Revert "Revert "math64: New div64_u64_rem helper""

index b8ba855..931a619 100644
@@ -30,6 +30,15 @@ static inline s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder)
 }
 
 /**
+ * div64_u64_rem - unsigned 64bit divide with 64bit divisor
+ */
+static inline u64 div64_u64_rem(u64 dividend, u64 divisor, u64 *remainder)
+{
+	*remainder = dividend % divisor;
+	return dividend / divisor;
+}
+
+/**
  * div64_u64 - unsigned 64bit divide with 64bit divisor
  */
 static inline u64 div64_u64(u64 dividend, u64 divisor)

@@ -61,8 +70,16 @@ static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder)
 extern s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder);
 #endif
 
+#ifndef div64_u64_rem
+extern u64 div64_u64_rem(u64 dividend, u64 divisor, u64 *remainder);
+#endif
+
 #ifndef div64_u64
-extern u64 div64_u64(u64 dividend, u64 divisor);
+static inline u64 div64_u64(u64 dividend, u64 divisor)
+{
+	u64 remainder;
+	return div64_u64_rem(dividend, divisor, &remainder);
+}
 #endif
 
 #ifndef div64_s64

index a163b6c..3af5728 100644
@@ -79,9 +79,10 @@ EXPORT_SYMBOL(div_s64_rem);
 #endif
 
 /**
- * div64_u64 - unsigned 64bit divide with 64bit divisor
+ * div64_u64_rem - unsigned 64bit divide with 64bit divisor and 64bit remainder
  * @dividend:	64bit dividend
  * @divisor:	64bit divisor
+ * @remainder:  64bit remainder
  *
  * This implementation is a modified version of the algorithm proposed
  * by the book 'Hacker's Delight'.  The original source and full proof

@@ -89,27 +90,33 @@ EXPORT_SYMBOL(div_s64_rem);
  *
  * 'http://www.hackersdelight.org/HDcode/newCode/divDouble.c.txt'
  */
-#ifndef div64_u64
-u64 div64_u64(u64 dividend, u64 divisor)
+#ifndef div64_u64_rem
+u64 div64_u64_rem(u64 dividend, u64 divisor, u64 *remainder)
 {
 	u32 high = divisor >> 32;
 	u64 quot;
 
 	if (high == 0) {
-		quot = div_u64(dividend, divisor);
+		u32 rem32;
+		quot = div_u64_rem(dividend, divisor, &rem32);
+		*remainder = rem32;
 	} else {
 		int n = 1 + fls(high);
 		quot = div_u64(dividend >> n, divisor >> n);
 
 		if (quot != 0)
 			quot--;
-		if ((dividend - quot * divisor) >= divisor)
+
+		*remainder = dividend - quot * divisor;
+		if (*remainder >= divisor) {
 			quot++;
+			*remainder -= divisor;
+		}
 	}
 
 	return quot;
 }
-EXPORT_SYMBOL(div64_u64);
+EXPORT_SYMBOL(div64_u64_rem);
 #endif
 
 /**

index f1b7586..40e6dce 100644
@@ -1455,20 +1455,26 @@ static int table_status(struct dm_ioctl *param, size_t param_size)
 	return 0;
 }
 
-static bool buffer_test_overflow(char *result, unsigned maxlen)
-{
-	return !maxlen || strlen(result) + 1 >= maxlen;
-}
-
 /*
- * Process device-mapper dependent messages.
+ * Process device-mapper dependent messages.  Messages prefixed with '@'
+ * are processed by the DM core.  All others are delivered to the target.
  * Returns a number <= 1 if message was processed by device mapper.
  * Returns 2 if message should be delivered to the target.
  */
 static int message_for_md(struct mapped_device *md, unsigned argc, char **argv,
 			  char *result, unsigned maxlen)
 {
-	return 2;
+	int r;
+
+	if (**argv != '@')
+		return 2; /* no '@' prefix, deliver to target */
+
+	r = dm_stats_message(md, argc, argv, result, maxlen);
+	if (r < 2)
+		return r;
+
+	DMERR("Unsupported message sent to DM core: %s", argv[0]);
+	return -EINVAL;
 }
 
 /*

@@ -1542,7 +1548,7 @@ static int target_message(struct dm_ioctl *param, size_t param_size)
 
 	if (r == 1) {
 		param->flags |= DM_DATA_OUT_FLAG;
-		if (buffer_test_overflow(result, maxlen))
+		if (dm_message_test_buffer_overflow(result, maxlen))
 			param->flags |= DM_BUFFER_FULL_FLAG;
 		else
 			param->data_size = param->data_start + strlen(result) + 1;

950 lines not on this page · raw message

new file mode 100644
index 0000000..e7c4984
@@ -0,0 +1,40 @@
+#ifndef DM_STATS_H
+#define DM_STATS_H
+
+#include <linux/types.h>
+#include <linux/mutex.h>
+#include <linux/list.h>
+
+int dm_statistics_init(void);
+void dm_statistics_exit(void);
+
+struct dm_stats {
+	struct mutex mutex;
+	struct list_head list;	/* list of struct dm_stat */
+	struct dm_stats_last_position __percpu *last;
+	sector_t last_sector;
+	unsigned last_rw;
+};
+
+struct dm_stats_aux {
+	bool merged;
+};
+
+void dm_stats_init(struct dm_stats *st);
+void dm_stats_cleanup(struct dm_stats *st);
+
+struct mapped_device;
+
+int dm_stats_message(struct mapped_device *md, unsigned argc, char **argv,
+		     char *result, unsigned maxlen);
+
+void dm_stats_account_io(struct dm_stats *stats, unsigned long bi_rw,
+			 sector_t bi_sector, unsigned bi_sectors, bool end,
+			 unsigned long duration, struct dm_stats_aux *aux);
+
+static inline bool dm_stats_used(struct dm_stats *st)
+{
+	return !list_empty(&st->list);
+}
+
+#endif

