From: Al Viro <viro@zeniv.linux.org.uk> mainline inclusion from mainline-v6.17-rc1 commit 431cc1d8e2dab751b2b8f298a6d9caf83d8b49c3 category: cleanup bugzilla: https://atomgit.com/openeuler/kernel/issues/9218 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- mnt_set_mountpoint_beneath() consists of attaching new mount side-by-side with the one we want to mount beneath (by mnt_set_mountpoint()), followed by mnt_change_mountpoint() shifting the the top mount onto the new one (by mnt_change_mountpoint()). Both callers of mnt_set_mountpoint_beneath (both in attach_recursive_mnt()) have the same form - in 'beneath' case we call mnt_set_mountpoint_beneath(), otherwise - mnt_set_mountpoint(). The thing is, expressing that as unconditional mnt_set_mountpoint(), followed, in 'beneath' case, by mnt_change_mountpoint() is just as easy. And these mnt_change_mountpoint() callers are similar to the ones we do when it comes to attaching propagated copies, which will allow more cleanups in the next commits. Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Conflicts: fs/namespace.c [attach_recursive_mnt() has conflicts in move from anon. Commit 2eea9ce4310d ("mounts: keep list of mounts in an rbtree") has not been merged, not affect this patch.] Signed-off-by: Zizhi Wo <wozizhi@huawei.com> --- fs/namespace.c | 37 ++++--------------------------------- 1 file changed, 4 insertions(+), 33 deletions(-) diff --git a/fs/namespace.c b/fs/namespace.c index 8cb30a703db2..93e8b2cd3a24 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -928,37 +928,10 @@ void mnt_set_mountpoint(struct mount *mnt, child_mnt->mnt_parent = mnt; child_mnt->mnt_mp = mp; hlist_add_head(&child_mnt->mnt_mp_list, &mp->m_list); } -/** - * mnt_set_mountpoint_beneath - mount a mount beneath another one - * - * @new_parent: the source mount - * @top_mnt: the mount beneath which @new_parent is mounted - * @new_mp: the new mountpoint of @top_mnt on @new_parent - * - * Remove @top_mnt from its current mountpoint @top_mnt->mnt_mp and - * parent @top_mnt->mnt_parent and mount it on top of @new_parent at - * @new_mp. And mount @new_parent on the old parent and old - * mountpoint of @top_mnt. - * - * Context: This function expects namespace_lock() and lock_mount_hash() - * to have been acquired in that order. - */ -static void mnt_set_mountpoint_beneath(struct mount *new_parent, - struct mount *top_mnt, - struct mountpoint *new_mp) -{ - struct mount *old_top_parent = top_mnt->mnt_parent; - struct mountpoint *old_top_mp = top_mnt->mnt_mp; - - mnt_set_mountpoint(old_top_parent, old_top_mp, new_parent); - mnt_change_mountpoint(new_parent, new_mp, top_mnt); -} - - static void __attach_mnt(struct mount *mnt, struct mount *parent) { hlist_add_head_rcu(&mnt->mnt_hash, m_hash(&parent->mnt, mnt->mnt_mountpoint)); list_add_tail(&mnt->mnt_child, &parent->mnt_mounts); @@ -2334,25 +2307,23 @@ static int attach_recursive_mnt(struct mount *source_mnt, set_mnt_shared(p); } if (moving) { unhash_mnt(source_mnt); + mnt_set_mountpoint(dest_mnt, dest_mp, source_mnt); if (beneath) - mnt_set_mountpoint_beneath(source_mnt, top_mnt, smp); - else - mnt_set_mountpoint(top_mnt, dest_mp, source_mnt); + mnt_change_mountpoint(source_mnt, smp, top_mnt); __attach_mnt(source_mnt, source_mnt->mnt_parent); touch_mnt_namespace(source_mnt->mnt_ns); } else { if (source_mnt->mnt_ns) { /* move from anon - the caller will destroy */ list_del_init(&source_mnt->mnt_ns->list); } + mnt_set_mountpoint(dest_mnt, dest_mp, source_mnt); if (beneath) - mnt_set_mountpoint_beneath(source_mnt, top_mnt, smp); - else - mnt_set_mountpoint(dest_mnt, dest_mp, source_mnt); + mnt_change_mountpoint(source_mnt, smp, top_mnt); commit_tree(source_mnt); } hlist_for_each_entry_safe(child, n, &tree_list, mnt_hash) { struct mount *q; -- 2.52.0