[bcache] Add a new plugin for bcache

bcache is used as a caching device (typically an SSD) for
HDDs; bcache stats are useful to identify performance problems.

Closes: #2378
Resolves: #2384

Signed-off-by: Ponnuvel Palaniyappan <ponnuvel.palaniyappan@canonical.com>
Signed-off-by: Jake Hunsaker <jhunsake@redhat.com>

1 files changed, 56 insertions, 0 deletions

diff --git a/sos/report/plugins/bcache.py b/sos/report/plugins/bcache.py
new file mode 100644
index 00000000..3e3adb8d
--- /dev/null
+++ b/sos/report/plugins/bcache.py
@@ -0,0 +1,56 @@
+# Copyright (C) 2021, Canonical ltd
+# Ponnuvel Palaniyappan <ponnuvel.palaniyappan@canonical.com>
+
+# This file is part of the sos project: https://github.com/sosreport/sos
+#
+# This copyrighted material is made available to anyone wishing to use,
+# modify, copy, or redistribute it subject to the terms and conditions of
+# version 2 of the GNU General Public License.
+#
+# See the LICENSE file in the source distribution for further information.
+
+from sos.report.plugins import Plugin, IndependentPlugin, SoSPredicate
+
+
+class Bcache(Plugin, IndependentPlugin):
+
+    short_desc = 'Bcache statistics'
+
+    plugin_name = 'bcache'
+    profiles = ('storage', 'hardware')
+    files = ('/sys/fs/bcache',)
+
+    def setup(self):
+
+        # Caution: reading /sys/fs/bcache/*/cache0/priority_stats is known
+        # to degrade performance on old kernels. Needs care if that's ever
+        # considered for inclusion here.
+        # see: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1840043
+        self.add_forbidden_path([
+            '/sys/fs/bcache/*/*/priority_stats',
+        ])
+
+        self.add_copy_spec([
+            '/sys/block/bcache*/bcache/cache/internal/copy_gc_enabled',
+            '/sys/block/bcache*/bcache/cache_mode',
+            '/sys/block/bcache*/bcache/dirty_data',
+            '/sys/block/bcache*/bcache/io_errors',
+            '/sys/block/bcache*/bcache/sequential_cutoff',
+            '/sys/block/bcache*/bcache/stats_hour/bypassed',
+            '/sys/block/bcache*/bcache/stats_hour/cache_hit_ratio',
+            '/sys/block/bcache*/bcache/stats_hour/cache_hits',
+            '/sys/block/bcache*/bcache/stats_hour/cache_misses',
+            '/sys/block/bcache*/bcache/writeback_percent',
+            '/sys/fs/bcache/*/average_key_size',
+            '/sys/fs/bcache/*/bdev*/*',
+            '/sys/fs/bcache/*/bdev*/stat_*/*',
+            '/sys/fs/bcache/*/block_size',
+            '/sys/fs/bcache/*/bucket_size',
+            '/sys/fs/bcache/*/cache_available_percent',
+            '/sys/fs/bcache/*/congested_*_threshold_us',
+            '/sys/fs/bcache/*/internal/*',
+            '/sys/fs/bcache/*/stats_*/*',
+            '/sys/fs/bcache/*/tree_depth',
+        ], pred=SoSPredicate(self, kmods=['bcache']))
+
+# vim: set et ts=4 sw=4 :