Merge pull request #145 from brauner/2016-09-04/lxcfs_on_ramfs

[mirror_lxcfs.git] / bindings.c

diff --git a/bindings.c b/bindings.c
index 5f14ac634d5ed90b92ef96efc67501900a6ede8d..2f78ab5ebdd3ff7ef85501f2c164a8b374ab86eb 100644 (file)
--- a/bindings.c
+++ b/bindings.c
@@ -4201,12 +4201,32 @@ static bool is_on_ramfs(void)
        return false;
 }
 
-static int pivot_enter(const int oldroot, const int newroot)
+static int pivot_enter()
 {
+       int ret = -1, oldroot = -1, newroot = -1;
+
+       oldroot = open("/", O_DIRECTORY | O_RDONLY);
+       if (oldroot < 0) {
+               lxcfs_error("%s\n", "Failed to open old root for fchdir.");
+               return ret;
+       }
+
+       newroot = open(ROOTDIR, O_DIRECTORY | O_RDONLY);
+       if (newroot < 0) {
+               lxcfs_error("%s\n", "Failed to open new root for fchdir.");
+               goto err;
+       }
+
+       /* change into new root fs */
+       if (fchdir(newroot) < 0) {
+               lxcfs_error("Failed to change directory to new rootfs: %s.\n", ROOTDIR);
+               goto err;
+       }
+
        /* pivot_root into our new root fs */
        if (pivot_root(".", ".") < 0) {
                lxcfs_error("pivot_root() syscall failed: %s.\n", strerror(errno));
-               return -1;
+               goto err;
        }
 
        /*
@@ -4216,20 +4236,28 @@ static int pivot_enter(const int oldroot, const int newroot)
         */
        if (fchdir(oldroot) < 0) {
                lxcfs_error("%s\n", "Failed to enter old root.");
-               return -1;
+               goto err;
        }
 
        if (umount2(".", MNT_DETACH) < 0) {
                lxcfs_error("%s\n", "Failed to detach old root.");
-               return -1;
+               goto err;
        }
 
        if (fchdir(newroot) < 0) {
                lxcfs_error("%s\n", "Failed to re-enter new root.");
-               return -1;
+               goto err;
        }
 
-       return 0;
+       ret = 0;
+
+err:
+       if (oldroot > 0)
+               close(oldroot);
+       if (newroot > 0)
+               close(newroot);
+
+       return ret;
 }
 
 static int chroot_enter()
@@ -4254,12 +4282,11 @@ static int chroot_enter()
 
 static int permute_and_enter(void)
 {
-       int ret = -1, oldroot = -1, newroot = -1;
        struct statfs sb;
 
        if (statfs("/", &sb) < 0) {
                lxcfs_error("%s\n", "Could not stat / mountpoint.");
-               return ret;
+               return -1;
        }
 
        /* has_fs_type() is not reliable. When the ramfs is a tmpfs it will
@@ -4268,37 +4295,12 @@ static int permute_and_enter(void)
        if (has_fs_type(&sb, RAMFS_MAGIC) || is_on_ramfs())
                return chroot_enter();
 
-       oldroot = open("/", O_DIRECTORY | O_RDONLY);
-       if (oldroot < 0) {
-               lxcfs_error("%s\n", "Failed to open old root for fchdir.");
-               return ret;
-       }
-
-       newroot = open(ROOTDIR, O_DIRECTORY | O_RDONLY);
-       if (newroot < 0) {
-               lxcfs_error("%s\n", "Failed to open new root for fchdir.");
-               goto err;
-       }
-
-       /* change into new root fs */
-       if (fchdir(newroot) < 0) {
-               lxcfs_error("Failed to change directory to new rootfs: %s.\n", ROOTDIR);
-               goto err;
-       }
-
-       if (pivot_enter(oldroot, newroot) < 0) {
+       if (pivot_enter() < 0) {
                lxcfs_error("%s\n", "Could not perform pivot root.");
-               goto err;
+               return -1;
        }
 
-       ret = 0;
-
-err:
-       if (oldroot > 0)
-               close(oldroot);
-       if (newroot > 0)
-               close(newroot);
-       return ret;
+       return 0;
 }
 
 /* Prepare our new clean root. */