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nuttx/include/nuttx/fs/fs.h
Gregory Nutt b54ffe858a Standardization of some function headers.
2018-03-13 09:52:27 -06:00

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/****************************************************************************
* include/nuttx/fs/fs.h
*
* Copyright (C) 2007-2009, 2011-2013, 2015-2018 Gregory Nutt. All rights
* reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* 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.
*
****************************************************************************/
#ifndef __INCLUDE_NUTTX_FS_FS_H
#define __INCLUDE_NUTTX_FS_FS_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <nuttx/compiler.h>
#include <sys/types.h>
#include <stdarg.h>
#include <stdint.h>
#include <stdbool.h>
#include <semaphore.h>
#ifdef CONFIG_FS_NAMED_SEMAPHORES
# include <nuttx/semaphore.h>
#endif
#ifndef CONFIG_DISABLE_MQUEUE
# include <nuttx/mqueue.h>
#endif
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Most internal OS interfaces are not available in the user space in
* PROTECTED and KERNEL builds. In that context, the corresponding
* application interfaces must be used. The differences between the two
* sets of interfaces are: The internal OS interfaces (1) do not cause
* cancellation points and (2) they do not modify the errno variable.
*
* This is only important when compiling libraries (libc or libnx) that are
* used both by the OS (libkc.a and libknx.a) or by the applications
* (libuc.a and libunx.a). The that case, the correct interface must be
* used for the build context.
*
* The interfaces open(), close(), creat(), read(), pread(), write(),
* pwrite(), poll(), select(), fcntl(), and aio_suspend() are all
* cancellation points.
*
* REVISIT: These cancellation points are an issue and may cause
* violations: It use of these internally will cause the calling function
* to become a cancellation points!
*/
#if defined(CONFIG_BUILD_FLAT) || defined(__KERNEL__)
# define _NX_READ(f,b,s) nx_read(f,b,s)
# define _NX_WRITE(f,b,s) nx_write(f,b,s)
# define _NX_GETERRNO(r) (-(r))
# define _NX_SETERRNO(r) set_errno(-(r))
# define _NX_GETERRVAL(r) (r)
#else
# define _NX_READ(f,b,s) read(f,b,s)
# define _NX_WRITE(f,b,s) write(f,b,s)
# define _NX_GETERRNO(r) errno
# define _NX_SETERRNO(r)
# define _NX_GETERRVAL(r) (-errno)
#endif
/* Stream flags for the fs_flags field of in struct file_struct */
#define __FS_FLAG_EOF (1 << 0) /* EOF detected by a read operation */
#define __FS_FLAG_ERROR (1 << 1) /* Error detected by any operation */
#define __FS_FLAG_LBF (1 << 2) /* Line buffered */
#define __FS_FLAG_UBF (1 << 3) /* Buffer allocated by caller of setvbuf */
/* Inode i_flag values:
*
* Bit 0-3: Inode type (Bit 4 indicates internal OS types)
* Bit 4: Set if inode has been unlinked and is pending removal.
*/
#define FSNODEFLAG_TYPE_MASK 0x00000007 /* Isolates type field */
#define FSNODEFLAG_TYPE_DRIVER 0x00000000 /* Character driver */
#define FSNODEFLAG_TYPE_BLOCK 0x00000001 /* Block driver */
#define FSNODEFLAG_TYPE_MOUNTPT 0x00000002 /* Mount point */
#define FSNODEFLAG_TYPE_SPECIAL 0x00000004 /* Special OS type */
#define FSNODEFLAG_TYPE_NAMEDSEM 0x00000004 /* Named semaphore */
#define FSNODEFLAG_TYPE_MQUEUE 0x00000005 /* Message Queue */
#define FSNODEFLAG_TYPE_SHM 0x00000006 /* Shared memory region */
#define FSNODEFLAG_TYPE_SOFTLINK 0x00000007 /* Soft link */
#define FSNODEFLAG_DELETED 0x00000008 /* Unlinked */
