execute: Switch back to chroot()

pivot_root() seems to be very complicated to use and will require us to
have the container run on a different file system. That is however not
possible when Pakfire is running as an un-privileged user.

Since pivot_root() does not seem to offer any advantages over chroot(),
we switch back to chroot() which is easier to use.

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>

diff --git a/src/libpakfire/execute.c b/src/libpakfire/execute.c
index f4cde9465494849ffe7f823732b428dc72d2fe04..1780b3436828edaaca8148d5a2e24501f2bd75c2 100644 (file)
--- a/src/libpakfire/execute.c
+++ b/src/libpakfire/execute.c
@@ -84,10 +84,6 @@ static int clone3(struct clone_args* args, size_t size) {
        return syscall(__NR_clone3, args, size);
 }
 
-static int pivot_root(const char* new_root, const char* put_old) {
-       return syscall(__NR_pivot_root, new_root, put_old);
-}
-
 static int pakfire_execute_buffer_is_full(const struct pakfire_execute_buffer* buffer) {
        return (sizeof(buffer->data) == buffer->used);
 }
@@ -547,8 +543,6 @@ static int pakfire_execute_fork(void* data) {
        const char* root = pakfire_get_path(pakfire);
        const char* arch = pakfire_get_arch(pakfire);
 
-       char oldroot[PATH_MAX];
-
        DEBUG(pakfire, "Execution environment has been forked as PID %d\n", getpid());
        DEBUG(pakfire, "        root    : %s\n", root);
        DEBUG(pakfire, "        cgroup  : %s\n", env->cgroup);
@@ -561,11 +555,6 @@ static int pakfire_execute_fork(void* data) {
 
        // Change root (unless root is /)
        if (strcmp(root, "/") != 0) {
-               // Disable mount propagation on /
-               r = pakfire_disable_mount_propagation(pakfire, "/");
-               if (r)
-                       return r;
-
                // Mount everything
                r = pakfire_mount_all(pakfire, MOUNT_IN_NEW_NS);
                if (r)
@@ -574,23 +563,10 @@ static int pakfire_execute_fork(void* data) {
                // Log all mountpoints
                pakfire_mount_list(pakfire);
 
-               // Move the old root to here
-               r = pakfire_string_format(oldroot, "%s/.oldroot.XXXXXX", root);
-               if (r < 0) {
-                       ERROR(pakfire, "Could not figure out where the old root directory is going: %m\n");
-                       return r;
-               }
-
-               // Create temporary directory
-               if (!pakfire_mkdtemp(oldroot)) {
-                       ERROR(pakfire, "Could not create temporary directory: %m\n");
-                       return r;
-               }
-
-               // Call pivot_root()
-               r = pivot_root(root, oldroot);
+               // Call chroot()
+               r = chroot(root);
                if (r) {
-                       ERROR(pakfire, "pivot_root() to %s failed: %m\n", root);
+                       ERROR(pakfire, "chroot() to %s failed: %m\n", root);
                        return 1;
                }
 
@@ -600,22 +576,6 @@ static int pakfire_execute_fork(void* data) {
                        ERROR(pakfire, "chdir() after chroot() failed: %m\n");
                        return 1;
                }
-
-               const char* __oldroot = oldroot + strlen(root);
-
-               // Umount the old root directory
-               r = umount2(__oldroot, MNT_DETACH);
-               if (r) {
-                       ERROR(pakfire, "Could not umount old root directory: %m\n");
-                       return r;
-               }
-
-               // Remove the old root directory
-               r = rmdir(__oldroot);
-               if (r) {
-                       ERROR(pakfire, "Could not remove the old root directory: %m\n");
-                       return r;
-               }
        }
 
        // Set personality

diff --git a/src/libpakfire/include/pakfire/mount.h b/src/libpakfire/include/pakfire/mount.h
index 6f1b9a0568e0c204910a45687ecbce5667700b92..fba1ae735e1c17e7ac2a2a839a1d90f7dce7ec72 100644 (file)
--- a/src/libpakfire/include/pakfire/mount.h
+++ b/src/libpakfire/include/pakfire/mount.h
@@ -30,8 +30,6 @@ enum pakfire_mount_flags {
        MOUNT_IN_NEW_NS = (1 << 0),
 };
 
-int pakfire_disable_mount_propagation(struct pakfire* pakfire, const char* path);
-
 int pakfire_mount_list(struct pakfire* pakfire);
 
 int pakfire_mount(struct pakfire* pakfire, const char* source, const char* target,