int vfsub_create(struct inode *dir, struct path *path, int mode)
{
int err;
struct dentry *d;
IMustLock(dir);
d = path->dentry;
path->dentry = d->d_parent;
err = security_path_mknod(path, d, mode, 0);
path->dentry = d;
if (unlikely(err))
goto out;
if (au_test_fs_null_nd(dir->i_sb))
err = vfs_create(dir, path->dentry, mode, NULL);
else {
struct nameidata h_nd;
memset(&h_nd, 0, sizeof(h_nd));
h_nd.flags = LOOKUP_CREATE;
h_nd.intent.open.flags = O_CREAT
| vfsub_fmode_to_uint(FMODE_READ);
h_nd.intent.open.create_mode = mode;
h_nd.path.dentry = path->dentry->d_parent;
h_nd.path.mnt = path->mnt;
path_get(&h_nd.path);
err = vfs_create(dir, path->dentry, mode, &h_nd);
path_put(&h_nd.path);
}
if (!err) {
struct path tmp = *path;
int did;
vfsub_update_h_iattr(&tmp, &did);
if (did) {
tmp.dentry = path->dentry->d_parent;
vfsub_update_h_iattr(&tmp, /*did*/NULL);
}
/*ignore*/
}
out:
return err;
}
/* cf. open.c:do_sys_truncate() and do_sys_ftruncate() */
int vfsub_trunc(struct path *h_path, loff_t length, unsigned int attr,
struct file *h_file)
{
int err;
struct inode *h_inode;
h_inode = h_path->dentry->d_inode;
if (!h_file) {
err = mnt_want_write(h_path->mnt);
if (err)
goto out;
err = inode_permission(h_inode, MAY_WRITE);
if (err)
goto out_mnt;
err = get_write_access(h_inode);
if (err)
goto out_mnt;
err = break_lease(h_inode, vfsub_fmode_to_uint(FMODE_WRITE));
if (err)
goto out_inode;
}
err = locks_verify_truncate(h_inode, h_file, length);
if (!err)
err = security_path_truncate(h_path, length, attr);
if (!err) {
lockdep_off();
err = do_truncate(h_path->dentry, length, attr, h_file);
lockdep_on();
}
out_inode:
if (!h_file)
put_write_access(h_inode);
out_mnt:
if (!h_file)
mnt_drop_write(h_path->mnt);
out:
return err;
}
/* common functions to regular file and dir */
struct file *au_h_open(struct dentry *dentry, aufs_bindex_t bindex, int flags,
struct file *file)
{
struct file *h_file;
struct dentry *h_dentry;
struct inode *h_inode;
struct super_block *sb;
struct au_branch *br;
struct path h_path;
int err, exec_flag;
/* a race condition can happen between open and unlink/rmdir */
h_file = ERR_PTR(-ENOENT);
h_dentry = au_h_dptr(dentry, bindex);
if (au_test_nfsd() && !h_dentry)
goto out;
h_inode = h_dentry->d_inode;
if (au_test_nfsd() && !h_inode)
goto out;
if (unlikely((!d_unhashed(dentry) && d_unlinked(h_dentry))
|| !h_inode
/* || !dentry->d_inode->i_nlink */
))
goto out;
sb = dentry->d_sb;
br = au_sbr(sb, bindex);
h_file = ERR_PTR(-EACCES);
exec_flag = flags & vfsub_fmode_to_uint(FMODE_EXEC);
if (exec_flag && (br->br_mnt->mnt_flags & MNT_NOEXEC))
goto out;
/* drop flags for writing */
if (au_test_ro(sb, bindex, dentry->d_inode))
flags = au_file_roflags(flags);
flags &= ~O_CREAT;
atomic_inc(&br->br_count);
h_path.dentry = h_dentry;
h_path.mnt = br->br_mnt;
if (!au_special_file(h_inode->i_mode))
h_file = vfsub_dentry_open(&h_path, flags);
else {
/* this block depends upon the configuration */
di_read_unlock(dentry, AuLock_IR);
fi_write_unlock(file);
si_read_unlock(sb);
h_file = vfsub_dentry_open(&h_path, flags);
si_noflush_read_lock(sb);
fi_write_lock(file);
di_read_lock_child(dentry, AuLock_IR);
}
if (IS_ERR(h_file))
goto out_br;
if (exec_flag) {
err = deny_write_access(h_file);
if (unlikely(err)) {
fput(h_file);
h_file = ERR_PTR(err);
goto out_br;
}
}
fsnotify_open(h_dentry);
goto out; /* success */
out_br:
atomic_dec(&br->br_count);
out:
return h_file;
}