[PATCH 01/13] lib/vsprintf.c: pull out padding code from dentry_name()

From: Rasmus Villemoes
Date: Tue Oct 20 2015 - 16:30:38 EST


Pull out the logic in dentry_name() which handles field width space
padding, in preparation for reusing it from string(). Rename the
widen() helper to move_right(), since it is used for handling the
!(flags & LEFT) case.

Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
---
lib/vsprintf.c | 46 +++++++++++++++++++++++++++++++---------------
1 file changed, 31 insertions(+), 15 deletions(-)

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 98b0d7be3fb7..0edf8dd0518f 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -538,7 +538,7 @@ char *string(char *buf, char *end, const char *s, struct printf_spec spec)
return buf;
}

-static void widen(char *buf, char *end, unsigned len, unsigned spaces)
+static void move_right(char *buf, char *end, unsigned len, unsigned spaces)
{
size_t size;
if (buf >= end) /* nowhere to put anything */
@@ -556,6 +556,35 @@ static void widen(char *buf, char *end, unsigned len, unsigned spaces)
memset(buf, ' ', spaces);
}

+/*
+ * Handle field width padding for a string.
+ * @buf: current buffer position
+ * @n: length of string
+ * @end: end of output buffer
+ * @spec: for field width and flags
+ * Returns: new buffer position after padding.
+ */
+static noinline_for_stack
+char *widen_string(char *buf, int n, char *end, struct printf_spec spec)
+{
+ unsigned spaces;
+
+ if (likely(n >= spec.field_width))
+ return buf;
+ /* we want to pad the sucker */
+ spaces = spec.field_width - n;
+ if (!(spec.flags & LEFT)) {
+ move_right(buf - n, end, n, spaces);
+ return buf + spaces;
+ }
+ while (spaces--) {
+ if (buf < end)
+ *buf = ' ';
+ ++buf;
+ }
+ return buf;
+}
+
static noinline_for_stack
char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
const char *fmt)
@@ -597,20 +626,7 @@ char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_sp
*buf = c;
}
rcu_read_unlock();
- if (n < spec.field_width) {
- /* we want to pad the sucker */
- unsigned spaces = spec.field_width - n;
- if (!(spec.flags & LEFT)) {
- widen(buf - n, end, n, spaces);
- return buf + spaces;
- }
- while (spaces--) {
- if (buf < end)
- *buf = ' ';
- ++buf;
- }
- }
- return buf;
+ return widen_string(buf, n, end, spec);
}

static noinline_for_stack
--
2.6.1

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