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Date: Wed, 10 Dec 2014 10:52:43 -0500
From: Tejun Heo <tj@...nel.org>
To: akpm@...ux-foundation.org
Cc: linux-kernel@...r.kernel.org, Tejun Heo <tj@...nel.org>
Subject: [PATCH 01/12] bitmap: restructure bitmap_sn[list]printf()
bitmap_sn[list]printf() implement formatting a bitmap into the
specified string buffer. We want to add functions which target a
different output (printk). To enable that, this patch restructures
bitmap_sn[list]printf() so that the formatting and outputting are
separate.
Formatting is now handled by bitmap_print[_list]() and
bitmap_sn[list]printf() wrap the formatting functions with the output
callback bitmap_scnprintf_fn() which fills the string buffer. A later
patch will implement bitmap_pr_cont[_list]() by adding a different
outputting callback.
This patch doesn't change the behaviors of bitmap_sn[list]printf().
Signed-off-by: Tejun Heo <tj@...nel.org>
Cc: Andrew Morton <akpm@...ux-foundation.org>
---
lib/bitmap.c | 113 ++++++++++++++++++++++++++++++++++++++---------------------
1 file changed, 73 insertions(+), 40 deletions(-)
diff --git a/lib/bitmap.c b/lib/bitmap.c
index 324ea9e..f1d6351 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -372,25 +372,33 @@ EXPORT_SYMBOL(bitmap_find_next_zero_area_off);
* second version by Paul Jackson, third by Joe Korty.
*/
+struct bitmap_scnprintf_data {
+ char *buf;
+ unsigned int buflen;
+ unsigned int len;
+};
+
+typedef __printf(2, 3) void (*bitmap_printfn_t)(void *data, const char *fmt, ...);
+
+static void bitmap_scnprintf_fn(void *data, const char *fmt, ...)
+{
+ struct bitmap_scnprintf_data *bsd = data;
+ va_list args;
+
+ va_start(args, fmt);
+ bsd->len += vscnprintf(bsd->buf + bsd->len, bsd->buflen - bsd->len,
+ fmt, args);
+ va_end(args);
+}
+
#define CHUNKSZ 32
#define nbits_to_hold_value(val) fls(val)
#define BASEDEC 10 /* fancier cpuset lists input in decimal */
-/**
- * bitmap_scnprintf - convert bitmap to an ASCII hex string.
- * @buf: byte buffer into which string is placed
- * @buflen: reserved size of @buf, in bytes
- * @maskp: pointer to bitmap to convert
- * @nmaskbits: size of bitmap, in bits
- *
- * Exactly @nmaskbits bits are displayed. Hex digits are grouped into
- * comma-separated sets of eight digits per set. Returns the number of
- * characters which were written to *buf, excluding the trailing \0.
- */
-int bitmap_scnprintf(char *buf, unsigned int buflen,
- const unsigned long *maskp, int nmaskbits)
+static void bitmap_print(const unsigned long *maskp, int nmaskbits,
+ bitmap_printfn_t printfn, void *printfn_data)
{
- int i, word, bit, len = 0;
+ int i, word, bit;
unsigned long val;
const char *sep = "";
int chunksz;
@@ -406,12 +414,30 @@ int bitmap_scnprintf(char *buf, unsigned int buflen,
word = i / BITS_PER_LONG;
bit = i % BITS_PER_LONG;
val = (maskp[word] >> bit) & chunkmask;
- len += scnprintf(buf+len, buflen-len, "%s%0*lx", sep,
- (chunksz+3)/4, val);
+ printfn(printfn_data, "%s%0*lx", sep, (chunksz+3)/4, val);
chunksz = CHUNKSZ;
sep = ",";
}
- return len;
+}
+
+/**
+ * bitmap_scnprintf - convert bitmap to an ASCII hex string.
