diff options
author | Zahoor Mohamed <zahoor@zahoor.in> | 2017-03-23 21:56:06 +0800 |
---|---|---|
committer | Felix Lange <fjl@users.noreply.github.com> | 2017-03-23 21:56:06 +0800 |
commit | 11e7a712f469fb24ddb88ecebcefab6ed8880eb8 (patch) | |
tree | c052776c80475767eb7a038bef99ff784b071ef7 /vendor/bazil.org/fuse/options.go | |
parent | 61d2150a0750a554250c3bf090ef994be6c060f0 (diff) | |
download | dexon-11e7a712f469fb24ddb88ecebcefab6ed8880eb8.tar.gz dexon-11e7a712f469fb24ddb88ecebcefab6ed8880eb8.tar.zst dexon-11e7a712f469fb24ddb88ecebcefab6ed8880eb8.zip |
swarm/api: support mounting manifests via FUSE (#3690)
Diffstat (limited to 'vendor/bazil.org/fuse/options.go')
-rw-r--r-- | vendor/bazil.org/fuse/options.go | 310 |
1 files changed, 310 insertions, 0 deletions
diff --git a/vendor/bazil.org/fuse/options.go b/vendor/bazil.org/fuse/options.go new file mode 100644 index 000000000..65ce8a541 --- /dev/null +++ b/vendor/bazil.org/fuse/options.go @@ -0,0 +1,310 @@ +package fuse + +import ( + "errors" + "strings" +) + +func dummyOption(conf *mountConfig) error { + return nil +} + +// mountConfig holds the configuration for a mount operation. +// Use it by passing MountOption values to Mount. +type mountConfig struct { + options map[string]string + maxReadahead uint32 + initFlags InitFlags + osxfuseLocations []OSXFUSEPaths +} + +func escapeComma(s string) string { + s = strings.Replace(s, `\`, `\\`, -1) + s = strings.Replace(s, `,`, `\,`, -1) + return s +} + +// getOptions makes a string of options suitable for passing to FUSE +// mount flag `-o`. Returns an empty string if no options were set. +// Any platform specific adjustments should happen before the call. +func (m *mountConfig) getOptions() string { + var opts []string + for k, v := range m.options { + k = escapeComma(k) + if v != "" { + k += "=" + escapeComma(v) + } + opts = append(opts, k) + } + return strings.Join(opts, ",") +} + +type mountOption func(*mountConfig) error + +// MountOption is passed to Mount to change the behavior of the mount. +type MountOption mountOption + +// FSName sets the file system name (also called source) that is +// visible in the list of mounted file systems. +// +// FreeBSD ignores this option. +func FSName(name string) MountOption { + return func(conf *mountConfig) error { + conf.options["fsname"] = name + return nil + } +} + +// Subtype sets the subtype of the mount. The main type is always +// `fuse`. The type in a list of mounted file systems will look like +// `fuse.foo`. +// +// OS X ignores this option. +// FreeBSD ignores this option. +func Subtype(fstype string) MountOption { + return func(conf *mountConfig) error { + conf.options["subtype"] = fstype + return nil + } +} + +// LocalVolume sets the volume to be local (instead of network), +// changing the behavior of Finder, Spotlight, and such. +// +// OS X only. Others ignore this option. +func LocalVolume() MountOption { + return localVolume +} + +// VolumeName sets the volume name shown in Finder. +// +// OS X only. Others ignore this option. +func VolumeName(name string) MountOption { + return volumeName(name) +} + +// NoAppleDouble makes OSXFUSE disallow files with names used by OS X +// to store extended attributes on file systems that do not support +// them natively. +// +// Such file names are: +// +// ._* +// .DS_Store +// +// OS X only. Others ignore this option. +func NoAppleDouble() MountOption { + return noAppleDouble +} + +// NoAppleXattr makes OSXFUSE disallow extended attributes with the +// prefix "com.apple.". This disables persistent Finder state and +// other such information. +// +// OS X only. Others ignore this option. +func NoAppleXattr() MountOption { + return noAppleXattr +} + +// ExclCreate causes O_EXCL flag to be set for only "truly" exclusive creates, +// i.e. create calls for which the initiator explicitly set the O_EXCL flag. +// +// OSXFUSE expects all create calls to return EEXIST in case the file +// already exists, regardless of whether O_EXCL was specified or not. +// To ensure this behavior, it normally sets OpenExclusive for all +// Create calls, regardless of whether the original call had it set. +// For distributed filesystems, that may force every file create to be +// a distributed consensus action, causing undesirable delays. +// +// This option makes the FUSE filesystem see the original flag value, +// and better decide when to ensure global consensus. +// +// Note that returning EEXIST on existing file create is still +// expected with OSXFUSE, regardless of the presence of the +// OpenExclusive flag. +// +// For more information, see +// https://github.com/osxfuse/osxfuse/issues/209 +// +// OS X only. Others ignore this options. +// Requires OSXFUSE 3.4.1 or newer. +func ExclCreate() MountOption { + return exclCreate +} + +// DaemonTimeout sets the time in seconds between a request and a reply before +// the FUSE mount is declared dead. +// +// OS X and FreeBSD only. Others ignore this option. +func DaemonTimeout(name string) MountOption { + return daemonTimeout(name) +} + +var ErrCannotCombineAllowOtherAndAllowRoot = errors.New("cannot combine AllowOther