pkg/mount/flags.go
Dan Walsh bd052b6116 This patch adds --tmpfs as a option for mounting tmpfs on directories
It will Tar up contents of child directory onto tmpfs if mounted over

This patch will use the new PreMount and PostMount hooks to "tar"
up the contents of the base image on top of tmpfs mount points.

Signed-off-by: Dan Walsh <dwalsh@redhat.com>
2015-12-02 10:06:59 -05:00

91 lines
2.4 KiB
Go

package mount
import (
"fmt"
"strings"
)
// Parse fstab type mount options into mount() flags
// and device specific data
func parseOptions(options string) (int, string) {
var (
flag int
data []string
)
flags := map[string]struct {
clear bool
flag int
}{
"defaults": {false, 0},
"ro": {false, RDONLY},
"rw": {true, RDONLY},
"suid": {true, NOSUID},
"nosuid": {false, NOSUID},
"dev": {true, NODEV},
"nodev": {false, NODEV},
"exec": {true, NOEXEC},
"noexec": {false, NOEXEC},
"sync": {false, SYNCHRONOUS},
"async": {true, SYNCHRONOUS},
"dirsync": {false, DIRSYNC},
"remount": {false, REMOUNT},
"mand": {false, MANDLOCK},
"nomand": {true, MANDLOCK},
"atime": {true, NOATIME},
"noatime": {false, NOATIME},
"diratime": {true, NODIRATIME},
"nodiratime": {false, NODIRATIME},
"bind": {false, BIND},
"rbind": {false, RBIND},
"unbindable": {false, UNBINDABLE},
"runbindable": {false, RUNBINDABLE},
"private": {false, PRIVATE},
"rprivate": {false, RPRIVATE},
"shared": {false, SHARED},
"rshared": {false, RSHARED},
"slave": {false, SLAVE},
"rslave": {false, RSLAVE},
"relatime": {false, RELATIME},
"norelatime": {true, RELATIME},
"strictatime": {false, STRICTATIME},
"nostrictatime": {true, STRICTATIME},
}
for _, o := range strings.Split(options, ",") {
// If the option does not exist in the flags table or the flag
// is not supported on the platform,
// then it is a data value for a specific fs type
if f, exists := flags[o]; exists && f.flag != 0 {
if f.clear {
flag &= ^f.flag
} else {
flag |= f.flag
}
} else {
data = append(data, o)
}
}
return flag, strings.Join(data, ",")
}
// ParseTmpfsOptions parse fstab type mount options into flags and data
func ParseTmpfsOptions(options string) (int, string, error) {
flags, data := parseOptions(options)
validFlags := map[string]bool{
"size": true,
"mode": true,
"uid": true,
"gid": true,
"nr_inodes": true,
"nr_blocks": true,
"mpol": true,
}
for _, o := range strings.Split(data, ",") {
opt := strings.SplitN(o, "=", 2)
if !validFlags[opt[0]] {
return 0, "", fmt.Errorf("Invalid tmpfs option %q", opt)
}
}
return flags, data, nil
}