libblock: Add block device statistics

3 files changed, 115 insertions, 0 deletions

diff --git a/cpukit/libblock/include/rtems/bdbuf.h b/cpukit/libblock/include/rtems/bdbuf.h
index f63c1c548c..6c6eb76a42 100644
--- a/cpukit/libblock/include/rtems/bdbuf.h
+++ b/cpukit/libblock/include/rtems/bdbuf.h
@@ -662,6 +662,19 @@ rtems_bdbuf_purge_dev (rtems_disk_device *dd);
 rtems_status_code
 rtems_bdbuf_set_block_size (rtems_disk_device *dd, uint32_t block_size);
 
+/**
+ * @brief Returns the block device statistics.
+ */
+void
+rtems_bdbuf_get_device_stats (const rtems_disk_device *dd,
+                              rtems_blkdev_stats      *stats);
+
+/**
+ * @brief Resets the block device statistics.
+ */
+void
+rtems_bdbuf_reset_device_stats (rtems_disk_device *dd);
+
 /** @} */
 
 #ifdef __cplusplus
diff --git a/cpukit/libblock/include/rtems/blkdev.h b/cpukit/libblock/include/rtems/blkdev.h
index 7c2787204a..ccc8981c35 100644
--- a/cpukit/libblock/include/rtems/blkdev.h
+++ b/cpukit/libblock/include/rtems/blkdev.h
@@ -16,7 +16,9 @@
 
 #include <rtems.h>
 #include <rtems/diskdevs.h>
+#include <rtems/bspIo.h>
 #include <sys/ioctl.h>
+#include <stdio.h>
 
 #ifdef __cplusplus
 extern "C" {
@@ -161,6 +163,8 @@ typedef struct rtems_blkdev_request {
 #define RTEMS_BLKIO_CAPABILITIES    _IO('B', 8)
 #define RTEMS_BLKIO_GETDISKDEV      _IOR('B', 9, rtems_disk_device *)
 #define RTEMS_BLKIO_PURGEDEV        _IO('B', 10)
+#define RTEMS_BLKIO_GETDEVSTATS     _IOR('B', 11, rtems_blkdev_stats *)
+#define RTEMS_BLKIO_RESETDEVSTATS   _IO('B', 12)
 
 /** @} */
 
@@ -208,6 +212,19 @@ static inline int rtems_disk_fd_purge(int fd)
   return ioctl(fd, RTEMS_BLKIO_PURGEDEV);
 }
 
+static inline int rtems_disk_fd_get_device_stats(
+  int fd,
+  rtems_blkdev_stats *stats
+)
+{
+  return ioctl(fd, RTEMS_BLKIO_GETDEVSTATS, stats);
+}
+
+static inline int rtems_disk_fd_reset_device_stats(int fd)
+{
+  return ioctl(fd, RTEMS_BLKIO_RESETDEVSTATS);
+}
+
 /**
  * Only consecutive multi-sector buffer requests are supported.
  *
@@ -361,6 +378,24 @@ rtems_status_code rtems_blkdev_create_partition(
   rtems_blkdev_bnum block_count
 );
 
+/**
+ * @brief Prints the block device statistics.
+ */
+void rtems_blkdev_print_stats(
+  const rtems_blkdev_stats *stats,
+  rtems_printk_plugin_t print,
+  void *print_arg
+);
+
+/**
+ * @brief Block device statistics command.
+ */
+void rtems_blkstats(
+  FILE *output,
+  const char *device,
+  bool reset
+);
+
 /** @} */
 
 #ifdef __cplusplus
diff --git a/cpukit/libblock/include/rtems/diskdevs.h b/cpukit/libblock/include/rtems/diskdevs.h
index 6e6be5e9b7..3a9967ecb2 100644
--- a/cpukit/libblock/include/rtems/diskdevs.h
+++ b/cpukit/libblock/include/rtems/diskdevs.h
@@ -87,6 +87,68 @@ typedef struct {
 } rtems_blkdev_read_ahead;
 
 /**
+ * @brief Block device statistics.
+ *
+ * Integer overflows in the statistic counters may happen.
+ */
+typedef struct {
+  /**
+   * @brief Read hit count.
+   * 
+   * A read hit occurs in the rtems_bdbuf_read() function in case the block is
+   * in the cached or modified state.
+   */
+  uint32_t read_hits;
+
+  /**
+   * @brief Read miss count.
+   * 
+   * A read miss occurs in the rtems_bdbuf_read() function in case the block is
+   * in the empty state and a read transfer must be initiated to read the data
+   * from the device.
+   */
+  uint32_t read_misses;
+
+  /**
+   * @brief Read-ahead transfer count.
+   *
+   * Each read-ahead transfer may read multiple blocks.
+   */
+  uint32_t read_ahead_transfers;
+
+  /**
+   * @brief Count of blocks transfered from the device.
+   */
+  uint32_t read_blocks;
+
+  /**
+   * @brief Read error count.
+   *
+   * Error count of transfers issued by the read or read-ahead requests.
+   */
+  uint32_t read_errors;
+
+  /**
+   * @brief Write transfer count.
+   *
+   * Each write transfer may write multiple blocks.
+   */
+  uint32_t write_transfers;
+
+  /**
+   * @brief Count of blocks transfered to the device.
+   */
+  uint32_t write_blocks;
+
+  /**
+   * @brief Write error count.
+   *
+   * Error count of transfers issued by write requests.
+   */
+  uint32_t write_errors;
+} rtems_blkdev_stats;
+
+/**
  * @brief Description of a disk device (logical and physical disks).
  *
  * An array of pointer tables to rtems_disk_device structures is maintained.
@@ -202,6 +264,11 @@ struct rtems_disk_device {
   bool deleted;
 
   /**
+   * @brief Device statistics for this disk.
+   */
+  rtems_blkdev_stats stats;
+
+  /**
    * @brief Read-ahead control for this disk.
    */
   rtems_blkdev_read_ahead read_ahead;