ceph_volume: Rejecting locked devices

If we cannot open a block device in O_RDWR in exclusive mode, it means
someone is actually using it like a raw database or similar.

In that case, the device should be considered as unusable as OSDs will
not be in a position to use it.

Signed-off-by: Erwan Velu <erwan@redhat.com>
(cherry picked from commit d5de9583ee6c4d9ccaab2b1146606a0ee316cc27)

diff --git a/src/ceph-volume/ceph_volume/util/device.py b/src/ceph-volume/ceph_volume/util/device.py
index 7831c14ca816c68938d450e043dbb28aa4a0d514..a8b236fd1ee1327f08fdb25c01e2f3c55b31cfc0 100644 (file)
--- a/src/ceph-volume/ceph_volume/util/device.py
+++ b/src/ceph-volume/ceph_volume/util/device.py
@@ -142,6 +142,7 @@ class Device(object):
                 pass
         reject_device('removable', 1, 'removable')
         reject_device('ro', 1, 'read-only')
+        reject_device('locked', 1, 'locked')
 
         self._valid = len(self._rejected_reasons) == 0
         return self._valid

diff --git a/src/ceph-volume/ceph_volume/util/disk.py b/src/ceph-volume/ceph_volume/util/disk.py
index 6b08e92b6167f929c06e94417b11a540ee4ba3fd..df7b47c5918e3c5aaa289ccfb3ea54eb33b7969f 100644 (file)
--- a/src/ceph-volume/ceph_volume/util/disk.py
+++ b/src/ceph-volume/ceph_volume/util/disk.py
@@ -653,6 +653,28 @@ def is_mapper_device(device_name):
     return device_name.startswith(('/dev/mapper', '/dev/dm-'))
 
 
+def is_locked_raw_device(disk_path):
+    """
+    A device can be locked by a third party software like a database.
+    To detect that case, the device is opened in Read/Write and exclusive mode
+    """
+    open_flags = (os.O_RDWR | os.O_EXCL)
+    open_mode = 0
+    fd = None
+
+    try:
+        fd = os.open(disk_path, open_flags, open_mode)
+    except OSError:
+        return 1
+
+    try:
+        os.close(fd)
+    except OSError:
+        return 1
+
+    return 0
+
+
 def get_devices(_sys_block_path='/sys/block', _dev_path='/dev', _mapper_path='/dev/mapper'):
     """
     Captures all available devices from /sys/block/, including its partitions,
@@ -729,6 +751,7 @@ def get_devices(_sys_block_path='/sys/block', _dev_path='/dev', _mapper_path='/d
         metadata['human_readable_size'] = human_readable_size(float(size) * 512)
         metadata['size'] = float(size) * 512
         metadata['path'] = diskname
+        metadata['locked'] = is_locked_raw_device(metadata['path'])
 
         device_facts[diskname] = metadata
     return device_facts