#define INODE_IS_TYPE(i,t) \
(((i)->i_flags & FSNODEFLAG_TYPE_MASK) == (t))
#define INODE_IS_SPECIAL(i) \
(((i)->i_flags & FSNODEFLAG_TYPE_SPECIAL) != 0)
#define INODE_IS_DRIVER(i) INODE_IS_TYPE(i,FSNODEFLAG_TYPE_DRIVER)
#define INODE_IS_BLOCK(i) INODE_IS_TYPE(i,FSNODEFLAG_TYPE_BLOCK)
#define INODE_IS_MOUNTPT(i) INODE_IS_TYPE(i,FSNODEFLAG_TYPE_MOUNTPT)
#define INODE_IS_NAMEDSEM(i) INODE_IS_TYPE(i,FSNODEFLAG_TYPE_NAMEDSEM)
#define INODE_IS_MQUEUE(i) INODE_IS_TYPE(i,FSNODEFLAG_TYPE_MQUEUE)
#define INODE_IS_SHM(i) INODE_IS_TYPE(i,FSNODEFLAG_TYPE_SHM)
#define INODE_IS_SOFTLINK(i) INODE_IS_TYPE(i,FSNODEFLAG_TYPE_SOFTLINK)
#define INODE_GET_TYPE(i) ((i)->i_flags & FSNODEFLAG_TYPE_MASK)
#define INODE_SET_TYPE(i,t) \
do \
{ \
(i)->i_flags = ((i)->i_flags & ~FSNODEFLAG_TYPE_MASK) | (t); \
} \
while (0)
#define INODE_SET_DRIVER(i) INODE_SET_TYPE(i,FSNODEFLAG_TYPE_DRIVER)
#define INODE_SET_BLOCK(i) INODE_SET_TYPE(i,FSNODEFLAG_TYPE_BLOCK)
#define INODE_SET_MOUNTPT(i) INODE_SET_TYPE(i,FSNODEFLAG_TYPE_MOUNTPT)
#define INODE_SET_NAMEDSEM(i) INODE_SET_TYPE(i,FSNODEFLAG_TYPE_NAMEDSEM)
#define INODE_SET_MQUEUE(i) INODE_SET_TYPE(i,FSNODEFLAG_TYPE_MQUEUE)
#define INODE_SET_SHM(i) INODE_SET_TYPE(i,FSNODEFLAG_TYPE_SHM)
#define INODE_SET_SOFTLINK(i) INODE_SET_TYPE(i,FSNODEFLAG_TYPE_SOFTLINK)
/* Mountpoint fd_flags values */
#define DIRENTFLAGS_PSEUDONODE 1
#define DIRENT_SETPSEUDONODE(f) do (f) |= DIRENTFLAGS_PSEUDONODE; while (0)
#define DIRENT_ISPSEUDONODE(f) (((f) & DIRENTFLAGS_PSEUDONODE) != 0)
/* The struct file_operations open(0) normally returns zero on success and
* a negated errno value on failure. There is one case, however, where
* the open method will redirect to another driver and return a file
* descriptor instead.
*
* This case is when SUSv1 pseudo-terminals are used (CONFIG_PSEUDOTERM_SUSV1=y).
* In this case, the output is encoded and decoded using these macros in
* order to support (a) returning file descriptor 0 (which really should
* not happen), and (b) avoiding confusion if some other open method returns
* a positive, non-zero value which is not a file descriptor.
*
* OPEN_ISFD(r) tests if the return value from the open method is
* really a file descriptor.
* OPEN_SETFD(f) is used by an implementation of the open() method
* in order to encode a file descriptor in the return value.
* OPEN_GETFD(r) is use by the upper level open() logic to decode
* the file descriptor encoded in the return value.
*
* REVISIT: This only works for file descriptors in the in range 0-255.
*/
#define OPEN_MAGIC 0x4200
#define OPEN_MASK 0x00ff
#define OPEN_MAXFD 0x00ff
#define OPEN_ISFD(r) (((r) & ~OPEN_MASK) == OPEN_MAGIC)
#define OPEN_SETFD(f) ((f) | OPEN_MAGIC)
#define OPEN_GETFD(r) ((r) & OPEN_MASK)
/****************************************************************************
* Public Type Definitions
****************************************************************************/
/* This structure is provided by devices when they are registered with the
* system. It is used to call back to perform device specific operations.
*/
struct file; /* Forward reference */
struct pollfd; /* Forward reference */
struct inode; /* Forward reference */
struct file_operations
{
/* The device driver open method differs from the mountpoint open method */
int (*open)(FAR struct file *filep);
/* The following methods must be identical in signature and position because
* the struct file_operations and struct mountp_operations are treated like
* unions.
