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GVfs (abbreviation for GNOME virtual file system) is GNOME's userspace ftp://username:password@ftp.example.net/public_html , but are also
Along with generally useful APIs such as networking and D-Bus support, GIO also provides a VFS API to applications. GVfs provides implementations that go beyond that and allow to access files and storage using many protocols. GVfs provides implementations for various network file systems as loadable modules. Additionally GVfs also provides support for trash, network or recent folders, for CD burning and for monitoring interesting devices and volumes on the computer.
The goal of GVfs has been to overcome the shortcomings of GnomeVFS and provide an API that is so good that developers prefer it over raw POSIX calls. Among other things that means using GObject. It also means not cloning the POSIX API, but providing higher-level, document-centric interfaces. GTK can directly use it, e.g. in the filechooser.
Applications use GVfs indirectly, by means of GIO loading the GVfs module that implements the GIO extension points. The GVfs main daemon gvfsd spawns further mount daemons for each individual connection. The GVfs support for volume monitoring is included in a separate loadable module.
The actual GVfs implementation is distributed over a number of processes.
GVfs can use FUSE to mount its VFS directly onto the filesystem. It consists of two parts:
# a shared library which is loaded by applications supporting GIO
# GVfs itself, which contains a collection of
gvfsgvfs-daemonsgvfs-bin
an
gvfs-backends
virtual filesystem
A virtual file system (VFS) or virtual filesystem switch is an abstract layer on top of a more concrete file system. The purpose of a VFS is to allow client applications to access different types of concrete file systems in a uniform way. A VFS ...
designed to work with the I/O abstraction of GIO, a library available in GLib
GLib is a bundle of three (formerly five) low-level system libraries written in C and developed mainly by GNOME. GLib's code was separated from GTK, so it can be used by software other than GNOME and has been developed in parallel ever sin ...
since version 2.15.1. It installs several modules that are automatically used by applications using the APIs of libgio. There is also FUSE support that allows applications not using GIO to access the GVfs filesystems.
A cause of confusion is the fact that the file system abstraction used by the Linux kernel is also called the virtual file system
A virtual file system (VFS) or virtual filesystem switch is an abstract layer on top of a more concrete file system. The purpose of a VFS is to allow client applications to access different types of concrete file systems in a uniform way. A VFS ...
(VFS) layer. This is however at a lower level.
The GVfs model differs from e.g. GnomeVFS, which it replaces, in that file systems must be mounted before they are used. There is a master daemon (gvfsd) that handles coordinating mounts, and then each mount is (typically) in its own daemon process (although mounts can share daemon process).
GVfs comes with a set of back-ends, including trash support, SFTP, FTP
The File Transfer Protocol (FTP) is a standard communication protocol used for the transfer of computer files from a server to a client on a computer network. FTP is built on a client–server model architecture using separate control and data ...
, WebDAV
WebDAV (Web Distributed Authoring and Versioning) is a set of extensions to the Hypertext Transfer Protocol (HTTP), which allows user agents to collaboratively author contents ''directly'' in an HTTP web server by providing facilities for con ...
, SMB, and local data via Udev
udev (userspace ) is a device manager for the Linux kernel. As the successor of devfsd and hotplug, udev primarily manages device nodes in the directory. At the same time, udev also handles all user space events raised when hardware devices ...
integration, OBEX
OBEX (abbreviation of OBject EXchange, also termed IrOBEX) is a communications protocol that facilitates the exchange of binary objects between devices. It is maintained by the Infrared Data Association but has also been adopted by the Bluetooth S ...
, MTP and others. GVfs does not seem to support the Files transferred over shell protocol
Files transferred over Shell protocol (FISH) is a network protocol that uses Secure Shell (SSH) or Remote Shell (RSH) to transfer files between computers and manage remote files.
The advantage of FISH is that all it requires on the server-side ...
(FISH).
GVfs also contains modules for GIO that implement volume monitors and the GNOME URI scheme handler configuration.
There is a set of arguments to the command line program "gio" that lets you run commands (like cat, ls, stat, mount, etc.) on files in the GVfs mounts.
Attached resources are exposed via a URI syntax, for example smb://server01/gamedata or mounted
Mount is often used as part of the name of specific mountains, e.g. Mount Everest.
