FUSE_MOUNT(3) | Library Functions Manual | FUSE_MOUNT(3)

# NAME

`fuse_mount`, `fuse_unmount` — mount or dismount a FUSE file system

# SYNOPSIS

library “libfuse”
`#include <fuse.h>`

struct fuse_chan *
`fuse_mount`(const char *dir, struct fuse_args *args);

void
`fuse_unmount`(const char *dir, struct fuse_chan *ch);

# DESCRIPTION

The `fuse_mount`() function calls the mount(2) system call to graft the FUSE file system on to the file system tree at the point dir. args are FUSE specific mount options as documented by mount(2).

The following mount options can be specified by preceding them with `-o`, either individually or together separated by a comma.

allow_other
  Allow other users to access the file system. By default, FUSE prevents other users from accessing the file system or to statfs(2) the file system. This security measure is particularly important for network file system that may expose private files. It also guards against system processes being blocked indefinitely if the file system stops responding.
default_permissions
  Request that the kernel enforce file access permissions. Alternatively, FUSE file systems can choose to implement access checks internally. On OpenBSD, this option is always set.
kernel_cache
  Enables buffering of files in the kernel. Not recommended for file systems that can be updated external to FUSE, such as network file systems. Not implemented.
max_read=%u
  Specify the maximum size of read operations. Note that the kernel limits this to FUSEBUFMAXSIZE. This option should not be specified on the command line. The correct (or optimum) value depends on the filesystem implementation and should thus be specified by the filesystem internally.
ro
  Mount the file system read-only. Can also be specified by itself with `-r`.

`fuse_unmount`() closes the FUSE device and attempts to unmount the file system mounted at dir by calling the unmount(2) system call. To avoid a deadlock, the kernel will not send the `FBT_DESTROY` message to the file system. There is no way to determine whether this call was successful.

Only the super user can mount and unmount FUSE file systems.

# RETURN VALUES

`fuse_main`() returns `NULL` if the file system cannot be mounted.

# ERRORS

`fuse_mount`() fails when one of the following occurs: dir does not exist or is not a directory. The fuse device cannot be opened for reading and writing. There was an error parsing the options specified by args. The file system could not be mounted.

# SEE ALSO

mount(2), fuse_main(3), fuse_setup(3), fuse(4)

# STANDARDS

The `fuse_mount`() and `fuse_unmount`() functions conforms to FUSE 2.6.

# HISTORY

The `fuse_mount`() and `fuse_unmount`() functions first appeared in OpenBSD 5.4.

# AUTHORS

Sylvestre Gallon <ccna.syl@gmail.com>
Helg Bredow <helg@openbsd.org>

September 23, 2025 | Debian