*/
int (*close)(FAR struct file *filep);
ssize_t (*read)(FAR struct file *filep, FAR char *buffer, size_t buflen);
ssize_t (*write)(FAR struct file *filep, FAR const char *buffer, size_t buflen);
off_t (*seek)(FAR struct file *filep, off_t offset, int whence);
int (*ioctl)(FAR struct file *filep, int cmd, unsigned long arg);
/* The two structures need not be common after this point */
#ifndef CONFIG_DISABLE_POLL
int (*poll)(FAR struct file *filep, struct pollfd *fds, bool setup);
#endif
#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
int (*unlink)(FAR struct inode *inode);
#endif
};
/* This structure provides information about the state of a block driver */
#ifndef CONFIG_DISABLE_MOUNTPOINT
struct geometry
{
bool geo_available; /* true: The device is available */
bool geo_mediachanged; /* true: The media has changed since last query */
bool geo_writeenabled; /* true: It is okay to write to this device */
size_t geo_nsectors; /* Number of sectors on the device */
size_t geo_sectorsize; /* Size of one sector */
};
/* This structure is provided by block devices when they register with the
* system. It is used by file systems to perform filesystem transfers. It
* differs from the normal driver vtable in several ways -- most notably in
* that it deals in struct inode vs. struct filep.
*/
struct inode;
struct block_operations
{
int (*open)(FAR struct inode *inode);
int (*close)(FAR struct inode *inode);
ssize_t (*read)(FAR struct inode *inode, FAR unsigned char *buffer,
size_t start_sector, unsigned int nsectors);
ssize_t (*write)(FAR struct inode *inode, FAR const unsigned char *buffer,
size_t start_sector, unsigned int nsectors);
int (*geometry)(FAR struct inode *inode, FAR struct geometry *geometry);
int (*ioctl)(FAR struct inode *inode, int cmd, unsigned long arg);
#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
int (*unlink)(FAR struct inode *inode);
#endif
};
/* This structure is provided by a filesystem to describe a mount point.
* Note that this structure differs from file_operations ONLY in the form of
* the open method. Once the file is opened, it can be accessed either as a
* struct file_operations or struct mountpt_operations
*/
struct inode;
struct fs_dirent_s;
struct stat;
struct statfs;
struct mountpt_operations
{
/* The mountpoint open method differs from the driver open method
* because it receives (1) the inode that contains the mountpoint
* private data, (2) the relative path into the mountpoint, and (3)
* information to manage privileges.
*/
int (*open)(FAR struct file *filep, FAR const char *relpath,
int oflags, mode_t mode);
/* The following methods must be identical in signature and position
* because the struct file_operations and struct mountpt_operations are
* treated like unions.
*/
int (*close)(FAR struct file *filep);
ssize_t (*read)(FAR struct file *filep, FAR char *buffer, size_t buflen);
ssize_t (*write)(FAR struct file *filep, FAR const char *buffer,
size_t buflen);
off_t (*seek)(FAR struct file *filep, off_t offset, int whence);
int (*ioctl)(FAR struct file *filep, int cmd, unsigned long arg);
/* The two structures need not be common after this point. The following
* are extended methods needed to deal with the unique needs of mounted
* file systems.
*
* Additional open-file-specific mountpoint operations:
*/
int (*sync)(FAR struct file *filep);
int (*dup)(FAR const struct file *oldp, FAR struct file *newp);
int (*fstat)(FAR const struct file *filep, FAR struct stat *buf);
int (*truncate)(FAR struct file *filep, off_t length);
/* Directory operations */
int (*opendir)(FAR struct inode *mountpt, FAR const char *relpath,
FAR struct fs_dirent_s *dir);
int (*closedir)(FAR struct inode *mountpt,
FAR struct fs_dirent_s *dir);
int (*readdir)(FAR struct inode *mountpt,
FAR struct fs_dirent_s *dir);
int (*rewinddir)(FAR struct inode *mountpt,
FAR struct fs_dirent_s *dir);
/* General volume-related mountpoint operations: */
int (*bind)(FAR struct inode *blkdriver, FAR const void *data,
FAR void **handle);
int (*unbind)(FAR void *handle, FAR struct inode **blkdriver,
unsigned int flags);
int (*statfs)(FAR struct inode *mountpt, FAR struct statfs *buf);
/* Operations on paths */
int (*unlink)(FAR struct inode *mountpt, FAR const char *relpath);
int (*mkdir)(FAR struct inode *mountpt, FAR const char *relpath,
mode_t mode);
int (*rmdir)(FAR struct inode *mountpt, FAR const char *relpath);
int (*rename)(FAR struct inode *mountpt, FAR const char *oldrelpath,
FAR const char *newrelpath);
int (*stat)(FAR struct inode *mountpt, FAR const char *relpath,
FAR struct stat *buf);
/* NOTE: More operations will be needed here to support: disk usage
* stats file stat(), file attributes, file truncation, etc.
