PERFUSED(8)

PERFUSED(8) | System Manager's Manual | PERFUSED(8)

# NAME

`perfused` —
PUFFS Enabled Relay to FUSE Daemon

# SYNOPSIS

`perfused` | [`-fs`] [`-d` types] [`-i` `-fd`]

# DESCRIPTION

`perfused` is a userland daemon implementing the FUSE kernel level API. It creates a /dev/fuse socket for FUSE file system daemons to connect to. `perfused` takes care of mounting the file system using puffs(3).

When the kernel sends a puffs(3) operation for the mounted file system, `perfused` will translate it into a FUSE request, and will send it to the file system daemon through /dev/fuse. The FUSE reply will be converted back into a puffs(3) reply and will be relayed to the kernel.

FUSE file system daemons must be modified so that they request `perfused` to perform the mount(2) system call instead of doing it on their own. This is done by replacing mount(2) and the open(2) calls for /dev/fuse with `perfuse_mount`() and `perfuse_open`(), respectively, in their sources. libperfuse(3) must be used at link time. Most FUSE file system daemons use `libfuse` and will work unmodified, provided the modification is done in `libfuse` itself.

The following options are available:

`-d` types
  Print additional debug information. types is a comma-separated list of information types to print:
  puffs
    Display PUFFS requests and replies.
  fuse
    Display FUSE requests and replies.
  dump
    Dump content of FUSE frames.
  fh
    Display file handle activity.
  reclaim
    Display reclaim activity.
  readdir
    Display readdir activity.
  requeue
    Display requeue activity.
  sync
    Display dirty flags and sync operations.
`-f`
  Do not fork, but stay in the foreground.
`-i` fd
  Do not open /dev/fuse but use the socket available from the file descriptor fd. This is used when `perfused` is started from libperfuse(3).
`-s`
  Enable debug output only when receiving `SIGINFO`.

# ENVIRONMENT

See libperfuse(3) for environment variables affecting `perfused` behavior.

# SIGNALS

`SIGINFO`
  If the `-s` flag was used, toggle debug output. Do nothing otherwise.
`SIGUSR1`
  Toggle FUSE operation dump on and off. When toggling off, the trace is is stored in /var/run/perfuse-xxx.trace (xxx is the filesystem mount point).

# ERRORS

The program logs to the syslog daemon as facility “daemon”. For detailed debugging use the `-d` (debug) option.

# SEE ALSO

mount(2), perfuse_mount(3), puffs(4)

# AUTHORS

The program was written by Emmanuel Dreyfus ⟨manu@NetBSD.org⟩.

# BUGS

When `perfused` runs in the foreground (using the `-f` flag), some processes using the FUSE file system will sometimes hang on ‘uvn_fp2’.

January 29, 2012 | NetBSD 10.1