/**************************************************************************** * fs/vfs/fs_symlink.c * * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. The * ASF licenses this file to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance with the * License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations * under the License. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include #include #include #include "inode/inode.h" /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ #ifdef CONFIG_PSEUDOFS_SOFTLINKS /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: symlink * * Description: * The symlink() function will create a new link (directory entry) for the * existing file, path2. This implementation is simplied for use with * NuttX in these ways: * * - Links may be created only within the NuttX top-level, pseudo file * system. No file system currently supported by NuttX provides * symbolic links. * - For the same reason, only soft links are implemented. * - File privileges are ignored. * - c_time is not updated. * * Input Parameters: * path1 - Points to a pathname naming an existing file. * path2 - Points to a pathname naming the new directory entry to be * created. * * Returned Value: * On success, zero (OK) is returned. Otherwise, -1 (ERROR) is returned * the errno variable is set appropriately. * ****************************************************************************/ int symlink(FAR const char *path1, FAR const char *path2) { struct inode_search_s desc; FAR struct inode *inode = NULL; int errcode; int ret; if (path1 == NULL) { errcode = EINVAL; goto errout; } /* Check that no inode exists at the 'path2' and that the path up to * 'path2' does not lie on a mounted volume. */ SETUP_SEARCH(&desc, path2, false); ret = inode_find(&desc); if (ret >= 0) { /* Something exists at the path2 where we are trying to create the * link. */ #ifndef CONFIG_DISABLE_MOUNTPOINT /* Check if the inode is a mountpoint. */ DEBUGASSERT(desc.node != NULL); if (INODE_IS_MOUNTPT(desc.node)) { /* Symbolic links within the mounted volume are not supported */ errcode = ENOSYS; } else #endif { /* A node already exists in the pseudofs at 'path1' */ errcode = EEXIST; } goto errout_with_inode; } /* No inode exists that contains this path. Create a new inode in the * pseudo-filesystem at this location. */ else { /* Copy path1 */ FAR char *newpath2 = strdup(path1); if (newpath2 == NULL) { errcode = ENOMEM; goto errout_with_search; } /* Create an inode in the pseudo-filesystem at this path. * NOTE that the new inode will be created with a reference * count of zero. */ ret = inode_semtake(); if (ret < 0) { kmm_free(newpath2); errcode = -ret; goto errout_with_search; } ret = inode_reserve(path2, &inode); inode_semgive(); if (ret < 0) { kmm_free(newpath2); errcode = -ret; goto errout_with_search; } /* Initialize the inode */ INODE_SET_SOFTLINK(inode); inode->u.i_link = newpath2; } /* Symbolic link successfully created */ RELEASE_SEARCH(&desc); return OK; errout_with_inode: inode_release(inode); errout_with_search: RELEASE_SEARCH(&desc); errout: set_errno(errcode); return ERROR; } #endif /* CONFIG_PSEUDOFS_SOFTLINKS */