/**************************************************************************** * fs/vfs/fs_rename.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 "inode/inode.h" /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ #undef FS_HAVE_WRITABLE_MOUNTPOINT #if !defined(CONFIG_DISABLE_MOUNTPOINT) && 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_RENAME #if defined(FS_HAVE_WRITABLE_MOUNTPOINT) || defined(FS_HAVE_PSEUDOFS_OPERATIONS) # define FS_HAVE_RENAME 1 #endif #ifdef FS_HAVE_RENAME /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: pseudorename * * Description: * Rename an inode in the pseudo file system * ****************************************************************************/ #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS static int pseudorename(FAR const char *oldpath, FAR struct inode *oldinode, FAR const char *newpath) { struct inode_search_s newdesc; FAR struct inode *newinode; FAR char *subdir = NULL; FAR const char *name; int ret; /* Special case the root directory. There is no root inode and there is * no name for the root. inode_find() will fail to the find the root * inode -- because there isn't one. */ name = newpath; while (*name == '/') { name++; } if (*name == '\0') { FAR char *subdirname; /* In the newpath is the root directory, the target of the rename must * be a directory entry under the root. */ subdirname = basename((FAR char *)oldpath); asprintf(&subdir, "/%s", subdirname); if (subdir == NULL) { ret = -ENOMEM; goto errout; } newpath = subdir; } /* According to POSIX, any old inode at this path should be removed * first, provided that it is not a directory. */ next_subdir: SETUP_SEARCH(&newdesc, newpath, true); ret = inode_find(&newdesc); if (ret >= 0) { /* We found it. Get the search results */ newinode = newdesc.node; DEBUGASSERT(newinode != NULL); /* If the old and new inodes are the same, then this is an attempt to * move the directory entry onto itself. Let's not but say we did. */ if (oldinode == newinode) { ret = OK; goto errout; /* Bad naming, this is not an error case. */ } #ifndef CONFIG_DISABLE_MOUNTPOINT /* Make sure that the old path does not lie on a mounted volume. */ if (INODE_IS_MOUNTPT(newinode)) { inode_release(newinode); ret = -EXDEV; goto errout; } #endif /* We found it and it appears to be a "normal" inode. Is it a * directory (i.e, an operation-less inode or an inode with children)? */ if (newinode->u.i_ops == NULL || newinode->i_child != NULL) { FAR char *subdirname; FAR char *tmp; /* Yes.. In this case, the target of the rename must be a * subdirectory of newinode, not the newinode itself. For * example: mv b a/ must move b to a/b. */ subdirname = basename((FAR char *)oldpath); tmp = subdir; subdir = NULL; asprintf(&subdir, "%s/%s", newpath, subdirname); if (tmp != NULL) { kmm_free(tmp); } if (subdir == NULL) { ret = -ENOMEM; goto errout; } newpath = subdir; /* This can be a recursive case, another inode may already exist * at oldpth/subdirname. In that case, we need to do this all * over again. A nasty goto is used because I am lazy. */ goto next_subdir; } else { /* Not a directory... remove it. It may still be something * important (like a driver), but we will just have to suffer * the consequences. * * NOTE (1) that we not bother to check the error. If we * failed to remove the inode for some reason, then * inode_reserve() will complain below, and (2) the inode * won't really be removed until we call inode_release(); */ inode_remove(newpath); } inode_release(newinode); } /* Create a new, empty inode at the destination location. * NOTE that the new inode will be created with a reference count * of zero. */ ret = inode_semtake(); if (ret < 0) { goto errout; } ret = inode_reserve(newpath, &newinode); if (ret < 0) { /* It is an error if a node at newpath already exists in the tree * OR if we fail to allocate memory for the new inode (and possibly * any new intermediate path segments). */ ret = -EEXIST; goto errout_with_sem; } /* Copy the inode state from the old inode to the newly allocated inode */ newinode->i_child = oldinode->i_child; /* Link to lower level inode */ newinode->i_flags = oldinode->i_flags; /* Flags for inode */ newinode->u.i_ops = oldinode->u.i_ops; /* Inode operations */ #ifdef CONFIG_FILE_MODE newinode->i_mode = oldinode->i_mode; /* Access mode flags */ #endif newinode->i_private = oldinode->i_private; /* Per inode driver private data */ #ifdef CONFIG_PSEUDOFS_SOFTLINKS /* Prevent the link target string from being deallocated. The pointer to * the allocated link target path was copied above (under the guise of * u.i_ops). Now we must nullify the u.i_link pointer so that it is not * deallocated when inode_free() is (eventually called. */ oldinode->u.i_link = NULL; #endif /* We now have two copies of the inode. One with a reference count of * zero (the new one), and one that may have multiple references * including one by this logic (the old one) * * 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 in remove()). inode_remove() should return * -EBUSY to indicate that the inode was not deleted now. */ ret = inode_remove(oldpath); if (ret < 0 && ret != -EBUSY) { /* Remove the new node we just recreated */ inode_remove(newpath); goto errout_with_sem; } /* Remove all of the children from the unlinked inode */ oldinode->i_child = NULL; ret = OK; errout_with_sem: inode_semgive(); errout: if (subdir != NULL) { kmm_free(subdir); } return ret; } #endif /* CONFIG_DISABLE_PSEUDOFS_OPERATIONS */ /**************************************************************************** * Name: mountptrename * * Description: * Rename a file residing on a mounted volume. * ****************************************************************************/ #ifndef CONFIG_DISABLE_MOUNTPOINT static int mountptrename(FAR const char *oldpath, FAR struct inode *oldinode, FAR const char *oldrelpath, FAR const char *newpath) { struct inode_search_s newdesc; FAR struct inode *newinode; FAR const char *newrelpath; FAR char *subdir = NULL; int ret; DEBUGASSERT(oldinode->u.i_mops); /* If the file system does not support the rename() method, then bail now. * As of this writing, only NXFFS does not support the rename method. A * good fallback might be to copy the oldrelpath to the correct location, * then unlink it. */ if (oldinode->u.i_mops->rename == NULL) { return -ENOSYS; } /* Get an inode for the new relpath -- it should lie on the same * mountpoint */ SETUP_SEARCH(&newdesc, newpath, true); ret = inode_find(&newdesc); if (ret < 0) { /* There is no mountpoint that includes in this path */ goto errout_with_newsearch; } /* Get the search results */ newinode = newdesc.node; newrelpath = newdesc.relpath; DEBUGASSERT(newinode != NULL && newrelpath != NULL); /* Verify that the two paths lie on the same mountpoint inode */ if (oldinode != newinode) { ret = -EXDEV; goto errout_with_newinode; } /* Does a directory entry already exist at the 'rewrelpath'? And is it * not the same directory entry that we are moving? * * If the directory entry at the newrelpath is a regular file, then that * file should be removed first. * * If the directory entry at the target is a directory, then the source * file should be moved "under" the directory, i.e., if newrelpath is a * directory, then rename(b,a) should use move the olrelpath should be * moved as if rename(b,a/basename(b)) had been called. */ if (oldinode->u.i_mops->stat != NULL && strcmp(oldrelpath, newrelpath) != 0) { struct stat buf; next_subdir: /* Something exists for this directory entry. Do nothing in the * degenerate case where a directory or file is being moved to * itself. */ if (strcmp(oldrelpath, newrelpath) != 0) { ret = oldinode->u.i_mops->stat(oldinode, newrelpath, &buf); if (ret >= 0) { /* Is the directory entry a directory? */ if (S_ISDIR(buf.st_mode)) { FAR char *subdirname; /* Yes.. In this case, the target of the rename must be a * subdirectory of newinode, not the newinode itself. For * example: mv b a/ must move b to a/b. */ subdirname = basename((FAR char *)oldrelpath); /* Special case the root directory */ if (*newrelpath == '\0') { if (subdir != NULL) { kmm_free(subdir); subdir = NULL; } newrelpath = subdirname; } else { FAR char *tmp = subdir; subdir = NULL; asprintf(&subdir, "%s/%s", newrelpath, subdirname); if (tmp != NULL) { kmm_free(tmp); } if (subdir == NULL) { ret = -ENOMEM; goto errout_with_newinode; } newrelpath = subdir; } /* This can be a recursive, another directory may already * exist at the newrelpath. In that case, we need to * do this all over again. A nasty goto is used because * I am lazy. */ goto next_subdir; } else if (oldinode->u.i_mops->unlink) { /* No.. newrelpath must refer to a regular file. Attempt * to remove the file before doing the rename. * * NOTE that errors are not handled here. If we failed to * remove the file, then the file system 'rename' method * should check that. */ oldinode->u.i_mops->unlink(oldinode, newrelpath); } } } } /* Just declare success of the oldrepath and the newrelpath point to * the same directory entry. That directory entry should have been * stat'ed above to assure that it exists. */ ret = OK; if (strcmp(oldrelpath, newrelpath) != 0) { /* Perform the rename operation using the relative paths at the common * mountpoint. */ ret = oldinode->u.i_mops->rename(oldinode, oldrelpath, newrelpath); } errout_with_newinode: inode_release(newinode); errout_with_newsearch: RELEASE_SEARCH(&newdesc); if (subdir != NULL) { kmm_free(subdir); } return ret; } #endif /* CONFIG_DISABLE_MOUNTPOINT */ /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: rename * * Description: * Rename a file or directory. * ****************************************************************************/ int rename(FAR const char *oldpath, FAR const char *newpath) { struct inode_search_s olddesc; FAR struct inode *oldinode; int ret; /* Ignore paths that are interpreted as the root directory which has no * name and cannot be moved */ if (!oldpath || *oldpath == '\0' || oldpath[0] != '/' || !newpath || *newpath == '\0' || newpath[0] != '/') { ret = -EINVAL; goto errout; } /* Get an inode that includes the oldpath */ SETUP_SEARCH(&olddesc, oldpath, true); ret = inode_find(&olddesc); if (ret < 0) { /* There is no inode that includes in this path */ goto errout_with_oldsearch; } /* Get the search results */ oldinode = olddesc.node; DEBUGASSERT(oldinode != NULL); #ifndef CONFIG_DISABLE_MOUNTPOINT /* Verify that the old inode is a valid mountpoint. */ if (INODE_IS_MOUNTPT(oldinode)) { ret = mountptrename(oldpath, oldinode, olddesc.relpath, newpath); } else #endif /* CONFIG_DISABLE_MOUNTPOINT */ #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS { ret = pseudorename(oldpath, oldinode, newpath); } #else { ret = -ENXIO; } #endif inode_release(oldinode); errout_with_oldsearch: RELEASE_SEARCH(&olddesc); errout: if (ret < 0) { set_errno(-ret); return ERROR; } return OK; } #endif /* FS_HAVE_RENAME */