Mount or Mounts may also refer to:
Places
* Mount, Cornwall, a village in Warleggan parish, England
* Mount, Perranzabuloe, a hamlet in Perranzabuloe parish, Co ...
in the traditional manner under ~/.gvfs/ or /run/user/$UID/gvfs or $XDG_RUNTIME_DIR/gvfs directory to make them available to applications using standard POSIX
The Portable Operating System Interface (POSIX) is a family of standards specified by the IEEE Computer Society for maintaining compatibility between operating systems. POSIX defines both the system- and user-level application programming inter ...
commands and I/O.
Technical details
Along with generally useful APIs such as networking and D-Bus support, GIO also provides a VFS API to applications. GVfs provides implementations that go beyond that and allow to access files and storage using many protocols. GVfs provides implementations for various network file systems as loadable modules. Additionally GVfs also provides support for trash, network or recent folders, for CD burning and for monitoring interesting devices and volumes on the computer.
The goal of GVfs has been to overcome the shortcomings of GnomeVFS and provide an API that is so good that developers prefer it over raw POSIX calls. Among other things that means using GObject. It also means not cloning the POSIX API, but providing higher-level, document-centric interfaces. GTK can directly use it, e.g. in the filechooser.
Applications use GVfs indirectly, by means of GIO loading the GVfs module that implements the GIO extension points. The GVfs main daemon gvfsd spawns further mount daemons for each individual connection. The GVfs support for volume monitoring is included in a separate loadable module.
The actual GVfs implementation is distributed over a number of processes.
GVfs can use FUSE to mount its VFS directly onto the filesystem. It consists of two parts:
# a shared library which is loaded by applications supporting GIO
# GVfs itself, which contains a collection of daemon
Daimon or Daemon (Ancient Greek: , "god", "godlike", "power", "fate") originally referred to a lesser deity or guiding spirit such as the daimons of ancient Greek religion and Greek mythology, mythology and of later Hellenistic religion and Hell ...
s which communicate with each other and the GIO module over D-Bus
In computing, D-Bus (short for "Desktop Bus")
is a message-oriented middleware mechanism that allows communication between multiple processes running concurrently on the same machine. D-Bus was developed as part of the freedesktop.org project, ...
.
A collection of command-line utilities (such as gvfs-mount, gvfs-less) works with VFS resources.
* https://developer.gnome.org/gio/stable/ch01.html#gvfs-overview
Please refer to https://wiki.gnome.org/Projects/gvfs/backends for the official documentation.
Hot plugging
Devices connected over eSATA or USB are (supposed to be) physically hot-pluggable. When a device is physically connected to or physically removed from the computer system, the Linux kernel notices and sends out an event to user-space. systemd-udevd receives such events and responds to them according to its quite comprehensive configuration:
* manages the special file system devfs mounted to /dev
In Unix-like operating systems, a device file or special file is an interface to a device driver that appears in a file system as if it were an ordinary file. There are also special files in DOS, OS/2, and Windows. These special files allow a ...
, hence systemd-udevd dynamically creates and removes device nodes from /dev, it also loads drivers as necessary at boot time
* in case of a block device systemd-udevd notifies udisksd, and gvfsd and gvfs-udisks2-volume-monitor.
The udisks2 daemon udisksd serves as an interface to system block devices, implemented via D-Bus. It handles operations such as querying, mounting, unmounting, formatting, or detaching storage devices such as hard disks or USB thumb drives. This package also provides the udisksctl utility, which can be used to trigger these operations from the command line (if permitted by PolicyKit
Polkit (formerly PolicyKit) is a component for controlling system-wide privileges in Unix-like operating systems. It provides an organized way for non-privileged processes to communicate with privileged ones. Polkit allows a level of control ...
).
Packaging
In Debian the GVfs is packaged into four packagesgvfs
an
gvfs-backends
See also
*GNOME Files
GNOME Files, formerly and internally known as Nautilus, is the official file manager for the GNOME desktop. Nautilus was originally developed by Eazel with many luminaries from the tech world including Andy Hertzfeld (Apple), chief architect for ...
, the file manager for GNOME desktops, allows users to interact with GVfs filesystems
* Thunar, the file manager for the Xfce desktop environment, also provides filesytem abstraction using the GVfs library
* KIO, a similar facility for KDE systems
* Archivemount, a virtual filesystem implementation specifically for accessing archive
An archive is an accumulation of historical records or materials – in any medium – or the physical facility in which they are located.
Archives contain primary source documents that have accumulated over the course of an individual or ...
files
References
External links
* {{DEFAULTSORT:Gvfs Applications using D-Bus GNOME Software that uses Meson