btrfs-progs v4.1 add support to change uuid of btrfs fs. Signed-off-by: Chen Hanxiao <chenhanxiao(a)cn.fujitsu.com&gt; --- 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'. + * 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 +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"; +} + $g->shutdown (); $g->close (); -- 2.1.0

Fine. [snip] > > 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 { > > + $g->set_uuid ("/dev/sda1", "12345678-1234-1234-1234-123456789012"); > > +}; > > +# FIXME: ignore ESRCH > What is ESRCH about? The problem is every time I got a ESRCH here. I have no idea about this. Can we just ignore it by: } elsif ($err == Errno::ESRCH()) { ; } else { die $@; } > > +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. Can we just: } else { die $@; } or some hints? Regards, - Chen

Thanks for your hints. v4 will come soon. Regards, - Chen

Signed-off-by: Chen Hanxiao <chenhanxiao(a)cn.fujitsu.com&gt; --- v3: improve commit log daemon/uuids.c | 12 +----------- 1 file changed, 1 insertion(+), 11 deletions(-) diff --git a/daemon/uuids.c b/daemon/uuids.c index f98d8e5..b8b820a 100644 --- a/daemon/uuids.c +++ b/daemon/uuids.c @@ -27,16 +27,12 @@ #include "actions.h" #include "optgroups.h" -GUESTFSD_EXT_CMD(str_tune2fs, tune2fs); GUESTFSD_EXT_CMD(str_xfs_admin, xfs_admin); GUESTFSD_EXT_CMD(str_swaplabel, swaplabel); static int e2uuid (const char *device, const char *uuid) { - int r; - CLEANUP_FREE char *err = NULL; - /* Don't allow the magic values here. If callers want to do this * we'll add alternate set_uuid_* calls. */ @@ -46,13 +42,7 @@ e2uuid (const char *device, const char *uuid) return -1; } - r = command (NULL, &err, str_tune2fs, "-U", uuid, device, NULL); - if (r == -1) { - reply_with_error ("%s", err); - return -1; - } - - return 0; + return do_set_e2uuid (device, uuid); } static int -- 2.1.0

Signed-off-by: Chen Hanxiao <chenhanxiao(a)cn.fujitsu.com&gt; --- v3: move swapuuid to swap.c rename it as swap_set_uuid daemon/daemon.h | 3 +++ daemon/swap.c | 16 ++++++++++++++++ daemon/uuids.c | 18 +----------------- 3 files changed, 20 insertions(+), 17 deletions(-) diff --git a/daemon/daemon.h b/daemon/daemon.h index 7d5691f..d4c8c11 100644 --- a/daemon/daemon.h +++ b/daemon/daemon.h @@ -274,6 +274,9 @@ extern int btrfs_set_uuid (const char *device, const char *uuid); /*-- in ntfs.c --*/ extern char *ntfs_get_label (const char *device); +/*-- in swap.c --*/ +extern int swap_set_uuid (const char *device, const char *uuid); + /* ordinary daemon functions use these to indicate errors * NB: you don't need to prefix the string with the current command, * it is added automatically by the client-side RPC stubs. diff --git a/daemon/swap.c b/daemon/swap.c index 83f4d7c..26fe30d 100644 --- a/daemon/swap.c +++ b/daemon/swap.c @@ -33,6 +33,7 @@ GUESTFSD_EXT_CMD(str_mkswap, mkswap); GUESTFSD_EXT_CMD(str_swapon, swapon); GUESTFSD_EXT_CMD(str_swapoff, swapoff); +GUESTFSD_EXT_CMD(str_swaplabel, swaplabel); /* Confirmed this is true for Linux swap partitions from the Linux sources. */ #define SWAP_LABEL_MAX 16 @@ -239,3 +240,18 @@ do_swapoff_uuid (const char *uuid) { return swaponoff (str_swapoff, "-U", uuid); } + +int +swap_set_uuid (const char *device, const char *uuid) +{ + int r; + CLEANUP_FREE char *err = NULL; + + r = command (NULL, &err, str_swaplabel, "-U", uuid, device, NULL); + if (r == -1) { + reply_with_error ("%s", err); + return -1; + } + + return 0; +} diff --git a/daemon/uuids.c b/daemon/uuids.c index dce0d60..5238f3e 100644 --- a/daemon/uuids.c +++ b/daemon/uuids.c @@ -27,7 +27,6 @@ #include "actions.h" #include "optgroups.h" -GUESTFSD_EXT_CMD(str_swaplabel, swaplabel); static int e2uuid (const char *device, const char *uuid) @@ -56,21 +55,6 @@ xfsuuid (const char *device, const char *uuid) return xfs_set_uuid (device, uuid); } -static int -swapuuid (const char *device, const char *uuid) -{ - int r; - CLEANUP_FREE char *err = NULL; - - r = command (NULL, &err, str_swaplabel, "-U", uuid, device, NULL); - if (r == -1) { - reply_with_error ("%s", err); - return -1; - } - - return 0; -} - int do_set_uuid (const char *device, const char *uuid) { @@ -88,7 +72,7 @@ do_set_uuid (const char *device, const char *uuid) r = xfsuuid (device, uuid); else if (STREQ (vfs_type, "swap")) - r = swapuuid (device, uuid); + r = swap_set_uuid (device, uuid); else if (STREQ (vfs_type, "btrfs")) r = btrfs_set_uuid (device, uuid); -- 2.1.0

