/**************************************************************************** * fs/vfs/fs_unlink.c * * Copyright (C) 2007-2009, 2017 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * 3. Neither the name NuttX nor the names of its contributors may be * used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include "inode/inode.h" /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ #undef FS_HAVE_WRITABLE_MOUNTPOINT #if !defined(CONFIG_DISABLE_MOUNTPOINT) && defined(CONFIG_FS_WRITABLE) && \ CONFIG_NFILE_STREAMS > 0 # define FS_HAVE_WRITABLE_MOUNTPOINT 1 #endif #undef FS_HAVE_PSEUDOFS_OPERATIONS #if !defined(CONFIG_DISABLE_PSEUDOFS_OPERATIONS) && CONFIG_NFILE_STREAMS > 0 # define FS_HAVE_PSEUDOFS_OPERATIONS 1 #endif #undef FS_HAVE_UNLINK #if defined(FS_HAVE_WRITABLE_MOUNTPOINT) || defined(FS_HAVE_PSEUDOFS_OPERATIONS) # define FS_HAVE_UNLINK 1 #endif #ifdef FS_HAVE_UNLINK /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: unlink * * Description: Remove a file managed a mountpoint * ****************************************************************************/ int unlink(FAR const char *pathname) { struct inode_search_s desc; FAR struct inode *inode; int errcode; int ret; /* Get an inode for this file (without deference the final node in the path * which may be a symbolic link) */ SETUP_SEARCH(&desc, pathname, true); ret = inode_find(&desc); if (ret < 0) { /* There is no inode that includes in this path */ errcode = -ret; goto errout_with_search; } /* Get the search results */ inode = desc.node; DEBUGASSERT(inode != NULL); #ifndef CONFIG_DISABLE_MOUNTPOINT /* Check if the inode is a valid mountpoint. */ if (INODE_IS_MOUNTPT(inode) && inode->u.i_mops) { /* Perform the unlink operation using the relative path at the * mountpoint. */ if (inode->u.i_mops->unlink) { ret = inode->u.i_mops->unlink(inode, desc.relpath); if (ret < 0) { errcode = -ret; goto errout_with_inode; } } else { errcode = ENOSYS; goto errout_with_inode; } } else #endif #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS /* If this is a "dangling" pseudo-file node (i.e., it has no operations) * or a soft link, then rm should remove the node. */ #ifdef CONFIG_PSEUDOFS_SOFTLINKS /* A soft link is the only "specal" file that we can remove via unlink(). */ if (!INODE_IS_SPECIAL(inode) || INODE_IS_SOFTLINK(inode)) #else if (!INODE_IS_SPECIAL(inode)) #endif { /* If this is a pseudo-file node (i.e., it has no operations) * then unlink should remove the node. */ if (inode->u.i_ops != NULL) { inode_semtake(); /* Refuse to unlink the inode if it has children. I.e., if it is * functioning as a directory and the directory is not empty. */ if (inode->i_child != NULL) { errcode = ENOTEMPTY; inode_semgive(); goto errout_with_inode; } /* Notify the driver that it has been unlinked. If there are no * open references to the driver instance, then the driver should * release all resources because it is no longer accessible. */ if (INODE_IS_DRIVER(inode) && inode->u.i_ops->unlink) { /* Notify the character driver that it has been unlinked */ ret = inode->u.i_ops->unlink(inode); if (ret < 0) { errcode = -ret; goto errout_with_inode; } } #ifndef CONFIG_DISABLE_MOUNTPOINT else if (INODE_IS_BLOCK(inode) && inode->u.i_bops->unlink) { /* Notify the block driver that it has been unlinked */ ret = inode->u.i_bops->unlink(inode); if (ret < 0) { errcode = -ret; goto errout_with_inode; } } #endif /* Remove the old inode. Because we hold a reference count on the * inode, it will not be deleted now. It will be deleted when all * of the references to the inode have been released (perhaps * when inode_release() is called below). inode_remove() will * return -EBUSY to indicate that the inode was not deleted now. */ ret = inode_remove(pathname); inode_semgive(); if (ret < 0 && ret != -EBUSY) { errcode = -ret; goto errout_with_inode; } } else { errcode = EISDIR; goto errout_with_inode; } } else #endif { errcode = ENXIO; goto errout_with_inode; } /* Successfully unlinked */ inode_release(inode); RELEASE_SEARCH(&desc); return OK; errout_with_inode: inode_release(inode); errout_with_search: RELEASE_SEARCH(&desc); set_errno(errcode); return ERROR; } #endif /* FS_HAVE_UNLINK */