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authorAl Viro <viro@zeniv.linux.org.uk>2008-03-22 18:00:39 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2008-04-21 23:13:47 -0400
commit8c3ee42e80ccead805806b3cb50b9855ceb957a2 (patch)
tree2ab48755381fa7f7170145c1f40aa15e2e409c35
parentb5266eb4c8d1a2887a19aaec8144ee4ad1b054c3 (diff)
downloadop-kernel-dev-8c3ee42e80ccead805806b3cb50b9855ceb957a2.zip
op-kernel-dev-8c3ee42e80ccead805806b3cb50b9855ceb957a2.tar.gz
[PATCH] get rid of more nameidata passing in namespace.c
Further reduction of stack footprint (sys_pivot_root()); lose useless BKL in there, while we are at it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-rw-r--r--fs/namespace.c53
1 files changed, 25 insertions, 28 deletions
diff --git a/fs/namespace.c b/fs/namespace.c
index 87d2d82..1bf302d 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1205,32 +1205,32 @@ static int attach_recursive_mnt(struct vfsmount *source_mnt,
return 0;
}
-static int graft_tree(struct vfsmount *mnt, struct nameidata *nd)
+static int graft_tree(struct vfsmount *mnt, struct path *path)
{
int err;
if (mnt->mnt_sb->s_flags & MS_NOUSER)
return -EINVAL;
- if (S_ISDIR(nd->path.dentry->d_inode->i_mode) !=
+ if (S_ISDIR(path->dentry->d_inode->i_mode) !=
S_ISDIR(mnt->mnt_root->d_inode->i_mode))
return -ENOTDIR;
err = -ENOENT;
- mutex_lock(&nd->path.dentry->d_inode->i_mutex);
- if (IS_DEADDIR(nd->path.dentry->d_inode))
+ mutex_lock(&path->dentry->d_inode->i_mutex);
+ if (IS_DEADDIR(path->dentry->d_inode))
goto out_unlock;
- err = security_sb_check_sb(mnt, &nd->path);
+ err = security_sb_check_sb(mnt, path);
if (err)
goto out_unlock;
err = -ENOENT;
- if (IS_ROOT(nd->path.dentry) || !d_unhashed(nd->path.dentry))
- err = attach_recursive_mnt(mnt, &nd->path, NULL);
+ if (IS_ROOT(path->dentry) || !d_unhashed(path->dentry))
+ err = attach_recursive_mnt(mnt, path, NULL);
out_unlock:
- mutex_unlock(&nd->path.dentry->d_inode->i_mutex);
+ mutex_unlock(&path->dentry->d_inode->i_mutex);
if (!err)
- security_sb_post_addmount(mnt, &nd->path);
+ security_sb_post_addmount(mnt, path);
return err;
}
@@ -1294,7 +1294,7 @@ static noinline int do_loopback(struct nameidata *nd, char *old_name,
if (!mnt)
goto out;
- err = graft_tree(mnt, nd);
+ err = graft_tree(mnt, &nd->path);
if (err) {
LIST_HEAD(umount_list);
spin_lock(&vfsmount_lock);
@@ -1501,7 +1501,7 @@ int do_add_mount(struct vfsmount *newmnt, struct nameidata *nd,
goto unlock;
newmnt->mnt_flags = mnt_flags;
- if ((err = graft_tree(newmnt, nd)))
+ if ((err = graft_tree(newmnt, &nd->path)))
goto unlock;
if (fslist) /* add to the specified expiration list */
@@ -1987,15 +1987,13 @@ asmlinkage long sys_pivot_root(const char __user * new_root,
const char __user * put_old)
{
struct vfsmount *tmp;
- struct nameidata new_nd, old_nd, user_nd;
- struct path parent_path, root_parent;
+ struct nameidata new_nd, old_nd;
+ struct path parent_path, root_parent, root;
int error;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
- lock_kernel();
-
error = __user_walk(new_root, LOOKUP_FOLLOW | LOOKUP_DIRECTORY,
&new_nd);
if (error)
@@ -2015,7 +2013,7 @@ asmlinkage long sys_pivot_root(const char __user * new_root,
}
read_lock(&current->fs->lock);
- user_nd.path = current->fs->root;
+ root = current->fs->root;
path_get(&current->fs->root);
read_unlock(&current->fs->lock);
down_write(&namespace_sem);
@@ -2023,9 +2021,9 @@ asmlinkage long sys_pivot_root(const char __user * new_root,
error = -EINVAL;
if (IS_MNT_SHARED(old_nd.path.mnt) ||
IS_MNT_SHARED(new_nd.path.mnt->mnt_parent) ||
- IS_MNT_SHARED(user_nd.path.mnt->mnt_parent))
+ IS_MNT_SHARED(root.mnt->mnt_parent))
goto out2;
- if (!check_mnt(user_nd.path.mnt))
+ if (!check_mnt(root.mnt))
goto out2;
error = -ENOENT;
if (IS_DEADDIR(new_nd.path.dentry->d_inode))
@@ -2035,13 +2033,13 @@ asmlinkage long sys_pivot_root(const char __user * new_root,
if (d_unhashed(old_nd.path.dentry) && !IS_ROOT(old_nd.path.dentry))
goto out2;
error = -EBUSY;
- if (new_nd.path.mnt == user_nd.path.mnt ||
- old_nd.path.mnt == user_nd.path.mnt)
+ if (new_nd.path.mnt == root.mnt ||
+ old_nd.path.mnt == root.mnt)
goto out2; /* loop, on the same file system */
error = -EINVAL;
- if (user_nd.path.mnt->mnt_root != user_nd.path.dentry)
+ if (root.mnt->mnt_root != root.dentry)
goto out2; /* not a mountpoint */
- if (user_nd.path.mnt->mnt_parent == user_nd.path.mnt)
+ if (root.mnt->mnt_parent == root.mnt)
goto out2; /* not attached */
if (new_nd.path.mnt->mnt_root != new_nd.path.dentry)
goto out2; /* not a mountpoint */
@@ -2063,27 +2061,26 @@ asmlinkage long sys_pivot_root(const char __user * new_root,
} else if (!is_subdir(old_nd.path.dentry, new_nd.path.dentry))
goto out3;
detach_mnt(new_nd.path.mnt, &parent_path);
- detach_mnt(user_nd.path.mnt, &root_parent);
+ detach_mnt(root.mnt, &root_parent);
/* mount old root on put_old */
- attach_mnt(user_nd.path.mnt, &old_nd.path);
+ attach_mnt(root.mnt, &old_nd.path);
/* mount new_root on / */
attach_mnt(new_nd.path.mnt, &root_parent);
touch_mnt_namespace(current->nsproxy->mnt_ns);
spin_unlock(&vfsmount_lock);
- chroot_fs_refs(&user_nd.path, &new_nd.path);
- security_sb_post_pivotroot(&user_nd.path, &new_nd.path);
+ chroot_fs_refs(&root, &new_nd.path);
+ security_sb_post_pivotroot(&root, &new_nd.path);
error = 0;
path_put(&root_parent);
path_put(&parent_path);
out2:
mutex_unlock(&old_nd.path.dentry->d_inode->i_mutex);
up_write(&namespace_sem);
- path_put(&user_nd.path);
+ path_put(&root);
path_put(&old_nd.path);
out1:
path_put(&new_nd.path);
out0:
- unlock_kernel();
return error;
out3:
spin_unlock(&vfsmount_lock);
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