From 72ae343f772120ec52533e071e8bea58fd76ad3a Mon Sep 17 00:00:00 2001
From: David Sterba <dsterba@suse.com>
Date: Tue, 3 Jan 2017 18:03:44 +0100
Subject: [PATCH] btrfs-progs: make negative number pretty printing optional

Add a unit mode that will interpret the input number as a signed 64bit,
optionally and not by default for all numbers.

Signed-off-by: David Sterba <dsterba@suse.com>
---
 utils.c | 44 ++++++++++++++++++++++++++++++++++----------
 utils.h |  6 ++++--
 2 files changed, 38 insertions(+), 12 deletions(-)

diff --git a/utils.c b/utils.c
index 16eefc62..06c90c7d 100644
--- a/utils.c
+++ b/utils.c
@@ -2579,7 +2579,7 @@ out:
  * Note: this function uses a static per-thread buffer. Do not call this
  * function more than 10 times within one argument list!
  */
-const char *pretty_size_mode(s64 size, unsigned mode)
+const char *pretty_size_mode(u64 size, unsigned mode)
 {
 	static __thread int ps_index = 0;
 	static __thread char ps_array[10][32];
@@ -2598,20 +2598,27 @@ static const char* unit_suffix_binary[] =
 static const char* unit_suffix_decimal[] =
 	{ "B", "kB", "MB", "GB", "TB", "PB", "EB"};
 
-int pretty_size_snprintf(s64 size, char *str, size_t str_size, unsigned unit_mode)
+int pretty_size_snprintf(u64 size, char *str, size_t str_size, unsigned unit_mode)
 {
 	int num_divs;
 	float fraction;
-	s64 base = 0;
+	u64 base = 0;
 	int mult = 0;
 	const char** suffix = NULL;
-	s64 last_size;
+	u64 last_size;
+	int negative;
 
 	if (str_size == 0)
 		return 0;
 
+	negative = !!(unit_mode & UNITS_NEGATIVE);
+	unit_mode &= ~UNITS_NEGATIVE;
+
 	if ((unit_mode & ~UNITS_MODE_MASK) == UNITS_RAW) {
-		snprintf(str, str_size, "%lld", size);
+		if (negative)
+			snprintf(str, str_size, "%lld", size);
+		else
+			snprintf(str, str_size, "%llu", size);
 		return 0;
 	}
 
@@ -2646,10 +2653,22 @@ int pretty_size_snprintf(s64 size, char *str, size_t str_size, unsigned unit_mod
 			   num_divs = 0;
 			   break;
 	default:
-		while ((size < 0 ? -size : size) >= mult) {
-			last_size = size;
-			size /= mult;
-			num_divs++;
+		if (negative) {
+			s64 ssize = (s64)size;
+			s64 last_ssize = ssize;
+
+			while ((ssize < 0 ? -ssize : ssize) >= mult) {
+				last_ssize = ssize;
+				ssize /= mult;
+				num_divs++;
+			}
+			last_size = (u64)last_ssize;
+		} else {
+			while (size >= mult) {
+				last_size = size;
+				size /= mult;
+				num_divs++;
+			}
 		}
 		/*
 		 * If the value is smaller than base, we didn't do any
@@ -2667,7 +2686,12 @@ int pretty_size_snprintf(s64 size, char *str, size_t str_size, unsigned unit_mod
 		assert(0);
 		return -1;
 	}
-	fraction = (float)last_size / base;
+
+	if (negative) {
+		fraction = (float)(s64)last_size / base;
+	} else {
+		fraction = (float)last_size / base;
+	}
 
 	return snprintf(str, str_size, "%.2f%s", fraction, suffix[num_divs]);
 }
diff --git a/utils.h b/utils.h
index 525bde9f..a99bd701 100644
--- a/utils.h
+++ b/utils.h
@@ -95,6 +95,8 @@ void set_argv0(char **argv);
 #define UNITS_RAW			(1U << UNITS_MODE_SHIFT)
 #define UNITS_BINARY			(2U << UNITS_MODE_SHIFT)
 #define UNITS_DECIMAL			(3U << UNITS_MODE_SHIFT)
+/* Interpret the u64 value as s64 */
+#define UNITS_NEGATIVE			(4U << UNITS_MODE_SHIFT)
 #define UNITS_MODE_MASK			((1U << UNITS_MODE_SHIFT) - 1)
 #define UNITS_MODE_SHIFT		(8)
 #define UNITS_HUMAN_BINARY		(UNITS_BINARY)
@@ -174,9 +176,9 @@ int check_mounted_where(int fd, const char *file, char *where, int size,
 int btrfs_device_already_in_root(struct btrfs_root *root, int fd,
 				 int super_offset);
 
-int pretty_size_snprintf(s64 size, char *str, size_t str_bytes, unsigned unit_mode);
+int pretty_size_snprintf(u64 size, char *str, size_t str_bytes, unsigned unit_mode);
 #define pretty_size(size) 	pretty_size_mode(size, UNITS_DEFAULT)
-const char *pretty_size_mode(s64 size, unsigned mode);
+const char *pretty_size_mode(u64 size, unsigned mode);
 
 u64 parse_size(char *s);
 u64 parse_qgroupid(const char *p);