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{{short description|Userspace virtual filesystem software for the GNOME desktop environment}}{{redirect-multi|2|GVFS|GNOME Virtual file system|the previous filesystem GNOME Virtual File System|GnomeVFS|VFS for Git (formerly known as Git Virtual File System or GVFS)|Virtual File System for Git}}{{primary sources|date=February 2017}}

factoids

qualifiersingleP348P577}}propertyreferencesQ1533273P548=Q51930650}}qualifiersingleP348P577}}| operating system = Linux| platform = GNOMEAbstraction (computer science)>abstraction layer for the files systemGNU Lesser General Public License>LGPL-2.0-or-later}}GVfs (abbreviation for GNOME virtual file system) is GNOME's userspace virtual filesystem designed to work with the I/O abstraction of GIO, a library available in GLib 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 (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, WebDAV, SMB, and local data via Udev integration, OBEX, MTP and others.GNOME 2.22 Release Notes, 6.1: GVfs and GIO GVfs does not seem to support the Files transferred over shell protocol (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 orweblink but are also mounted in the traditional manner under ~/.gvfs/ or /run/user/$UID/gvfs or $XDG_RUNTIME_DIR/gvfs directoryWEB,weblink gvfsd-fuse.1 - manned.org, manned.org, 18 April 2018, WEB,weblink Nautilus' remote folder default mount point, askubuntu.com, 18 April 2018, to make them available to applications using standard POSIX commands and I/O.

Technical details

File:X-gvfs-show.png|thumb|The option x-gvfs-show for the gvfs-udisks2-volume-monitor process determines whether a mounted device is shown or notWEB,weblink udisks2/what-is-shown.txt, . in GNOME Files. Screenshot of GNOME DisksGNOME DisksAlong 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 GnomeVFSWEB,weblink Plans for gnome-vfs replacement, mail.gnome.org, 18 April 2018, 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.WEB,weblink gvfs status report, mail.gnome.org, 18 April 2018, It consists of two parts:"Using GNOMEvfs to manipulate files", Linux.com

1. a shared library which is loaded by applications supporting GIO
2. GVfs itself, which contains a collection of daemons which communicate with each other and the GIO module over D-Bus.

A collection of command-line utilities (such as gvfs-mount, gvfs-less) works with VFS resources.WEB,weblink OpenSolaris 2009.06 - man page for gvfs-mount (opensolaris section 1) - Unix & Linux Commands, www.unix.com, 18 April 2018,

• weblink

{|class="wikitable" style="text-align: left;"! Daemon !! task! colspan=2 | Main| gvfsd is the main daemon of GVfs. It provides the "org.gtk.vfs.Daemon" name on the session bus. gvfsd is autostarted by GIO clients if it is not running. The primary task of gvfsd is to act as a mount tracker/manager. It spawns new back-ends when requested and keeps track of their lifecycle, maintaining a list of active mounts and creates direct connections to them. gvfsd also starts the gvfsd-fuse(1), and provides it the mount point where the fuse file system should be mounted.| gvfsd-fuse maintains a FUSE (Filesystem in Userspace) mount to make GVfs back-ends available to POSIX applications. The mount point for the fuse filesystem is provided by the [PATH] argument. gvfsd-fuse is normally started by gvfsd.GIO (software)>GIO clients when they make metadata changes. Read operations are done by client-side GIO code directly, and don't require the daemon to be running. The gvfs metadata capabilities are used by the GNOME Files file manager, for example.! colspan=2 | Volume monitors| support for GNOME Online Accounts (cf. GNOME Online Accounts in the GNOME wiki) style="white-space: nowrap;"| support for the Picture Transfer Protocol as implemented in gPhoto| support for the Media Transfer Protocolfstab entries shown in the desktop user interface. In particular, GNOME Shell, GNOME Files as well as any other application using the GLib APIs, is using information from this process. In Debian it is distributed as part of the gvfs-daemons package.HTTPS://PACKAGES.DEBIAN.ORG/STRETCH/AMD64/GVFS-DAEMONS/FILELIST udisks: The udisks daemon 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.| support for Apple File Conduit! colspan=2 | Mount back-ends| mounts iPhone/iPod touch volumes| mounts Apple Filing Protocol volumes| browses Apple Filing Protocol volumes| mounts archive files in various formats| provides a location for burning CDs/optical discs| mounts audio CDs| provides computer://| mounts DAV filesystems| browses DNS-SD| mounts over FTPgPhoto>libgphoto2 to expose on-camera photos to GNOME applications via the VFS| mounts over HTTP| a test backend| mounts over MTP| provides network://Network File System>NFS protocol| provides recent://| mounts over sftpServer Message Block>SMB (i.e. Windows Shares Filesystem) volumes| browses Windows Shares Filesystem volumes| provides trash://Please refer toweblink 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, 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.WEB,weblink Modern Mounting with Udisks2, 2014-05-28, David Zeuthen,

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).

Packaging

In Debian the GVfs is packaged into four packages: gvfs, gvfs-daemons, gvfs-bin and gvfs-backends.

See also

• GNOME Files, 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 files

References

{{Reflist|30em}}

External links

• {{official website}}

{{GNOME}}