switch_root: use err.h, clean up return codes

Signed-off-by: Peter Jones <pjones@redhat.com>
Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/sys-utils/switch_root.c b/sys-utils/switch_root.c
index 3c42c3d11c700a59129d9443a10cf7f83464bb07..5dcc7f1e4b669ec6741402500683c1fa242be270 100644 (file)
--- a/sys-utils/switch_root.c
+++ b/sys-utils/switch_root.c
@@ -32,6 +32,7 @@
 #include <errno.h>
 #include <ctype.h>
 #include <dirent.h>
+#include <err.h>
 
 #ifndef MS_MOVE
 #define MS_MOVE 8192
@@ -52,14 +53,14 @@ static int recursiveRemove(char *dirName)
        int dfd;
 
        if (!(dir = opendir(dirName))) {
-               printf("error opening %s: %m\n", dirName);
+               warn("failed to open %s", dirName);
                goto done;
        }
 
        dfd = dirfd(dir);
 
        if (fstat(dfd, &rb)) {
-               printf("unable to stat %s: %m\n", dirName);
+               warn("failed to stat %s", dirName);
                goto done;
        }
 
@@ -69,7 +70,7 @@ static int recursiveRemove(char *dirName)
                errno = 0;
                if (!(d = readdir(dir))) {
                        if (errno) {
-                               printf("error reading from %s: %m\n", dirName);
+                               warn("failed to read %s", dirName);
                                goto done;
                        }
                        break;  /* end of directory */
@@ -82,8 +83,7 @@ static int recursiveRemove(char *dirName)
                        struct stat sb;
 
                        if (fstatat(dfd, d->d_name, &sb, AT_SYMLINK_NOFOLLOW)) {
-                               printf("failed to stat %s/%s: %m\n",
-                                               dirName, d->d_name);
+                               warn("failed to stat %s/%s", dirName, d->d_name);
                                continue;
                        }
 
@@ -100,7 +100,7 @@ static int recursiveRemove(char *dirName)
 
                if (unlinkat(dfd, d->d_name,
                             d->d_type == DT_DIR ? AT_REMOVEDIR : 0))
-                       printf("failed to unlink %s/%s: %m\n", dirName, d->d_name);
+                       warn("failed to unlink %s/%s", dirName, d->d_name);
        }
 
        rc = 0; /* success */
@@ -123,42 +123,39 @@ static int switchroot(const char *newroot)
                strcpy(newmount, newroot);
                strcat(newmount, umounts[i]);
                if (mount(umounts[i], newmount, NULL, MS_MOVE, NULL) < 0) {
-                       fprintf(stderr, "Error mount moving old %s %s %m\n",
+                       warn("failed to mount moving %s to %s",
                                umounts[i], newmount);
-                       fprintf(stderr, "Forcing unmount of %s\n", umounts[i]);
+                       warnx("forcing unmount of %s", umounts[i]);
                        umount2(umounts[i], MNT_FORCE);
                }
        }
 
-       if (chdir(newroot) < 0) {
-               errnum=errno;
-               fprintf(stderr, "switchroot: chdir failed: %m\n");
-               errno=errnum;
+       if (chdir(newroot)) {
+               warn("failed to change directory to %s", newroot);
                return -1;
        }
+
        recursiveRemove("/");
+
        if (mount(newroot, "/", NULL, MS_MOVE, NULL) < 0) {
-               errnum = errno;
-               fprintf(stderr, "switchroot: mount failed: %m\n");
-               errno = errnum;
+               warn("failed to mount moving %s to /", newroot);
                return -1;
        }
 
        if (chroot(".")) {
-               errnum = errno;
-               fprintf(stderr, "switchroot: chroot failed: %m\n");
-               errno = errnum;
-               return -2;
+               warn("failed to change root");
+               return -1;
        }
-       return 1;
+       return 0;
 }
 
 static void usage(FILE *output)
 {
-       fprintf(output, "usage: switchroot <newrootdir> <init> <args to init>\n");
+       fprintf(output, "usage: %s <newrootdir> <init> <args to init>\n",
+                       program_invocation_short_name);
        if (output == stderr)
-               exit(err_usage);
-       exit(ok);
+               exit(EXIT_FAILURE);
+       exit(EXIT_SUCCESS);
 }
 
 int main(int argc, char *argv[])
@@ -172,12 +169,11 @@ int main(int argc, char *argv[])
                usage(stderr);
        }
 
-       if (switchroot(newroot) < 0) {
-               fprintf(stderr, "switchroot has failed.  Sorry.\n");
-               return 1;
-       }
+       if (switchroot(newroot))
+               errx(EXIT_FAILURE, "failed. Sorry.");
+
        if (access(initargs[0], X_OK))
-               fprintf(stderr, "WARNING: can't access %s\n", initargs[0]);
+               warn("cannot access %s", initargs[0]);
 
        /* get session leader */
        setsid();
@@ -185,5 +181,6 @@ int main(int argc, char *argv[])
        ioctl (0, TIOCSCTTY, 1);
 
        execv(initargs[0], initargs);
+       err(EXIT_FAILURE, "failed to execute %s", initargs[0]);
 }