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fix: more complex algorithm to sort volumes correctly when orphans ar…
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…e found (#7)
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@speed47
speed47 committed Jan 3, 2022
1 parent d3c1839 commit 8e9a2ec
Showing 1 changed file with 74 additions and 24 deletions.
98 changes: 74 additions & 24 deletions btrfs-list
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Original file line number Diff line number Diff line change
Expand Up @@ -32,6 +32,10 @@ use constant GiB => 1024**3;
use constant TiB => 1024**4;
use constant PiB => 1024**5;

use constant PARENT_UUID_DF => '*';
use constant PARENT_UUID_NONE_MAINVOL => '+';
use constant PARENT_UUID_NONE => '-';

sub help {
print <<EOF;
Usage: $0 [options] [mountpoint]
Expand Down Expand Up @@ -401,14 +405,16 @@ foreach my $fuuid (keys %filesystems) {
$devFree{$1} = human2raw($2) + 0;
}
}

# this is the first line of the output, to ensure it, set id == -1
$vol{$fuuid}{df} = {
id => '-1',
path => $filesystems{$fuuid}{label},
gen => 0,
cgen => 0,
parent => '-',
top => '-', # top_level
puuid => '*', # parent_uuid
puuid => PARENT_UUID_DF, # parent_uuid
ruuid => '-', # received_uuid
type => 'fs',
mode => 'rw',
Expand Down Expand Up @@ -508,7 +514,7 @@ foreach my $fuuid (keys %filesystems) {
}

# ID 257 gen 17 cgen 11 parent 5 top level 5 parent_uuid - received_uuid - uuid 9bc47c09-fe59-4b4c-8ed6-b01a941bfd75 path sub1
$vol{$fuuid}{$vuuid}{puuid} = '-'; # old btrfsprogs don't have puuid, set a sane default
$vol{$fuuid}{$vuuid}{puuid} = PARENT_UUID_NONE; # old btrfsprogs don't have puuid, set a sane default
/(\s|^)ID (\d+)/ and $vol{$fuuid}{$vuuid}{id} = $2;
/(\s|^)gen (\d+)/ and $vol{$fuuid}{$vuuid}{gen} = $2;
/(\s|^)cgen (\d+)/ and $vol{$fuuid}{$vuuid}{cgen} = $2;
Expand Down Expand Up @@ -605,7 +611,7 @@ foreach my $fuuid (keys %filesystems) {
cgen => 0,
parent => '-',
top => '-',
puuid => '+',
puuid => PARENT_UUID_NONE_MAINVOL,
ruuid => '-',
type => 'mainvol',
mode => 'rw',
Expand All @@ -625,7 +631,7 @@ foreach my $fuuid (keys %filesystems) {
cgen => 0,
parent => '-',
top => '-',
puuid => '+',
puuid => PARENT_UUID_NONE_MAINVOL,
ruuid => '-',
type => 'mainvol',
mode => 'rw',
Expand All @@ -646,16 +652,15 @@ foreach my $fuuid (keys %filesystems) {
}
}
}
debug("VOL HASH DUMP:", Dumper \%vol);
debug("VOL HASH DUMP (filesystem uuid - volume uuid - data):", Dumper \%vol);

# ok, now, do the magic

my @ordered = ();
my $maxdepth = 0;
my $biggestpath = 0;
my @ordered = ();
my $maxdepth = 0;
my %seen;

sub order_recursive {
sub recursive_add_children_of {
my %params = @_;
my $volumes = $params{'volumes'};
my $depth = $params{'depth'};
Expand All @@ -664,34 +669,79 @@ sub order_recursive {
$depth > $maxdepth and $maxdepth = $depth;

