From 5d409034017e9f9f8c4392157d95511fc2e05d87 Mon Sep 17 00:00:00 2001 From: Martin Pitt Date: Wed, 27 May 2015 09:56:03 +0200 Subject: path-util: Fix path_is_mount_point for files MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Commits 27cc6f166 and f25afeb broke path_is_mount_point() for files (such as /etc/machine-id → /run/machine-id bind mounts) as with the factorization of fd_is_mount_point() we lost the parent directory. We cannot determine that from an fd only as openat(fd, "..") only works for directory fds. Change fd_is_mount_point() to behave like openat(): It now takes a file descriptor of the containing directory, a file name in it, and flags (which can be 0 or AT_SYMLINK_FOLLOW). Unlike name_to_handle_at() or openat(), fstatat() only accepts the inverse flag AT_SYMLINK_NOFOLLOW and complains with EINVAL about AT_SYMLINK_FOLLOW; so we need to transform the flags for that fallback. Adjust rm_rf_children() accordingly (only other caller of fd_is_mount_point() aside from path_is_mount_point()). Add test cases for files, links, and file bind mounts (the latter will only work when running as root). Split out a new test_path_is_mount_point() test case function as it got significantly larger now. --- src/test/test-path-util.c | 76 +++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 63 insertions(+), 13 deletions(-) (limited to 'src/test/test-path-util.c') diff --git a/src/test/test-path-util.c b/src/test/test-path-util.c index 09f0f2f89e..80782ff902 100644 --- a/src/test/test-path-util.c +++ b/src/test/test-path-util.c @@ -21,6 +21,7 @@ #include #include +#include #include "path-util.h" #include "util.h" @@ -88,21 +89,9 @@ static void test_path(void) { test_parent("/aa///file...", "/aa///"); test_parent("file.../", NULL); - assert_se(path_is_mount_point("/", true) > 0); - assert_se(path_is_mount_point("/", false) > 0); - fd = open("/", O_RDONLY|O_CLOEXEC|O_DIRECTORY|O_NOCTTY); assert_se(fd >= 0); - assert_se(fd_is_mount_point(fd) > 0); - - assert_se(path_is_mount_point("/proc", true) > 0); - assert_se(path_is_mount_point("/proc", false) > 0); - - assert_se(path_is_mount_point("/proc/1", true) == 0); - assert_se(path_is_mount_point("/proc/1", false) == 0); - - assert_se(path_is_mount_point("/sys", true) > 0); - assert_se(path_is_mount_point("/sys", false) > 0); + assert_se(fd_is_mount_point(fd, "/", 0) > 0); { char p1[] = "aaa/bbb////ccc"; @@ -322,6 +311,66 @@ static void test_prefix_root(void) { test_prefix_root_one("/foo///", "//bar", "/foo/bar"); } +static void test_path_is_mount_point(void) { + int fd, rt, rf, rlt, rlf; + char tmp_dir[] = "/tmp/test-path-is-mount-point-XXXXXX"; + _cleanup_free_ char *file1 = NULL, *file2 = NULL, *link1 = NULL, *link2 = NULL; + + assert_se(path_is_mount_point("/", true) > 0); + assert_se(path_is_mount_point("/", false) > 0); + + assert_se(path_is_mount_point("/proc", true) > 0); + assert_se(path_is_mount_point("/proc", false) > 0); + + assert_se(path_is_mount_point("/proc/1", true) == 0); + assert_se(path_is_mount_point("/proc/1", false) == 0); + + assert_se(path_is_mount_point("/sys", true) > 0); + assert_se(path_is_mount_point("/sys", false) > 0); + + /* file mountpoints */ + assert_se(mkdtemp(tmp_dir) != NULL); + file1 = path_join(NULL, tmp_dir, "file1"); + assert_se(file1); + file2 = path_join(NULL, tmp_dir, "file2"); + assert_se(file2); + fd = open(file1, O_WRONLY|O_CREAT|O_EXCL|O_CLOEXEC, 0664); + assert_se(fd > 0); + close(fd); + fd = open(file2, O_WRONLY|O_CREAT|O_EXCL|O_CLOEXEC, 0664); + assert_se(fd > 0); + close(fd); + link1 = path_join(NULL, tmp_dir, "link1"); + assert_se(link1); + assert_se(symlink("file1", link1) == 0); + link2 = path_join(NULL, tmp_dir, "link2"); + assert_se(link1); + assert_se(symlink("file2", link2) == 0); + + assert_se(path_is_mount_point(file1, true) == 0); + assert_se(path_is_mount_point(file1, false) == 0); + assert_se(path_is_mount_point(link1, true) == 0); + assert_se(path_is_mount_point(link1, false) == 0); + + /* this test will only work as root */ + if (mount(file1, file2, NULL, MS_BIND, NULL) >= 0) { + rf = path_is_mount_point(file2, false); + rt = path_is_mount_point(file2, true); + rlf = path_is_mount_point(link2, false); + rlt = path_is_mount_point(link2, true); + + assert_se(umount(file2) == 0); + + assert_se(rf == 1); + assert_se(rt == 1); + assert_se(rlf == 0); + assert_se(rlt == 1); + } else + printf("Skipping bind mount file test: %m\n"); + + assert_se(rm_rf(tmp_dir, REMOVE_ROOT|REMOVE_PHYSICAL) == 0); +} + int main(int argc, char **argv) { test_path(); test_find_binary(argv[0], true); @@ -333,6 +382,7 @@ int main(int argc, char **argv) { test_strv_resolve(); test_path_startswith(); test_prefix_root(); + test_path_is_mount_point(); return 0; } -- cgit v1.2.3-54-g00ecf