return mnt_context_get_hookset_data(cxt, hs);
}
-static int set_vfs_flags(int fd, struct libmnt_context *cxt, int recursive)
+static int hook_reconfigure_mount(struct libmnt_context *cxt __attribute__((__unused__)),
+ const struct libmnt_hookset *hs __attribute__((__unused__)),
+ void *data __attribute__((__unused__)))
+{
+ return 0;
+}
+
+static int hook_create_mount(struct libmnt_context *cxt __attribute__((__unused__)),
+ const struct libmnt_hookset *hs __attribute__((__unused__)),
+ void *data __attribute__((__unused__)))
+{
+ return 0;
+}
+
+static int hook_set_vfsflags(struct libmnt_context *cxt,
+ const struct libmnt_hookset *hs,
+ void *data __attribute__((__unused__)))
{
+ struct libmnt_sysapi *api;
struct libmnt_optlist *ol;
struct mount_attr attr = { .attr_clr = 0 };
unsigned int callflags = AT_EMPTY_PATH;
uint64_t mask = 0;
int rc;
- ol= mnt_context_get_optlist(cxt);
+ api = get_sysapi(cxt, hs);
+ assert(api);
+ assert(api->fd_tree >= 0);
+
+ ol = mnt_context_get_optlist(cxt);
if (!ol)
return -ENOMEM;
- mnt_optlist_get_attrs(ol, &mask);
- attr.attr_set = mask;
- if (recursive)
+ rc = mnt_optlist_get_attrs(ol, &mask);
+ if (rc)
+ return rc;
+
+ if (mnt_optlist_is_rbind(ol))
callflags |= AT_RECURSIVE;
- DBG(HOOK, ul_debug(" mount_setattr(set=0x%" PRIx64")", mask));
- rc = mount_setattr(fd, "", callflags, &attr, sizeof(attr));
+ DBG(HOOK, ul_debugobj(hs, "mount_setattr(set=0x%" PRIx64")", mask));
+ attr.attr_set = mask;
+
+ rc = mount_setattr(api->fd_tree, "", callflags, &attr, sizeof(attr));
set_syscall_status(cxt, "move_setattr", rc == 0);
return rc == 0 ? 0 : -errno;
}
-static int is_recursive_bind(struct libmnt_context *cxt)
+static int hook_set_propagation(struct libmnt_context *cxt __attribute__((__unused__)),
+ const struct libmnt_hookset *hs __attribute__((__unused__)),
+ void *data __attribute__((__unused__)))
{
- struct libmnt_optlist *ol = mnt_context_get_optlist(cxt);
-
- if (!ol)
- return 0;
-
- return mnt_optlist_is_rbind(ol);
+ return 0;
}
static int hook_attach_target(struct libmnt_context *cxt,
const char *target;
int rc;
- DBG(HOOK, ul_debugobj(hs, "attach"));
-
target = mnt_fs_get_target(cxt->fs);
if (!target)
return -EINVAL;
api = get_sysapi(cxt, hs);
- if (!api || api->fd_tree <= 0)
- return -EINVAL;
+ assert(api);
+ assert(api->fd_tree >= 0);
- DBG(HOOK, ul_debugobj(hs, " move_mount(to=%s)", target));
+ DBG(HOOK, ul_debugobj(hs, "move_mount(to=%s)", target));
rc = move_mount(api->fd_tree, "", AT_FDCWD, target, MOVE_MOUNT_F_EMPTY_PATH);
set_syscall_status(cxt, "move_mount", rc == 0);
return rc == 0 ? 0 : -errno;
}
-static int hook_bind_setflags(struct libmnt_context *cxt,
- const struct libmnt_hookset *hs,
- void *data __attribute__((__unused__)))
-{
- struct libmnt_sysapi *api;
- int rc;
-
- DBG(HOOK, ul_debugobj(hs, "bind: setting VFS"));
-
- api = get_sysapi(cxt, hs);
- if (!api || api->fd_tree <= 0)
- return -EINVAL;
-
- rc = set_vfs_flags(api->fd_tree, cxt, is_recursive_bind(cxt));
- if (rc)
- return rc;
-
- return mnt_context_append_hook(cxt, hs,
- MNT_STAGE_MOUNT_POST, NULL, hook_attach_target);
-}
-
-/*
-static int hook_remount(struct libmnt_context *cxt,
- const struct libmnt_hookset *hs, void *data)
-{
- return 0;
-}
-
-
-static int hook_move(struct libmnt_context *cxt,
- const struct libmnt_hookset *hs, void *data)
-{
- return 0;
-}
-
-static int hook_propagation(struct libmnt_context *cxt,
