space.go RawHistoryFolder

1// SPDX-License-Identifier: MIT
2
3package sandbox
4
5import (
6	"context"
7
8	"github.com/bnema/zerowrap"
9	"golang.org/x/sys/unix"
10)
11
12// FreeMiB returns the space available to unprivileged users on the filesystem
13// of path, in MiB.
14func FreeMiB(path string) (int64, error) {
15	var st unix.Statfs_t
16	if err := unix.Statfs(path, &st); err != nil {
17		return 0, err
18	}
19	return int64(st.Bavail) * st.Bsize >> 20, nil
20}
21
22// WarnIfLowSpace logs a warning when the filesystem of dir has less free space
23// than capacity sandboxes of diskMiB would need if they all filled their sparse
24// scratch disk. It is only a warning: scratch disks are sparse and jobs rarely
25// fill them, so a smaller filesystem works until it does not. free is FreeMiB in
26// production.
27func WarnIfLowSpace(ctx context.Context, dir string, capacity, diskMiB int, free func(string) (int64, error)) {
28	if free == nil {
29		free = FreeMiB
30	}
31	log := zerowrap.FromCtx(ctx)
32	have, err := free(dir)
33	if err != nil {
34		log.Warn().Err(err).Str("dir", dir).Msg("cannot check the free space of the state directory")
35		return
36	}
37	need := int64(capacity) * int64(diskMiB)
38	if have < need {
39		log.Warn().Str("dir", dir).Int64("free_mib", have).Int64("worst_case_mib", need).
40			Int("capacity", capacity).Int("job_disk_mib", diskMiB).
41			Msg("the state directory has less free space than capacity x job disk: jobs that fill their scratch disk will fail with 'no space left on device'")
42	}
43}