Create a -d option to mkfs.xfs that enables administrators to set
the CoW extent size hint on the created files.
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
libxfs/util.c | 26 ++++++++++++++++++++++++--
man/man8/mkfs.xfs.8 | 7 +++++++
mkfs/xfs_mkfs.c | 20 ++++++++++++++++++++
3 files changed, 51 insertions(+), 2 deletions(-)
diff --git a/libxfs/util.c b/libxfs/util.c
index 0e2f29e..4f82d7f 100644
--- a/libxfs/util.c
+++ b/libxfs/util.c
@@ -175,6 +175,26 @@ libxfs_trans_ichgtime(
}
}
+static inline uint16_t
+xflags_to_diflags(
+ __u32 xflags)
+{
+ /* bottom 15 xflag bits correspond to diflag bits */
+ return xflags & 0x7FFF;
+}
+
+static inline uint64_t
+xflags_to_diflags2(
+ __u32 xflags)
+{
+ uint64_t ret = 0;
+
+ if (xflags & FS_XFLAG_COWEXTSIZE)
+ ret |= XFS_DIFLAG2_COWEXTSIZE;
+
+ return ret;
+}
+
/*
* Allocate an inode on disk and return a copy of its in-core version.
* Set mode, nlink, and rdev appropriately within the inode.
@@ -254,15 +274,17 @@ libxfs_ialloc(
ip->i_d.di_extsize = pip ? 0 : fsx->fsx_extsize;
ip->i_d.di_dmevmask = 0;
ip->i_d.di_dmstate = 0;
- ip->i_d.di_flags = pip ? 0 : fsx->fsx_xflags;
+ ip->i_d.di_flags = pip ? 0 : xflags_to_diflags(fsx->fsx_xflags);
if (ip->i_d.di_version == 3) {
ASSERT(ip->i_d.di_ino == ino);
ASSERT(uuid_equal(&ip->i_d.di_uuid, &mp->m_sb.sb_meta_uuid));
VFS_I(ip)->i_version = 1;
- ip->i_d.di_flags2 = 0;
+ ip->i_d.di_flags2 = pip ? 0 :
+ xflags_to_diflags2(fsx->fsx_xflags);
ip->i_d.di_crtime.t_sec = (int32_t)VFS_I(ip)->i_mtime.tv_sec;
ip->i_d.di_crtime.t_nsec = (int32_t)VFS_I(ip)->i_mtime.tv_nsec;
+ ip->i_d.di_cowextsize = pip ? 0 : fsx->fsx_cowextsize;
}
flags = XFS_ILOG_CORE;
diff --git a/man/man8/mkfs.xfs.8 b/man/man8/mkfs.xfs.8
index 33831c9..bbbe1c5 100644
--- a/man/man8/mkfs.xfs.8
+++ b/man/man8/mkfs.xfs.8
@@ -279,6 +279,13 @@ and
.B agsize
suboptions are mutually exclusive.
.TP
+.BI cowextsize= value
+Set the copy-on-write extent size hint on all inodes created by
+.BR mkfs.xfs "."
+The value must be provided in units of filesystem blocks.
+If the value is zero, the default value (currently 32 blocks) will be used.
+Directories will pass on this hint to newly created children.
+.TP
.BI name= value
This can be used to specify the name of the special file containing
the filesystem. In this case, the log section must be specified as
diff --git a/mkfs/xfs_mkfs.c b/mkfs/xfs_mkfs.c
index 024cb02..ea0a317 100644
--- a/mkfs/xfs_mkfs.c
+++ b/mkfs/xfs_mkfs.c
@@ -187,6 +187,8 @@ struct opt_params dopts = {
"projinherit",
#define D_EXTSZINHERIT 14
"extszinherit",
+#define D_COWEXTSIZE 15
+ "cowextsize",
NULL
},
.subopt_params = {
@@ -303,6 +305,12 @@ struct opt_params dopts = {
.maxval = UINT_MAX,
.defaultval = SUBOPT_NEEDS_VAL,
},
+ { .index = D_COWEXTSIZE,
+ .conflicts = { LAST_CONFLICT },
+ .minval = 0,
+ .maxval = UINT_MAX,
+ .defaultval = SUBOPT_NEEDS_VAL,
+ },
},
};
@@ -1638,6 +1646,13 @@ main(
fsx.fsx_xflags |=
XFS_DIFLAG_EXTSZINHERIT;
break;
+ case D_COWEXTSIZE:
+ fsx.fsx_cowextsize = getnum(value,
+ &dopts,
+ D_COWEXTSIZE);
+ fsx.fsx_xflags |=
+ FS_XFLAG_COWEXTSIZE;
+ break;
default:
unknown('d', value);
}
@@ -2142,6 +2157,11 @@ _("reflink not supported without CRC support\n"));
sb_feat.reflink = false;
}
+ if ((fsx.fsx_xflags & FS_XFLAG_COWEXTSIZE) && !sb_feat.reflink) {
+ fprintf(stderr,
+_("cowextsize not supported without reflink support\n"));
+ usage();
+ }
if (nsflag || nlflag) {
if (dirblocksize < blocksize ||
--
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