Added mounts module

Signed-off-by: Gautham Ananthakrishna <[email protected]>

doc/api.rst

@@ -112,3 +112,10 @@ drgn_tools.cpuinfo
 
 .. automodule:: drgn_tools.cpuinfo
    :members:
+
+
+drgn_tools.mounts
+-----------------------
+
+.. automodule:: drgn_tools.mounts
+   :members:

drgn_tools/corelens.py

@@ -175,6 +175,7 @@ def all_corelens_modules() -> Dict[str, CorelensModule]:
     # with simply maintaining a list of Python modules which contain
     # CorelensModule subclasses.
     python_mods = [
+        "drgn_tools.mounts",
         "drgn_tools.printk",
         "drgn_tools.nvme",
         "drgn_tools.virtio",

drgn_tools/mounts.py

@@ -0,0 +1,58 @@
+# Copyright (c) 2023, Oracle and/or its affiliates.
+# Licensed under the Universal Permissive License v 1.0 as shown at https://oss.oracle.com/licenses/upl/
+import argparse
+from typing import Any
+from typing import List
+
+import drgn.helpers.linux.fs
+
+from drgn_tools.corelens import CorelensModule
+from drgn_tools.table import print_table
+
+
+def get_mountinfo(prog: drgn.Program) -> List[List[Any]]:
+    """
+    Get all the mount points from the vmcore
+
+    :param prog: drgn program
+    :returns: List of mount points
+    """
+
+    mount_table = [["DEVNAME", "TYPE", "DIRNAME"]]
+    mount_table.append(["-------", "------", "-------"])
+
+    mounts = prog["init_task"].nsproxy.mnt_ns
+    for mnt in drgn.helpers.linux.fs.for_each_mount(mounts):
+        devname = mnt.mnt_devname
+        fstype = mnt.mnt.mnt_sb.s_type.name
+        mntpt = drgn.helpers.linux.fs.d_path(
+            mnt.mnt.address_of_(), mnt.mnt_mountpoint
+        )
+
+        mount_stats = [
+            devname.string_().decode("utf-8"),
+            fstype.string_().decode("utf-8"),
+            mntpt.decode("utf-8"),
+        ]
+        mount_table.append(mount_stats)
+    return mount_table
+
+
+def mountinfo(prog: drgn.Program) -> None:
+    """
+    Print all the mount points from the vmcore
+
+    :param prog: drgn program
+    :returns: None
+    """
+    mnt_tbl = get_mountinfo(prog)
+    print_table(mnt_tbl)
+
+
+class Mounts(CorelensModule):
+    """Print info about all mount points"""
+
+    name = "mounts"
+
+    def run(self, prog: drgn.Program, args: argparse.Namespace) -> None:
+        mountinfo(prog)

tests/test_mounts.py

@@ -0,0 +1,34 @@
+# Copyright (c) 2023, Oracle and/or its affiliates.
+# Licensed under the Universal Permissive License v 1.0 as shown at https://oss.oracle.com/licenses/upl/
+from operator import itemgetter
+
+from drgn_tools import mounts
+from drgn_tools.table import print_table
+
+
+def get_proc_mounts():
+    fields_0_2_1 = itemgetter(0, 2, 1)
+    proc_mount_table = [["DEVNAME", "TYPE", "DIRNAME"]]
+    proc_mount_table.append(["-------", "------", "-------"])
+    with open("/proc/mounts", "r") as f:
+        for line in f.readlines():
+            field_0, field_2, field_1 = fields_0_2_1(line.split())
+            proc_mount_table.append([field_0, field_2, field_1])
+    return proc_mount_table
+
+
+def test_show_mounts(prog):
+    differences = []
+    prog_table = mounts.get_mountinfo(prog)
+    proc_table = get_proc_mounts()
+
+    for row in prog_table:
+        if row not in proc_table:
+            differences.append(row)
+
+    difflen = len(differences)
+    if difflen > 0:
+        print("The /proc/mount is")
+        print_table(proc_table)
+        print("The mounts from the vmcore are")
+        print_table(prog_table)