The threaded mount interaction test validates that the idmapping of a
mount behaves correctly when changed while another process already has a
writable file descriptor to that mount. In newer kernels it isn't
possible to change a mount's idmapped if someone has a writable file
descriptor to that mount.
Link: e1bbcd277a53 ("fs: hold writers when changing mount's idmapping")
Signed-off-by: Christian Brauner (Microsoft) <brauner@xxxxxxxxxx>
---
src/vfs/idmapped-mounts.c | 241 --------------------------------------
src/vfs/vfstest.c | 1 -
2 files changed, 242 deletions(-)
diff --git a/src/vfs/idmapped-mounts.c b/src/vfs/idmapped-mounts.c
index d3763c2d..63297d5f 100644
--- a/src/vfs/idmapped-mounts.c
+++ b/src/vfs/idmapped-mounts.c
@@ -6438,246 +6438,6 @@ out:
return fret;
}
-#define PTR_TO_INT(p) ((int)((intptr_t)(p)))
-#define INT_TO_PTR(u) ((void *)((intptr_t)(u)))
-
-struct threaded_args {
- const struct vfstest_info *info;
- int open_tree_fd;
-};
-
-static void *idmapped_mount_create_cb(void *data)
-{
- int fret = EXIT_FAILURE;
- struct mount_attr attr = {
- .attr_set = MOUNT_ATTR_IDMAP,
- };
- struct threaded_args *args = data;
-
- /* Changing mount properties on a detached mount. */
- attr.userns_fd = get_userns_fd(0, 10000, 10000);
- if (attr.userns_fd < 0) {
- log_stderr("failure: get_userns_fd");
- goto out;
- }
-
- if (sys_mount_setattr(args->open_tree_fd, "", AT_EMPTY_PATH, &attr, sizeof(attr))) {
- log_stderr("failure: sys_mount_setattr");
- goto out;
- }
-
- fret = EXIT_SUCCESS;
-
-out:
- safe_close(attr.userns_fd);
- pthread_exit(INT_TO_PTR(fret));
-}
-
-/* This tries to verify that we never see an inconistent ownership on-disk and
- * can't write invalid ids to disk. To do this we create a race between
- * idmapping a mount and creating files on it.
- * Note, while it is perfectly fine to see overflowuid and overflowgid as owner
- * if we create files through the open_tree_fd before the mount is idmapped but
- * look at the files after the mount has been idmapped in this test it can never
- * be the case that we see overflowuid and overflowgid when we access the file
- * through a non-idmapped mount (in the initial user namespace).
- */
-static void *idmapped_mount_operations_cb(void *data)
-{
- int file1_fd = -EBADF, file2_fd = -EBADF, dir1_fd = -EBADF,
- dir1_fd2 = -EBADF, fret = EXIT_FAILURE;
- struct threaded_args *args = data;
- const struct vfstest_info *info = args->info;
-
- if (!switch_fsids(10000, 10000)) {
- log_stderr("failure: switch fsids");
- goto out;
- }
-
- file1_fd = openat(args->open_tree_fd, FILE1,
- O_CREAT | O_EXCL | O_CLOEXEC, 0644);
- if (file1_fd < 0) {
- log_stderr("failure: openat");
- goto out;
- }
-
- file2_fd = openat(args->open_tree_fd, FILE2,
- O_CREAT | O_EXCL | O_CLOEXEC, 0644);
- if (file2_fd < 0) {
- log_stderr("failure: openat");
- goto out;
- }
-
- if (mkdirat(args->open_tree_fd, DIR1, 0777)) {
- log_stderr("failure: mkdirat");
- goto out;
- }
-
- dir1_fd = openat(args->open_tree_fd, DIR1,
- O_RDONLY | O_DIRECTORY | O_CLOEXEC);
- if (dir1_fd < 0) {
- log_stderr("failure: openat");
- goto out;
- }
-
- if (!__expected_uid_gid(args->open_tree_fd, FILE1, 0, 0, 0, false) &&
- !__expected_uid_gid(args->open_tree_fd, FILE1, 0, 10000, 10000, false) &&
- !__expected_uid_gid(args->open_tree_fd, FILE1, 0, info->t_overflowuid, info->t_overflowgid, false)) {
- log_stderr("failure: expected_uid_gid");
- goto out;
- }
-
- if (!__expected_uid_gid(args->open_tree_fd, FILE2, 0, 0, 0, false) &&
- !__expected_uid_gid(args->open_tree_fd, FILE2, 0, 10000, 10000, false) &&
- !__expected_uid_gid(args->open_tree_fd, FILE2, 0, info->t_overflowuid, info->t_overflowgid, false)) {
- log_stderr("failure: expected_uid_gid");
- goto out;
- }
-
- if (!__expected_uid_gid(args->open_tree_fd, DIR1, 0, 0, 0, false) &&
- !__expected_uid_gid(args->open_tree_fd, DIR1, 0, 10000, 10000, false) &&
- !__expected_uid_gid(args->open_tree_fd, DIR1, 0, info->t_overflowuid, info->t_overflowgid, false)) {
- log_stderr("failure: expected_uid_gid");
- goto out;
- }
-
