/**************************************************************************** * fs/inode/inode.h * * 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. * ****************************************************************************/ #ifndef __FS_INODE_H #define __FS_INODE_H /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include #include /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ #ifdef CONFIG_PSEUDOFS_SOFTLINKS # define SETUP_SEARCH(d,p,n) \ do \ { \ (d)->path = (p); \ (d)->node = NULL; \ (d)->peer = NULL; \ (d)->parent = NULL; \ (d)->relpath = NULL; \ (d)->linktgt = NULL; \ (d)->buffer = NULL; \ (d)->nofollow = (n); \ } \ while (0) # define RELEASE_SEARCH(d) \ if ((d)->buffer != NULL) \ { \ kmm_free((d)->buffer); \ (d)->buffer = NULL; \ } #else # define SETUP_SEARCH(d,p,n) \ do \ { \ (d)->path = (p); \ (d)->node = NULL; \ (d)->peer = NULL; \ (d)->parent = NULL; \ (d)->relpath = NULL; \ } \ while (0) # define RELEASE_SEARCH(d) #endif /**************************************************************************** * Public Types ****************************************************************************/ /* This is the type of the argument to inode_search(). * * path - INPUT: Path of inode to find * OUTPUT: Residual part of path not traversed * node - INPUT: (not used) * OUTPUT: On success, holds the pointer to the inode found. * peer - INPUT: (not used) * OUTPUT: The inode to the "left" of the inode found. * parent - INPUT: (not used) * OUTPUT: The inode to the "above" of the inode found. * relpath - INPUT: (not used) * OUTPUT: If the returned inode is a mountpoint, this is the * relative path from the mountpoint. * linktgt - INPUT: (not used) * OUTPUT: If a symobolic link into a mounted file system is * detected while traversing the path, then the link * will be converted to a mountpoint inode if the * mountpoint link is in an intermediate node of the * path or at the final node of the path with * nofollow=true. * nofollow - INPUT: true: terminal node is returned; false: if the * terminal is a soft link, then return the inode of * the link target. * - OUTPUT: (not used) * buffer - INPUT: Not used * - OUTPUT: May hold an allocated intermediate path which is * probably of no interest to the caller unless it holds * the relpath. */ struct inode_search_s { FAR const char *path; /* Path of inode to find */ FAR struct inode *node; /* Pointer to the inode found */ FAR struct inode *peer; /* Node to the "left" for the found inode */ FAR struct inode *parent; /* Node "above" the found inode */ FAR const char *relpath; /* Relative path into the mountpoint */ #ifdef CONFIG_PSEUDOFS_SOFTLINKS FAR const char *linktgt; /* Target of symbolic link if linked to a directory */ FAR char *buffer; /* Path expansion buffer */ bool nofollow; /* true: Don't follow terminal soft link */ #endif }; /* Callback used by foreach_inode to traverse all inodes in the pseudo- * file system. */ typedef int (*foreach_inode_t)(FAR struct inode *node, FAR char dirpath[PATH_MAX], FAR void *arg); /**************************************************************************** * Public Data ****************************************************************************/ #undef EXTERN #if defined(__cplusplus) #define EXTERN extern "C" extern "C" { #else #define EXTERN extern #endif EXTERN FAR struct inode *g_root_inode; /**************************************************************************** * Public Function Prototypes ****************************************************************************/ /**************************************************************************** * Name: inode_initialize * * Description: * This is called from the OS initialization logic to configure the file * system. * ****************************************************************************/ void inode_initialize(void); /**************************************************************************** * Name: inode_semtake * * Description: * Get exclusive access to the in-memory inode tree (tree_sem). * ****************************************************************************/ int inode_semtake(void); /**************************************************************************** * Name: inode_semgive * * Description: * Relinquish exclusive access to the in-memory inode tree (tree_sem). * ****************************************************************************/ void inode_semgive(void); /**************************************************************************** * Name: inode_checkflags * * Description: * Check if the access described by 'oflags' is supported on 'inode' * ****************************************************************************/ int inode_checkflags(FAR struct inode *inode, int oflags); /**************************************************************************** * Name: inode_search * * Description: * Find the inode associated with 'path' returning the inode references * and references to its companion nodes. * * If a mountpoint is encountered in the search prior to encountering the * terminal node, the search will terminate at the mountpoint inode. That * inode and the relative path from the mountpoint, 'relpath' will be * returned. * * inode_search will follow soft links in path leading up to the terminal * node. Whether or no inode_search() will deference that terminal node * depends on the 'nofollow' input. * * If a soft link is encountered that is not the terminal node in the path, * that link WILL be deferenced unconditionally. * * Assumptions: * The caller holds the g_inode_sem semaphore * ****************************************************************************/ int inode_search(FAR struct inode_search_s *desc); /**************************************************************************** * Name: inode_find * * Description: * This is called from the open() logic to get a reference to the inode * associated with a path. This is accomplished by calling inode_search(). * inode_find() is a simple wrapper around inode_search(). The primary * difference between inode_find() and inode_search is that inode_find() * will lock the inode tree and increment the reference count on the