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fix(disk): do not divide by zero on a filesystem with no capacity #1062

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Merged
kesselb merged 1 commit into from
Aug 2, 2026
Merged

fix(disk): do not divide by zero on a filesystem with no capacity #1062

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14 changes: 9 additions & 5 deletions lib/OperatingSystems/FreeBSD.php
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Original file line number Diff line number Diff line change
Expand Up @@ -189,8 +189,8 @@ public function getDiskInfo(): array {
$matches = [];
// `df -P` prints one record per line with the mount point last, so the mount
// point is everything after the capacity column. Used and Capacity are loose
// because nothing reads them and `df` prints "-" for filesystems without
// usage numbers.
// because nothing reads them and `df` prints "-" in those two columns when
// it has no usage numbers.
$pattern = '/^(?<Filesystem>\S+)[ \t]+(?<Type>\S+)[ \t]+(?<Blocks>\d+)[ \t]+(?<Used>\S+)[ \t]+(?<Available>\d+)[ \t]+(?<Capacity>\S+)[ \t]+(?<Mounted>\S.*?)[ \t\r]*$/m';

$result = preg_match_all($pattern, $disks, $matches);
Expand All @@ -204,13 +204,17 @@ public function getDiskInfo(): array {
continue;
}

$blocks = (int)$matches['Blocks'][$i];
$available = (int)$matches['Available'][$i];
// Clamped: more available than total would give a negative size
$used = max(0, $blocks - $available);

$disk = new Disk();
$disk->setDevice($filesystem);
$disk->setFs($matches['Type'][$i]);
$used = (int)((int)$matches['Blocks'][$i] - (int)$matches['Available'][$i]);
$disk->setUsed((int)ceil($used / 1024));
$disk->setAvailable((int)floor((int)$matches['Available'][$i] / 1024));
$disk->setPercent(round(($used * 100 / (int)$matches['Blocks'][$i]), 2) . '%');
$disk->setAvailable((int)floor($available / 1024));
$disk->setPercent($blocks > 0 ? (string)round($used * 100 / $blocks, 2) . '%' : '0%');
$disk->setMount($matches['Mounted'][$i]);

$data[] = $disk;
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15 changes: 10 additions & 5 deletions lib/OperatingSystems/Linux.php
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Original file line number Diff line number Diff line change
Expand Up @@ -208,8 +208,8 @@ public function getDiskInfo(): array {
$matches = [];
// `df -P` prints one record per line with the mount point last, so the mount
// point is everything after the capacity column. Used and Capacity are loose
// because nothing reads them and `df` prints "-" for filesystems without
// usage numbers.
// because nothing reads them and `df` prints "-" in those two columns when
// it has no usage numbers.
$pattern = '/^(?<Filesystem>\S+)[ \t]+(?<Type>\S+)[ \t]+(?<Blocks>\d+)[ \t]+(?<Used>\S+)[ \t]+(?<Available>\d+)[ \t]+(?<Capacity>\S+)[ \t]+(?<Mounted>\S.*?)[ \t\r]*$/m';

$result = preg_match_all($pattern, $disks, $matches);
Expand All @@ -224,13 +224,18 @@ public function getDiskInfo(): array {
continue;
}

$blocks = (int)$matches['Blocks'][$i];
$available = (int)$matches['Available'][$i];
// Clamped: more available than total would give a negative size
$used = max(0, $blocks - $available);

$disk = new Disk();
$disk->setDevice($filesystem);
$disk->setFs($matches['Type'][$i]);
$used = (int)((int)$matches['Blocks'][$i] - (int)$matches['Available'][$i]);
$disk->setUsed((int)ceil($used / 1024));
$disk->setAvailable((int)floor((int)$matches['Available'][$i] / 1024));
$disk->setPercent(round(($used * 100 / (int)$matches['Blocks'][$i]), 2) . '%');
$disk->setAvailable((int)floor($available / 1024));
// busybox df lists zero-block filesystems, coreutils does not
$disk->setPercent($blocks > 0 ? (string)round($used * 100 / $blocks, 2) . '%' : '0%');
$disk->setMount($matches['Mounted'][$i]);

$data[] = $disk;
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4 changes: 4 additions & 0 deletions tests/data/freebsd_df_tp_edge_cases
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Original file line number Diff line number Diff line change
@@ -0,0 +1,4 @@
Filesystem Type 1024-blocks Used Available Capacity Mounted on
/dev/gpt/rootfs ufs 56422560 6205468 47321220 12% /
empty nullfs 0 0 0 0% /mnt/empty
inverted zfs 1000 0 2000 0% /tank
4 changes: 4 additions & 0 deletions tests/data/linux_df_tp_edge_cases
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Original file line number Diff line number Diff line change
@@ -0,0 +1,4 @@
Filesystem Type 1024-blocks Used Available Capacity Mounted on
/dev/vda1 ext4 56422560 6205468 47321220 12% /
nsfs nsfs 0 0 0 0% /run/snapd/ns
inverted zfs 1000 0 2000 0% /tank
34 changes: 34 additions & 0 deletions tests/lib/FreeBSDTest.php
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Original file line number Diff line number Diff line change
Expand Up @@ -200,6 +200,40 @@ public function testGetNetworkInterfacesError(): void {
$this->assertEquals($expected, $actual);
}

public function testGetDiskInfoZeroCapacityAndInvertedUsage(): void {
$this->os->method('executeCommand')
->with('df -TPk')
->willReturn(file_get_contents(__DIR__ . '/../data/freebsd_df_tp_edge_cases'));

