page-types: introduce checked_open()

This helps merge duplicate code (now and future) and outstand the main
logic.

Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/Documentation/vm/page-types.c b/Documentation/vm/page-types.c
index e46fb5b..6bdcc06 100644 (file)
--- a/Documentation/vm/page-types.c
+++ b/Documentation/vm/page-types.c
@@ -214,6 +214,18 @@ static void fatal(const char *x, ...)
        exit(EXIT_FAILURE);
 }
 
+int checked_open(const char *pathname, int flags)
+{
+       int fd = open(pathname, flags);
+
+       if (fd < 0) {
+               perror(pathname);
+               exit(EXIT_FAILURE);
+       }
+
+       return fd;
+}
+
 
 /*
  * page flag names
@@ -534,11 +546,7 @@ static void walk_addr_ranges(void)
 {
        int i;
 
-       kpageflags_fd = open(PROC_KPAGEFLAGS, O_RDONLY);
-       if (kpageflags_fd < 0) {
-               perror(PROC_KPAGEFLAGS);
-               exit(EXIT_FAILURE);
-       }
+       kpageflags_fd = checked_open(PROC_KPAGEFLAGS, O_RDONLY);
 
        if (!nr_addr_ranges)
                add_addr_range(0, ULONG_MAX);
@@ -631,11 +639,7 @@ static void parse_pid(const char *str)
        opt_pid = parse_number(str);
 
        sprintf(buf, "/proc/%d/pagemap", opt_pid);
-       pagemap_fd = open(buf, O_RDONLY);
-       if (pagemap_fd < 0) {
-               perror(buf);
-               exit(EXIT_FAILURE);
-       }
+       pagemap_fd = checked_open(buf, O_RDONLY);
 
        sprintf(buf, "/proc/%d/maps", opt_pid);
        file = fopen(buf, "r");