package mount // import "github.com/docker/docker/pkg/mount" import ( "fmt" "strings" ) var 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}, } var validFlags = map[string]bool{ "": true, "size": true, "mode": true, "uid": true, "gid": true, "nr_inodes": true, "nr_blocks": true, "mpol": true, } var propagationFlags = map[string]bool{ "bind": true, "rbind": true, "unbindable": true, "runbindable": true, "private": true, "rprivate": true, "shared": true, "rshared": true, "slave": true, "rslave": true, } // MergeTmpfsOptions merge mount options to make sure there is no duplicate. func MergeTmpfsOptions(options []string) ([]string, error) { // We use collisions maps to remove duplicates. // For flag, the key is the flag value (the key for propagation flag is -1) // For data=value, the key is the data flagCollisions := map[int]bool{} dataCollisions := map[string]bool{} var newOptions []string // We process in reverse order for i := len(options) - 1; i >= 0; i-- { option := options[i] if option == "defaults" { continue } if f, ok := flags[option]; ok && f.flag != 0 { // There is only one propagation mode key := f.flag if propagationFlags[option] { key = -1 } // Check to see if there is collision for flag if !flagCollisions[key] { // We prepend the option and add to collision map newOptions = append([]string{option}, newOptions...) flagCollisions[key] = true } continue } opt := strings.SplitN(option, "=", 2) if len(opt) != 2 || !validFlags[opt[0]] { return nil, fmt.Errorf("Invalid tmpfs option %q", opt) } if !dataCollisions[opt[0]] { // We prepend the option and add to collision map newOptions = append([]string{option}, newOptions...) dataCollisions[opt[0]] = true } } return newOptions, nil } // Parse fstab type mount options into mount() flags // and device specific data func parseOptions(options string) (int, string) { var ( flag int data []string ) 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, ",") }