$disk1 = new Disk();
$disk1->setDevice('/dev/gpt/rootfs');
$disk1->setFs('ufs');
$disk1->setUsed(8889);
$disk1->setAvailable(46212);
$disk1->setPercent('16.13%');
$disk1->setMount('/');

// Zero blocks: used to be a DivisionByZeroError
$disk2 = new Disk();
$disk2->setDevice('empty');
$disk2->setFs('nullfs');
$disk2->setUsed(0);
$disk2->setAvailable(0);
$disk2->setPercent('0%');
$disk2->setMount('/mnt/empty');

// More available than total: used is clamped
$disk3 = new Disk();
$disk3->setDevice('inverted');
$disk3->setFs('zfs');
$disk3->setUsed(0);
$disk3->setAvailable(1);
$disk3->setPercent('0%');
$disk3->setMount('/tank');

$this->assertEquals([$disk1, $disk2, $disk3], $this->os->getDiskInfo());
}

public function testSupported(): void {
$this->assertFalse($this->os->supported());
}
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40 changes: 37 additions & 3 deletions tests/lib/LinuxTest.php
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Original file line number Diff line number Diff line change
Expand Up @@ -235,17 +235,51 @@ public function testGetDiskInfo(): void {
$this->assertEquals([$disk1, $disk2, $disk3, $disk4, $disk5, $disk6, $disk7], $this->os->getDiskInfo());
}

public function testGetDiskInfoZeroCapacityAndInvertedUsage(): void {
$this->os->method('executeCommand')
->with('df -TPk')
->willReturn(file_get_contents(__DIR__ . '/../data/linux_df_tp_edge_cases'));

$disk1 = new Disk();
$disk1->setDevice('/dev/vda1');
$disk1->setFs('ext4');
$disk1->setUsed(8889);
$disk1->setAvailable(46212);
$disk1->setPercent('16.13%');
$disk1->setMount('/');

// Zero blocks: used to be a DivisionByZeroError
$disk2 = new Disk();
$disk2->setDevice('nsfs');
$disk2->setFs('nsfs');
$disk2->setUsed(0);
$disk2->setAvailable(0);
$disk2->setPercent('0%');
$disk2->setMount('/run/snapd/ns');

// More available than total: used is clamped
$disk3 = new Disk();
$disk3->setDevice('inverted');
$disk3->setFs('zfs');
$disk3->setUsed(0);
$disk3->setAvailable(1);
$disk3->setPercent('0%');
$disk3->setMount('/tank');

$this->assertEquals([$disk1, $disk2, $disk3], $this->os->getDiskInfo());
}

public function testGetDiskInfoNoCommandOutput(): void {
$this->os->method('executeCommand')
->with('df -TP')
->willThrowException(new RuntimeException('No output for command "df -TP"'));
->with('df -TPk')
->willThrowException(new RuntimeException('No output for command "df -TPk"'));

$this->assertEquals([], $this->os->getDiskInfo());
}

public function testGetDiskInfoInvalidCommandOutput(): void {
$this->os->method('executeCommand')
->with('df -TP')
->with('df -TPk')
->willReturn('invalid_data');

$this->assertEquals([], $this->os->getDiskInfo());
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2 changes: 0 additions & 2 deletions tests/psalm-baseline.xml
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Original file line number Diff line number Diff line change
Expand Up @@ -52,7 +52,6 @@
<InvalidOperand>
<code><![CDATA[$lines[0] / 1024 / 1024]]></code>
<code><![CDATA[($lines[1] * ($lines[2] + $lines[3] + $lines[4])) / 1024 / 1024]]></code>
<code><![CDATA[round(($used * 100 / (int)$matches['Blocks'][$i]), 2)]]></code>
</InvalidOperand>
</file>
<file src="lib/OperatingSystems/Linux.php">
Expand All @@ -62,7 +61,6 @@
</ForbiddenCode>
<InvalidOperand>
<code><![CDATA[$speed / 1000]]></code>
<code><![CDATA[round(($used * 100 / (int)$matches['Blocks'][$i]), 2)]]></code>
</InvalidOperand>
</file>
<file src="lib/Os.php">
Expand Down
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