SymbX/systemd
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

mount-util: refactor make_mount_point_inode_from_xyz()

Browse Source 
This replaces make_mount_point_inode_from_stat() by
make_mount_point_inode_from_mode() and makes it take a single mode_t
rather than a "struct stat". Moreover, at an "atfd" style directory
parameter.

Then port all users over to new feature, and in particular make use of
the directory fd: use chase() to create and pin parent directories first where
needed.
This commit is contained in:
Lennart Poettering
2025-02-18 13:49:24 +01:00
parent 8e0193aabf
commit 3075ea0bc9
4 changed files with 43 additions and 35 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/shared/mount-util.c
+26 -24
View File
@@ -958,10 +958,7 @@ static int mount_in_namespace_legacy(
/* Second, we mount the source file or directory to a directory inside of our MS_SLAVE playground. */
mount_tmp = strjoina(mount_slave, "/mount");
if (flags & MOUNT_IN_NAMESPACE_IS_IMAGE)
r = mkdir_p(mount_tmp, 0700);
else
r = make_mount_point_inode_from_stat(chased_src_st, mount_tmp, 0700);
r = make_mount_point_inode_from_mode(AT_FDCWD, mount_tmp, (flags & MOUNT_IN_NAMESPACE_IS_IMAGE) ? S_IFDIR : chased_src_st->st_mode, 0700);
if (r < 0) {
log_debug_errno(r, "Failed to create temporary mount point %s: %m", mount_tmp);
goto finish;
@@ -1057,12 +1054,15 @@ static int mount_in_namespace_legacy(
errno_pipe_fd[0] = safe_close(errno_pipe_fd[0]);
if (flags & MOUNT_IN_NAMESPACE_MAKE_FILE_OR_DIRECTORY) {
if (!(flags & MOUNT_IN_NAMESPACE_IS_IMAGE)) {
(void) mkdir_parents(dest, 0755);
(void) make_mount_point_inode_from_stat(chased_src_st, dest, 0700);
} else
(void) mkdir_p(dest, 0755);
_cleanup_close_ int dest_fd = -EBADF;
_cleanup_free_ char *dest_fn = NULL;
r = chase(dest, /* root= */ NULL, CHASE_PARENT|CHASE_EXTRACT_FILENAME|((flags & MOUNT_IN_NAMESPACE_MAKE_FILE_OR_DIRECTORY) ? CHASE_MKDIR_0755 : 0), &dest_fn, &dest_fd);
if (r < 0)
log_debug_errno(r, "Failed to pin parent directory of mount '%s', ignoring: %m", dest);
else if (flags & MOUNT_IN_NAMESPACE_MAKE_FILE_OR_DIRECTORY) {
r = make_mount_point_inode_from_mode(dest_fd, dest_fn, (flags & MOUNT_IN_NAMESPACE_IS_IMAGE) ? S_IFDIR : chased_src_st->st_mode, 0700);
if (r < 0)
log_debug_errno(r, "Failed to make mount point inode of mount '%s', ignoring: %m", dest);
}
/* Fifth, move the mount to the right place inside */
@@ -1076,7 +1076,7 @@ static int mount_in_namespace_legacy(
if (!mount_inside)
report_errno_and_exit(errno_pipe_fd[1], log_oom_debug());
r = mount_nofollow_verbose(LOG_DEBUG, mount_inside, dest, NULL, MS_MOVE, NULL);
r = mount_nofollow_verbose(LOG_DEBUG, mount_inside, dest_fd >= 0 ? FORMAT_PROC_FD_PATH(dest_fd) : dest, /* fstype= */ NULL, MS_MOVE, /* options= */ NULL);
if (r < 0)
report_errno_and_exit(errno_pipe_fd[1], r);
@@ -1247,8 +1247,14 @@ static int mount_in_namespace(
if (r == 0) {
errno_pipe_fd[0] = safe_close(errno_pipe_fd[0]);
_cleanup_close_ int dest_fd = -EBADF;
_cleanup_free_ char *dest_fn = NULL;
r = chase(dest, /* root= */ NULL, CHASE_PARENT|CHASE_EXTRACT_FILENAME|((flags & MOUNT_IN_NAMESPACE_MAKE_FILE_OR_DIRECTORY) ? CHASE_MKDIR_0755 : 0), &dest_fn, &dest_fd);
if (r < 0)
report_errno_and_exit(errno_pipe_fd[1], r);
if (flags & MOUNT_IN_NAMESPACE_MAKE_FILE_OR_DIRECTORY)
(void) mkdir_parents(dest, 0755);
(void) make_mount_point_inode_from_mode(dest_fd, dest_fn, img ? S_IFDIR : st.st_mode, 0700);
if (img) {
DissectImageFlags f =
@@ -1268,12 +1274,8 @@ static int mount_in_namespace(
/* uid_range= */ UID_INVALID,
/* userns_fd= */ -EBADF,
f);
} else {
if (flags & MOUNT_IN_NAMESPACE_MAKE_FILE_OR_DIRECTORY)
(void) make_mount_point_inode_from_stat(&st, dest, 0700);
} else
r = mount_exchange_graceful(new_mount_fd, dest, /* mount_beneath= */ true);
}
report_errno_and_exit(errno_pipe_fd[1], r);
}
@@ -1698,17 +1700,17 @@ int bind_mount_submounts(