- const struct libmnt_hookset *hs, void *data)
-{
- return 0;
-}
-
-static int hook_newmount(struct libmnt_context *cxt,
- const struct libmnt_hookset *hs, void *data)
-{
- return 0;
-}
-*/
-
/*
- * analyze library context and register hook to call mount-like syscalls
+ * open_tree() and fsopen()
*/
-static int hook_prepare(struct libmnt_context *cxt,
- const struct libmnt_hookset *hs,
- void *data __attribute__((__unused__)))
+static int init_sysapi(struct libmnt_context *cxt,
+ const struct libmnt_hookset *hs,
+ unsigned long flags)
{
- int rc = 0, next_stage = 0;
- int (*next_hook)(struct libmnt_context *, const struct libmnt_hookset *, void *) = NULL;
- unsigned long flags = 0, open_flags = 0;
- const char *tree_path = NULL, *src = NULL, *target = NULL;
struct libmnt_sysapi *api;
+ const char *path = NULL;
assert(cxt);
- assert(hs == &hookset_mount);
+ assert(hs);
- DBG(HOOK, ul_debugobj(hs, "prepare new API mount"));
-
- target = mnt_fs_get_target(cxt->fs);
- if (!target)
- return -EINVAL;
-
- src = mnt_fs_get_srcpath(cxt->fs);
+ /* A) tree based operation -- the tree is mount source */
+ if ((flags & MS_BIND)
+ || (flags & MS_MOVE)) {
+ path = mnt_fs_get_srcpath(cxt->fs);
+ if (!path)
+ return -EINVAL;
- rc = mnt_context_get_mflags(cxt, &flags);
- if (rc)
- return rc;
+ /* B) tree based operation -- the tree is mount point */
+ } else if ((flags & MS_REMOUNT)
+ || mnt_context_propagation_only(cxt)) {
+ path = mnt_fs_get_target(cxt->fs);
+ if (!path)
+ return -EINVAL;
+ }
api = new_hookset_data(cxt, hs);
if (!api)
return -ENOMEM;
- open_flags = OPEN_TREE_CLOEXEC;
-
- if (flags & MS_REMOUNT) {
- DBG(HOOK, ul_debugobj(hs, " prepare remount"));
- tree_path = target;
- next_stage = MNT_STAGE_MOUNT;
- /*next_hook = hook_remount;*/
-
- } else if (flags & MS_BIND) {
- DBG(HOOK, ul_debugobj(hs, " prepare bind"));
- tree_path = src;
- if (flags & MNT_BIND_SETTABLE) { /* -obind,ro */
- next_stage = MNT_STAGE_MOUNT;
- next_hook = hook_bind_setflags;
- } else {
- next_stage = MNT_STAGE_MOUNT_POST; /* only bind */
- next_hook = hook_attach_target;
- }
- open_flags |= OPEN_TREE_CLONE;
- if (is_recursive_bind(cxt))
- open_flags |= AT_RECURSIVE;
-
- } else if (flags & MS_MOVE) {
- DBG(HOOK, ul_debugobj(hs, " prepare move"));
- tree_path = src;
- next_stage = MNT_STAGE_MOUNT_POST;
- next_hook = hook_attach_target;
-
- } else if (mnt_context_propagation_only(cxt)) {
- DBG(HOOK, ul_debugobj(hs, " prepare propagation change"));
- tree_path = target;
- next_stage = MNT_STAGE_MOUNT_POST;
- /*next_hook = hook_propagation;*/
+ if (path) {
+ unsigned long oflg = OPEN_TREE_CLOEXEC;
- } else {
- const char *type;
+ /* TODO
+ if (mnt_context_is_recursive(cxt))
+ oflg |= AT_RECURSIVE;
+ */
+ if (flags & MS_BIND)
+ oflg |= OPEN_TREE_CLONE;
- DBG(HOOK, ul_debugobj(hs, " prepare mount"));
- next_stage = MNT_STAGE_MOUNT;
- /*next_hook = hook_newmount;*/
+ DBG(HOOK, ul_debugobj(hs, "open_tree(%s)", path));
+ if (mnt_context_is_fake(cxt))
+ goto fake;
+
+ api->fd_tree = open_tree(AT_FDCWD, path, oflg);
+ set_syscall_status(cxt, "open_tree", api->fd_tree >= 0);
+ if (api->fd_tree <= 0)
+ goto fail;
+
+ /* C) FS based operation */
+ } else {
+ const char *type = mnt_fs_get_fstype(cxt->fs);
- type = mnt_fs_get_fstype(cxt->fs);
if (!type)
return -EINVAL;
-
if (mnt_context_is_fake(cxt))
goto fake;
DBG(HOOK, ul_debugobj(hs, "fsopen(%s)", type));
+ if (mnt_context_is_fake(cxt))
+ goto fake;
+
