[PATCH 10/17] namespace.c: get rid of mnt_ghosts

From: Al Viro
Date: Thu Oct 03 2013 - 02:19:13 EST



Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
fs/mount.h | 2 +-
fs/namespace.c | 22 +++++++---------------
fs/pnode.c | 3 +--
3 files changed, 9 insertions(+), 18 deletions(-)

diff --git a/fs/mount.h b/fs/mount.h
index 64a8581..3168dc4 100644
--- a/fs/mount.h
+++ b/fs/mount.h
@@ -55,7 +55,7 @@ struct mount {
int mnt_group_id; /* peer group identifier */
int mnt_expiry_mark; /* true if marked for expiry */
int mnt_pinned;
- int mnt_ghosts;
+ struct path mnt_ex_mountpoint;
};

#define MNT_NS_INTERNAL ERR_PTR(-EINVAL) /* distinct from any mnt_namespace */
diff --git a/fs/namespace.c b/fs/namespace.c
index 632c551..6985d52 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1136,20 +1136,8 @@ static void namespace_unlock(void)
while (!list_empty(&head)) {
mnt = list_first_entry(&head, struct mount, mnt_hash);
list_del_init(&mnt->mnt_hash);
- if (mnt_has_parent(mnt)) {
- struct dentry *dentry;
- struct mount *m;
-
- br_write_lock(&vfsmount_lock);
- dentry = mnt->mnt_mountpoint;
- m = mnt->mnt_parent;
- mnt->mnt_mountpoint = mnt->mnt.mnt_root;
- mnt->mnt_parent = mnt;
- m->mnt_ghosts--;
- br_write_unlock(&vfsmount_lock);
- dput(dentry);
- mntput(&m->mnt);
- }
+ if (mnt->mnt_ex_mountpoint.mnt)
+ path_put(&mnt->mnt_ex_mountpoint);
mntput(&mnt->mnt);
}
}
@@ -1181,8 +1169,12 @@ void umount_tree(struct mount *mnt, int propagate)
p->mnt_ns = NULL;
list_del_init(&p->mnt_child);
if (mnt_has_parent(p)) {
- p->mnt_parent->mnt_ghosts++;
put_mountpoint(p->mnt_mp);
+ /* move the reference to mountpoint into ->mnt_ex_mountpoint */
+ p->mnt_ex_mountpoint.dentry = p->mnt_mountpoint;
+ p->mnt_ex_mountpoint.mnt = &p->mnt_parent->mnt;
+ p->mnt_mountpoint = p->mnt.mnt_root;
+ p->mnt_parent = p;
p->mnt_mp = NULL;
}
change_mnt_propagation(p, MS_PRIVATE);
diff --git a/fs/pnode.c b/fs/pnode.c
index 9af0df1..3cfd48c 100644
--- a/fs/pnode.c
+++ b/fs/pnode.c
@@ -278,8 +278,7 @@ out:
*/
static inline int do_refcount_check(struct mount *mnt, int count)
{
- int mycount = mnt_get_count(mnt) - mnt->mnt_ghosts;
- return (mycount > count);
+ return mnt_get_count(mnt) > count;
}

/*
--
1.7.2.5


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