Enabling wideextcnt option on mkfs.xfs command line causes the
filesystem inodes to have 47-bit data fork extent counters and 32-bit
attr fork extent counters. This also sets the
XFS_SB_FEAT_INCOMPAT_WIDEEXTCNT incompat flag on the superblock
preventing older kernels from mounting such a filesystem.
Signed-off-by: Chandan Babu R <chandanrlinux@xxxxxxxxx>
---
man/man8/mkfs.xfs.8 | 7 +++++++
mkfs/xfs_mkfs.c | 23 +++++++++++++++++++++++
2 files changed, 30 insertions(+)
diff --git a/man/man8/mkfs.xfs.8 b/man/man8/mkfs.xfs.8
index 9d762a43..80378722 100644
--- a/man/man8/mkfs.xfs.8
+++ b/man/man8/mkfs.xfs.8
@@ -522,6 +522,13 @@ 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.
+.TP
+.BI wideextcnt[= value]
+Extend inode data and attr fork extent counters from signed 32-bits and signed
+16-bits to unsigned 47-bits and unsigned 32-bits respectively. If the value is
+omitted, 1 is assumed. Wide extent count feature is disabled by default. This
+feature is only available for filesystems formatted with -m crc=1.
+.TP
.RE
.TP
.BI \-l " log_section_options"
diff --git a/mkfs/xfs_mkfs.c b/mkfs/xfs_mkfs.c
index 2e6cd280..ff3e0705 100644
--- a/mkfs/xfs_mkfs.c
+++ b/mkfs/xfs_mkfs.c
@@ -71,6 +71,7 @@ enum {
I_ATTR,
I_PROJID32BIT,
I_SPINODES,
+ I_WIDEEXTCNT,
I_MAX_OPTS,
};
@@ -383,6 +384,7 @@ static struct opt_params iopts = {
[I_ATTR] = "attr",
[I_PROJID32BIT] = "projid32bit",
[I_SPINODES] = "sparse",
+ [I_WIDEEXTCNT] = "wideextcnt",
},
.subopt_params = {
{ .index = I_ALIGN,
@@ -431,6 +433,12 @@ static struct opt_params iopts = {
.maxval = 1,
.defaultval = 1,
},
+ { .index = I_WIDEEXTCNT,
+ .conflicts = { { NULL, LAST_CONFLICT } },
+ .minval = 0,
+ .maxval = 1,
+ .defaultval = 1,
+ }
},
};
@@ -734,6 +742,7 @@ struct sb_feat_args {
bool reflink; /* XFS_SB_FEAT_RO_COMPAT_REFLINK */
bool nodalign;
bool nortalign;
+ bool wideextcnt;
};
struct cli_params {
@@ -1469,6 +1478,9 @@ inode_opts_parser(
case I_SPINODES:
cli->sb_feat.spinodes = getnum(value, opts, subopt);
break;
+ case I_WIDEEXTCNT:
+ cli->sb_feat.wideextcnt = getnum(value, opts, subopt);
+ break;
default:
return -EINVAL;
}
@@ -1972,6 +1984,14 @@ _("reflink not supported without CRC support\n"));
usage();
}
cli->sb_feat.reflink = false;
+
+ if (cli->sb_feat.wideextcnt &&
+ cli_opt_set(&iopts, I_WIDEEXTCNT)) {
+ fprintf(stderr,
+_("wideextcnt inodes not supported without CRC support\n"));
+ usage();
+ }
+ cli->sb_feat.wideextcnt = false;
}
if ((cli->fsx.fsx_xflags & FS_XFLAG_COWEXTSIZE) &&
@@ -2953,6 +2973,8 @@ sb_set_features(
sbp->sb_features_incompat |= XFS_SB_FEAT_INCOMPAT_SPINODES;
}
+ if (fp->wideextcnt)
+ sbp->sb_features_incompat |= XFS_SB_FEAT_INCOMPAT_WIDEEXTCNT;
}
/*
@@ -3608,6 +3630,7 @@ main(
.parent_pointers = false,
.nodalign = false,
.nortalign = false,
+ .wideextcnt = false,
},
};
--
2.28.0