*/
};
#endif /* CONFIG_DISABLE_MOUNTPOINT */
/* Named OS resources are also maintained by the VFS. This includes:
*
* - Named semaphores: sem_open(), sem_close(), and sem_unlink()
* - POSIX Message Queues: mq_open() and mq_close()
* - Shared memory: shm_open() and shm_unlink();
*
* These are a special case in that they do not follow quite the same
* pattern as the other file system types in that they have operations.
*/
/* These are the various kinds of operations that can be associated with
* an inode.
*/
union inode_ops_u
{
FAR const struct file_operations *i_ops; /* Driver operations for inode */
#ifndef CONFIG_DISABLE_MOUNTPOINT
FAR const struct block_operations *i_bops; /* Block driver operations */
FAR const struct mountpt_operations *i_mops; /* Operations on a mountpoint */
#endif
#ifdef CONFIG_FS_NAMED_SEMAPHORES
FAR struct nsem_inode_s *i_nsem; /* Named semaphore */
#endif
#ifndef CONFIG_DISABLE_MQUEUE
FAR struct mqueue_inode_s *i_mqueue; /* POSIX message queue */
#endif
#ifdef CONFIG_PSEUDOFS_SOFTLINKS
FAR char *i_link; /* Full path to link target */
#endif
};
/* This structure represents one inode in the NuttX pseudo-file system */
struct inode
{
FAR struct inode *i_peer; /* Link to same level inode */
FAR struct inode *i_child; /* Link to lower level inode */
int16_t i_crefs; /* References to inode */
uint16_t i_flags; /* Flags for inode */
union inode_ops_u u; /* Inode operations */
#ifdef CONFIG_FILE_MODE
mode_t i_mode; /* Access mode flags */
#endif
FAR void *i_private; /* Per inode driver private data */
char i_name[1]; /* Name of inode (variable) */
};
#define FSNODE_SIZE(n) (sizeof(struct inode) + (n))
/* This is the underlying representation of an open file. A file
* descriptor is an index into an array of such types. The type associates
* the file descriptor to the file state and to a set of inode operations.
*/
struct file
{
int f_oflags; /* Open mode flags */
off_t f_pos; /* File position */
FAR struct inode *f_inode; /* Driver or file system interface */
void *f_priv; /* Per file driver private data */
};
/* This defines a list of files indexed by the file descriptor */
#if CONFIG_NFILE_DESCRIPTORS > 0
struct filelist
{
sem_t fl_sem; /* Manage access to the file list */
struct file fl_files[CONFIG_NFILE_DESCRIPTORS];
};
#endif
/* The following structure defines the list of files used for standard C I/O.
* Note that NuttX can support the standard C APIs without or without buffering
*
* When buffering us used, the following described the usage of the I/O buffer.
* The buffer can be used for reading or writing -- but not both at the same time.
* An fflush is implied between each change in direction of access.
*
* The field fs_bufread determines whether the buffer is being used for reading or
* for writing as follows:
*
* BUFFER
* +----------------------+ <- fs_bufstart Points to the beginning of the buffer.
* | WR: Buffered data | WR: Start of buffered write data.
* | RD: Already read | RD: Start of already read data.
* +----------------------+
* | WR: Available buffer | <- fs_bufpos Points to next byte:
* | RD: Read-ahead data | WR: End+1 of buffered write data.
* | | RD: Points to next char to return
* +----------------------+
* | WR: Available | <- fs_bufread Top+1 of buffered read data
* | RD: Available | WR: bufstart buffer used for writing.
* | | RD: Pointer to last buffered read char+1
* +----------------------+
* <- fs_bufend Points to end end of the buffer+1
*/
#if CONFIG_NFILE_STREAMS > 0
struct file_struct
{
int fs_fd; /* File descriptor associated with stream */
#ifndef CONFIG_STDIO_DISABLE_BUFFERING
sem_t fs_sem; /* For thread safety */
pid_t fs_holder; /* Holder of sem */
int fs_counts; /* Number of times sem is held */
FAR unsigned char *fs_bufstart; /* Pointer to start of buffer */
FAR unsigned char *fs_bufend; /* Pointer to 1 past end of buffer */
FAR unsigned char *fs_bufpos; /* Current position in buffer */
FAR unsigned char *fs_bufread; /* Pointer to 1 past last buffered read char. */
#endif
uint16_t fs_oflags; /* Open mode flags */
uint8_t fs_flags; /* Stream flags */
#if CONFIG_NUNGET_CHARS > 0
uint8_t fs_nungotten; /* The number of characters buffered for ungetc */
unsigned char fs_ungotten[CONFIG_NUNGET_CHARS];
#endif
};
struct streamlist
{
sem_t sl_sem; /* For thread safety */
struct file_struct sl_streams[CONFIG_NFILE_STREAMS];
};
#endif /* CONFIG_NFILE_STREAMS */
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
#undef EXTERN
#if defined(__cplusplus)
#define EXTERN extern "C"
extern "C"
{
#else
#define EXTERN extern
#endif
/****************************************************************************
* Name: fs_initialize
*
* Description:
* This is called from the OS initialization logic to configure the file
* system.
