perf header: Revamp do_write()

Now that writen takes a const buffer, use it in do_write instead of
duplicating its functionality.

Export do_write to use it consistently in header.c and build_id.c .

Signed-off-by: David Carrillo-Cisneros <[email protected]>
Acked-by: David Ahern <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: He Kuang <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Paul Turner <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Simon Que <[email protected]>
Cc: Stephane Eranian <[email protected]>
Cc: Wang Nan <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

3 files changed, 8 insertions, 10 deletions

diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
index e9665150e9b1..4baa5329439f 100644
--- a/tools/perf/util/build-id.c
+++ b/tools/perf/util/build-id.c
@@ -304,7 +304,7 @@ static int write_buildid(const char *name, size_t name_len, u8 *build_id,
 	b.header.misc = misc;
 	b.header.size = sizeof(b) + len;
 
-	err = writen(fd, &b, sizeof(b));
+	err = do_write(fd, &b, sizeof(b));
 	if (err < 0)
 		return err;
 
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 8dda19b68ac4..954f0ef8e712 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -75,17 +75,13 @@ bool perf_header__has_feat(const struct perf_header *header, int feat)
 }
 
 /* Return: 0 if succeded, -ERR if failed. */
-static int do_write(int fd, const void *buf, size_t size)
+int do_write(int fd, const void *buf, size_t size)
 {
-	while (size) {
-		int ret = write(fd, buf, size);
-
-		if (ret < 0)
-			return -errno;
+	ssize_t ret;
 
-		size -= ret;
-		buf += ret;
-	}
+	ret  = writen(fd, buf, size);
+	if (ret != (ssize_t)size)
+		return ret < 0 ? (int)ret : -1;
 
 	return 0;
 }
diff --git a/tools/perf/util/header.h b/tools/perf/util/header.h
index d30109b421ee..e98489c8bba7 100644
--- a/tools/perf/util/header.h
+++ b/tools/perf/util/header.h
@@ -144,6 +144,8 @@ bool is_perf_magic(u64 magic);
 
 #define NAME_ALIGN 64
 
+int do_write(int fd, const void *buf, size_t size);
+
 int write_padded(int fd, const void *bf, size_t count, size_t count_aligned);
 
 /*