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) <sforshee@kernel.org>
Message-Id: <20230202-fs-move-mount-replace-v2-2-f53cd31d6392@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
This commit is contained in:
Christian Brauner 2023-03-28 18:13:07 +02:00
parent 113348a44b
commit 4ea2a8d84c
No known key found for this signature in database
GPG Key ID: 91C61BC06578DCA2

View File

@ -214,7 +214,6 @@ static struct mount *next_group(struct mount *m, struct mount *origin)
/* all accesses are serialized by namespace_sem */ /* all accesses are serialized by namespace_sem */
static struct mount *last_dest, *first_source, *last_source, *dest_master; static struct mount *last_dest, *first_source, *last_source, *dest_master;
static struct mountpoint *mp;
static struct hlist_head *list; static struct hlist_head *list;
static inline bool peers(struct mount *m1, struct mount *m2) 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; 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; struct mount *child;
int type; int type;
@ -230,7 +229,7 @@ static int propagate_one(struct mount *m)
if (IS_MNT_NEW(m)) if (IS_MNT_NEW(m))
return 0; return 0;
/* skip if mountpoint isn't covered by it */ /* 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; return 0;
if (peers(m, last_dest)) { if (peers(m, last_dest)) {
type = CL_MAKE_SHARED; type = CL_MAKE_SHARED;
@ -262,7 +261,7 @@ static int propagate_one(struct mount *m)
if (IS_ERR(child)) if (IS_ERR(child))
return PTR_ERR(child); return PTR_ERR(child);
read_seqlock_excl(&mount_lock); read_seqlock_excl(&mount_lock);
mnt_set_mountpoint(m, mp, child); mnt_set_mountpoint(m, dest_mp, child);
if (m->mnt_master != dest_master) if (m->mnt_master != dest_master)
SET_MNT_MARK(m->mnt_master); SET_MNT_MARK(m->mnt_master);
read_sequnlock_excl(&mount_lock); read_sequnlock_excl(&mount_lock);
@ -299,13 +298,12 @@ int propagate_mnt(struct mount *dest_mnt, struct mountpoint *dest_mp,
last_dest = dest_mnt; last_dest = dest_mnt;
first_source = source_mnt; first_source = source_mnt;
last_source = source_mnt; last_source = source_mnt;
mp = dest_mp;
list = tree_list; list = tree_list;
dest_master = dest_mnt->mnt_master; dest_master = dest_mnt->mnt_master;
/* all peers of dest_mnt, except dest_mnt itself */ /* all peers of dest_mnt, except dest_mnt itself */
for (n = next_peer(dest_mnt); n != dest_mnt; n = next_peer(n)) { 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) if (ret)
goto out; goto out;
} }
@ -316,7 +314,7 @@ int propagate_mnt(struct mount *dest_mnt, struct mountpoint *dest_mp,
/* everything in that slave group */ /* everything in that slave group */
n = m; n = m;
do { do {
ret = propagate_one(n); ret = propagate_one(n, dest_mp);
if (ret) if (ret)
goto out; goto out;
n = next_peer(n); n = next_peer(n);