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OpenCloudOS-Kernel
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vfs: spread struct mount - clone_mnt/copy_tree argument 

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2011-11-24 21:24:27 -05:00
parent 692afc312b
commit 87129cc0e3
3 changed files with 35 additions and 32 deletions
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63
fs/namespace.c
View File

@ -687,17 +687,17 @@ vfs_kern_mount(struct file_system_type *type, int flags, const char *name, void
}
EXPORT_SYMBOL_GPL(vfs_kern_mount);
static struct mount *clone_mnt(struct vfsmount *old, struct dentry *root,
static struct mount *clone_mnt(struct mount *old, struct dentry *root,
int flag)
{
struct super_block *sb = old->mnt_sb;
struct mount *mnt = alloc_vfsmnt(old->mnt_devname);
struct super_block *sb = old->mnt.mnt_sb;
struct mount *mnt = alloc_vfsmnt(old->mnt.mnt_devname);
if (mnt) {
if (flag & (CL_SLAVE | CL_PRIVATE))
mnt->mnt.mnt_group_id = 0; /* not a peer of original */
else
mnt->mnt.mnt_group_id = old->mnt_group_id;
mnt->mnt.mnt_group_id = old->mnt.mnt_group_id;
if ((flag & CL_MAKE_SHARED) && !mnt->mnt.mnt_group_id) {
int err = mnt_alloc_group_id(mnt);
@ -705,7 +705,7 @@ static struct mount *clone_mnt(struct vfsmount *old, struct dentry *root,
goto out_free;
}
mnt->mnt.mnt_flags = old->mnt_flags & ~MNT_WRITE_HOLD;
mnt->mnt.mnt_flags = old->mnt.mnt_flags & ~MNT_WRITE_HOLD;
atomic_inc(&sb->s_active);
mnt->mnt.mnt_sb = sb;
mnt->mnt.mnt_root = dget(root);
@ -713,15 +713,15 @@ static struct mount *clone_mnt(struct vfsmount *old, struct dentry *root,
mnt->mnt.mnt_parent = &mnt->mnt;
if (flag & CL_SLAVE) {
list_add(&mnt->mnt.mnt_slave, &old->mnt_slave_list);
mnt->mnt.mnt_master = old;
list_add(&mnt->mnt.mnt_slave, &old->mnt.mnt_slave_list);
mnt->mnt.mnt_master = &old->mnt;
CLEAR_MNT_SHARED(&mnt->mnt);
} else if (!(flag & CL_PRIVATE)) {
if ((flag & CL_MAKE_SHARED) || IS_MNT_SHARED(old))
list_add(&mnt->mnt.mnt_share, &old->mnt_share);
if (IS_MNT_SLAVE(old))
list_add(&mnt->mnt.mnt_slave, &old->mnt_slave);
mnt->mnt.mnt_master = old->mnt_master;
if ((flag & CL_MAKE_SHARED) || IS_MNT_SHARED(&old->mnt))
list_add(&mnt->mnt.mnt_share, &old->mnt.mnt_share);
if (IS_MNT_SLAVE(&old->mnt))
list_add(&mnt->mnt.mnt_slave, &old->mnt.mnt_slave);
mnt->mnt.mnt_master = old->mnt.mnt_master;
}
if (flag & CL_MAKE_SHARED)
set_mnt_shared(mnt);
@ -729,8 +729,8 @@ static struct mount *clone_mnt(struct vfsmount *old, struct dentry *root,
/* stick the duplicate mount on the same expiry list
* as the original if that was on one */
if (flag & CL_EXPIRE) {
if (!list_empty(&old->mnt_expire))
list_add(&mnt->mnt.mnt_expire, &old->mnt_expire);
if (!list_empty(&old->mnt.mnt_expire))
list_add(&mnt->mnt.mnt_expire, &old->mnt.mnt_expire);
}
}
return mnt;
@ -1408,23 +1408,23 @@ static int mount_is_safe(struct path *path)
#endif
}
struct mount *copy_tree(struct vfsmount *mnt, struct dentry *dentry,
struct mount *copy_tree(struct mount *mnt, struct dentry *dentry,
int flag)
{
struct mount *res, *q;
struct vfsmount *p, *r;
struct mount *res, *p, *q;
struct vfsmount *r;
struct path path;
if (!(flag & CL_COPY_ALL) && IS_MNT_UNBINDABLE(mnt))
