Added FUSE support #55

Merged
Elara6331 merged 65 commits from yannickulrich/itd:fuse into master 2023-03-25 22:23:52 +00:00
2 changed files with 77 additions and 68 deletions
Showing only changes of commit 8dd8f3d012 - Show all commits

76
fuse.go Normal file
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@ -0,0 +1,76 @@
package main
import (
"go.arsenm.dev/itd/internal/fusefs"
"os"
"github.com/hanwen/go-fuse/v2/fs"
"github.com/hanwen/go-fuse/v2/fuse"
"go.arsenm.dev/logger/log"
"context"
"go.arsenm.dev/infinitime"
)
func startFuse(ctx context.Context, dev *infinitime.Device) error {
yannickulrich marked this conversation as resolved Outdated

This function should be called startFUSE instead to adhere to Go naming conventions

This function should be called `startFUSE` instead to adhere to Go naming conventions

Thanks, I'm relatively new to Go, sorry for these issues

Done in 673383f

Thanks, I'm relatively new to Go, sorry for these issues Done in 673383f
// This is where we'll mount the FS
os.Mkdir(k.String("fuse.mountpoint"), 0755)
yannickulrich marked this conversation as resolved Outdated

Use os.MkdirAll here instead so that it creates parent directories, and handle the error (just return it).

Use `os.MkdirAll` here instead so that it creates parent directories, and handle the error (just return it).

This is actually a bit more complicated than that. If the mountpoint already exists, fuse will crash. We also can't delete the mountpoint beforehand (rm: cannot remove '/tmp/itd/mnt': Transport endpoint is not connected). The best way to solve this should be calling the unmount function. How would you suggest going about doing this?

This is actually a bit more complicated than that. If the mountpoint already exists, fuse will crash. We also can't delete the mountpoint beforehand (`rm: cannot remove '/tmp/itd/mnt': Transport endpoint is not connected`). The best way to solve this should be calling the [unmount function](https://pkg.go.dev/github.com/hanwen/go-fuse/v2@v2.2.0/fuse#Server.Unmount). How would you suggest going about doing this?

Yeah, this one is going to be a bit more complicated. The FUSE library does have a different unmount function that you could call before trying to mount the fs, but it's not exported, so we'll need to do a small hack to get access to it anyway. In the fusefs package, add a file called unmount.go with the following contents:

unmount.go
package fusefs

import (
    _ "unsafe"

    "github.com/hanwen/go-fuse/v2/fuse"
)

func Unmount(mountPoint string) error {
    return unmount(mountPoint, &fuse.MountOptions{DirectMount: false})
}

// Unfortunately, the FUSE library does not export its unmount function,
// so this is required until that changes
//go:linkname unmount github.com/hanwen/go-fuse/v2/fuse.unmount
func unmount(mountPoint string, opts *fuse.MountOptions) error

Then, you can simply call that function at the top of startFUSE like so:

// Ignore the error because nothing might be mounted on the mountpoint
_ = fusefs.Unmount(k.String("fuse.mountpoint"))

I'll file an issue with the fuse library to export that function once this is merged.

The best way to solve this should be calling the unmount function.

I agree that this should be done. However, this doesn't solve the problem completely because if ITD panics for whatever reason, it won't get run and then the user will get a confusing message. Let me see what the best way would be to call this function on shutdown.

Yeah, this one is going to be a bit more complicated. The FUSE library does have [a different unmount function](https://github.com/hanwen/go-fuse/blob/0f728ba15b38579efefc3dc47821882ca18ffea7/fuse/mount_linux.go#L133) that you could call before trying to mount the fs, but it's not exported, so we'll need to do a small hack to get access to it anyway. In the `fusefs` package, add a file called `unmount.go` with the following contents: <details> <summary><code>unmount.go</code></summary> ```go package fusefs import ( _ "unsafe" "github.com/hanwen/go-fuse/v2/fuse" ) func Unmount(mountPoint string) error { return unmount(mountPoint, &fuse.MountOptions{DirectMount: false}) } // Unfortunately, the FUSE library does not export its unmount function, // so this is required until that changes //go:linkname unmount github.com/hanwen/go-fuse/v2/fuse.unmount func unmount(mountPoint string, opts *fuse.MountOptions) error ``` </details> Then, you can simply call that function at the top of `startFUSE` like so: ```go // Ignore the error because nothing might be mounted on the mountpoint _ = fusefs.Unmount(k.String("fuse.mountpoint")) ``` I'll file an issue with the fuse library to export that function once this is merged. > The best way to solve this should be calling the unmount function. I agree that this should be done. However, this doesn't solve the problem completely because if ITD panics for whatever reason, it won't get run and then the user will get a confusing message. Let me see what the best way would be to call this function on shutdown.

