@@ -8,12 +8,25 @@ package mount

 import "C"

 const (

-	RDONLY      = C.MNT_RDONLY

-	NOSUID      = C.MNT_NOSUID

-	NOEXEC      = C.MNT_NOEXEC

+	// RDONLY will mount the filesystem as read-only.

+	RDONLY = C.MNT_RDONLY

+

+	// NOSUID will not allow set-user-identifier or set-group-identifier bits to

+	// take effect.

+	NOSUID = C.MNT_NOSUID

+

+	// NOEXEC will not allow execution of any binaries on the mounted file system.

+	NOEXEC = C.MNT_NOEXEC

+

+	// SYNCHRONOUS will allow any I/O to the file system to be done synchronously.

 	SYNCHRONOUS = C.MNT_SYNCHRONOUS

-	NOATIME     = C.MNT_NOATIME

+	// NOATIME will not update the file access time when reading from a file.

+	NOATIME = C.MNT_NOATIME

+)

+

+// These flags are unsupported.

+const (

 	BIND        = 0

 	DIRSYNC     = 0

 	MANDLOCK    = 0

@@ -5,26 +5,81 @@ import (

 )

 const (

-	RDONLY      = syscall.MS_RDONLY

-	NOSUID      = syscall.MS_NOSUID

-	NODEV       = syscall.MS_NODEV

-	NOEXEC      = syscall.MS_NOEXEC

+	// RDONLY will mount the file system read-only.

+	RDONLY = syscall.MS_RDONLY

+

+	// NOSUID will not allow set-user-identifier or set-group-identifier bits to

+	// take effect.

+	NOSUID = syscall.MS_NOSUID

+

+	// NODEV will not interpret character or block special devices on the file

+	// system.

+	NODEV = syscall.MS_NODEV

+

+	// NOEXEC will not allow execution of any binaries on the mounted file system.

+	NOEXEC = syscall.MS_NOEXEC

+

+	// SYNCHRONOUS will allow I/O to the file system to be done synchronously.

 	SYNCHRONOUS = syscall.MS_SYNCHRONOUS

-	DIRSYNC     = syscall.MS_DIRSYNC

-	REMOUNT     = syscall.MS_REMOUNT

-	MANDLOCK    = syscall.MS_MANDLOCK

-	NOATIME     = syscall.MS_NOATIME

-	NODIRATIME  = syscall.MS_NODIRATIME

-	BIND        = syscall.MS_BIND

-	RBIND       = syscall.MS_BIND | syscall.MS_REC

-	UNBINDABLE  = syscall.MS_UNBINDABLE

+

+	// DIRSYNC will force all directory updates within the file system to be done

+	// synchronously. This affects the following system calls: creat, link,

+	// unlink, symlink, mkdir, rmdir, mknod and rename.

+	DIRSYNC = syscall.MS_DIRSYNC

+

+	// REMOUNT will attempt to remount an already-mounted file system. This is

+	// commonly used to change the mount flags for a file system, especially to

+	// make a readonly file system writeable. It does not change device or mount

+	// point.

+	REMOUNT = syscall.MS_REMOUNT

+

+	// MANDLOCK will force mandatory locks on a filesystem.

+	MANDLOCK = syscall.MS_MANDLOCK

+

+	// NOATIME will not update the file access time when reading from a file.

+	NOATIME = syscall.MS_NOATIME

+

+	// NODIRATIME will not update the directory access time.

+	NODIRATIME = syscall.MS_NODIRATIME

+

+	// BIND remounts a subtree somewhere else.

+	BIND = syscall.MS_BIND

+

+	// RBIND remounts a subtree and all possible submounts somewhere else.

+	RBIND = syscall.MS_BIND | syscall.MS_REC

+

+	// UNBINDABLE creates a mount which cannot be cloned through a bind operation.

+	UNBINDABLE = syscall.MS_UNBINDABLE

+

+	// RUNBINDABLE marks the entire mount tree as UNBINDABLE.

 	RUNBINDABLE = syscall.MS_UNBINDABLE | syscall.MS_REC

-	PRIVATE     = syscall.MS_PRIVATE

-	RPRIVATE    = syscall.MS_PRIVATE | syscall.MS_REC

-	SLAVE       = syscall.MS_SLAVE

-	RSLAVE      = syscall.MS_SLAVE | syscall.MS_REC

-	SHARED      = syscall.MS_SHARED

-	RSHARED     = syscall.MS_SHARED | syscall.MS_REC

-	RELATIME    = syscall.MS_RELATIME

+

+	// PRIVATE creates a mount which carries no propagation abilities.

