Unverified Commit 4ea2a8d8 authored by Christian Brauner's avatar Christian Brauner
Browse files

pnode: pass mountpoint directly 



Currently, we use a global variable to stash the destination
mountpoint. All global variables are changed in propagate_one(). The
mountpoint variable is one of the few which doesn't change after
initialization. Instead, just pass the destination mountpoint directly
making it easy to verify directly in propagate_mnt() that the
destination mountpoint never changes.

Reviewed-by: default avatarSeth Forshee (DigitalOcean) <sforshee@kernel.org>
Message-Id: <20230202-fs-move-mount-replace-v2-2-f53cd31d6392@kernel.org>
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent 113348a4

fs/pnode.c

+5 −7
Original line number Diff line number Diff line
@@ -214,7 +214,6 @@ static struct mount *next_group(struct mount *m, struct mount *origin) 


/* all accesses are serialized by namespace_sem */

static struct mount *last_dest, *first_source, *last_source, *dest_master;

static struct mountpoint *mp;

static struct hlist_head *list;



static inline bool peers(struct mount *m1, struct mount *m2)
@@ -222,7 +221,7 @@ static inline bool peers(struct mount *m1, struct mount *m2) 
	return m1->mnt_group_id == m2->mnt_group_id && m1->mnt_group_id;

}



static int propagate_one(struct mount *m)

static int propagate_one(struct mount *m, struct mountpoint *dest_mp)

{

	struct mount *child;

	int type;
@@ -230,7 +229,7 @@ static int propagate_one(struct mount *m) 
	if (IS_MNT_NEW(m))

		return 0;

	/* skip if mountpoint isn't covered by it */

	if (!is_subdir(mp->m_dentry, m->mnt.mnt_root))

	if (!is_subdir(dest_mp->m_dentry, m->mnt.mnt_root))

		return 0;

	if (peers(m, last_dest)) {

		type = CL_MAKE_SHARED;
@@ -262,7 +261,7 @@ static int propagate_one(struct mount *m) 
	if (IS_ERR(child))

		return PTR_ERR(child);

	read_seqlock_excl(&mount_lock);

	mnt_set_mountpoint(m, mp, child);

	mnt_set_mountpoint(m, dest_mp, child);

	if (m->mnt_master != dest_master)

		SET_MNT_MARK(m->mnt_master);

	read_sequnlock_excl(&mount_lock);
@@ -299,13 +298,12 @@ int propagate_mnt(struct mount *dest_mnt, struct mountpoint *dest_mp, 
	last_dest = dest_mnt;

	first_source = source_mnt;

	last_source = source_mnt;

	mp = dest_mp;

	list = tree_list;

	dest_master = dest_mnt->mnt_master;



	/* all peers of dest_mnt, except dest_mnt itself */

	for (n = next_peer(dest_mnt); n != dest_mnt; n = next_peer(n)) {

		ret = propagate_one(n);

		ret = propagate_one(n, dest_mp);

		if (ret)

			goto out;

	}
@@ -316,7 +314,7 @@ int propagate_mnt(struct mount *dest_mnt, struct mountpoint *dest_mp, 
		/* everything in that slave group */

		n = m;

		do {

			ret = propagate_one(n);

			ret = propagate_one(n, dest_mp);

			if (ret)

				goto out;

			n = next_peer(n);