Cool, thank you! I have implemented this 🙂

Cool, thank you! I have implemented this 🙂
root := &ITNode{kind: 0}
server, err := fs.Mount(k.String("fuse.mountpoint"), root, &fs.Options{
MountOptions: fuse.MountOptions{
// Set to true to see how the file system works.
Debug: false,
SingleThreaded: true,
},
yannickulrich marked this conversation as resolved Outdated

err is returned twice here

`err` is returned twice here

Oh, sorry, fixed now

Oh, sorry, fixed now
})
if err != nil {
log.Error("Mounting failed").
Str("target", k.String("fuse.mountpoint")).
Err(err).
Send()
return err
}
log.Info("Mounted on target").
Str("target", k.String("fuse.mountpoint")).
Send()
properties[0] = ITProperty{"heartrate", 2,
func(ctx context.Context) (<-chan []byte, error) {
ans, err := dev.WatchHeartRate(ctx)
return converterU8(ctx, ans), err
}}
properties[1] = ITProperty{"battery", 3,
func(ctx context.Context) (<-chan []byte, error) {
ans, err := dev.WatchBatteryLevel(ctx)
return converterU8(ctx, ans), err
}}
properties[2] = ITProperty{"motion", 4,
func(ctx context.Context) (<-chan []byte, error) {
ans, err := dev.WatchMotion(ctx)
return converterMotionValues(ctx, ans), err
}}
properties[3] = ITProperty{"stepcount", 5,
func(ctx context.Context) (<-chan []byte, error) {
ans, err := dev.WatchStepCount(ctx)
return converterU32(ctx, ans), err
}}
properties[4] = ITProperty{"version", 6,
func(ctx context.Context) (<-chan []byte, error) {
ans, err := dev.Version()
return converter1String(ctx, ans), err
}}
properties[5] = ITProperty{"address", 7,
func(ctx context.Context) (<-chan []byte, error) {
ans := dev.Address()
return converter1String(ctx, ans), nil
}}
myfs, err = dev.FS()
if err != nil {
log.Warn("Error getting BLE filesystem").Err(err).Send()
return err
}
inodemap = make(map[string]uint64)
// Wait until unmount before exiting
go server.Serve()
return nil
}

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@ -1,10 +1,9 @@
package main
package fusefs
import (
"go.arsenm.dev/infinitime"
"go.arsenm.dev/infinitime/blefs"
"go.arsenm.dev/logger/log"
"os"
"context"
"syscall"
"github.com/hanwen/go-fuse/v2/fs"
@ -550,69 +549,3 @@ var _ = (fs.NodeRmdirer)((*ITNode)(nil))
func (f *ITNode) Rmdir(ctx context.Context, name string) syscall.Errno {
return f.Unlink(ctx, name)
}
func startFuse(ctx context.Context, dev *infinitime.Device) error {
// This is where we'll mount the FS
os.Mkdir(k.String("fuse.mountpoint"), 0755)
root := &ITNode{kind: 0}
server, err := fs.Mount(k.String("fuse.mountpoint"), root, &fs.Options{
MountOptions: fuse.MountOptions{
// Set to true to see how the file system works.
Debug: false,
SingleThreaded: true,
},
})
if err != nil {
log.Error("Mounting failed").
Str("target", k.String("fuse.mountpoint")).
Err(err).
Send()
return err
}
log.Info("Mounted on target").
Str("target", k.String("fuse.mountpoint")).
Send()
properties[0] = ITProperty{"heartrate", 2,
func(ctx context.Context) (<-chan []byte, error) {
ans, err := dev.WatchHeartRate(ctx)
return converterU8(ctx, ans), err
}}
properties[1] = ITProperty{"battery", 3,
func(ctx context.Context) (<-chan []byte, error) {
ans, err := dev.WatchBatteryLevel(ctx)
return converterU8(ctx, ans), err
}}
properties[2] = ITProperty{"motion", 4,
func(ctx context.Context) (<-chan []byte, error) {
ans, err := dev.WatchMotion(ctx)
return converterMotionValues(ctx, ans), err
}}
properties[3] = ITProperty{"stepcount", 5,
func(ctx context.Context) (<-chan []byte, error) {
ans, err := dev.WatchStepCount(ctx)
return converterU32(ctx, ans), err
}}
properties[4] = ITProperty{"version", 6,
func(ctx context.Context) (<-chan []byte, error) {
ans, err := dev.Version()
return converter1String(ctx, ans), err
}}
properties[5] = ITProperty{"address", 7,
func(ctx context.Context) (<-chan []byte, error) {
ans := dev.Address()
return converter1String(ctx, ans), nil
}}
myfs, err = dev.FS()
if err != nil {
log.Warn("Error getting BLE filesystem").Err(err).Send()
return err
}
inodemap = make(map[string]uint64)
// Wait until unmount before exiting
go server.Serve()
return nil
}