+	PRIVATE = syscall.MS_PRIVATE

+

+	// RPRIVATE marks the entire mount tree as PRIVATE.

+	RPRIVATE = syscall.MS_PRIVATE | syscall.MS_REC

+

+	// SLAVE creates a mount which receives propagation from its master, but not

+	// vice versa.

+	SLAVE = syscall.MS_SLAVE

+

+	// RSLAVE marks the entire mount tree as SLAVE.

+	RSLAVE = syscall.MS_SLAVE | syscall.MS_REC

+

+	// SHARED creates a mount which provides the ability to create mirrors of

+	// that mount such that mounts and unmounts within any of the mirrors

+	// propagate to the other mirrors.

+	SHARED = syscall.MS_SHARED

+

+	// RSHARED marks the entire mount tree as SHARED.

+	RSHARED = syscall.MS_SHARED | syscall.MS_REC

+

+	// RELATIME updates inode access times relative to modify or change time.

+	RELATIME = syscall.MS_RELATIME

+

+	// STRICTATIME allows to explicitly request full atime updates.  This makes

+	// it possible for the kernel to default to relatime or noatime but still

+	// allow userspace to override it.

 	STRICTATIME = syscall.MS_STRICTATIME

 )

@@ -2,6 +2,7 @@

 package mount

+// These flags are unsupported.

 const (

 	BIND        = 0

 	DIRSYNC     = 0

@@ -4,11 +4,12 @@ import (

 	"time"

 )

+// GetMounts retrieves a list of mounts for the current running process.

 func GetMounts() ([]*MountInfo, error) {

 	return parseMountTable()

 }

-// Looks at /proc/self/mountinfo to determine of the specified

+// Mounted looks at /proc/self/mountinfo to determine of the specified

 // mountpoint has been mounted

 func Mounted(mountpoint string) (bool, error) {

 	entries, err := parseMountTable()

@@ -25,9 +26,10 @@ func Mounted(mountpoint string) (bool, error) {

 	return false, nil

 }

-// Mount the specified options at the target path only if

-// the target is not mounted

-// Options must be specified as fstab style

+// Mount will mount filesystem according to the specified configuration, on the

+// condition that the target path is *not* already mounted. Options must be

+// specified like the mount or fstab unix commands: "opt1=val1,opt2=val2". See

+// flags.go for supported option flags.

 func Mount(device, target, mType, options string) error {

 	flag, _ := parseOptions(options)

 	if flag&REMOUNT != REMOUNT {

@@ -38,9 +40,10 @@ func Mount(device, target, mType, options string) error {

 	return ForceMount(device, target, mType, options)

 }

-// Mount the specified options at the target path

-// reguardless if the target is mounted or not

-// Options must be specified as fstab style

+// ForceMount will mount a filesystem according to the specified configuration,

+// *regardless* if the target path is not already mounted. Options must be

+// specified like the mount or fstab unix commands: "opt1=val1,opt2=val2". See

+// flags.go for supported option flags.

 func ForceMount(device, target, mType, options string) error {

 	flag, data := parseOptions(options)

 	if err := mount(device, target, mType, uintptr(flag), data); err != nil {

@@ -49,7 +52,7 @@ func ForceMount(device, target, mType, options string) error {

 	return nil

 }

-// Unmount the target only if it is mounted

+// Unmount will unmount the target filesystem, so long as it is mounted.

 func Unmount(target string) error {

 	if mounted, err := Mounted(target); err != nil || !mounted {

 		return err

@@ -57,7 +60,8 @@ func Unmount(target string) error {

 	return ForceUnmount(target)

 }

-// Unmount the target reguardless if it is mounted or not

+// ForceUnmount will force an unmount of the target filesystem, regardless if

+// it is mounted or not.

 func ForceUnmount(target string) (err error) {

 	// Simple retry logic for unmount

 	for i := 0; i < 10; i++ {

@@ -1,7 +1,40 @@

 package mount

+// MountInfo reveals information about a particular mounted filesystem. This

+// struct is populated from the content in the /proc/<pid>/mountinfo file.

 type MountInfo struct {

-	Id, Parent, Major, Minor         int

-	Root, Mountpoint, Opts, Optional string

-	Fstype, Source, VfsOpts          string

+	// Id is a unique identifier of the mount (may be reused after umount).