foreach my $vuuid (sort { $volumes->{$a}{id} <=> $volumes->{$b}{id} } keys %$volumes) {
debug(".." x ($depth) . " called with volume_uuid=$vuuid and parent_uuid=$parentuuid now working on vol w/ parent_uuid=" . $volumes->{$vuuid}{puuid});
if ($parentuuid eq $volumes->{$vuuid}{puuid}) {
my $hash = $volumes->{$vuuid};
$hash->{depth} = $depth;
length($hash->{path}) > $biggestpath and $biggestpath = length($hash->{path});
push @ordered, $hash;
next if $seen{$vuuid}; # not needed, but just in case
my $vol = $volumes->{$vuuid};
debug( "..." x ($depth)
. "parent_uuid=$parentuuid, currently working on id "
. $vol->{id}
. " volume_uuid=$vuuid having parent_uuid="
. $vol->{puuid}
. " and path-type "
. $vol->{path} . "-"
. $vol->{type});
if ($parentuuid eq $vol->{puuid}) {
$vol->{depth} = $depth;
push @ordered, $vol;
debug("..." x ($depth) . "^^^");
$seen{$vuuid} = 1;
order_recursive(volumes => $volumes, depth => $depth + 1, parentuuid => $vuuid); # unless $parentuuid eq '-';
recursive_add_children_of(volumes => $volumes, depth => $depth + 1, parentuuid => $vuuid); # unless $parentuuid eq '-';
}
}
return;
}

my $isFirstFS = 1;
foreach my $fuuid (sort keys %filesystems) {
@ordered = ();
$maxdepth = 0;
$biggestpath = 0;
order_recursive(volumes => $vol{$fuuid}, depth => 0, parentuuid => '*');
order_recursive(volumes => $vol{$fuuid}, depth => 1, parentuuid => '+');
order_recursive(volumes => $vol{$fuuid}, depth => 1, parentuuid => '-');
@ordered = ();
%seen = ();
$maxdepth = 0;
my @orphans = ();

# first, we want the so-called "df" line, which conveniently has a fake specific parent_uuid
debug(">>> order df");
recursive_add_children_of(volumes => $vol{$fuuid}, depth => 0, parentuuid => PARENT_UUID_DF);

# then, the builtin main volume (id=5) and all its descendants
debug(">>> order mainvol");
recursive_add_children_of(volumes => $vol{$fuuid}, depth => 1, parentuuid => PARENT_UUID_NONE_MAINVOL);

# then, all the other top-level volumes (i.e. that have no parent uuid)
debug(">>> order top level vols");
recursive_add_children_of(volumes => $vol{$fuuid}, depth => 1, parentuuid => PARENT_UUID_NONE);

next if !@ordered;

# then, we might still have unseen volumes, which are orphans (they have a parent_uuid)
# but the parent_uuid no longer exists). get all those in a hash

foreach my $vuuid (keys %{$vol{$fuuid}}) {
next if $seen{$vuuid};
push @ordered, $vol{$fuuid}{$vuuid};
push @orphans, $vuuid;
}

next if !@ordered;
# those orphans might however have parents/children between themselves,
# so find the first one that has no known parent among the other orphans
foreach my $orphan (sort @orphans) {
my $no_known_parent = 1;
foreach my $potential_parent (@orphans) {
next if $orphan eq $potential_parent; # skip myself
$no_known_parent = 0 if ($potential_parent eq $vol{$fuuid}{$orphan}{puuid});
}
debug(">>> orphan loop on $orphan, no known parent: $no_known_parent");
if ($no_known_parent == 1) {
push @ordered, $vol{$fuuid}{$orphan};
$seen{$orphan} = 1;
$vol{$fuuid}{$orphan}{depth} = 1;
recursive_add_children_of(volumes => $vol{$fuuid}, depth => 2, parentuuid => $orphan);
}
}

# do we still have unseen volumes? (we shouldn't)
foreach my $vuuid (keys %{$vol{$fuuid}}) {
next if $seen{$vuuid};
print STDERR "WARN: we shouldn't have orphaned volumne $vuuid\n";
push @ordered, $vuuid;
}

# find the longest path (including leading spaces)
my $longestpath = 0;
Expand Down

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