From: Miklos Szeredi <mszeredi@xxxxxxx>
Allow clone_mnt() to return errors other than ENOMEM. This will be used for
returning a different error value when the number of user mounts goes over the
limit.
Fix copy_tree() to return EPERM for unbindable mounts.
Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxx>
Acked-by: Serge Hallyn <serue@xxxxxxxxxx>
---
Index: linux/fs/namespace.c
===================================================================
--- linux.orig/fs/namespace.c 2008-01-16 13:25:06.000000000 +0100
+++ linux/fs/namespace.c 2008-01-16 13:25:07.000000000 +0100
@@ -490,41 +490,42 @@ static struct vfsmount *clone_mnt(struct
struct super_block *sb = old->mnt_sb;
struct vfsmount *mnt = alloc_vfsmnt(old->mnt_devname);
- if (mnt) {
- mnt->mnt_flags = old->mnt_flags;
- atomic_inc(&sb->s_active);
- mnt->mnt_sb = sb;
- mnt->mnt_root = dget(root);
- mnt->mnt_mountpoint = mnt->mnt_root;
- mnt->mnt_parent = mnt;
-
- /* don't copy the MNT_USER flag */
- mnt->mnt_flags &= ~MNT_USER;
- if (flag & CL_SETUSER)
- set_mnt_user(mnt);
-
- if (flag & CL_SLAVE) {
- list_add(&mnt->mnt_slave, &old->mnt_slave_list);
- mnt->mnt_master = old;
- CLEAR_MNT_SHARED(mnt);
- } else if (!(flag & CL_PRIVATE)) {
- if ((flag & CL_PROPAGATION) || IS_MNT_SHARED(old))
- list_add(&mnt->mnt_share, &old->mnt_share);
- if (IS_MNT_SLAVE(old))
- list_add(&mnt->mnt_slave, &old->mnt_slave);
- mnt->mnt_master = old->mnt_master;
- }
- if (flag & CL_MAKE_SHARED)
- set_mnt_shared(mnt);
+ if (!mnt)
+ return ERR_PTR(-ENOMEM);
- /* stick the duplicate mount on the same expiry list
- * as the original if that was on one */
- if (flag & CL_EXPIRE) {
- spin_lock(&vfsmount_lock);
- if (!list_empty(&old->mnt_expire))
- list_add(&mnt->mnt_expire, &old->mnt_expire);
- spin_unlock(&vfsmount_lock);
- }
+ mnt->mnt_flags = old->mnt_flags;
+ atomic_inc(&sb->s_active);
+ mnt->mnt_sb = sb;
+ mnt->mnt_root = dget(root);
+ mnt->mnt_mountpoint = mnt->mnt_root;
+ mnt->mnt_parent = mnt;
+
+ /* don't copy the MNT_USER flag */
+ mnt->mnt_flags &= ~MNT_USER;
+ if (flag & CL_SETUSER)
+ set_mnt_user(mnt);
+
+ if (flag & CL_SLAVE) {
+ list_add(&mnt->mnt_slave, &old->mnt_slave_list);
+ mnt->mnt_master = old;
+ CLEAR_MNT_SHARED(mnt);
+ } else if (!(flag & CL_PRIVATE)) {
+ if ((flag & CL_PROPAGATION) || IS_MNT_SHARED(old))
+ list_add(&mnt->mnt_share, &old->mnt_share);
+ if (IS_MNT_SLAVE(old))
+ list_add(&mnt->mnt_slave, &old->mnt_slave);
+ mnt->mnt_master = old->mnt_master;
+ }
+ if (flag & CL_MAKE_SHARED)
+ set_mnt_shared(mnt);
+
+ /* stick the duplicate mount on the same expiry list
+ * as the original if that was on one */
+ if (flag & CL_EXPIRE) {
+ spin_lock(&vfsmount_lock);
+ if (!list_empty(&old->mnt_expire))
+ list_add(&mnt->mnt_expire, &old->mnt_expire);
+ spin_unlock(&vfsmount_lock);
}
return mnt;
}
@@ -998,11 +999,11 @@ struct vfsmount *copy_tree(struct vfsmou
struct nameidata nd;
if (!(flag & CL_COPY_ALL) && IS_MNT_UNBINDABLE(mnt))
- return NULL;
+ return ERR_PTR(-EPERM);
res = q = clone_mnt(mnt, dentry, flag);
- if (!q)
- goto Enomem;
+ if (IS_ERR(q))
+ goto error;
q->mnt_mountpoint = mnt->mnt_mountpoint;
p = mnt;
@@ -1023,8 +1024,8 @@ struct vfsmount *copy_tree(struct vfsmou
nd.path.mnt = q;
nd.path.dentry = p->mnt_mountpoint;
q = clone_mnt(p, p->mnt_root, flag);
- if (!q)
- goto Enomem;
+ if (IS_ERR(q))
+ goto error;
spin_lock(&vfsmount_lock);
list_add_tail(&q->mnt_list, &res->mnt_list);
attach_mnt(q, &nd);
@@ -1032,7 +1033,7 @@ struct vfsmount *copy_tree(struct vfsmou
}
}
return res;
-Enomem:
+ error:
if (res) {
LIST_HEAD(umount_list);
spin_lock(&vfsmount_lock);
@@ -1040,7 +1041,7 @@ Enomem:
spin_unlock(&vfsmount_lock);
release_mounts(&umount_list);
}
- return NULL;
+ return q;
}
struct vfsmount *collect_mounts(struct vfsmount *mnt, struct dentry *dentry)
@@ -1239,13 +1240,13 @@ static int do_loopback(struct nameidata
goto out;
clone_fl = (flags & MS_SETUSER) ? CL_SETUSER : 0;
- err = -ENOMEM;
if (flags & MS_REC)
mnt = copy_tree(old_nd.path.mnt, old_nd.path.dentry, clone_fl);
else
mnt = clone_mnt(old_nd.path.mnt, old_nd.path.dentry, clone_fl);
- if (!mnt)
+ err = PTR_ERR(mnt);
+ if (IS_ERR(mnt))
goto out;
err = graft_tree(mnt, nd);
@@ -1816,10 +1817,10 @@ static struct mnt_namespace *dup_mnt_ns(
/* First pass: copy the tree topology */
new_ns->root = copy_tree(mnt_ns->root, mnt_ns->root->mnt_root,
CL_COPY_ALL | CL_EXPIRE);
- if (!new_ns->root) {
+ if (IS_ERR(new_ns->root)) {
up_write(&namespace_sem);
kfree(new_ns);
- return ERR_PTR(-ENOMEM);;
+ return ERR_CAST(new_ns->root);
}
spin_lock(&vfsmount_lock);
list_add_tail(&new_ns->list, &new_ns->root->mnt_list);
Index: linux/fs/pnode.c
===================================================================
--- linux.orig/fs/pnode.c 2008-01-16 13:24:53.000000000 +0100
+++ linux/fs/pnode.c 2008-01-16 13:25:07.000000000 +0100
@@ -189,8 +189,9 @@ int propagate_mnt(struct vfsmount *dest_
source = get_source(m, prev_dest_mnt, prev_src_mnt, &type);
- if (!(child = copy_tree(source, source->mnt_root, type))) {
- ret = -ENOMEM;
+ child = copy_tree(source, source->mnt_root, type);
+ if (IS_ERR(child)) {
+ ret = PTR_ERR(child);
list_splice(tree_list, tmp_list.prev);
goto out;
}
--
-
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