1 files changed, 76 insertions, 0 deletions
diff --git a/psutil/_pslinux.py b/psutil/_pslinux.py
index 1917e20d..f6a83301 100644
--- a/psutil/_pslinux.py
+++ b/psutil/_pslinux.py
@@ -1189,6 +1189,80 @@ def disk_io_counters(perdisk=False):
     return retdict
 
 
+class RootFsDeviceFinder:
+    """disk_partitions() may return partitions with device == "/dev/root"
+    or "rootfs". This container class uses different strategies to try to
+    obtain the real device path. Resources:
+    https://bootlin.com/blog/find-root-device/
+    https://www.systutorials.com/how-to-find-the-disk-where-root-is-on-in-bash-on-linux/
+    """
+    __slots__ = ['major', 'minor']
+
+    def __init__(self):
+        dev = os.stat("/").st_dev
+        self.major = os.major(dev)
+        self.minor = os.minor(dev)
+
+    def ask_proc_partitions(self):
+        with open_text("%s/partitions" % get_procfs_path()) as f:
+            for line in f.readlines()[2:]:
+                fields = line.split()
+                if len(fields) < 4:  # just for extra safety
+                    continue
+                major = int(fields[0]) if fields[0].isdigit() else None
+                minor = int(fields[1]) if fields[1].isdigit() else None
+                name = fields[3]
+                if major == self.major and minor == self.minor:
+                    if name:  # just for extra safety
+                        return "/dev/%s" % name
+
+    def ask_sys_dev_block(self):
+        path = "/sys/dev/block/%s:%s/uevent" % (self.major, self.minor)
+        with open_text(path) as f:
+            for line in f:
+                if line.startswith("DEVNAME="):
+                    name = line.strip().rpartition("DEVNAME=")[2]
+                    if name:  # just for extra safety
+                        return "/dev/%s" % name
+
+    def ask_sys_class_block(self):
+        needle = "%s:%s" % (self.major, self.minor)
+        files = glob.iglob("/sys/class/block/*/dev")
+        for file in files:
+            try:
+                f = open_text(file)
+            except FileNotFoundError:  # race condition
+                continue
+            else:
+                with f:
+                    data = f.read().strip()
+                    if data == needle:
+                        name = os.path.basename(os.path.dirname(file))
+                        return "/dev/%s" % name
+
+    def find(self):
+        path = None
+        if path is None:
+            try:
+                path = self.ask_proc_partitions()
+            except (IOError, OSError) as err:
+                debug(err)
+        if path is None:
+            try:
+                path = self.ask_sys_dev_block()
+            except (IOError, OSError) as err:
+                debug(err)
+        if path is None:
+            try:
+                path = self.ask_sys_class_block()
+            except (IOError, OSError) as err:
+                debug(err)
+        # We use exists() because the "/dev/*" part of the path is hard
+        # coded, so we want to be sure.
+        if path is not None and os.path.exists(path):
+            return path
+
+
 def disk_partitions(all=False):
     """Return mounted disk partitions as a list of namedtuples."""
     fstypes = set()
@@ -1216,6 +1290,8 @@ def disk_partitions(all=False):
         device, mountpoint, fstype, opts = partition
         if device == 'none':
             device = ''
+        if device in ("/dev/root", "rootfs"):
+            device = RootFsDeviceFinder().find() or device
         if not all:
             if device == '' or fstype not in fstypes:
                 continue