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Date: Thu, 14 May 2015 09:28:11 +0200
From: Milos Vyletel <milos@...hat.com>
To: Peter Zijlstra <a.p.zijlstra@...llo.nl>,
Paul Mackerras <paulus@...ba.org>,
Ingo Molnar <mingo@...hat.com>,
Arnaldo Carvalho de Melo <acme@...nel.org>,
Masami Hiramatsu <masami.hiramatsu.pt@...achi.com>,
Namhyung Kim <namhyung@...nel.org>,
Milos Vyletel <milos@...hat.com>, Jiri Olsa <jolsa@...nel.org>,
He Kuang <hekuang@...wei.com>,
Adrian Hunter <adrian.hunter@...el.com>,
linux-kernel@...r.kernel.org (open list:PERFORMANCE EVENT...)
Subject: [PATCH 2/2] perf/tools: put new buildid locks to use
Use new read/write locks when accesing buildid directory on places where
we may race if multiple instances are run simultaneously.
Signed-off-by: Milos Vyletel <milos@...hat.com>
---
tools/perf/builtin-buildid-cache.c | 12 +++++++++++
tools/perf/util/build-id.c | 41 ++++++++++++++++++++++++++++++--------
2 files changed, 45 insertions(+), 8 deletions(-)
diff --git a/tools/perf/builtin-buildid-cache.c b/tools/perf/builtin-buildid-cache.c
index d47a0cd..4cf0a1d 100644
--- a/tools/perf/builtin-buildid-cache.c
+++ b/tools/perf/builtin-buildid-cache.c
@@ -94,8 +94,13 @@ static int build_id_cache__kcore_existing(const char *from_dir, char *to_dir,
char to_subdir[PATH_MAX];
struct dirent *dent;
int ret = -1;
+ int lockfd;
DIR *d;
+ buildid_dir_read_lock(&lockfd);
+ if (lockfd == -1)
+ return -1;
+
d = opendir(to_dir);
if (!d)
return -1;
@@ -121,6 +126,7 @@ static int build_id_cache__kcore_existing(const char *from_dir, char *to_dir,
}
closedir(d);
+ buildid_dir_read_unlock(lockfd);
return ret;
}
@@ -130,6 +136,7 @@ static int build_id_cache__add_kcore(const char *filename, bool force)
char dir[32], sbuildid[BUILD_ID_SIZE * 2 + 1];
char from_dir[PATH_MAX], to_dir[PATH_MAX];
char *p;
+ int lockfd;
strlcpy(from_dir, filename, sizeof(from_dir));
@@ -156,6 +163,10 @@ static int build_id_cache__add_kcore(const char *filename, bool force)
scnprintf(to_dir, sizeof(to_dir), "%s/[kernel.kcore]/%s/%s",
buildid_dir, sbuildid, dir);
+ buildid_dir_write_lock(&lockfd);
+ if (lockfd == -1)
+ return -1;
+
if (mkdir_p(to_dir, 0755))
return -1;
@@ -176,6 +187,7 @@ static int build_id_cache__add_kcore(const char *filename, bool force)
}
return -1;
}
+ buildid_dir_write_unlock(lockfd);
pr_debug("kcore added to build-id cache directory %s\n", to_dir);
diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
index 46c41e1..13d23aa 100644
--- a/tools/perf/util/build-id.c
+++ b/tools/perf/util/build-id.c
@@ -17,6 +17,7 @@
#include "tool.h"
#include "header.h"
#include "vdso.h"
+#include <sys/file.h>
static bool no_buildid_cache;
@@ -308,6 +309,7 @@ int build_id_cache__list_build_ids(const char *pathname,
DIR *dir;
struct dirent *d;
int ret = 0;
+ int lockfd = -1;
list = strlist__new(true, NULL);
dir_name = build_id_cache__dirname_from_path(pathname, false, false);
@@ -316,11 +318,17 @@ int build_id_cache__list_build_ids(const char *pathname,
goto out;
}
+ buildid_dir_read_lock(&lockfd);
+ if (lockfd == -1) {
+ ret = -errno;
+ goto out;
+ }
+
/* List up all dirents */
dir = opendir(dir_name);
if (!dir) {
ret = -errno;
- goto out;
+ goto out_unlock;
}
while ((d = readdir(dir)) != NULL) {
@@ -330,6 +338,8 @@ int build_id_cache__list_build_ids(const char *pathname,
}
closedir(dir);
+out_unlock:
+ buildid_dir_read_unlock(lockfd);
out:
free(dir_name);
if (ret)
@@ -347,6 +357,7 @@ int build_id_cache__add_s(const char *sbuild_id, const char *name,
char *realname = NULL, *filename = NULL, *dir_name = NULL,
*linkname = zalloc(size), *targetname, *tmp;
int err = -1;
+ int lockfd;
if (!is_kallsyms) {
realname = realpath(name, NULL);
@@ -358,30 +369,34 @@ int build_id_cache__add_s(const char *sbuild_id, const char *name,
if (!dir_name)
goto out_free;
- if (mkdir_p(dir_name, 0755))
+ buildid_dir_write_lock(&lockfd);
+ if (lockfd == -1)
goto out_free;
+ if (mkdir_p(dir_name, 0755))
+ goto out_unlock;
+
if (asprintf(&filename, "%s/%s", dir_name, sbuild_id) < 0) {
filename = NULL;
- goto out_free;
+ goto out_unlock;
}
if (access(filename, F_OK)) {
if (is_kallsyms) {
if (copyfile("/proc/kallsyms", filename))
- goto out_free;
+ goto out_unlock;
} else if (link(realname, filename) && errno != EEXIST &&
copyfile(name, filename))
- goto out_free;
+ goto out_unlock;
}
if (!build_id__filename(sbuild_id, linkname, size))
- goto out_free;
+ goto out_unlock;
tmp = strrchr(linkname, '/');
*tmp = '\0';
if (access(linkname, X_OK) && mkdir_p(linkname, 0755))
- goto out_free;
+ goto out_unlock;
*tmp = '/';
targetname = filename + strlen(buildid_dir) - 5;
@@ -389,6 +404,8 @@ int build_id_cache__add_s(const char *sbuild_id, const char *name,
if (symlink(targetname, linkname) == 0)
err = 0;
+out_unlock:
+ buildid_dir_write_unlock(lockfd);
out_free:
if (!is_kallsyms)
free(realname);
@@ -427,6 +444,7 @@ int build_id_cache__remove_s(const char *sbuild_id)
char *filename = zalloc(size),
*linkname = zalloc(size), *tmp;
int err = -1;
+ int lockfd = -1;
if (filename == NULL || linkname == NULL)
goto out_free;
@@ -449,10 +467,17 @@ int build_id_cache__remove_s(const char *sbuild_id)
tmp = strrchr(linkname, '/') + 1;
snprintf(tmp, size - (tmp - linkname), "%s", filename);
- if (unlink(linkname))
+ buildid_dir_write_lock(&lockfd);
+ if (lockfd == -1)
goto out_free;
+ if (unlink(linkname))
+ goto out_unlock;
+
+
err = 0;
+out_unlock:
+ buildid_dir_write_unlock(lockfd);
out_free:
free(filename);
free(linkname);
--
2.4.0
--
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