and AllowRoot") + +// AllowOther allows other users to access the file system. +// +// Only one of AllowOther or AllowRoot can be used. +func AllowOther() MountOption { + return func(conf *mountConfig) error { + if _, ok := conf.options["allow_root"]; ok { + return ErrCannotCombineAllowOtherAndAllowRoot + } + conf.options["allow_other"] = "" + return nil + } +} + +// AllowRoot allows other users to access the file system. +// +// Only one of AllowOther or AllowRoot can be used. +// +// FreeBSD ignores this option. +func AllowRoot() MountOption { + return func(conf *mountConfig) error { + if _, ok := conf.options["allow_other"]; ok { + return ErrCannotCombineAllowOtherAndAllowRoot + } + conf.options["allow_root"] = "" + return nil + } +} + +// AllowDev enables interpreting character or block special devices on the +// filesystem. +func AllowDev() MountOption { + return func(conf *mountConfig) error { + conf.options["dev"] = "" + return nil + } +} + +// AllowSUID allows set-user-identifier or set-group-identifier bits to take +// effect. +func AllowSUID() MountOption { + return func(conf *mountConfig) error { + conf.options["suid"] = "" + return nil + } +} + +// DefaultPermissions makes the kernel enforce access control based on +// the file mode (as in chmod). +// +// Without this option, the Node itself decides what is and is not +// allowed. This is normally ok because FUSE file systems cannot be +// accessed by other users without AllowOther/AllowRoot. +// +// FreeBSD ignores this option. +func DefaultPermissions() MountOption { + return func(conf *mountConfig) error { + conf.options["default_permissions"] = "" + return nil + } +} + +// ReadOnly makes the mount read-only. +func ReadOnly() MountOption { + return func(conf *mountConfig) error { + conf.options["ro"] = "" + return nil + } +} + +// MaxReadahead sets the number of bytes that can be prefetched for +// sequential reads. The kernel can enforce a maximum value lower than +// this. +// +// This setting makes the kernel perform speculative reads that do not +// originate from any client process. This usually tremendously +// improves read performance. +func MaxReadahead(n uint32) MountOption { + return func(conf *mountConfig) error { + conf.maxReadahead = n + return nil + } +} + +// AsyncRead enables multiple outstanding read requests for the same +// handle. Without this, there is at most one request in flight at a +// time. +func AsyncRead() MountOption { + return func(conf *mountConfig) error { + conf.initFlags |= InitAsyncRead + return nil + } +} + +// WritebackCache enables the kernel to buffer writes before sending +// them to the FUSE server. Without this, writethrough caching is +// used. +func WritebackCache() MountOption { + return func(conf *mountConfig) error { + conf.initFlags |= InitWritebackCache + return nil + } +} + +// OSXFUSEPaths describes the paths used by an installed OSXFUSE +// version. See OSXFUSELocationV3 for typical values. +type OSXFUSEPaths struct { + // Prefix for the device file. At mount time, an incrementing + // number is suffixed until a free FUSE device is found. + DevicePrefix string + // Path of the load helper, used to load the kernel extension if + // no device files are found. + Load string + // Path of the mount helper, used for the actual mount operation. + Mount string + // Environment variable used to pass the path to the executable + // calling the mount helper. + DaemonVar string +} + +// Default paths for OSXFUSE. See OSXFUSELocations. +var ( + OSXFUSELocationV3 = OSXFUSEPaths{ + DevicePrefix: "/dev/osxfuse", + Load: "/Library/Filesystems/osxfuse.fs/Contents/Resources/load_osxfuse", + Mount: "/Library/Filesystems/osxfuse.fs/Contents/Resources/mount_osxfuse", + DaemonVar: "MOUNT_OSXFUSE_DAEMON_PATH", + } + OSXFUSELocationV2 = OSXFUSEPaths{ + DevicePrefix: "/dev/osxfuse", + Load: "/Library/Filesystems/osxfusefs.fs/Support/load_osxfusefs", + Mount: "/Library/Filesystems/osxfusefs.fs/Support/mount_osxfusefs", + DaemonVar: "MOUNT_FUSEFS_DAEMON_PATH", + } +) + +// OSXFUSELocations sets where to look for OSXFUSE files. The +// arguments are all the possible locations. The previous locations +// are replaced. +// +// Without this option, OSXFUSELocationV3 and OSXFUSELocationV2 are +// used. +// +// OS X only. Others ignore this option. +func OSXFUSELocations(paths ...OSXFUSEPaths) MountOption { + return func(conf *mountConfig) error { + if len(paths) == 0 { + return errors.New("must specify at least one location for OSXFUSELocations") + } + // replace previous values, but make a copy so there's no + // worries about caller mutating their slice + conf.osxfuseLocations = append(conf.osxfuseLocations[:0], paths...) + return nil + } +} + +// AllowNonEmptyMount allows the mounting over a non-empty directory. +// +// The files in it will be shadowed by the freshly created mount. By +// default these mounts are rejected to prevent accidental covering up +// of data, which could for example prevent automatic backup. +func AllowNonEmptyMount() MountOption { + return func(conf *mountConfig) error { + conf.options["nonempty"] = "" + return nil + } +} |