[tip:perf/core] perf dso: Separate generic code in dso_cache__read

[tip-bot for Jiri Olsa <tipbot@zytor.com>]

Commit-ID:  ea5db1bd5a04b865bc86bb8e3267c27939dfb5ee
Gitweb:     https://git.kernel.org/tip/ea5db1bd5a04b865bc86bb8e3267c27939dfb5ee
Author:     Jiri Olsa <jolsa@kernel.org>
AuthorDate: Wed, 8 May 2019 15:20:00 +0200
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Tue, 28 May 2019 18:37:44 -0300

perf dso: Separate generic code in dso_cache__read

Move the file specific code in the dso_cache__read function to a
separate file_read function. I'll add BPF specific code in the following
patches.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stanislav Fomichev <sdf@google.com>
Link: http://lkml.kernel.org/r/20190508132010.14512-3-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/dso.c | 48 +++++++++++++++++++++++++++---------------------
 1 file changed, 27 insertions(+), 21 deletions(-)

diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index cb6199c1390a..7734f50a6912 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -794,6 +794,31 @@ dso_cache__memcpy(struct dso_cache *cache, u64 offset,
 	return cache_size;
 }
 
+static ssize_t file_read(struct dso *dso, struct machine *machine,
+			 u64 offset, char *data)
+{
+	ssize_t ret;
+
+	pthread_mutex_lock(&dso__data_open_lock);
+
+	/*
+	 * dso->data.fd might be closed if other thread opened another
+	 * file (dso) due to open file limit (RLIMIT_NOFILE).
+	 */
+	try_to_open_dso(dso, machine);
+
+	if (dso->data.fd < 0) {
+		dso->data.status = DSO_DATA_STATUS_ERROR;
+		ret = -errno;
+		goto out;
+	}
+
+	ret = pread(dso->data.fd, data, DSO__DATA_CACHE_SIZE, offset);
+out:
+	pthread_mutex_unlock(&dso__data_open_lock);
+	return ret;
+}
+
 static ssize_t
 dso_cache__read(struct dso *dso, struct machine *machine,
 		u64 offset, u8 *data, ssize_t size)
@@ -803,37 +828,18 @@ dso_cache__read(struct dso *dso, struct machine *machine,
 	ssize_t ret;
 
 	do {
-		u64 cache_offset;
+		u64 cache_offset = offset & DSO__DATA_CACHE_MASK;
 
 		cache = zalloc(sizeof(*cache) + DSO__DATA_CACHE_SIZE);
 		if (!cache)
 			return -ENOMEM;
 
-		pthread_mutex_lock(&dso__data_open_lock);
-
-		/*
-		 * dso->data.fd might be closed if other thread opened another
-		 * file (dso) due to open file limit (RLIMIT_NOFILE).
-		 */
-		try_to_open_dso(dso, machine);
-
-		if (dso->data.fd < 0) {
-			ret = -errno;
-			dso->data.status = DSO_DATA_STATUS_ERROR;
-			break;
-		}
-
-		cache_offset = offset & DSO__DATA_CACHE_MASK;
-
-		ret = pread(dso->data.fd, cache->data, DSO__DATA_CACHE_SIZE, cache_offset);
-		if (ret <= 0)
-			break;
+		ret = file_read(dso, machine, cache_offset, cache->data);
 
 		cache->offset = cache_offset;
 		cache->size   = ret;
 	} while (0);
 
-	pthread_mutex_unlock(&dso__data_open_lock);
 
 	if (ret > 0) {
 		old = dso_cache__insert(dso, cache);