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| author | Karel Zak <kzak@redhat.com> | 2022-05-25 14:01:52 +0200 |
|---|---|---|
| committer | Karel Zak <kzak@redhat.com> | 2023-01-03 12:53:12 +0100 |
| commit | b0a165dc76c024614a930325877a25555d4ff819 (patch) | |
| tree | 3aeb54c393c16da209ee34f012e63ef6f45403d9 /libmount/src/utils.c | |
| parent | 17de67aa1d7dee8cb8ea3040867a989af44a8243 (diff) | |
| download | util-linux-b0a165dc76c024614a930325877a25555d4ff819.tar.gz | |
libmount: reimplement X-mount.subdir= by hooks
* "prepare-target hook" checks for X-mount.subdir= and define pre-mount hook
* "mount-pre hook" unshares temporary directory, redirect the next
mount(2) to this temporary directory
* "mount-post hook" binds subdirectory to the final target, umounts
temporary directory
Signed-off-by: Karel Zak <kzak@redhat.com>
Diffstat (limited to 'libmount/src/utils.c')
| -rw-r--r-- | libmount/src/utils.c | 73 |
1 files changed, 0 insertions, 73 deletions
diff --git a/libmount/src/utils.c b/libmount/src/utils.c index 5693cf8adf..26c5aef7b1 100644 --- a/libmount/src/utils.c +++ b/libmount/src/utils.c @@ -1240,79 +1240,6 @@ done: return 1; } -/* - * Initialize MNT_PATH_TMPTGT; mkdir, create a new namespace and - * mark (bind mount) the directory as private. - */ -int mnt_tmptgt_unshare(int *old_ns_fd) -{ -#ifdef USE_LIBMOUNT_SUPPORT_NAMESPACES - int rc = 0, fd = -1; - - assert(old_ns_fd); - - *old_ns_fd = -1; - - /* remember the current namespace */ - fd = open("/proc/self/ns/mnt", O_RDONLY | O_CLOEXEC); - if (fd < 0) - goto fail; - - /* create new namespace */ - if (unshare(CLONE_NEWNS) != 0) - goto fail; - - /* create directory */ - rc = ul_mkdir_p(MNT_PATH_TMPTGT, S_IRWXU); - if (rc) - goto fail; - - /* try to set top-level directory as private, this is possible if - * MNT_RUNTIME_TOPDIR (/run) is a separated filesystem. */ - if (mount("none", MNT_RUNTIME_TOPDIR, NULL, MS_PRIVATE, NULL) != 0) { - - /* failed; create a mountpoint from MNT_PATH_TMPTGT */ - if (mount(MNT_PATH_TMPTGT, MNT_PATH_TMPTGT, "none", MS_BIND, NULL) != 0) - goto fail; - if (mount("none", MNT_PATH_TMPTGT, NULL, MS_PRIVATE, NULL) != 0) - goto fail; - } - - DBG(UTILS, ul_debug(MNT_PATH_TMPTGT " unshared")); - *old_ns_fd = fd; - return 0; -fail: - if (rc == 0) - rc = errno ? -errno : -EINVAL; - - mnt_tmptgt_cleanup(fd); - DBG(UTILS, ul_debug(MNT_PATH_TMPTGT " unshare failed")); - return rc; -#else - return -ENOSYS; -#endif -} - -/* - * Clean up MNT_PATH_TMPTGT; umount and switch back to old namespace - */ -int mnt_tmptgt_cleanup(int old_ns_fd) -{ -#ifdef USE_LIBMOUNT_SUPPORT_NAMESPACES - umount(MNT_PATH_TMPTGT); - - if (old_ns_fd >= 0) { - setns(old_ns_fd, CLONE_NEWNS); - close(old_ns_fd); - } - - DBG(UTILS, ul_debug(MNT_PATH_TMPTGT " cleanup done")); - return 0; -#else - return -ENOSYS; -#endif -} - #ifdef TEST_PROGRAM static int test_match_fstype(struct libmnt_test *ts, int argc, char *argv[]) { |