restic/vendor/bazil.org/fuse/doc/mount-osx.seq
2017-07-23 14:25:38 +02:00

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Text

seqdiag {
// seqdiag -T svg -o doc/mount-osx.svg doc/mount-osx.seq
app;
fuse [label="bazil.org/fuse"];
wait [label="callMount\nhelper goroutine"];
mount_osxfusefs;
kernel;
mounts;
app -> fuse [label="Mount"];
fuse -> kernel [label="open /dev/osxfuseN"];
fuse -> mount_osxfusefs [label="spawn, pass fd"];
fuse -> wait [label="goroutine", note="blocks on cmd.Wait"];
app <-- fuse [label="Mount returns"];
mount_osxfusefs -> kernel [label="mount(2)"];
app -> fuse [label="fs.Serve"];
fuse => kernel [label="read /dev/osxfuseN fd", note="starts with InitRequest,\nalso seen before mount exits:\ntwo StatfsRequest calls"];
fuse => app [label="FS/Node/Handle methods"];
fuse => kernel [label="write /dev/osxfuseN fd"];
... repeat ...
kernel ->> mounts [label="mount is visible"];
mount_osxfusefs <-- kernel [label="mount(2) returns"];
wait <<-- mount_osxfusefs [diagonal, label="exit", leftnote="on OS X, successful exit\nhere means we finally know\nthe mount has happened\n(can't trust InitRequest,\nkernel might have timed out\nwaiting for InitResponse)"];
app <<-- wait [diagonal, label="mount is ready,\nclose Conn.Ready", rightnote="InitRequest and StatfsRequest\nmay or may not be seen\nbefore Conn.Ready,\ndepending on platform"];
... shutting down ...
app -> fuse [label="Unmount"];
fuse -> kernel [label="umount(2)"];
kernel <<-- mounts;
fuse <-- kernel;
app <-- fuse [label="Unmount returns"];
// actually triggers before above
fuse <<-- kernel [diagonal, label="/dev/osxfuseN EOF"];
app <-- fuse [label="fs.Serve returns"];
app -> fuse [label="conn.Close"];
fuse -> kernel [label="close /dev/osxfuseN"];
fuse <-- kernel;
app <-- fuse;
}