From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933310AbbBIPly (ORCPT ); Mon, 9 Feb 2015 10:41:54 -0500 Received: from cdptpa-outbound-snat.email.rr.com ([107.14.166.230]:3984 "EHLO cdptpa-oedge-vip.email.rr.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1760815AbbBIPkk (ORCPT ); Mon, 9 Feb 2015 10:40:40 -0500 Message-Id: <20150209154037.632023073@goodmis.org> User-Agent: quilt/0.61-1 Date: Mon, 09 Feb 2015 10:39:50 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Jiri Olsa , Arnaldo Carvalho de Melo , Masami Hiramatsu , Namhyung Kim Subject: [PATCH 2/6 v3] tools lib fs: Add helper to find mounted file systems References: <20150209153948.933115386@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Disposition: inline; filename=0002-tools-lib-fs-Add-helper-to-find-mounted-file-systems.patch X-RR-Connecting-IP: 107.14.168.142:25 X-Cloudmark-Score: 0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Steven Rostedt (Red Hat)" In preparation for adding tracefs for perf to use, create a findfs helper utility that find_debugfs uses instead of hard coding the search in the code. This will allow for a find_tracefs to be used as well. Signed-off-by: Steven Rostedt --- tools/lib/api/Makefile | 2 ++ tools/lib/api/fs/debugfs.c | 51 ++++++------------------------------- tools/lib/api/fs/debugfs.h | 11 +------- tools/lib/api/fs/findfs.c | 63 ++++++++++++++++++++++++++++++++++++++++++++++ tools/lib/api/fs/findfs.h | 21 ++++++++++++++++ 5 files changed, 94 insertions(+), 54 deletions(-) create mode 100644 tools/lib/api/fs/findfs.c create mode 100644 tools/lib/api/fs/findfs.h diff --git a/tools/lib/api/Makefile b/tools/lib/api/Makefile index 36c08b1f4afb..22b2f15d7255 100644 --- a/tools/lib/api/Makefile +++ b/tools/lib/api/Makefile @@ -9,11 +9,13 @@ LIB_H= LIB_OBJS= LIB_H += fs/debugfs.h +LIB_H += fs/findfs.h LIB_H += fs/fs.h # See comment below about piggybacking... LIB_H += fd/array.h LIB_OBJS += $(OUTPUT)fs/debugfs.o +LIB_OBJS += $(OUTPUT)fs/findfs.o LIB_OBJS += $(OUTPUT)fs/fs.o # XXX piggybacking here, need to introduce libapikfd, or rename this # to plain libapik.a and make it have it all api goodies diff --git a/tools/lib/api/fs/debugfs.c b/tools/lib/api/fs/debugfs.c index d21d4d6b4fd2..91e1668348ce 100644 --- a/tools/lib/api/fs/debugfs.c +++ b/tools/lib/api/fs/debugfs.c @@ -20,58 +20,21 @@ static const char * const debugfs_known_mountpoints[] = { static bool debugfs_found; -/* verify that a mountpoint is actually a debugfs instance */ - -static int debugfs_valid_mountpoint(const char *debugfs) -{ - struct statfs st_fs; - - if (statfs(debugfs, &st_fs) < 0) - return -ENOENT; - else if ((long)st_fs.f_type != (long)DEBUGFS_MAGIC) - return -ENOENT; - - return 0; -} - /* find the path to the mounted debugfs */ const char *debugfs_find_mountpoint(void) { - const char * const *ptr; - char type[100]; - FILE *fp; + const char *ret; if (debugfs_found) return (const char *)debugfs_mountpoint; - ptr = debugfs_known_mountpoints; - while (*ptr) { - if (debugfs_valid_mountpoint(*ptr) == 0) { - debugfs_found = true; - strcpy(debugfs_mountpoint, *ptr); - return debugfs_mountpoint; - } - ptr++; - } + ret = find_mountpoint("debugfs", (long) DEBUGFS_MAGIC, + debugfs_mountpoint, PATH_MAX + 1, + debugfs_known_mountpoints); + if (ret) + debugfs_found = true; - /* give up and parse /proc/mounts */ - fp = fopen("/proc/mounts", "r"); - if (fp == NULL) - return NULL; - - while (fscanf(fp, "%*s %" STR(PATH_MAX) "s %99s %*s %*d %*d\n", - debugfs_mountpoint, type) == 2) { - if (strcmp(type, "debugfs") == 0) - break; - } - fclose(fp); - - if (strcmp(type, "debugfs") != 0) - return NULL; - - debugfs_found = true; - - return debugfs_mountpoint; + return ret; } /* mount the debugfs somewhere if it's not mounted */ diff --git a/tools/lib/api/fs/debugfs.h b/tools/lib/api/fs/debugfs.h index 77bb36a95b07..1074ac81358e 100644 --- a/tools/lib/api/fs/debugfs.h +++ b/tools/lib/api/fs/debugfs.h @@ -1,16 +1,7 @@ #ifndef __API_DEBUGFS_H__ #define __API_DEBUGFS_H__ -#define _STR(x) #x -#define STR(x) _STR(x) - -/* - * On most systems would have given us this, but not on some systems - * (e.g. GNU/Hurd). - */ -#ifndef PATH_MAX -#define PATH_MAX 4096 -#endif +#include "findfs.h" #ifndef DEBUGFS_MAGIC #define DEBUGFS_MAGIC 0x64626720 diff --git a/tools/lib/api/fs/findfs.c b/tools/lib/api/fs/findfs.c new file mode 100644 index 000000000000..49946cb6d7af --- /dev/null +++ b/tools/lib/api/fs/findfs.c @@ -0,0 +1,63 @@ +#include +#include +#include +#include +#include +#include + +#include "findfs.h" + +/* verify that a mountpoint is actually the type we want */ + +int valid_mountpoint(const char *mount, long magic) +{ + struct statfs st_fs; + + if (statfs(mount, &st_fs) < 0) + return -ENOENT; + else if ((long)st_fs.f_type != magic) + return -ENOENT; + + return 0; +} + +/* find the path to a mounted file system */ +const char *find_mountpoint(const char *fstype, long magic, + char *mountpoint, int len, + const char * const *known_mountpoints) +{ + const char * const *ptr; + char format[128]; + char type[100]; + FILE *fp; + + if (known_mountpoints) { + ptr = known_mountpoints; + while (*ptr) { + if (valid_mountpoint(*ptr, magic) == 0) { + strncpy(mountpoint, *ptr, len - 1); + mountpoint[len-1] = 0; + return mountpoint; + } + ptr++; + } + } + + /* give up and parse /proc/mounts */ + fp = fopen("/proc/mounts", "r"); + if (fp == NULL) + return NULL; + + snprintf(format, 128, "%%*s %%%ds %%99s %%*s %%*d %%*d\n", len); + + while (fscanf(fp, format, mountpoint, type) == 2) { + if (strcmp(type, fstype) == 0) + break; + } + fclose(fp); + + if (strcmp(type, fstype) != 0) + return NULL; + + return mountpoint; +} diff --git a/tools/lib/api/fs/findfs.h b/tools/lib/api/fs/findfs.h new file mode 100644 index 000000000000..9e7d876791e1 --- /dev/null +++ b/tools/lib/api/fs/findfs.h @@ -0,0 +1,21 @@ +#ifndef __API_FINDFS_H__ +#define __API_FINDFS_H__ + +#define _STR(x) #x +#define STR(x) _STR(x) + +/* + * On most systems would have given us this, but not on some systems + * (e.g. GNU/Hurd). + */ +#ifndef PATH_MAX +#define PATH_MAX 4096 +#endif + +const char *find_mountpoint(const char *fstype, long magic, + char *mountpoint, int len, + const char * const *known_mountpoints); + +int valid_mountpoint(const char *mount, long magic); + +#endif /* __API_FINDFS_H__ */ -- 2.1.4