Signed-off-by: Chen Hanxiao <chenhanxiao(a)cn.fujitsu.com&gt; --- daemon/daemon.h | 1 + daemon/ext2.c | 15 +++++++++++++++ 2 files changed, 16 insertions(+) diff --git a/daemon/daemon.h b/daemon/daemon.h index 5087327..9c8476c 100644 --- a/daemon/daemon.h +++ b/daemon/daemon.h @@ -219,6 +219,7 @@ extern int sync_disks (void); /* Confirmed this is true up to ext4 from the Linux sources. */ #define EXT2_LABEL_MAX 16 extern int fstype_is_extfs (const char *fstype); +extern int set_e2uuid_random (const char *device); /*-- in blkid.c --*/ extern char *get_blkid_tag (const char *device, const char *tag); diff --git a/daemon/ext2.c b/daemon/ext2.c index 8ef6d5f..625e5ae 100644 --- a/daemon/ext2.c +++ b/daemon/ext2.c @@ -159,6 +159,21 @@ do_set_e2uuid (const char *device, const char *uuid) return 0; } +int +set_e2uuid_random (const char *device) +{ + int r; + CLEANUP_FREE char *err = NULL; + + r = command (NULL, &err, str_tune2fs, "-U", "random", device, NULL); + if (r == -1) { + reply_with_error ("%s", err); + return -1; + } + + return 0; +} + char * do_get_e2uuid (const char *device) { -- 2.1.0

In data venerdì 26 giugno 2015 17:35:42, Chen Hanxiao ha scritto: The addition of the get_random_uuid() is worth an own commit. Also, it is not specific to swap, so I'd say to put it directly in guestfsd.c, named like uuidgen() (much like the OCaml equivalent in Common_utils). Furthermore, you should make sure uuidgen is actually in the appliance: while in Fedora is in util-linux (already part of the appliance), e.g. in Debian/Ubuntu is in uuid-runtime. Thus you need to add that package to the Debian ones in appliance/packagelist.in. This is nothing specific for swap, and could just be done directly in the set_uuid_random implementation, for all the filesystems we have tools to change their UUIDs (so swap only so far). In practice something like: else if (STREQ (vfs_type, "swap")) { CLEANUP_FREE char *uuid = uuidgen (); if (uuid == NULL) return -1; r = swap_set_uuid (device, uuid); } Thanks, -- Pino Toscano

Signed-off-by: Chen Hanxiao <chenhanxiao(a)cn.fujitsu.com&gt; --- daemon/daemon.h | 1 + daemon/xfs.c | 7 +++++++ 2 files changed, 8 insertions(+) diff --git a/daemon/daemon.h b/daemon/daemon.h index 6c07c6a..6d98eb9 100644 --- a/daemon/daemon.h +++ b/daemon/daemon.h @@ -262,6 +262,7 @@ extern int copy_xattrs (const char *src, const char *dest); /* Documented in xfs_admin(8). */ #define XFS_LABEL_MAX 12 extern int xfs_set_uuid (const char *device, const char *uuid); +extern int xfs_set_uuid_random (const char *device); /*-- debug-bmap.c --*/ extern char *debug_bmap (const char *subcmd, size_t argc, char *const *const argv); diff --git a/daemon/xfs.c b/daemon/xfs.c index fb7acb4..2c93311 100644 --- a/daemon/xfs.c +++ b/daemon/xfs.c @@ -463,6 +463,13 @@ xfs_set_uuid (const char *device, const char *uuid) } int +xfs_set_uuid_random (const char *device) +{ + optargs_bitmask = GUESTFS_XFS_ADMIN_UUID_BITMASK; + return do_xfs_admin (device, 0, 0, 0, 0, 0, NULL, "generate"); +} + +int do_xfs_admin (const char *device, int extunwritten, int imgfile, int v2log, int projid32bit, -- 2.1.0

In data venerdì 26 giugno 2015 17:35:44, Chen Hanxiao ha scritto: Being a new API, we could make this return ENOTSUP, documenting this error on unsupported filesystems. This way, users could know an error is due to a filesystem not supported by this API, instead of a real failure of one of the programs used. This sounds like it is setting some particular random UUID. I'd be better as "set a random UUID for the filesystem" What is ESRCH about? You need to care in case $err is non-zero, that is a real error. Thanks, -- Pino Toscano