Adding upstream version 1.34.4.

Signed-off-by: Daniel Baumann <daniel@debian.org>

plugins/inputs/dmcache/README.md

@@ -0,0 +1,64 @@
+# Device Mapper Cache Input Plugin
+
+This plugin provide a native collection for dmsetup based statistics for
+[dm-cache][dmcache].
+
+> [!NOTE]
+> This plugin requires super-user permissions! Please make sure, Telegraf is
+> able to run `sudo /sbin/dmsetup status --target cache` without requiring a
+> password.
+
+⭐ Telegraf v1.3.0
+🏷️ system
+💻 linux
+
+[dmcache]: https://docs.kernel.org/admin-guide/device-mapper/cache.html
+
+## Global configuration options <!-- @/docs/includes/plugin_config.md -->
+
+In addition to the plugin-specific configuration settings, plugins support
+additional global and plugin configuration settings. These settings are used to
+modify metrics, tags, and field or create aliases and configure ordering, etc.
+See the [CONFIGURATION.md][CONFIGURATION.md] for more details.
+
+[CONFIGURATION.md]: ../../../docs/CONFIGURATION.md#plugins
+
+## Configuration
+
+```toml @sample.conf
+# Provide a native collection for dmsetup based statistics for dm-cache
+# This plugin ONLY supports Linux
+[[inputs.dmcache]]
+  ## Whether to report per-device stats or not
+  per_device = true
+```
+
+## Metrics
+
+- dmcache
+  - length
+  - target
+  - metadata_blocksize
+  - metadata_used
+  - metadata_total
+  - cache_blocksize
+  - cache_used
+  - cache_total
+  - read_hits
+  - read_misses
+  - write_hits
+  - write_misses
+  - demotions
+  - promotions
+  - dirty
+
+## Tags
+
+- All measurements have the following tags:
+  - device
+
+## Example Output
+
+```text
+dmcache,device=example cache_blocksize=0i,read_hits=995134034411520i,read_misses=916807089127424i,write_hits=195107267543040i,metadata_used=12861440i,write_misses=563725346013184i,promotions=3265223720960i,dirty=0i,metadata_blocksize=0i,cache_used=1099511627776ii,cache_total=0i,length=0i,metadata_total=1073741824i,demotions=3265223720960i 1491482035000000000
+```