diff options
| -rw-r--r-- | fs/dcache.c | 25 | ||||
| -rw-r--r-- | fs/namespace.c | 42 | ||||
| -rw-r--r-- | fs/pnode.c | 15 | ||||
| -rw-r--r-- | fs/pnode.h | 2 |
4 files changed, 29 insertions, 55 deletions
diff --git a/fs/dcache.c b/fs/dcache.c index 8a75e3b0f49..64c8ce4c147 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -2853,31 +2853,6 @@ int is_subdir(struct dentry *new_dentry, struct dentry *old_dentry) return result; } -int path_is_under(struct path *path1, struct path *path2) -{ - struct vfsmount *mnt = path1->mnt; - struct dentry *dentry = path1->dentry; - int res; - - br_read_lock(vfsmount_lock); - if (mnt != path2->mnt) { - for (;;) { - if (!mnt_has_parent(mnt)) { - br_read_unlock(vfsmount_lock); - return 0; - } - if (mnt->mnt_parent == path2->mnt) - break; - mnt = mnt->mnt_parent; - } - dentry = mnt->mnt_mountpoint; - } - res = is_subdir(dentry, path2->dentry); - br_read_unlock(vfsmount_lock); - return res; -} -EXPORT_SYMBOL(path_is_under); - void d_genocide(struct dentry *root) { struct dentry *this_parent; diff --git a/fs/namespace.c b/fs/namespace.c index ec8512478b0..7aad258dcaf 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1876,8 +1876,7 @@ static int do_move_mount(struct path *path, char *old_name) /* * Don't move a mount residing in a shared parent. */ - if (old_path.mnt->mnt_parent && - IS_MNT_SHARED(old_path.mnt->mnt_parent)) + if (IS_MNT_SHARED(old_path.mnt->mnt_parent)) goto out1; /* * Don't move a mount tree containing unbindable mounts to a destination @@ -2534,6 +2533,31 @@ out_type: } /* + * Return true if path is reachable from root + * + * namespace_sem or vfsmount_lock is held + */ +bool is_path_reachable(struct vfsmount *mnt, struct dentry *dentry, + const struct path *root) +{ + while (mnt != root->mnt && mnt_has_parent(mnt)) { + dentry = mnt->mnt_mountpoint; + mnt = mnt->mnt_parent; + } + return mnt == root->mnt && is_subdir(dentry, root->dentry); +} + +int path_is_under(struct path *path1, struct path *path2) +{ + int res; + br_read_lock(vfsmount_lock); + res = is_path_reachable(path1->mnt, path1->dentry, path2); + br_read_unlock(vfsmount_lock); + return res; +} +EXPORT_SYMBOL(path_is_under); + +/* * pivot_root Semantics: * Moves the root file system of the current process to the directory put_old, * makes new_root as the new root file system of the current process, and sets @@ -2561,7 +2585,6 @@ out_type: SYSCALL_DEFINE2(pivot_root, const char __user *, new_root, const char __user *, put_old) { - struct vfsmount *tmp; struct path new, old, parent_path, root_parent, root; int error; @@ -2611,18 +2634,7 @@ SYSCALL_DEFINE2(pivot_root, const char __user *, new_root, if (!mnt_has_parent(new.mnt)) goto out4; /* not attached */ /* make sure we can reach put_old from new_root */ - tmp = old.mnt; - if (tmp != new.mnt) { - for (;;) { - if (!mnt_has_parent(tmp)) - goto out4; /* already mounted on put_old */ - if (tmp->mnt_parent == new.mnt) - break; - tmp = tmp->mnt_parent; - } - if (!is_subdir(tmp->mnt_mountpoint, new.dentry)) - goto out4; - } else if (!is_subdir(old.dentry, new.dentry)) + if (!is_path_reachable(old.mnt, old.dentry, &new)) goto out4; br_write_lock(vfsmount_lock); detach_mnt(new.mnt, &parent_path); diff --git a/fs/pnode.c b/fs/pnode.c index f1cd958b92e..4d5a06ea57a 100644 --- a/fs/pnode.c +++ b/fs/pnode.c @@ -28,21 +28,6 @@ static inline struct vfsmount *next_slave(struct vfsmount *p) return list_entry(p->mnt_slave.next, struct vfsmount, mnt_slave); } -/* - * Return true if path is reachable from root - * - * namespace_sem is held, and mnt is attached - */ -static bool is_path_reachable(struct vfsmount *mnt, struct dentry *dentry, - const struct path *root) -{ - while (mnt != root->mnt && mnt_has_parent(mnt)) { - dentry = mnt->mnt_mountpoint; - mnt = mnt->mnt_parent; - } - return mnt == root->mnt && is_subdir(dentry, root->dentry); -} - static struct vfsmount *get_peer_under_root(struct vfsmount *mnt, struct mnt_namespace *ns, const struct path *root) diff --git a/fs/pnode.h b/fs/pnode.h index 7f0c13ae948..723399e7613 100644 --- a/fs/pnode.h +++ b/fs/pnode.h @@ -42,4 +42,6 @@ void mnt_set_mountpoint(struct vfsmount *, struct dentry *, void release_mounts(struct list_head *); void umount_tree(struct vfsmount *, int, struct list_head *); struct vfsmount *copy_tree(struct vfsmount *, struct dentry *, int); +bool is_path_reachable(struct vfsmount *, struct dentry *, + const struct path *root); #endif /* _LINUX_PNODE_H */ |