[PATCH 1/3] bcachefs: add a printbuf formatter for percentages

[Daniel Hill]

Signed-off-by: Daniel Hill <dan...@gluo.nz>
---
 fs/bcachefs/printbuf.c | 14 ++++++++++++++
 fs/bcachefs/printbuf.h |  1 +
 2 files changed, 15 insertions(+)

diff --git a/fs/bcachefs/printbuf.c b/fs/bcachefs/printbuf.c
index b27d22925929..8e1f5b0bc2e9 100644
--- a/fs/bcachefs/printbuf.c
+++ b/fs/bcachefs/printbuf.c
@@ -446,3 +446,17 @@ void bch2_prt_bitflags_vector(struct printbuf *out,
                bch2_prt_printf(out, "%s", list[i]);
        }
 }
+
+/* format a ratio of two u64s as a percentage (to three decimal places)
+ * supplying a default value for when the denominator is zero
+ */
+
+void bch2_prt_percent_rational_u64(struct printbuf *out,
+                                  u64 numerator, u64 denominator, u64 def)
+{
+       u64 rem = 0;
+
+       bch2_prt_printf(out, "%3llu.%03llu%%",
+                       denominator ? div64_u64_rem(numerator * 100, 
denominator, &rem) : def,
+                       div64_u64(rem * 100, denominator));
+}
diff --git a/fs/bcachefs/printbuf.h b/fs/bcachefs/printbuf.h
index 9a4a56c40937..e8a87d17793b 100644
--- a/fs/bcachefs/printbuf.h
+++ b/fs/bcachefs/printbuf.h
@@ -126,6 +126,7 @@ void bch2_prt_string_option(struct printbuf *, const char * 
const[], size_t);
 void bch2_prt_bitflags(struct printbuf *, const char * const[], u64);
 void bch2_prt_bitflags_vector(struct printbuf *, const char * const[],
                              unsigned long *, unsigned);
+void bch2_prt_percent_rational_u64(struct printbuf *, u64, u64, u64);
 
 /* Initializer for a heap allocated printbuf: */
 #define PRINTBUF ((struct printbuf) { .heap_allocated = true })
-- 
2.43.0