*
****************************************************************************/
void fs_initialize(void);
/****************************************************************************
* Name: register_driver
*
* Description:
* Register a character driver inode the pseudo file system.
*
* Input Parameters:
* path - The path to the inode to create
* fops - The file operations structure
* mode - inmode privileges (not used)
* priv - Private, user data that will be associated with the inode.
*
* Returned Value:
* Zero on success (with the inode point in 'inode'); A negated errno
* value is returned on a failure (all error values returned by
* inode_reserve):
*
* 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 register_driver(FAR const char *path,
FAR const struct file_operations *fops, mode_t mode,
FAR void *priv);
/****************************************************************************
* Name: register_blockdriver
*
* Description:
* Register a block driver inode the pseudo file system.
*
* Input Parameters:
* path - The path to the inode to create
* bops - The block driver operations structure
* mode - inmode privileges (not used)
* priv - Private, user data that will be associated with the inode.
*
* Returned Value:
* Zero on success (with the inode point in 'inode'); A negated errno
* value is returned on a failure (all error values returned by
* inode_reserve):
*
* EINVAL - 'path' is invalid for this operation
* EEXIST - An inode already exists at 'path'
* ENOMEM - Failed to allocate in-memory resources for the operation
*
****************************************************************************/
#ifndef CONFIG_DISABLE_MOUNTPOINT
int register_blockdriver(FAR const char *path,
FAR const struct block_operations *bops,
mode_t mode, FAR void *priv);
#endif
/****************************************************************************
* Name: unregister_driver
*
* Description:
* Remove the character driver inode at 'path' from the pseudo-file system
*
****************************************************************************/
int unregister_driver(FAR const char *path);
/****************************************************************************
* Name: unregister_blockdriver
*
* Description:
* Remove the block driver inode at 'path' from the pseudo-file system
*
****************************************************************************/
int unregister_blockdriver(FAR const char *path);
/****************************************************************************
* 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: files_initlist
*
* Description:
* Initializes the list of files for a new task
*
****************************************************************************/
#if CONFIG_NFILE_DESCRIPTORS > 0
void files_initlist(FAR struct filelist *list);
#endif
/****************************************************************************
* Name: files_releaselist
*
* Description:
* Release a reference to the file list
*
****************************************************************************/
#if CONFIG_NFILE_DESCRIPTORS > 0
void files_releaselist(FAR struct filelist *list);
#endif
/****************************************************************************
* Name: file_dup2
*
* Description:
* Assign an inode to a specific files structure. This is the heart of
* dup2.
*
* Equivalent to the non-standard fs_dupfd2() function except that it
* accepts struct file instances instead of file descriptors and it does
* not set the errno variable.
*
* Returned Value:
* Zero (OK) is returned on success; a negated errno value is return on
* any failure.
*
****************************************************************************/
#if CONFIG_NFILE_DESCRIPTORS > 0
int file_dup2(FAR struct file *filep1, FAR struct file *filep2);
#endif
/****************************************************************************
* Name: fs_dupfd OR dup
*
* Description:
* Clone a file descriptor 'fd' to an arbitrary descriptor number (any value
* greater than or equal to 'minfd'). If socket descriptors are
* implemented, then this is called by dup() for the case of file
* descriptors. If socket descriptors are not implemented, then this
* function IS dup().
*
* This alternative naming is used when dup could operate on both file and
* socket descriptors to avoid drawing unused socket support into the link.
*
* Returned Value:
* fs_dupfd is sometimes an OS internal function and sometimes is a direct
* substitute for dup(). So it must return an errno value as though it
* were dup().
*
****************************************************************************/
#if CONFIG_NFILE_DESCRIPTORS > 0
int fs_dupfd(int fd, int minfd);
#endif
/****************************************************************************
* Name: file_dup
*
* Description:
* Equivalent to the non-standard fs_dupfd() function except that it
* accepts a struct file instance instead of a file descriptor and does
* not set the errno variable.
