From 4ea2a8d84c75e20b4d9b5d9010879cdb89f2e384 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Tue, 28 Mar 2023 18:13:07 +0200 Subject: [PATCH] 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: Seth Forshee (DigitalOcean) Message-Id: <20230202-fs-move-mount-replace-v2-2-f53cd31d6392@kernel.org> Signed-off-by: Christian Brauner --- fs/pnode.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) diff --git a/fs/pnode.c b/fs/pnode.c index 468e4e6..3cede8b 100644 --- a/fs/pnode.c +++ b/fs/pnode.c @@ -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); -- 2.7.4