+ * @buf: byte buffer into which string is placed
+ * @buflen: reserved size of @buf, in bytes
+ * @maskp: pointer to bitmap to convert
+ * @nmaskbits: size of bitmap, in bits
+ *
+ * Exactly @nmaskbits bits are displayed. Hex digits are grouped into
+ * comma-separated sets of eight digits per set. Returns the number of
+ * characters which were written to *buf, excluding the trailing \0.
+ */
+int bitmap_scnprintf(char *buf, unsigned int buflen,
+ const unsigned long *maskp, int nmaskbits)
+{
+ struct bitmap_scnprintf_data bsd = { .buf = buf, .buflen = buflen };
+
+ bitmap_print(maskp, nmaskbits, bitmap_scnprintf_fn, &bsd);
+ return bsd.len;
}
EXPORT_SYMBOL(bitmap_scnprintf);
@@ -531,20 +557,37 @@ EXPORT_SYMBOL(bitmap_parse_user);
/*
* bscnl_emit(buf, buflen, rbot, rtop, bp)
*
- * Helper routine for bitmap_scnlistprintf(). Write decimal number
- * or range to buf, suppressing output past buf+buflen, with optional
- * comma-prefix. Return len of what was written to *buf, excluding the
- * trailing \0.
+ * Helper routine for bitmap_scnlistprintf(). Write decimal number or
+ * range to buf, with optional comma-prefix.
*/
-static inline int bscnl_emit(char *buf, int buflen, int rbot, int rtop, int len)
+static inline void bscnl_emit(int rbot, int rtop, bool first,
+ bitmap_printfn_t printfn, void *printfn_data)
{
- if (len > 0)
- len += scnprintf(buf + len, buflen - len, ",");
+ if (!first)
+ printfn(printfn_data, ",");
if (rbot == rtop)
- len += scnprintf(buf + len, buflen - len, "%d", rbot);
+ printfn(printfn_data, "%d", rbot);
else
- len += scnprintf(buf + len, buflen - len, "%d-%d", rbot, rtop);
- return len;
+ printfn(printfn_data, "%d-%d", rbot, rtop);
+}
+
+static void bitmap_print_list(const unsigned long *maskp, int nmaskbits,
+ bitmap_printfn_t printfn, void *printfn_data)
+{
+ bool first = true;
+ /* current bit is 'cur', most recently seen range is [rbot, rtop] */
+ int cur, rbot, rtop;
+
+ rbot = cur = find_first_bit(maskp, nmaskbits);
+ while (cur < nmaskbits) {
+ rtop = cur;
+ cur = find_next_bit(maskp, nmaskbits, cur+1);
+ if (cur >= nmaskbits || cur > rtop + 1) {
+ bscnl_emit(rbot, rtop, first, printfn, printfn_data);
+ rbot = cur;
+ first = false;
+ }
+ }
}
/**
@@ -566,24 +609,14 @@ static inline int bscnl_emit(char *buf, int buflen, int rbot, int rtop, int len)
int bitmap_scnlistprintf(char *buf, unsigned int buflen,
const unsigned long *maskp, int nmaskbits)
{
- int len = 0;
- /* current bit is 'cur', most recently seen range is [rbot, rtop] */
- int cur, rbot, rtop;
+ struct bitmap_scnprintf_data bsd = { .buf = buf, .buflen = buflen };
if (buflen == 0)
return 0;
buf[0] = 0;
- rbot = cur = find_first_bit(maskp, nmaskbits);
- while (cur < nmaskbits) {
- rtop = cur;
- cur = find_next_bit(maskp, nmaskbits, cur+1);
- if (cur >= nmaskbits || cur > rtop + 1) {
- len = bscnl_emit(buf, buflen, rbot, rtop, len);
- rbot = cur;
- }
- }
- return len;
+ bitmap_print_list(maskp, nmaskbits, bitmap_scnprintf_fn, &bsd);
+ return bsd.len;
}
EXPORT_SYMBOL(bitmap_scnlistprintf);
--
2.1.0
--
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