- if (!__expected_uid_gid(dir1_fd, "", AT_EMPTY_PATH, 0, 0, false) &&
- !__expected_uid_gid(dir1_fd, "", AT_EMPTY_PATH, 10000, 10000, false) &&
- !__expected_uid_gid(dir1_fd, "", AT_EMPTY_PATH, info->t_overflowuid, info->t_overflowgid, false)) {
- log_stderr("failure: expected_uid_gid");
- goto out;
- }
-
- dir1_fd2 = openat(info->t_dir1_fd, DIR1,
- O_RDONLY | O_DIRECTORY | O_CLOEXEC);
- if (dir1_fd2 < 0) {
- log_stderr("failure: openat");
- goto out;
- }
-
- if (!__expected_uid_gid(info->t_dir1_fd, FILE1, 0, 0, 0, false) &&
- !__expected_uid_gid(info->t_dir1_fd, FILE1, 0, 10000, 10000, false)) {
- log_stderr("failure: expected_uid_gid");
- goto out;
- }
-
- if (!__expected_uid_gid(info->t_dir1_fd, FILE2, 0, 0, 0, false) &&
- !__expected_uid_gid(info->t_dir1_fd, FILE2, 0, 10000, 10000, false)) {
- log_stderr("failure: expected_uid_gid");
- goto out;
- }
-
- if (!__expected_uid_gid(info->t_dir1_fd, DIR1, 0, 0, 0, false) &&
- !__expected_uid_gid(info->t_dir1_fd, DIR1, 0, 10000, 10000, false)) {
- log_stderr("failure: expected_uid_gid");
- goto out;
- }
-
- if (!__expected_uid_gid(info->t_dir1_fd, DIR1, 0, 0, 0, false) &&
- !__expected_uid_gid(info->t_dir1_fd, DIR1, 0, 10000, 10000, false)) {
- log_stderr("failure: expected_uid_gid");
- goto out;
- }
-
- if (!__expected_uid_gid(dir1_fd2, "", AT_EMPTY_PATH, 0, 0, false) &&
- !__expected_uid_gid(dir1_fd2, "", AT_EMPTY_PATH, 10000, 10000, false)) {
- log_stderr("failure: expected_uid_gid");
- goto out;
- }
-
- fret = EXIT_SUCCESS;
-
-out:
- safe_close(file1_fd);
- safe_close(file2_fd);
- safe_close(dir1_fd);
- safe_close(dir1_fd2);
-
- pthread_exit(INT_TO_PTR(fret));
-}
-
-static int threaded_idmapped_mount_interactions(const struct vfstest_info *info)
-{
- int i;
- int fret = -1;
- pid_t pid;
- pthread_attr_t thread_attr;
- pthread_t threads[2];
-
- pthread_attr_init(&thread_attr);
-
- for (i = 0; i < 1000; i++) {
- int ret1 = 0, ret2 = 0, tret1 = 0, tret2 = 0;
-
- pid = fork();
- if (pid < 0) {
- log_stderr("failure: fork");
- goto out;
- }
- if (pid == 0) {
- int open_tree_fd = -EBADF;
- struct threaded_args args = {
- .info = info,
- .open_tree_fd = -EBADF,
- };
-
- open_tree_fd = sys_open_tree(info->t_dir1_fd, "",
- AT_EMPTY_PATH |
- AT_NO_AUTOMOUNT |
- AT_SYMLINK_NOFOLLOW |
- OPEN_TREE_CLOEXEC |
- OPEN_TREE_CLONE);
- if (open_tree_fd < 0)
- die("failure: sys_open_tree");
-
- args.open_tree_fd = open_tree_fd;
-
- if (pthread_create(&threads[0], &thread_attr,
- idmapped_mount_create_cb,
- &args))
- die("failure: pthread_create");
-
- if (pthread_create(&threads[1], &thread_attr,
- idmapped_mount_operations_cb,
- &args))
- die("failure: pthread_create");
-
- ret1 = pthread_join(threads[0], INT_TO_PTR(tret1));
- ret2 = pthread_join(threads[1], INT_TO_PTR(tret2));
-
- if (ret1) {
- errno = ret1;
- die("failure: pthread_join");
- }
-
- if (ret2) {
- errno = ret2;
- die("failure: pthread_join");
- }
-
- if (tret1 || tret2)
- exit(EXIT_FAILURE);
-
- exit(EXIT_SUCCESS);
-
- }
-
- if (wait_for_pid(pid)) {
- log_stderr("failure: iteration %d", i);
- goto out;
- }
-
- rm_r(info->t_dir1_fd, ".");
-
- }
-
- fret = 0;
- log_debug("Ran test");
-
-out:
- return fret;
-}
-
static int nested_userns(const struct vfstest_info *info)
{
int fret = -1;
@@ -7941,7 +7701,6 @@ static const struct test_struct t_idmapped_mounts[] = {
{ sticky_bit_rename_idmapped_mounts_in_userns, true, "sticky bit rename operations on idmapped mounts in user namespace", },
{ symlink_idmapped_mounts, true, "symlink from idmapped mounts", },
{ symlink_idmapped_mounts_in_userns, true, "symlink from idmapped mounts in user namespace", },
- { threaded_idmapped_mount_interactions, true, "threaded operations on idmapped mounts", },
};
const struct test_suite s_idmapped_mounts = {
diff --git a/src/vfs/vfstest.c b/src/vfs/vfstest.c
index 67aa3bda..29ac0bec 100644
--- a/src/vfs/vfstest.c
+++ b/src/vfs/vfstest.c
@@ -13,7 +13,6 @@
#include <limits.h>
#include <linux/limits.h>
#include <linux/types.h>
-#include <pthread.h>
#include <pwd.h>
#include <sched.h>
#include <stdbool.h>
--
2.34.1