if (!(flag & CL_COPY_ALL) && IS_MNT_UNBINDABLE(&mnt->mnt))
return NULL;
res = q = clone_mnt(mnt, dentry, flag);
if (!q)
goto Enomem;
q->mnt.mnt_mountpoint = mnt->mnt_mountpoint;
q->mnt.mnt_mountpoint = mnt->mnt.mnt_mountpoint;
p = mnt;
list_for_each_entry(r, &mnt->mnt_mounts, mnt_child) {
list_for_each_entry(r, &mnt->mnt.mnt_mounts, mnt_child) {
struct mount *s;
if (!is_subdir(r->mnt_mountpoint, dentry))
continue;
@ -1434,14 +1434,14 @@ struct mount *copy_tree(struct vfsmount *mnt, struct dentry *dentry,
s = skip_mnt_tree(s);
continue;
}
while (p != s->mnt.mnt_parent) {
p = p->mnt_parent;
while (p != real_mount(s->mnt.mnt_parent)) {
p = real_mount(p->mnt.mnt_parent);
q = real_mount(q->mnt.mnt_parent);
}
p = &s->mnt;
p = s;
path.mnt = &q->mnt;
path.dentry = p->mnt_mountpoint;
q = clone_mnt(p, p->mnt_root, flag);
path.dentry = p->mnt.mnt_mountpoint;
q = clone_mnt(p, p->mnt.mnt_root, flag);
if (!q)
goto Enomem;
br_write_lock(vfsmount_lock);
@ -1466,7 +1466,8 @@ struct vfsmount *collect_mounts(struct path *path)
{
struct mount *tree;
down_write(&namespace_sem);
tree = copy_tree(path->mnt, path->dentry, CL_COPY_ALL | CL_PRIVATE);
tree = copy_tree(real_mount(path->mnt), path->dentry,
CL_COPY_ALL | CL_PRIVATE);
up_write(&namespace_sem);
return tree ? &tree->mnt : NULL;
}
@ -1740,7 +1741,7 @@ static int do_loopback(struct path *path, char *old_name,
{
LIST_HEAD(umount_list);
struct path old_path;
struct mount *mnt = NULL;
struct mount *mnt = NULL, *old;
int err = mount_is_safe(path);
if (err)
return err;
@ -1754,6 +1755,8 @@ static int do_loopback(struct path *path, char *old_name,
if (err)
goto out;
old = real_mount(old_path.mnt);
err = -EINVAL;
if (IS_MNT_UNBINDABLE(old_path.mnt))
goto out2;
@ -1763,9 +1766,9 @@ static int do_loopback(struct path *path, char *old_name,
err = -ENOMEM;
if (recurse)
mnt = copy_tree(old_path.mnt, old_path.dentry, 0);
mnt = copy_tree(old, old_path.dentry, 0);
else
mnt = clone_mnt(old_path.mnt, old_path.dentry, 0);
mnt = clone_mnt(old, old_path.dentry, 0);
if (!mnt)
goto out2;
@ -2394,7 +2397,7 @@ static struct mnt_namespace *dup_mnt_ns(struct mnt_namespace *mnt_ns,
down_write(&namespace_sem);
/* First pass: copy the tree topology */
new = copy_tree(mnt_ns->root, mnt_ns->root->mnt_root,
new = copy_tree(real_mount(mnt_ns->root), mnt_ns->root->mnt_root,
CL_COPY_ALL | CL_EXPIRE);
if (!new) {
up_write(&namespace_sem);

2
fs/pnode.c
View File

@ -239,7 +239,7 @@ int propagate_mnt(struct vfsmount *dest_mnt, struct dentry *dest_dentry,
source = get_source(m, prev_dest_mnt, prev_src_mnt, &type);
if (!(child = copy_tree(source, source->mnt_root, type))) {
if (!(child = copy_tree(real_mount(source), source->mnt_root, type))) {
ret = -ENOMEM;
list_splice(tree_list, tmp_list.prev);
goto out;

2
fs/pnode.h
View File

@ -41,7 +41,7 @@ void mnt_set_mountpoint(struct vfsmount *, struct dentry *,
struct vfsmount *);
void release_mounts(struct list_head *);
void umount_tree(struct mount *, int, struct list_head *);
struct mount *copy_tree(struct vfsmount *, struct dentry *, int);
struct mount *copy_tree(struct mount *, struct dentry *, int);
bool is_path_reachable(struct vfsmount *, struct dentry *,
const struct path *root);
#endif /* _LINUX_PNODE_H */