inode. * ****************************************************************************/ int inode_find(FAR struct inode_search_s *desc); /**************************************************************************** * Name: inode_stat * * Description: * The inode_stat() function will obtain information about an 'inode' in * the pseudo file system and will write it to the area pointed to by * 'buf'. * * The 'buf' argument is a pointer to a stat structure, as defined in * , into which information is placed concerning the file. * * Input Parameters: * inode - The inode of interest * buf - The caller provide location in which to return information * about the inode. * resolve - Whether to resolve the symbolic link * * Returned Value: * Zero (OK) returned on success. Otherwise, a negated errno value is * returned to indicate the nature of the failure. * ****************************************************************************/ struct stat; /* Forward reference */ int inode_stat(FAR struct inode *inode, FAR struct stat *buf, int resolve); /**************************************************************************** * Name: inode_free * * Description: * Free resources used by an inode * ****************************************************************************/ void inode_free(FAR struct inode *node); /**************************************************************************** * Name: inode_nextname * * Description: * Given a path with node names separated by '/', return the next node * name. * ****************************************************************************/ const char *inode_nextname(FAR const char *name); /**************************************************************************** * Name: inode_reserve * * Description: * Reserve an (initialized) inode the pseudo file system. * * NOTE: Caller must hold the inode semaphore * * Input Parameters: * path - The path to the inode to create * inode - The location to return the inode pointer * * Returned Value: * Zero on success (with the inode point in 'inode'); A negated errno * value is returned on failure: * * EINVAL - 'path' is invalid for this operation * EEXIST - An inode already exists at 'path' * ENOMEM - Failed to allocate in-memory resources for the operation * ****************************************************************************/ int inode_reserve(FAR const char *path, FAR struct inode **inode); /**************************************************************************** * Name: inode_unlink * * Description: * Given a path, remove a the node from the in-memory, inode tree that the * path refers to. This is normally done in preparation to removing or * moving an inode. * * Assumptions/Limitations: * The caller must hold the inode semaphore * ****************************************************************************/ FAR struct inode *inode_unlink(FAR const char *path); /**************************************************************************** * Name: inode_remove * * Description: * Given a path, remove a the node from the in-memory, inode tree that the * path refers to and free all resources related to the inode. If the * inode is in-use, then it will be unlinked, but will not be freed until * the last reference to the inode is released. * * Assumptions/Limitations: * The caller must hold the inode semaphore * ****************************************************************************/ int inode_remove(FAR const char *path); /**************************************************************************** * Name: inode_addref * * Description: * Increment the reference count on an inode (as when a file descriptor * is dup'ed). * ****************************************************************************/ int inode_addref(FAR struct inode *inode); /**************************************************************************** * Name: inode_release * * Description: * This is called from close() logic when it no longer refers to the inode. * ****************************************************************************/ void inode_release(FAR struct inode *inode); /**************************************************************************** * Name: foreach_inode * * Description: * Visit each inode in the pseudo-file system. The traversal is terminated * when the callback 'handler' returns a non-zero value, or when all of * the inodes have been visited. * * NOTE 1: Use with caution... The pseudo-file system is locked throughout * the traversal. * NOTE 2: The search algorithm is recursive and could, in principle, use * an indeterminate amount of stack space. This will not usually be a * real work issue. * ****************************************************************************/ int foreach_inode(foreach_inode_t handler, FAR void *arg); /**************************************************************************** * Name: files_initialize * * Description: * This is called from the FS initialization logic to configure the files. * ****************************************************************************/ void weak_function files_initialize(void); /**************************************************************************** * Name: files_allocate * * Description: * Allocate a struct files instance and associate it with an inode * instance. Returns the file descriptor == index into the files array. * ****************************************************************************/ int files_allocate(FAR struct inode *inode, int oflags, off_t pos, int minfd); /**************************************************************************** * Name: files_close * * Description: * Close an inode (if open) * * Assumptions: * Caller holds the list semaphore because the file descriptor will be * freed. * ****************************************************************************/ int files_close(int fd); /**************************************************************************** * Name: files_release * * Assumptions: * Similar to files_close(). Called only from open() logic on error * conditions. * ****************************************************************************/ void files_release(int fd); #undef EXTERN #if defined(__cplusplus) } #endif #endif /* __FS_INODE_H */