mkfs: pass a custom cowextsize into the created filesystem

Create a -d option to mkfs.xfs that enables administrators to set
the CoW extent size hint on the created files.

[sandeen: Note, the switch to xfs_flags2diflags looks like
a bugfix, but it's not - the flags set by mkfs up to this
point just happened to line up without any translation.]

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>

diff --git a/libxfs/util.c b/libxfs/util.c
index 7938e317894ac40037d7bc211c24159569ae2a29..74b1bdb8c8e8e0e6c23d6fa5842bac6f59562569 100644 (file)
--- a/libxfs/util.c
+++ b/libxfs/util.c
@@ -175,6 +175,64 @@ libxfs_trans_ichgtime(
        }
 }
 
+STATIC uint16_t
+xfs_flags2diflags(
+       struct xfs_inode        *ip,
+       unsigned int            xflags)
+{
+       /* can't set PREALLOC this way, just preserve it */
+       uint16_t                di_flags =
+               (ip->i_d.di_flags & XFS_DIFLAG_PREALLOC);
+
+       if (xflags & FS_XFLAG_IMMUTABLE)
+               di_flags |= XFS_DIFLAG_IMMUTABLE;
+       if (xflags & FS_XFLAG_APPEND)
+               di_flags |= XFS_DIFLAG_APPEND;
+       if (xflags & FS_XFLAG_SYNC)
+               di_flags |= XFS_DIFLAG_SYNC;
+       if (xflags & FS_XFLAG_NOATIME)
+               di_flags |= XFS_DIFLAG_NOATIME;
+       if (xflags & FS_XFLAG_NODUMP)
+               di_flags |= XFS_DIFLAG_NODUMP;
+       if (xflags & FS_XFLAG_NODEFRAG)
+               di_flags |= XFS_DIFLAG_NODEFRAG;
+       if (xflags & FS_XFLAG_FILESTREAM)
+               di_flags |= XFS_DIFLAG_FILESTREAM;
+       if (S_ISDIR(VFS_I(ip)->i_mode)) {
+               if (xflags & FS_XFLAG_RTINHERIT)
+                       di_flags |= XFS_DIFLAG_RTINHERIT;
+               if (xflags & FS_XFLAG_NOSYMLINKS)
+                       di_flags |= XFS_DIFLAG_NOSYMLINKS;
+               if (xflags & FS_XFLAG_EXTSZINHERIT)
+                       di_flags |= XFS_DIFLAG_EXTSZINHERIT;
+               if (xflags & FS_XFLAG_PROJINHERIT)
+                       di_flags |= XFS_DIFLAG_PROJINHERIT;
+       } else if (S_ISREG(VFS_I(ip)->i_mode)) {
+               if (xflags & FS_XFLAG_REALTIME)
+                       di_flags |= XFS_DIFLAG_REALTIME;
+               if (xflags & FS_XFLAG_EXTSIZE)
+                       di_flags |= XFS_DIFLAG_EXTSIZE;
+       }
+
+       return di_flags;
+}
+
+STATIC uint64_t
+xfs_flags2diflags2(
+       struct xfs_inode        *ip,
+       unsigned int            xflags)
+{
+       uint64_t                di_flags2 =
+               (ip->i_d.di_flags2 & XFS_DIFLAG2_REFLINK);
+
+       if (xflags & FS_XFLAG_DAX)
+               di_flags2 |= XFS_DIFLAG2_DAX;
+       if (xflags & FS_XFLAG_COWEXTSIZE)
+               di_flags2 |= XFS_DIFLAG2_COWEXTSIZE;
+
+       return di_flags2;
+}
+
 /*
  * 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 +312,17 @@ 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 : xfs_flags2diflags(ip, 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 : xfs_flags2diflags2(ip,
+                               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 33831c9a23d92ea65797b54afb97e6856d118135..bbbe1c534611ad586271ee372c47c2a71daf9fc8 100644 (file)
--- 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 e4330335870022d99ca0fc2ca6d24f89f9866bdf..3058129409010e32c76b6a805bb16b1eb8d391db 100644 (file)
--- 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 (sb_feat.rmapbt && xi.rtname) {
                fprintf(stderr,