Re: [Libguestfs] [PATCH] uuid: add support to change uuid of btrfs partition

-----Original Message----- From: libguestfs-bounces(a)redhat.com [mailto:libguestfs-bounces@redhat.com] On Behalf Of Pino Toscano Sent: Tuesday, June 23, 2015 5:50 PM To: libguestfs(a)redhat.com Subject: Re: [Libguestfs] [PATCH] uuid: add support to change uuid of btrfs partition Hi, In data martedì 23 giugno 2015 15:59:19, Chen Hanxiao ha scritto: > btrfs-progs v4.1 add support to change uuid of btrfs fs. This needs to support older btrfs-progs versions though, so run btrfstune to check whether it has the -U parameter, and if not return the old error message. Something like test_btrfs_device_add_needs_force for example.

Also: $ btrfs --version btrfs-progs v4.0 $ btrfstune --help btrfstune: invalid option -- '-' usage: btrfstune [options] device -S value positive value will enable seeding, zero to disable, negative is not allowed -r enable extended inode refs -x enable skinny metadata extent refs -f force to set or clear flags, make sure that you are aware of the dangers Would be cool if btrfs tools would support -h/--help, so it is not considered an error (i.e. exiting with 1).

> > Signed-off-by: Chen Hanxiao <chenhanxiao(a)cn.fujitsu.com&gt; > --- > daemon/uuids.c | 19 +++++++++++++++++-- > generator/actions.ml | 4 ++++ > 2 files changed, 21 insertions(+), 2 deletions(-) > > diff --git a/daemon/uuids.c b/daemon/uuids.c > index 06b33e9..c18cb55 100644 > --- a/daemon/uuids.c > +++ b/daemon/uuids.c > @@ -30,6 +30,7 @@ > GUESTFSD_EXT_CMD(str_tune2fs, tune2fs); > GUESTFSD_EXT_CMD(str_xfs_admin, xfs_admin); > GUESTFSD_EXT_CMD(str_swaplabel, swaplabel); > +GUESTFSD_EXT_CMD(str_btrfstune, btrfstune); > > static int > e2uuid (const char *device, const char *uuid) > @@ -91,6 +92,21 @@ swapuuid (const char *device, const char *uuid) > return 0; > } > > +static int > +btrfsuuid (const char *device, const char *uuid) > +{ > + int r; > + CLEANUP_FREE char *err = NULL; > + > + r = command (NULL, &err, str_btrfstune, "-f", "-U", uuid, device, NULL); > + if (r == -1) { > + reply_with_error ("%s", err); > + return -1; > + } > + > + return 0; > +} While other uuid methods are currently here in uuids.c, IMHO they would better fit together with their filesystem implementations. Similar to what I did with 6db3c100 and 8ad667f1 for labels.

> int > do_set_uuid (const char *device, const char *uuid) > { > @@ -111,8 +127,7 @@ do_set_uuid (const char *device, const char *uuid) > r = swapuuid (device, uuid); > > else if (STREQ (vfs_type, "btrfs")) { > - reply_with_error ("btrfs filesystems' UUID cannot be changed"); > - r = -1; > + r = btrfsuuid (device, uuid); > } > > else { > diff --git a/generator/actions.ml b/generator/actions.ml > index d5e5ccf..ca77c87 100644 > --- a/generator/actions.ml > +++ b/generator/actions.ml > @@ -11774,6 +11774,10 @@ parameter. In future we may allow other flags to be adjusted." }; > InitBasicFS, Always, TestResultString ( > [["set_uuid"; "/dev/sda1"; uuid]; > ["vfs_uuid"; "/dev/sda1"]], uuid), []; > + InitPartition, Always, TestResultString ( > + [["mkfs_btrfs"; "/dev/sda1"; ""; ""; "NOARG"; ""; "NOARG"; "NOARG"; ""; ""]; > + ["set_uuid"; "/dev/sda1"; uuid]; > + ["vfs_uuid"; "/dev/sda1"]], uuid), []; Unfortunately this cannot be added, as it will fail with btrfs-progs < 4.1. My suggestion is to add a simple shell test in tests/btrfs, which would create a simple btrfs fs, try to change the UUID and check that it either returned the old error message, or that it succeeded.

Thanks, -- Pino Toscano _______________________________________________ Libguestfs mailing list Libguestfs(a)redhat.com https://www.redhat.com/mailman/listinfo/libguestfs