api->fd_fs = fsopen(type, FSOPEN_CLOEXEC);
- set_syscall_status(cxt, "fsopen", api->fd_fs >= 0);
+ set_syscall_status(cxt, "fsopen", api->fd_fs >= 0);
if (api->fd_fs < 0)
- goto nothing;
- }
-
- if (mnt_context_is_fake(cxt))
- goto fake;
-
- if (api->fd_fs == -1) {
- if (!tree_path) {
- DBG(HOOK, ul_debugobj(hs, "tree path undefined"));
- return -EINVAL;
- }
- DBG(HOOK, ul_debugobj(hs, "open_tree(path=%s, flags=0x%lx)",
- tree_path, open_flags));
- api->fd_tree = open_tree(AT_FDCWD, tree_path, open_flags);
- set_syscall_status(cxt, "open_tree", api->fd_tree >= 0);
-
- if (api->fd_tree <= 0)
- goto nothing;
+ goto fail;
}
- return mnt_context_append_hook(cxt, hs, next_stage, NULL, next_hook);
-nothing:
- /* let's assume that fsopen/open_tree() is not supported */
- DBG(HOOK, ul_debugobj(hs, " open fs/tree failed [errno=%d %m]", errno));
- free_hookset_data(cxt, hs);
return 0;
+fail:
+ DBG(HOOK, ul_debugobj(hs, "init fs/tree failed [errno=%d %m]", errno));
+ return -errno;
fake:
- DBG(CXT, ul_debugobj(cxt, " FAKE (-f)"));
+ DBG(CXT, ul_debugobj(cxt, " FAKE (-f)"));
cxt->syscall_status = 0;
return 0;
}
+/*
+ * Analyze library context and register hook to call mount-like syscalls.
+ *
+ * Note that this function interprets classic MS_* flags by new Linux mount FD
+ * based API.
+ */
+static int hook_prepare(struct libmnt_context *cxt,
+ const struct libmnt_hookset *hs,
+ void *data __attribute__((__unused__)))
+{
+ struct libmnt_optlist *ol;
+ unsigned long flags = 0;
+ uint64_t attrs = 0;
+ int rc = 0;
+
+ assert(cxt);
+ assert(hs == &hookset_mount);
+
+ DBG(HOOK, ul_debugobj(hs, "prepare mount"));
+
+ ol = mnt_context_get_optlist(cxt);
+ if (!ol)
+ return -ENOMEM;
+
+ /* classic MS_* flags (include oprations like MS_REMOUNT, etc) */
+ rc = mnt_optlist_get_flags(ol, &flags, cxt->map_linux, 0);
+
+ /* MOUNT_ATTR_* flags for mount_setattr() */
+ if (!rc)
+ rc = mnt_optlist_get_attrs(ol, &attrs);
+
+ /* open_tree() or fsopen() */
+ if (!rc)
+ rc = init_sysapi(cxt, hs, flags);
+
+ /* check mutually exclusive operations */
+ if (!rc && (flags & MS_BIND) && (flags & MS_MOVE))
+ return -EINVAL;
+ if (!rc && (flags & MS_MOVE) && (flags & MS_REMOUNT))
+ return -EINVAL;
+
+ /* classic remount (note -oremount,bind,ro is handled as bind) */
+ if (!rc && (flags & MS_REMOUNT) && !(flags & MS_BIND))
+ rc = mnt_context_append_hook(cxt, hs, MNT_STAGE_MOUNT, NULL,
+ hook_reconfigure_mount);
+
+ /* call mount_setattr() */
+ if (!rc && attrs != 0)
+ rc = mnt_context_append_hook(cxt, hs, MNT_STAGE_MOUNT, NULL,
+ hook_set_vfsflags);
+
+ /* create a new FS instance */
+ if (!rc
+ && !(flags & MS_BIND)
+ && !(flags & MS_MOVE)
+ && !(flags & MS_REMOUNT)
+ && !mnt_optlist_is_propagation_only(ol))
+ rc = mnt_context_append_hook(cxt, hs, MNT_STAGE_MOUNT, NULL,
+ hook_create_mount);
+
+ /* call move_mount() to attach target */
+ if (!rc
+ && !(flags & MS_REMOUNT)
+ && !mnt_context_propagation_only(cxt))
+ rc = mnt_context_append_hook(cxt, hs, MNT_STAGE_MOUNT_POST, NULL,
+ hook_attach_target);
+
+ /* set propagation (has to be attached to VFS) */
+ if (!rc && mnt_optlist_get_propagation(ol) != 0)
+ rc = mnt_context_append_hook(cxt, hs, MNT_STAGE_MOUNT_POST, NULL,
+ hook_set_propagation);
+
+ DBG(HOOK, ul_debugobj(hs, "prepare mount done [rc=%d]", rc));
+ return rc;
+}
+
const struct libmnt_hookset hookset_mount =
{
.name = "__mount",
projects / thirdparty / util-linux.git / commitdiff
