mount: add -volumeName to name the disk explicitly (#11165)

* mount: let volumeName take an explicit override

volumeName only ever derived the disk's label from -filer.path, -dir,
or the filer address, so a name that happened to collide with
something else - e.g. a UNC share's own name - could not be changed
without moving what was mounted. Give it an override parameter that
wins over all three; nothing passes one yet.

* mount: add -volumeName to name the disk explicitly

Windows has no equivalent of the "weed fuse" -o passthrough that lets
a Linux or macOS mount override its derived volname, so a name picked
up from -dir - e.g. a UNC share's own name - could not be changed
short of moving what was mounted. -volumeName overrides it on every
platform.

* mount: document -volumeName

* mount: scope -volumeName's help text to macOS and Windows

Linux has no volume-label mount option for -volumeName to feed, so
the flag's own description says where it applies instead of leaving
that unstated.

* mount: forward -volumeName through the weed fuse option parser

weed fuse (the /etc/fstab helper) turns -o key=value into the same
MountOptions weed mount takes, but volumeName had no case, so it fell
through to being forwarded as a literal, unrecognized FUSE option
instead of ever reaching mountOptions.volumeName.

* mount: apply -volumeName to FsName on Linux and FreeBSD

FsName only ever took the filer address and -filer.path, so
-volumeName had nothing to override there and silently did nothing;
the skipAutofs case still forces "fuse", since that name is what
util-linux/mount requires to recognize the pseudo filesystem.

weed/command/mount.go

@@ -9,6 +9,7 @@ type MountOptions struct {
 	filer                *string
 	filerMountRootPath   *string
 	dir                  *string
+	volumeName           *string
 	dirAutoCreate        *bool
 	collection           *string
 	collectionQuota      *int
@@ -92,6 +93,7 @@ func init() {
 	mountOptions.filer = cmdMount.Flag.String("filer", "localhost:8888", "comma-separated weed filer location")
 	mountOptions.filerMountRootPath = cmdMount.Flag.String("filer.path", "/", "mount this remote path from filer server")
 	mountOptions.dir = cmdMount.Flag.String("dir", ".", "mount weed filer to this directory")
+	mountOptions.volumeName = cmdMount.Flag.String("volumeName", "", "name the mount shown by the platform (Finder/Explorer, or \"mount\"/\"df\" on Linux and FreeBSD), overriding the name taken from -filer.path or -dir")
 	mountOptions.dirAutoCreate = cmdMount.Flag.Bool("dirAutoCreate", false, "auto create the directory to mount to")
 	mountOptions.collection = cmdMount.Flag.String("collection", "", "collection to create the files")
 	mountOptions.collectionQuota = cmdMount.Flag.Int("collectionQuotaMB", 0, "quota for the collection")
@@ -188,6 +190,8 @@ var cmdMount = &Command{
   the whole tree takes the name from the mount point instead, so
   -dir=\\seaweedfs\Images labels the disk "Images" while still mounting
   everything, and only a bare drive letter falls back to the filer address.
+  -volumeName overrides whatever name either of those would otherwise give it,
+  including what Linux and FreeBSD show for the mount in "mount" and "df".
 
   `,
 }