*
* Returned Value:
* Zero (OK) is returned on success; a negated errno value is returned on
* any failure.
*
****************************************************************************/
int file_dup(FAR struct file *filep, int minfd);
/****************************************************************************
* Name: fs_dupfd2 OR dup2
*
* Description:
* Clone a file descriptor to a specific descriptor number. If socket
* descriptors are implemented, then this is called by dup2() for the
* case of file descriptors. If socket descriptors are not implemented,
* then this function IS dup2().
*
* This alternative naming is used when dup2 could operate on both file and
* socket descriptors to avoid drawing unused socket support into the link.
*
* Returned Value:
* fs_dupfd2 is sometimes an OS internal function and sometimes is a direct
* substitute for dup2(). So it must return an errno value as though it
* were dup2().
*
****************************************************************************/
#if CONFIG_NFILE_DESCRIPTORS > 0
#if defined(CONFIG_NET) && CONFIG_NSOCKET_DESCRIPTORS > 0
int fs_dupfd2(int fd1, int fd2);
#else
# define fs_dupfd2(fd1, fd2) dup2(fd1, fd2)
#endif
#endif
/****************************************************************************
* Name: file_detach
*
* Description:
* This function is used to device drivers to create a task-independent
* handle to an entity in the file system. file_detach() duplicates the
* 'struct file' that underlies the file descriptor, then closes the file
* descriptor.
*
* This function will fail if fd is not a valid file descriptor. In
* particular, it will fail if fd is a socket descriptor.
*
* Input Parameters:
* fd - The file descriptor to be detached. This descriptor will be
* closed and invalid if the file was successfully detached.
* filep - A pointer to a user provided memory location in which to
* received the duplicated, detached file structure.
*
* Returned Value:
* Zero (OK) is returned on success; A negated errno value is returned on
* any failure to indicate the nature of the failure.
*
****************************************************************************/
#if CONFIG_NFILE_DESCRIPTORS > 0
int file_detach(int fd, FAR struct file *filep);
#endif
/****************************************************************************
* Name: file_close_detached
*
* Description:
* Close a file that was previously detached with file_detach().
*
* Input Parameters:
* filep - A pointer to a user provided memory location containing the
* open file data returned by file_detach().
*
* Returned Value:
* Zero (OK) is returned on success; A negated errno value is returned on
* any failure to indicate the nature of the failure.
*
****************************************************************************/
int file_close_detached(FAR struct file *filep);
/****************************************************************************
* Name: open_blockdriver
*
* Description:
* Return the inode of the block driver specified by 'pathname'
*
* Input Parameters:
* pathname - the full path to the block driver to be opened
* mountflags - if MS_RDONLY is not set, then driver must support write
* operations (see include/sys/mount.h)
* ppinode - address of the location to return the inode reference
*
* Returned Value:
* Returns zero on success or a negated errno on failure:
*
* EINVAL - pathname or pinode is NULL
* ENOENT - No block driver of this name is registered
* ENOTBLK - The inode associated with the pathname is not a block driver
* EACCESS - The MS_RDONLY option was not set but this driver does not
* support write access
*
****************************************************************************/
#if CONFIG_NFILE_DESCRIPTORS > 0
int open_blockdriver(FAR const char *pathname, int mountflags,
FAR struct inode **ppinode);
#endif
/****************************************************************************
* Name: close_blockdriver
*
* Description:
* Call the close method and release the inode
*
* Input Parameters:
* inode - reference to the inode of a block driver opened by open_blockdriver
*
* Returned Value:
* Returns zero on success or a negated errno on failure:
*
* EINVAL - inode is NULL
* ENOTBLK - The inode is not a block driver
*
****************************************************************************/
#if CONFIG_NFILE_DESCRIPTORS > 0
int close_blockdriver(FAR struct inode *inode);
#endif
/****************************************************************************
* Name: fs_ioctl
*
* Description:
* Perform device specific operations.
*
* Input Parameters:
* fd File/socket descriptor of device
* req The ioctl command
* arg The argument of the ioctl cmd
*
* Returned Value:
* >=0 on success (positive non-zero values are cmd-specific)
* -1 on failure with errno set properly:
*
* EBADF
* 'fd' is not a valid descriptor.
* EFAULT
* 'arg' references an inaccessible memory area.
* EINVAL
* 'cmd' or 'arg' is not valid.
* ENOTTY
* 'fd' is not associated with a character special device.
* ENOTTY
* The specified request does not apply to the kind of object that the
* descriptor 'fd' references.