return ret;
}
int make_mount_point_inode_from_stat(const struct stat *st, const char *dest, mode_t mode) {
assert(st);
int make_mount_point_inode_from_mode(int dir_fd, const char *dest, mode_t source_mode, mode_t target_mode) {
assert(dir_fd >= 0 || dir_fd == AT_FDCWD);
assert(dest);
if (S_ISDIR(st->st_mode))
return mkdir_label(dest, mode);
if (S_ISDIR(source_mode))
return mkdirat_label(dir_fd, dest, target_mode & 07777);
else
return RET_NERRNO(mknod(dest, S_IFREG|(mode & ~0111), 0));
return RET_NERRNO(mknodat(dir_fd, dest, S_IFREG|(target_mode & 07666), 0)); /* Mask off X bit */
}
int make_mount_point_inode_from_path(const char *source, const char *dest, mode_t mode) {
int make_mount_point_inode_from_path(const char *source, const char *dest, mode_t access_mode) {
struct stat st;
assert(source);
@@ -1717,7 +1719,7 @@ int make_mount_point_inode_from_path(const char *source, const char *dest, mode_
if (stat(source, &st) < 0)
return -errno;
return make_mount_point_inode_from_stat(&st, dest, mode);
return make_mount_point_inode_from_mode(AT_FDCWD, dest, st.st_mode, access_mode);
}
int trigger_automount_at(int dir_fd, const char *path) {
src/shared/mount-util.h
+2 -2
View File
@@ -178,8 +178,8 @@ int bind_mount_submounts(
const char *source,
const char *target);
/* Creates a mount point (not parents) based on the source path or stat - ie, a file or a directory */
int make_mount_point_inode_from_stat(const struct stat *st, const char *dest, mode_t mode);
/* Creates a mount point (without any parents) based on the source path or mode - i.e., a file or a directory */
int make_mount_point_inode_from_mode(int dir_fd, const char *dest, mode_t source_mode, mode_t target_mode);
int make_mount_point_inode_from_path(const char *source, const char *dest, mode_t mode);
int trigger_automount_at(int dir_fd, const char *path);
src/sysext/sysext.c
+13 -7
View File
@@ -297,22 +297,28 @@ static int move_submounts(const char *src, const char *dst) {
assert_se(suffix = path_startswith(m->path, src));
if (fstat(m->mount_fd, &st) < 0)
return log_error_errno(errno, "Failed to stat %s: %m", m->path);
t = path_join(dst, suffix);
if (!t)
return log_oom();
if (fstat(m->mount_fd, &st) < 0)
return log_error_errno(errno, "Failed to stat %s: %m", m->path);
r = mkdir_parents(t, 0755);
_cleanup_free_ char *fn = NULL;
_cleanup_close_ int fd = -EBADF;
r = chase(t, /* root= */ NULL, CHASE_PARENT|CHASE_EXTRACT_FILENAME|CHASE_PROHIBIT_SYMLINKS|CHASE_MKDIR_0755, &fn, &fd);
if (r < 0)
return log_error_errno(r, "Failed to create parent directories of %s: %m", t);
return log_error_errno(r, "Failed to create and pin parent directory of %s: %m", t);
r = make_mount_point_inode_from_stat(&st, t, 0755);
r = make_mount_point_inode_from_mode(fd, fn, st.st_mode, 0755);
if (r < 0 && r != -EEXIST)
return log_error_errno(r, "Failed to create mountpoint %s: %m", t);
r = mount_follow_verbose(LOG_ERR, m->path, t, NULL, MS_BIND|MS_REC, NULL);
_cleanup_close_ int child_fd = openat(fd, fn, O_PATH|O_CLOEXEC);
if (child_fd < 0)
return log_error_errno(errno, "Failed to pin mountpoint %s: %m", t);
r = mount_follow_verbose(LOG_ERR, m->path, FORMAT_PROC_FD_PATH(child_fd), /* fstype= */ NULL, MS_BIND|MS_REC, /* options= */ NULL);
if (r < 0)
return r;
src/test/test-mount-util.c
+2 -2
View File
@@ -266,9 +266,9 @@ TEST(make_mount_point_inode) {
assert_se(rmdir(dst_dir) == 0);
assert_se(stat(src_file, &st) == 0);
assert_se(make_mount_point_inode_from_stat(&st, dst_file, 0755) >= 0);
assert_se(make_mount_point_inode_from_mode(AT_FDCWD, dst_file, st.st_mode, 0755) >= 0);
assert_se(stat(src_dir, &st) == 0);
assert_se(make_mount_point_inode_from_stat(&st, dst_dir, 0755) >= 0);
assert_se(make_mount_point_inode_from_mode(AT_FDCWD, dst_dir, st.st_mode, 0755) >= 0);
assert_se(stat(dst_dir, &st) == 0);
assert_se(S_ISDIR(st.st_mode));