QStorageInfo: Add support for obtaining subvolume names

[ChangeLog][QtCore][QStorageInfo] Added QStorageInfo::subvolume(), which
returns the name of the subvolume of a volume that was mounted, if one
was detected. This is currently implemented only for btrfs on Linux.

Change-Id: Ib57b52598e2f452985e9fffd1459f3145d733ce5
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 21 insertions, 1 deletions

diff --git a/src/corelib/io/qstorageinfo.cpp b/src/corelib/io/qstorageinfo.cpp
index 3773b72606..9885da1af9 100644
--- a/src/corelib/io/qstorageinfo.cpp
+++ b/src/corelib/io/qstorageinfo.cpp
@@ -260,7 +260,7 @@ QByteArray QStorageInfo::fileSystemType() const
     devpath like \c /dev/sda0 for local storages. On Windows, it returns the UNC
     path starting with \c \\\\?\\ for local storages (in other words, the volume GUID).
 
-    \sa rootPath()
+    \sa rootPath(), subvolume()
 */
 QByteArray QStorageInfo::device() const
 {
@@ -268,6 +268,26 @@ QByteArray QStorageInfo::device() const
 }
 
 /*!
+    \since 5.8
+    Returns the subvolume name for this volume.
+
+    Some filesystem types allow multiple subvolumes inside one device, which
+    may be mounted in different paths. If the subvolume could be detected, it
+    is returned here. The format of the subvolume name is specific to each
+    filesystem type.
+
+    If this volume was not mounted from a subvolume of a larger filesystem or
+    if the subvolume could not be detected, this function returns an empty byte
+    array.
+
+    \sa device()
+*/
+QByteArray QStorageInfo::subvolume() const
+{
+    return d->subvolume;
+}
+
+/*!
     Returns the human-readable name of a filesystem, usually called \c label.
 
     Not all filesystems support this feature. In this case, the value returned by