*
****************************************************************************/
#ifdef CONFIG_LIBC_IOCTL_VARIADIC
int fs_ioctl(int fd, int req, unsigned long arg);
#endif
/****************************************************************************
* Name: fs_fdopen
*
* Description:
* This function does the core operations for fopen and fdopen. It is
* used by the OS to clone stdin, stdout, stderr
*
****************************************************************************/
#if CONFIG_NFILE_STREAMS > 0
struct tcb_s; /* Forward reference */
FAR struct file_struct *fs_fdopen(int fd, int oflags, FAR struct tcb_s *tcb);
#endif
/****************************************************************************
* Name: lib_flushall
*
* Description:
* Called either (1) by the OS when a task exits, or (2) from fflush()
* when a NULL stream argument is provided.
*
****************************************************************************/
#if CONFIG_NFILE_STREAMS > 0
int lib_flushall(FAR struct streamlist *list);
#endif
/****************************************************************************
* Name: lib_sendfile
*
* Description:
* Transfer a file
*
****************************************************************************/
#ifdef CONFIG_NET_SENDFILE
ssize_t lib_sendfile(int outfd, int infd, off_t *offset, size_t count);
#endif
/****************************************************************************
* Name: fs_getfilep
*
* Description:
* Given a file descriptor, return the corresponding instance of struct
* file. NOTE that this function will currently fail if it is provided
* with a socket descriptor.
*
* Input Parameters:
* fd - The file descriptor
* filep - The location to return the struct file instance
*
* Returned Value:
* Zero (OK) is returned on success; a negated errno value is returned on
* any failure.
*
****************************************************************************/
#if CONFIG_NFILE_DESCRIPTORS > 0
int fs_getfilep(int fd, FAR struct file **filep);
#endif
/****************************************************************************
* Name: file_read
*
* Description:
* file_read() is an interanl OS interface. It is functionally similar to
* the standard read() interface except:
*
* - It does not modify the errno variable,
* - It is not a cancellation point,
* - It does not handle socket descriptors, and
* - It accepts a file structure instance instead of file descriptor.
*
* Input Parameters:
* filep - File structure instance
* buf - User-provided to save the data
* nbytes - The maximum size of the user-provided buffer
*
* Returned Value:
* The positive non-zero number of bytes read on success, 0 on if an
* end-of-file condition, or a negated errno value on any failure.
*
****************************************************************************/
#if CONFIG_NFILE_DESCRIPTORS > 0
ssize_t file_read(FAR struct file *filep, FAR void *buf, size_t nbytes);
#endif
/****************************************************************************
* Name: nx_read
*
* Description:
* nx_read() is an interanl OS interface. It is functionally similar to
* the standard read() interface except:
*
* - It does not modify the errno variable, and
* - It is not a cancellation point.
*
* Input Parameters:
* fd - File descriptor to read from
* buf - User-provided to save the data
* nbytes - The maximum size of the user-provided buffer
*
* Returned Value:
* The positive non-zero number of bytes read on success, 0 on if an
* end-of-file condition, or a negated errno value on any failure.
*
****************************************************************************/
ssize_t nx_read(int fd, FAR void *buf, size_t nbytes);
/****************************************************************************
* Name: file_write
*
* Description:
* Equivalent to the standard write() function except that is accepts a
* struct file instance instead of a file descriptor. Currently used
* only by aio_write();
*
****************************************************************************/
#if CONFIG_NFILE_DESCRIPTORS > 0
ssize_t file_write(FAR struct file *filep, FAR const void *buf, size_t nbytes);
#endif
/****************************************************************************
* Name: nx_write
*
* Description:
* nx_write() writes up to nytes bytes to the file referenced by the file
* descriptor fd from the buffer starting at buf. nx_write() is an
* internal OS function. It is functionally equivalent to write() except
* that:
*
* - It does not modify the errno variable, and
* - It is not a cancellation point.
*
* Input Parameters:
* fd - file descriptor (or socket descriptor) to write to
* buf - Data to write
* nbytes - Length of data to write
*
* Returned Value:
* On success, the number of bytes written are returned (zero indicates
* nothing was written). On any failure, a negated errno value is returned
* (see comments withwrite() for a description of the appropriate errno
* values).
