From: Xinze Chi <xinze@xsky.com>
Date: Tue, 13 Dec 2016 08:43:03 +0000 (+0800)
Subject: common/blkdev: use realpath instead of readlink to resolve the recursion symbol link
X-Git-Tag: v11.1.1~53^2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=refs%2Fpull%2F12462%2Fhead;p=ceph.git

common/blkdev: use realpath instead of readlink to resolve the recursion symbol link

Signed-off-by: Xinze Chi <xinze@xsky.com>
---

diff --git a/src/common/blkdev.cc b/src/common/blkdev.cc
index 26f3d580d2f..f3262d53a81 100644
--- a/src/common/blkdev.cc
+++ b/src/common/blkdev.cc
@@ -65,21 +65,23 @@ int get_block_device_base(const char *dev, char *out, size_t out_len)
   struct stat st;
   int r = 0;
   DIR *dir;
-  char devname[PATH_MAX], fn[PATH_MAX];
+  char devname[PATH_MAX] = {0}, fn[PATH_MAX] = {0};
   char *p;
   char realname[PATH_MAX] = {0};
 
   if (strncmp(dev, "/dev/", 5) != 0) {
-    if ((readlink(dev, realname, sizeof(realname)) == -1) || (strncmp(realname, "/dev/", 5) != 0))
+    if (realpath(dev, realname) == NULL || (strncmp(realname, "/dev/", 5) != 0)) {
       return -EINVAL;
+    }
   }
 
   if (strlen(realname))
-    strncpy(devname, realname + 5, PATH_MAX -1);
+    strncpy(devname, realname + 5, PATH_MAX - 5);
   else
-    strncpy(devname, dev + 5, PATH_MAX-1);
+    strncpy(devname, dev + 5, strlen(dev) - 5);
+
+  devname[PATH_MAX - 1] = '\0';
 
-  devname[PATH_MAX-1] = '\0';
   for (p = devname; *p; ++p)
     if (*p == '/')
       *p = '!';