+	Id int

+

+	// Parent indicates the ID of the mount parent (or of self for the top of the

+	// mount tree).

+	Parent int

+

+	// Major indicates one half of the device ID which identifies the device class.

+	Major int

+

+	// Minor indicates one half of the device ID which identifies a specific

+	// instance of device.

+	Minor int

+

+	// Root of the mount within the filesystem.

+	Root string

+

+	// Mountpoint indicates the mount point relative to the process's root.

+	Mountpoint string

+

+	// Opts represents mount-specific options.

+	Opts string

+

+	// Optional represents optional fields.

+	Optional string

+

+	// Fstype indicates the type of filesystem, such as EXT3.

+	Fstype string

+

+	// Source indicates filesystem specific information or "none".

+	Source string

+

+	// VfsOpts represents per super block options.

+	VfsOpts string

 }

@@ -13,7 +13,8 @@ import (

 	"unsafe"

 )

-// Parse /proc/self/mountinfo because comparing Dev and ino does not work from bind mounts

+// Parse /proc/self/mountinfo because comparing Dev and ino does not work from

+// bind mounts.

 func parseMountTable() ([]*MountInfo, error) {

 	var rawEntries *C.struct_statfs

@@ -28,7 +28,8 @@ const (

 	mountinfoFormat = "%d %d %d:%d %s %s %s %s"

 )

-// Parse /proc/self/mountinfo because comparing Dev and ino does not work from bind mounts

+// Parse /proc/self/mountinfo because comparing Dev and ino does not work from

+// bind mounts

 func parseMountTable() ([]*MountInfo, error) {

 	f, err := os.Open("/proc/self/mountinfo")

 	if err != nil {

@@ -80,7 +81,9 @@ func parseInfoFile(r io.Reader) ([]*MountInfo, error) {

 	return out, nil

 }

-// PidMountInfo collects the mounts for a specific Pid

+// PidMountInfo collects the mounts for a specific process ID. If the process

+// ID is unknown, it is better to use `GetMounts` which will inspect

+// "/proc/self/mountinfo" instead.

 func PidMountInfo(pid int) ([]*MountInfo, error) {

 	f, err := os.Open(fmt.Sprintf("/proc/%d/mountinfo", pid))

 	if err != nil {

@@ -2,34 +2,50 @@

 package mount

+// MakeShared ensures a mounted filesystem has the SHARED mount option enabled.

+// See the supported options in flags.go for further reference.

 func MakeShared(mountPoint string) error {

 	return ensureMountedAs(mountPoint, "shared")

 }

+// MakeRShared ensures a mounted filesystem has the RSHARED mount option enabled.

+// See the supported options in flags.go for further reference.

 func MakeRShared(mountPoint string) error {

 	return ensureMountedAs(mountPoint, "rshared")

 }

+// MakePrivate ensures a mounted filesystem has the PRIVATE mount option enabled.

+// See the supported options in flags.go for further reference.

 func MakePrivate(mountPoint string) error {

 	return ensureMountedAs(mountPoint, "private")

 }

+// MakeRPrivate ensures a mounted filesystem has the RPRIVATE mount option

+// enabled. See the supported options in flags.go for further reference.

 func MakeRPrivate(mountPoint string) error {

 	return ensureMountedAs(mountPoint, "rprivate")

 }

+// MakeSlave ensures a mounted filesystem has the SLAVE mount option enabled.

+// See the supported options in flags.go for further reference.

 func MakeSlave(mountPoint string) error {

 	return ensureMountedAs(mountPoint, "slave")

 }

+// MakeRSlave ensures a mounted filesystem has the RSLAVE mount option enabled.

+// See the supported options in flags.go for further reference.

 func MakeRSlave(mountPoint string) error {

 	return ensureMountedAs(mountPoint, "rslave")

 }

+// MakeUnbindable ensures a mounted filesystem has the UNBINDABLE mount option

+// enabled. See the supported options in flags.go for further reference.

 func MakeUnbindable(mountPoint string) error {

 	return ensureMountedAs(mountPoint, "unbindable")

 }

+// MakeRUnbindable ensures a mounted filesystem has the RUNBINDABLE mount

+// option enabled. See the supported options in flags.go for further reference.

 func MakeRUnbindable(mountPoint string) error {

 	return ensureMountedAs(mountPoint, "runbindable")

 }