ambiser
/
btrbk
mirror of https://github.com/digint/btrbk
9
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

btrbk: validate output of "btrfs subvolume show"; also return uuid for btrfs root (if present) 

Filesystems created with btrfs-progs < 4.16 have valid UUID, while
others have not [1]. Validate output of "btrfs subvolume show", and
provide uuid for btrfs root (id=5) only if it is valid.

  [1]: 0a0a03554a: btrfs-progs: mkfs: add uuid and otime to ROOT_ITEM of, FS_TREE
pull/245/head
Axel Burri 2018-06-29 16:56:59 +02:00
parent 9c70231859
commit 177671e920
1 changed files with 34 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

48
btrbk
View File

@ -874,8 +874,10 @@ sub btrfs_filesystem_usage($)
}
# returns hashref with keys: (name uuid parent_uuid id gen cgen top_level)
# returns hashref with keys: (uuid parent_uuid id gen cgen top_level)
# for btrfs root, returns at least: (id is_root)
# for btrfs-progs >= 4.1, also returns key: "received_uuid"
# if present, also returns (unvalidated) keys: (name creation_time flags)
sub btrfs_subvolume_show($)
{
my $vol = shift || die;
@ -935,9 +937,6 @@ sub btrfs_subvolume_show($)
$detail{id} = 5;
}
else {
# NOTE: received_uuid is not required here, as btrfs-progs < 4.1 does not give us that information.
# no worries, we get this from btrfs_subvolume_list() for all subvols.
my @required_keys = qw(name uuid parent_uuid id gen cgen top_level readonly);
my %trans = (
"Name" => "name",
"uuid" => "uuid",
@ -968,24 +967,45 @@ sub btrfs_subvolume_show($)
}
DEBUG "Parsed " . scalar(keys %detail) . " subvolume detail items: $vol->{PRINT}";
# validate required keys
unless((defined($detail{parent_uuid}) && (($detail{parent_uuid} eq '-') || ($detail{parent_uuid} =~ /^$uuid_match$/))) &&
(defined($detail{id}) && ($detail{id} =~ /^\d+$/) && ($detail{id} >= 5)) &&
(defined($detail{gen}) && ($detail{gen} =~ /^\d+$/)) &&
(defined($detail{cgen}) && ($detail{cgen} =~ /^\d+$/)) &&
(defined($detail{top_level}) && ($detail{top_level} =~ /^\d+$/)))
{
ERROR "Failed to parse subvolume detail (unsupported btrfs-progs) for: $vol->{PRINT}";
return undef;
}
# NOTE: filesystems created with btrfs-progs < 4.16 have no UUID for subvolid=5,
# assert {uuid} is either valid or undef
if(defined($detail{uuid}) && ($detail{uuid} !~ /^$uuid_match$/)) {
if($detail{id} == 5) {
DEBUG "No UUID on btrfs root (id=5): $vol->{PRINT}";
} else {
ERROR "Failed to parse subvolume detail (unsupported btrfs-progs) for: $vol->{PRINT}";
return undef;
}
delete $detail{uuid};
}
# NOTE: received_uuid is not required here, as btrfs-progs < 4.1 does not give us that information.
# no worries, we get this from btrfs_subvolume_list() for all subvols.
if(defined($detail{received_uuid}) && ($detail{received_uuid} ne '-') && ($detail{received_uuid} !~ /^$uuid_match$/)) {
ERROR "Failed to parse subvolume detail (unsupported btrfs-progs) for: $vol->{PRINT}";
return undef;
}
# NOTE: as of btrfs-progs v4.6.1, flags are either "-" or "readonly"
$detail{readonly} = ($detail{flags} =~ /readonly/) ? 1 : 0;
VINFO(\%detail, "detail") if($loglevel >=4);
foreach(@required_keys) {
unless(defined($detail{$_})) {
ERROR "Failed to parse subvolume detail (unsupported btrfs-progs) for: $vol->{PRINT}";
return undef;
}
}
}
if($detail{id} == 5) {
# NOTE: as of btrfs-progs v4.8.3, we get full output for root
# subvolume, with lots of '0' and '-' (especially uuid='-').
# This breaks things, set $detail to sane values:
DEBUG "found btrfs root: $vol->{PRINT}";
%detail = ( id => 5, is_root => 1 );
$detail{is_root} = 1;
}
return \%detail;