Added FUSE support #55

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Elara6331 merged 65 commits from yannickulrich/itd:fuse into master 2023-03-25 22:23:52 +00:00
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33
fuse.go
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@ -10,6 +10,8 @@ import (
"github.com/hanwen/go-fuse/v2/fs" "github.com/hanwen/go-fuse/v2/fs"
"github.com/hanwen/go-fuse/v2/fuse" "github.com/hanwen/go-fuse/v2/fuse"
"strconv" "strconv"
yannickulrich marked this conversation as resolved Outdated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
"io"
"bytes"
yannickulrich marked this conversation as resolved Outdated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 🙂
) )
type Device struct { type Device struct {
@ -266,8 +268,17 @@ func (fh *bytesFileWriteHandle) Flush(ctx context.Context) (errno syscall.Errno)
log.Error("Flush failed: create").Str("path", fh.path).Err(err).Send() log.Error("Flush failed: create").Str("path", fh.path).Err(err).Send()
return syscall.EROFS return syscall.EROFS
} }
nread, err := fp.Write(fh.content)
if err != nil || nread != len(fh.content) { go func() {
// For every progress event
for sent := range fp.Progress() {
log.Info("Progress").Int("bytes", int(sent)).Int("of", len(fh.content)).Send();
}
}()
r := bytes.NewReader(fh.content)
nread, err := io.Copy(fp, r)
if err != nil {
log.Error("Flush failed: write").Str("path", fh.path).Err(err).Send() log.Error("Flush failed: write").Str("path", fh.path).Err(err).Send()
fp.Close() fp.Close()
return syscall.EROFS return syscall.EROFS
@ -337,16 +348,24 @@ func (f *ITNode) Open(ctx context.Context, openFlags uint32) (fh fs.FileHandle,
defer fp.Close() defer fp.Close()
buf := make([]byte, f.self.size); b := &bytes.Buffer{}
nread, err := fp.Read(buf)
if err != nil || nread != int(f.self.size) { go func() {
log.Error("Reading file failed").Str("path", f.path).Err(err).Send(); // For every progress event
for sent := range fp.Progress() {
log.Info("Progress").Int("bytes", int(sent)).Int("of", int(f.self.size)).Send();
}
}()
_, err = io.Copy(b, fp)
if err != nil {
log.Error("Read failed").Str("path", f.path).Err(err).Send()
fp.Close() fp.Close()
return nil, 0, syscall.EROFS return nil, 0, syscall.EROFS
} }
fh = &bytesFileReadHandle{ fh = &bytesFileReadHandle{
content: buf, content: b.Bytes(),
} }
return fh, fuse.FOPEN_DIRECT_IO, 0 return fh, fuse.FOPEN_DIRECT_IO, 0
} }