*
****************************************************************************/
ssize_t nx_write(int fd, FAR const void *buf, size_t nbytes);
/****************************************************************************
* Name: file_pread
*
* Description:
* Equivalent to the standard pread function except that is accepts a
* struct file instance instead of a file descriptor. Currently used
* only by aio_read();
*
****************************************************************************/
#if CONFIG_NFILE_DESCRIPTORS > 0
ssize_t file_pread(FAR struct file *filep, FAR void *buf, size_t nbytes,
off_t offset);
#endif
/****************************************************************************
* Name: file_pwrite
*
* Description:
* Equivalent to the standard pwrite function except that is accepts a
* struct file instance instead of a file descriptor. Currently used
* only by aio_write();
*
****************************************************************************/
#if CONFIG_NFILE_DESCRIPTORS > 0
ssize_t file_pwrite(FAR struct file *filep, FAR const void *buf,
size_t nbytes, off_t offset);
#endif
/****************************************************************************
* Name: file_seek
*
* Description:
* Equivalent to the standard lseek() function except that is accepts a
* struct file instance instead of a file descriptor. Currently used
* only by net_sendfile()
*
****************************************************************************/
#if CONFIG_NFILE_DESCRIPTORS > 0
off_t file_seek(FAR struct file *filep, off_t offset, int whence);
#endif
/****************************************************************************
* Name: file_fsync
*
* Description:
* Equivalent to the standard fsync() function except that is accepts a
* struct file instance instead of a file descriptor and it does not set
* the errno variable.
*
****************************************************************************/
#if CONFIG_NFILE_DESCRIPTORS > 0 && !defined(CONFIG_DISABLE_MOUNTPOINT)
int file_fsync(FAR struct file *filep);
#endif
/****************************************************************************
* Name: file_truncate
*
* Description:
* Equivalent to the standard ftruncate() function except that is accepts
* a struct file instance instead of a file descriptor and it does not set
* the errno variable.
*
****************************************************************************/
#if CONFIG_NFILE_DESCRIPTORS > 0 && !defined(CONFIG_DISABLE_MOUNTPOINT)
int file_truncate(FAR struct file *filep, off_t length);
#endif
/****************************************************************************
* Name: file_ioctl
*
* Description:
* Perform device specific operations.
*
* Input Parameters:
* file File structure instance
* req The ioctl command
* arg The argument of the ioctl cmd
*
* Returned Value:
* Returns a non-negative number on success; A negated errno value is
* returned on any failure (see comments ioctl() for a list of appropriate
* errno values).
*
****************************************************************************/
#if CONFIG_NFILE_DESCRIPTORS > 0
int file_ioctl(FAR struct file *filep, int req, unsigned long arg);
#endif
/****************************************************************************
* Name: file_vfcntl
*
* Description:
* Similar to the standard vfcntl function except that is accepts a struct
* struct file instance instead of a file descriptor.
*
* Input Parameters:
* filep - Instance for struct file for the opened file.
* cmd - Indentifies the operation to be performed.
* ap - Variable argument following the command.
*
* Returned Value:
* The nature of the return value depends on the command. Non-negative
* values indicate success. Failures are reported as negated errno
* values.
*
****************************************************************************/
#if CONFIG_NFILE_DESCRIPTORS > 0
int file_vfcntl(FAR struct file *filep, int cmd, va_list ap);
#endif
/****************************************************************************
* Name: file_poll
*
* Description:
* Low-level poll operation based on struc file. This is used both to (1)
* support detached file, and also (2) by fdesc_poll() to perform all
* normal operations on file descriptors descriptors.
*
* Input Parameters:
* file File structure instance
* fds - The structure describing the events to be monitored, OR NULL if
* this is a request to stop monitoring events.
* setup - true: Setup up the poll; false: Teardown the poll
*
* Returned Value:
* 0: Success; Negated errno on failure
*
****************************************************************************/
#if CONFIG_NFILE_DESCRIPTORS > 0
int file_poll(FAR struct file *filep, FAR struct pollfd *fds, bool setup);
#endif
/****************************************************************************
* Name: fdesc_poll
*
* Description:
* The standard poll() operation redirects operations on file descriptors
* to this function.
*
* Input Parameters:
* fd - The file descriptor of interest
* fds - The structure describing the events to be monitored, OR NULL if
* this is a request to stop monitoring events.
* setup - true: Setup up the poll; false: Teardown the poll
*
* Returned Value:
* 0: Success; Negated errno on failure
*
****************************************************************************/
#if CONFIG_NFILE_DESCRIPTORS > 0
int fdesc_poll(int fd, FAR struct pollfd *fds, bool setup);
#endif
#undef EXTERN
#if defined(__cplusplus)
}
#endif
#endif /* __INCLUDE_NUTTX_FS_FS_H */
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