[Libguestfs] [PATCH v3.1 1/9] uuid: add support to change uuid of btrfs partition
Pino Toscano
ptoscano at redhat.com
Fri Jun 26 12:12:00 UTC 2015
In data venerdì 26 giugno 2015 17:35:36, Chen Hanxiao ha scritto:
> btrfs-progs v4.1 add support to change uuid of btrfs fs.
>
> Signed-off-by: Chen Hanxiao <chenhanxiao at cn.fujitsu.com>
> ---
> v3.1: fix a typo
> v3: set errno as ENOTSUP when btrfstune -u is not available
> v2: put btrfs operation back to daemon/btrfs.c
> move tests to tests/btrfs
>
> daemon/btrfs.c | 60 ++++++++++++++++++++++++++++++++++++++++++
> daemon/daemon.h | 1 +
> daemon/uuids.c | 6 ++---
> tests/btrfs/test-btrfs-misc.pl | 17 ++++++++++++
> 4 files changed, 80 insertions(+), 4 deletions(-)
>
> diff --git a/daemon/btrfs.c b/daemon/btrfs.c
> index 20e5e6b..a69c512 100644
> --- a/daemon/btrfs.c
> +++ b/daemon/btrfs.c
> @@ -790,6 +790,44 @@ do_btrfs_device_delete (char *const *devices, const char *fs)
> return 0;
> }
>
> +
> +/* btrfstune command add two new options
> + * -U UUID change fsid to UUID
> + * -u change fsid, use a random one
> + * since v4.1
> + * We could check wheter 'btrfstune' support
> + * '-u' and '-U UUID' option by checking the output of
> + * 'btrfstune' command.
> + */
> +static int
> +test_btrfstune_uuid_opt (void)
> +{
> + static int result = -1;
> + if (result != -1)
> + return result;
> +
> + CLEANUP_FREE char *err = NULL;
> +
> + int r = commandr (NULL, &err, str_btrfstune, NULL);
> +
> + if (r == -1) {
> + reply_with_error ("btrfstune: %s", err);
> + return -1;
> + }
> +
> + /* FIXME currently btrfstune do not support '--help'.
So --help should be passed anyway to the btrfstune invocation, so with
newer versions hopefully there will not be complaints about it anymore.
> + * If got an invalid options, it will print its usage
> + * in stderr.
> + * We had to check it there.
> + */
> + if (strstr (err, "-U") == NULL || strstr (err, "-u") == NULL)
> + result = 0;
> + else
> + result = 1;
> +
> + return result;
> +}
> +
> int
> do_btrfs_set_seeding (const char *device, int svalue)
> {
> @@ -807,6 +845,28 @@ do_btrfs_set_seeding (const char *device, int svalue)
> return 0;
> }
>
> +int
> +btrfs_set_uuid (const char *device, const char *uuid)
> +{
> + CLEANUP_FREE char *err = NULL;
> + int r;
> + int has_uuid_opts = test_btrfstune_uuid_opt ();
> +
> + if (has_uuid_opts <= 0) {
> + reply_with_error_errno (ENOTSUP, "btrfs filesystems' UUID cannot be changed");
> + return -1;
> + }
> +
> + r = commandr (NULL, &err, str_btrfstune, "-f", "-U", uuid, device, NULL);
> +
> + if (r == -1) {
> + reply_with_error ("%s: %s", device, err);
> + return -1;
> + }
> +
> + return 0;
> +}
> +
> /* Takes optional arguments, consult optargs_bitmask. */
> int
> do_btrfs_fsck (const char *device, int64_t superblock, int repair)
> diff --git a/daemon/daemon.h b/daemon/daemon.h
> index 136e9a9..b74ba3c 100644
> --- a/daemon/daemon.h
> +++ b/daemon/daemon.h
> @@ -268,6 +268,7 @@ extern char *debug_bmap_device (const char *subcmd, size_t argc, char *const *co
>
> /*-- in btrfs.c --*/
> extern char *btrfs_get_label (const char *device);
> +extern int btrfs_set_uuid (const char *device, const char *uuid);
>
> /*-- in ntfs.c --*/
> extern char *ntfs_get_label (const char *device);
> diff --git a/daemon/uuids.c b/daemon/uuids.c
> index 06b33e9..f98d8e5 100644
> --- a/daemon/uuids.c
> +++ b/daemon/uuids.c
> @@ -110,10 +110,8 @@ do_set_uuid (const char *device, const char *uuid)
> else if (STREQ (vfs_type, "swap"))
> r = swapuuid (device, uuid);
>
> - else if (STREQ (vfs_type, "btrfs")) {
> - reply_with_error ("btrfs filesystems' UUID cannot be changed");
> - r = -1;
> - }
> + else if (STREQ (vfs_type, "btrfs"))
> + r = btrfs_set_uuid (device, uuid);
>
> else {
> reply_with_error ("don't know how to set the UUID for '%s' filesystems",
> diff --git a/tests/btrfs/test-btrfs-misc.pl b/tests/btrfs/test-btrfs-misc.pl
> index 2fe7c59..b47caab 100755
> --- a/tests/btrfs/test-btrfs-misc.pl
> +++ b/tests/btrfs/test-btrfs-misc.pl
> @@ -20,6 +20,7 @@
>
> use strict;
> use warnings;
> +use Errno;
>
> use Sys::Guestfs;
>
> @@ -47,5 +48,21 @@ my $label = $g->vfs_label ("/dev/sda1");
> die "unexpected label: expecting 'newlabel' but got '$label'"
> unless $label eq "newlabel";
>
> +# Setting btrfs UUID
> +eval {
> + $g->set_uuid ("/dev/sda1", "12345678-1234-1234-1234-123456789012");
> +};
> +# FIXME: ignore ESRCH
What is ESRCH about?
> +my $err = $g->last_errno ();
> +
> +if ($err == 0) {
> + my $uuid = $g->vfs_uuid ("/dev/sda1");
> + die "unexpected uuid expecting
> + '12345678-1234-1234-1234-123456789012' but got '$uuid'"
> + unless $uuid eq "12345678-1234-1234-1234-123456789012";
> +} elsif ($err == Errno::ENOTSUP()) {
> + warn "$0: skipping test for btrfs UUID change feature is not available\n";
> +}
IIRC 'warn' prints the newline at the end already.
This is missing to check when $err is a valid error.
Thanks,
--
Pino Toscano
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