Count "free" operations in their own new tranaction type.

WARNING: libdevstat, iostat, vmstat, systat etc etc will need a recompile.

Add devstat_end_transaction_buf() which pulls all the vital data out
of a struct buf which is ready for biodone().

2 files changed, 40 insertions, 4 deletions

diff --git a/sys/kern/subr_devstat.c b/sys/kern/subr_devstat.c
index 448b869..699ec3e 100644
--- a/sys/kern/subr_devstat.c
+++ b/sys/kern/subr_devstat.c
@@ -33,6 +33,7 @@
 #include <sys/systm.h>
 #include <sys/time.h>
 #include <sys/types.h>
+#include <sys/buf.h>
 #include <sys/sysctl.h>
 
 #include <sys/devicestat.h>
@@ -212,13 +213,17 @@ devstat_end_transaction(struct devstat *ds, u_int32_t bytes,
 	} else if (flags == DEVSTAT_WRITE) {
 		ds->bytes_written += bytes;
 		ds->num_writes++;
+	} else if (flags == DEVSTAT_FREE) {
+		ds->bytes_freed += bytes;
+		ds->num_frees++;
 	} else
 		ds->num_other++;
 
 	/*
 	 * Keep a count of the various tag types sent.
 	 */
-	if (tag_type != DEVSTAT_TAG_NONE)
+	if ((ds->flags & DEVSTAT_NO_ORDERED_TAGS == 0) &&
+	    tag_type != DEVSTAT_TAG_NONE)
 		ds->tag_types[tag_type]++;
 
 	/*
@@ -238,6 +243,25 @@ devstat_end_transaction(struct devstat *ds, u_int32_t bytes,
 		       ds->unit_number, ds->busy_count);
 }
 
+void
+devstat_end_transaction_buf(struct devstat *ds, struct buf *bp)
+{
+	devstat_trans_flags flg;
+
+	if (bp->b_flags & B_FREEBUF)
+		flg = DEVSTAT_FREE;
+	else if (bp->b_flags & B_READ)
+		flg = DEVSTAT_READ;
+	else
+		flg = DEVSTAT_WRITE;
+
+	devstat_end_transaction(ds,
+	    bp->b_bcount - bp->b_resid,
+	    (bp->b_flags & B_ORDERED) ?
+	        DEVSTAT_TAG_ORDERED : DEVSTAT_TAG_SIMPLE,
+	    flg);
+}
+
 /*
  * This is the sysctl handler for the devstat package.  The data pushed out
  * on the kern.devstat.all sysctl variable consists of the current devstat
diff --git a/sys/sys/devicestat.h b/sys/sys/devicestat.h
index 8887744..3846935 100644
--- a/sys/sys/devicestat.h
+++ b/sys/sys/devicestat.h
@@ -62,7 +62,8 @@ typedef enum {
 typedef enum {
 	DEVSTAT_NO_DATA	= 0x00,
 	DEVSTAT_READ	= 0x01,
-	DEVSTAT_WRITE	= 0x02
+	DEVSTAT_WRITE	= 0x02,
+	DEVSTAT_FREE	= 0x03
 } devstat_trans_flags;
 
 typedef enum {
@@ -130,12 +131,16 @@ struct devstat {
 						      */
 	char			device_name[DEVSTAT_NAME_LEN];
 	int			unit_number;
+	u_int64_t		bytes_read;	     /*
+						      * Total bytes read
+						      * from a device.
+						      */
 	u_int64_t		bytes_written;	     /*
 						      * Total bytes written
 						      * to a device.
 						      */
-	u_int64_t		bytes_read;	     /*
-						      * Total bytes read
+	u_int64_t		bytes_freed;	     /*
+						      * Total bytes freed
 						      * from a device.
 						      */
 	u_int64_t		num_reads;	     /*
@@ -148,6 +153,11 @@ struct devstat {
 						      * write requests to 
 						      * the device.
 						      */
+	u_int64_t		num_frees;	     /*
+						      * Total number of
+						      * free requests to 
+						      * the device.
+						      */
 	u_int64_t		num_other;	     /*
 						      * Total number of
 						      * transactions that 
@@ -199,6 +209,7 @@ struct devstat {
 };
 
 #ifdef KERNEL
+struct buf;
 void devstat_add_entry(struct devstat *ds, const char *dev_name, 
 		       int unit_number, u_int32_t block_size,
 		       devstat_support_flags flags,
@@ -209,6 +220,7 @@ void devstat_start_transaction(struct devstat *ds);
 void devstat_end_transaction(struct devstat *ds, u_int32_t bytes, 
 			     devstat_tag_type tag_type,
 			     devstat_trans_flags flags);
+void devstat_end_transaction_buf(struct devstat *ds, struct buf *);
 #endif
 
 #endif /* _DEVICESTAT_H */