linux-next: manual merge of the userns tree with Linus' tree

From: Stephen Rothwell
Date: Tue Apr 08 2014 - 22:45:38 EST


Hi Eric,

Today's linux-next merge of the userns tree got a conflict in
fs/namespace.c between commits from Linus' tree and commits from the
userns tree.

I fixed it up (I used the conflict resolution that your sent to Linus -
see below) and can carry the fix as necessary (no action is required).

--
Cheers,
Stephen Rothwell sfr@xxxxxxxxxxxxxxxx

diff --cc fs/namespace.c
index 2ffc5a2905d4,52f4174e294c..000000000000
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@@ -665,13 -632,47 +666,47 @@@ struct vfsmount *lookup_mnt(struct pat
return m;
}

- static struct mountpoint *new_mountpoint(struct dentry *dentry)
+ /*
+ * __is_local_mountpoint - Test to see if dentry is a mountpoint in the
+ * current mount namespace.
+ *
+ * The common case is dentries are not mountpoints at all and that
+ * test is handled inline. For the slow case when we are actually
+ * dealing with a mountpoint of some kind, walk through all of the
+ * mounts in the current mount namespace and test to see if the dentry
+ * is a mountpoint.
+ *
+ * The mount_hashtable is not usable in the context because we
+ * need to identify all mounts that may be in the current mount
+ * namespace not just a mount that happens to have some specified
+ * parent mount.
+ */
+ bool __is_local_mountpoint(struct dentry *dentry)
+ {
+ struct mnt_namespace *ns = current->nsproxy->mnt_ns;
+ struct mount *mnt;
+ bool is_covered = false;
+
+ if (!d_mountpoint(dentry))
+ goto out;
+
+ down_read(&namespace_sem);
+ list_for_each_entry(mnt, &ns->list, mnt_list) {
+ is_covered = (mnt->mnt_mountpoint == dentry);
+ if (is_covered)
+ break;
+ }
+ up_read(&namespace_sem);
+ out:
+ return is_covered;
+ }
+
+ static struct mountpoint *lookup_mountpoint(struct dentry *dentry)
{
- struct list_head *chain = mountpoint_hashtable + hash(NULL, dentry);
+ struct hlist_head *chain = mp_hash(dentry);
struct mountpoint *mp;
- int ret;

- list_for_each_entry(mp, chain, m_hash) {
+ hlist_for_each_entry(mp, chain, m_hash) {
if (mp->m_dentry == dentry) {
/* might be worth a WARN_ON() */
if (d_unlinked(dentry))
@@@ -680,6 -681,14 +715,14 @@@
return mp;
}
}
+ return NULL;
+ }
+
+ static struct mountpoint *new_mountpoint(struct dentry *dentry)
+ {
- struct list_head *chain = mountpoint_hashtable + hash(NULL, dentry);
++ struct hlist_head *chain = mp_hash(dentry);
+ struct mountpoint *mp;
+ int ret;

mp = kmalloc(sizeof(struct mountpoint), GFP_KERNEL);
if (!mp)
@@@ -693,7 -702,8 +736,8 @@@

mp->m_dentry = dentry;
mp->m_count = 1;
- list_add(&mp->m_hash, chain);
+ hlist_add_head(&mp->m_hash, chain);
+ INIT_LIST_HEAD(&mp->m_list);
return mp;
}

@@@ -746,7 -757,8 +791,8 @@@ static void detach_mnt(struct mount *mn
mnt->mnt_parent = mnt;
mnt->mnt_mountpoint = mnt->mnt.mnt_root;
list_del_init(&mnt->mnt_child);
- list_del_init(&mnt->mnt_hash);
+ hlist_del_init_rcu(&mnt->mnt_hash);
+ list_del_init(&mnt->mnt_mp_list);
put_mountpoint(mnt->mnt_mp);
mnt->mnt_mp = NULL;
}

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