136 lines not on this page · raw message

index 45b97da..9236e7c 100644
@@ -16,6 +16,8 @@
 #include <linux/blkdev.h>
 #include <linux/hdreg.h>
 
+#include "dm-stats.h"
+
 /*
  * Suspend feature flags
  */

@@ -146,10 +148,16 @@ void dm_destroy(struct mapped_device *md);
 void dm_destroy_immediate(struct mapped_device *md);
 int dm_open_count(struct mapped_device *md);
 int dm_lock_for_deletion(struct mapped_device *md);
+int dm_request_based(struct mapped_device *md);
+sector_t dm_get_size(struct mapped_device *md);
+struct dm_stats *dm_get_stats(struct mapped_device *md);
 
 int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
 		      unsigned cookie);
 
+void dm_internal_suspend(struct mapped_device *md);
+void dm_internal_resume(struct mapped_device *md);
+
 int dm_io_init(void);
 void dm_io_exit(void);
 

@@ -162,4 +170,13 @@ void dm_kcopyd_exit(void);
 struct dm_md_mempools *dm_alloc_md_mempools(unsigned type, unsigned integrity, unsigned per_bio_data_size);
 void dm_free_md_mempools(struct dm_md_mempools *pools);
 
+
+/*
+ * Helpers that are used by DM core
+ */
+static inline bool dm_message_test_buffer_overflow(char *result, unsigned maxlen)
+{
+	return !maxlen || strlen(result) + 1 >= maxlen;
+}
+
 #endif

index e151d4c..a903e9b 100644
@@ -550,6 +550,19 @@ extern struct ratelimit_state dm_ratelimit_state;
 #define DM_MAPIO_REMAPPED	1
 #define DM_MAPIO_REQUEUE	DM_ENDIO_REQUEUE
 
+#if BITS_PER_LONG == 32 && defined(CONFIG_LBDAF)
+#include <linux/math64.h>
+#define dm_sector_div64(x, y)( \
+{ \
+	u64 _res; \
+	(x) = div64_u64_rem(x, y, &_res); \
+	_res; \
+} \
+)
+#else
+#define dm_sector_div64(x, y) sector_div(x, y)
+#endif
+
 /*
  * Ceiling(n / sz)
  */

index 2913b86..69ed5f5 100644
@@ -31,6 +31,15 @@ static inline s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder)
 }
 
 /**
+ * div64_u64_rem - unsigned 64bit divide with 64bit divisor and remainder
+ */
+static inline u64 div64_u64_rem(u64 dividend, u64 divisor, u64 *remainder)
+{
+	*remainder = dividend % divisor;
+	return dividend / divisor;
+}
+
+/**
  * div64_u64 - unsigned 64bit divide with 64bit divisor
  */
 static inline u64 div64_u64(u64 dividend, u64 divisor)

@@ -63,6 +72,10 @@ static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder)
 extern s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder);
 #endif
 
+#ifndef div64_u64_rem
+extern u64 div64_u64_rem(u64 dividend, u64 divisor, u64 *remainder);
+#endif
+
 #ifndef div64_u64
 extern u64 div64_u64(u64 dividend, u64 divisor);
 #endif

index a163b6c..4382ad7 100644
@@ -79,6 +79,46 @@ EXPORT_SYMBOL(div_s64_rem);
 #endif
 
 /**
+ * div64_u64_rem - unsigned 64bit divide with 64bit divisor and remainder
+ * @dividend:	64bit dividend
+ * @divisor:	64bit divisor
+ * @remainder:  64bit remainder
+ *
+ * This implementation is a comparable to algorithm used by div64_u64.
+ * But this operation, which includes math for calculating the remainder,
+ * is kept distinct to avoid slowing down the div64_u64 operation on 32bit
+ * systems.
+ */
+#ifndef div64_u64_rem
+u64 div64_u64_rem(u64 dividend, u64 divisor, u64 *remainder)
+{
+	u32 high = divisor >> 32;
+	u64 quot;
+
+	if (high == 0) {
+		u32 rem32;
+		quot = div_u64_rem(dividend, divisor, &rem32);
+		*remainder = rem32;
+	} else {
+		int n = 1 + fls(high);
+		quot = div_u64(dividend >> n, divisor >> n);
+
+		if (quot != 0)
+			quot--;
+
+		*remainder = dividend - quot * divisor;
+		if (*remainder >= divisor) {
+			quot++;
+			*remainder -= divisor;
+		}
+	}
+
+	return quot;
+}
+EXPORT_SYMBOL(div64_u64_rem);
+#endif
+
+/**
  * div64_u64 - unsigned 64bit divide with 64bit divisor
  * @dividend:	64bit dividend
  * @divisor:	64bit divisor