num,logdev=xxx,version=n\n\
sunit=value|su=num,sectlog=n|sectsize=num,\n\