1e5bfa623a
the argument passed to file_dup2 doesn't always come from task file list so it doesn't make sense to hold the file list lock and then it is better to do the protection in the new function files_dupfd2 Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com> Change-Id: Ibf02cea9b0b275e7472f9c04fd66b9242285b957
436 lines
15 KiB
C
436 lines
15 KiB
C
/****************************************************************************
|
|
* 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 <nuttx/config.h>
|
|
#include <nuttx/compiler.h>
|
|
|
|
#include <sys/types.h>
|
|
#include <stdint.h>
|
|
#include <stdbool.h>
|
|
#include <dirent.h>
|
|
|
|
#include <nuttx/kmalloc.h>
|
|
#include <nuttx/fs/fs.h>
|
|
|
|
/****************************************************************************
|
|
* Pre-processor Definitions
|
|
****************************************************************************/
|
|
|
|
#define SETUP_SEARCH(d,p,n) \
|
|
do \
|
|
{ \
|
|
(d)->path = (p); \
|
|
(d)->node = NULL; \
|
|
(d)->peer = NULL; \
|
|
(d)->parent = NULL; \
|
|
(d)->relpath = NULL; \
|
|
(d)->buffer = NULL; \
|
|
(d)->nofollow = (n); \
|
|
} \
|
|
while (0)
|
|
|
|
#define RELEASE_SEARCH(d) \
|
|
do \
|
|
{ \
|
|
if ((d)->buffer != NULL) \
|
|
{ \
|
|
kmm_free((d)->buffer); \
|
|
(d)->buffer = NULL; \
|
|
} \
|
|
} \
|
|
while (0)
|
|
|
|
/****************************************************************************
|
|
* 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.
|
|
* 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 */
|
|
FAR char *buffer; /* Path expansion buffer */
|
|
bool nofollow; /* true: Don't follow terminal soft link */
|
|
};
|
|
|
|
/* 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
|
|
* <sys/stat.h>, 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_root_reserve
|
|
*
|
|
* Description:
|
|
* Reserve the root node for the pseudo file system.
|
|
*
|
|
****************************************************************************/
|
|
|
|
void inode_root_reserve(void);
|
|
|
|
/****************************************************************************
|
|
* 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,
|
|
FAR void *priv, int minfd);
|
|
|
|
/****************************************************************************
|
|
* Name: files_dupfd2
|
|
*
|
|
* Description:
|
|
* Clone a file descriptor to a specific descriptor number.
|
|
*
|
|
* Returned Value:
|
|
* fd2 is returned on success; a negated errno value is return on
|
|
* any failure.
|
|
*
|
|
****************************************************************************/
|
|
|
|
int files_dupfd2(int fd1, int fd2);
|
|
|
|
/****************************************************************************
|
|
* 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 */
|