/*
* This file contains the support infrastructure used to manage the
* table of integer style file descriptors used by the low level
* POSIX system calls like open(), read, fstat(), etc.
*
* This provides the foundation for POSIX compliant IO system calls
* for RTEMS.
*
* COPYRIGHT (c) 1989-1998.
* On-Line Applications Research Corporation (OAR).
* Copyright assigned to U.S. Government, 1994.
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.OARcorp.com/rtems/license.html.
*
* $Id$
*/
#include "libio_.h" /* libio_.h pulls in rtems */
/*
* Global variables used to manage the File Descriptor Table.
* IOP = IO Pointer.
*/
rtems_id rtems_libio_semaphore;
rtems_libio_t *rtems_libio_iops;
rtems_libio_t *rtems_libio_last_iop;
rtems_libio_handler_t rtems_libio_handlers[15];
/*
* rtems_register_libio_handler
*
* This function registers an external IO handler set. This lets
* other subsystems have their own versions of many of the system
* calls. For example, the networking code registers handlers which
* map the system calls for read() and write() to socket calls.
*
*/
void rtems_register_libio_handler(
int handler_flag,
const rtems_libio_handler_t *handler
)
{
int handler_index = rtems_file_descriptor_type_index( handler_flag );
if ((handler_index < 0) || (handler_index >= 15))
rtems_fatal_error_occurred( RTEMS_INVALID_NUMBER );
rtems_libio_handlers[handler_index] = *handler;
}
/*
* rtems_libio_init
*
* Called by BSP startup code to initialize the libio subsystem.
*/
void rtems_libio_init( void )
{
rtems_status_code rc;
/*
* Allocate memory for the IOP Table
*/
if ( rtems_libio_number_iops > 0 ) {
rtems_libio_iops =
(rtems_libio_t *) calloc(rtems_libio_number_iops, sizeof(rtems_libio_t));
if (rtems_libio_iops == NULL)
rtems_fatal_error_occurred( RTEMS_NO_MEMORY );
rtems_libio_last_iop = rtems_libio_iops + (rtems_libio_number_iops - 1);
}
/*
* Create the binary semaphore used to provide mutual exclusion
* on the IOP Table.
*/
rc = rtems_semaphore_create(
RTEMS_LIBIO_SEM,
1,
RTEMS_BINARY_SEMAPHORE | RTEMS_INHERIT_PRIORITY | RTEMS_PRIORITY,
RTEMS_NO_PRIORITY,
&rtems_libio_semaphore
);
if ( rc != RTEMS_SUCCESSFUL )
rtems_fatal_error_occurred( rc );
/*
* Initialize the base file system infrastructure.
*/
rtems_filesystem_initialize();
}
/*
* rtems_libio_fcntl_flags
*
* Convert UNIX fnctl(2) flags to ones that RTEMS drivers understand
*/
rtems_assoc_t access_modes_assoc[] = {
{ "READ", LIBIO_FLAGS_READ, O_RDONLY },
{ "WRITE", LIBIO_FLAGS_WRITE, O_WRONLY },
{ "READ/WRITE", LIBIO_FLAGS_READ_WRITE, O_RDWR },
{ 0, 0, 0 },
};
rtems_assoc_t status_flags_assoc[] = {
{ "NO DELAY", LIBIO_FLAGS_NO_DELAY, O_NDELAY },
{ "APPEND", LIBIO_FLAGS_APPEND, O_APPEND },
{ "CREATE", LIBIO_FLAGS_CREATE, O_CREAT },
{ 0, 0, 0 },
};
unsigned32 rtems_libio_fcntl_flags(
unsigned32 fcntl_flags
)
{
unsigned32 flags = 0;
unsigned32 access_modes;
/*
* Access mode is a small integer
*/
access_modes = fcntl_flags & O_ACCMODE;
fcntl_flags &= ~O_ACCMODE;
flags = rtems_assoc_local_by_remote( access_modes_assoc, access_modes );
/*
* Everything else is single bits
*/
flags |=
rtems_assoc_local_by_remote_bitfield(status_flags_assoc, fcntl_flags);
return flags;
}
/*
* rtems_libio_allocate
*
* This routine searches the IOP Table for an unused entry. If it
* finds one, it returns it. Otherwise, it returns NULL.
*/
rtems_libio_t *rtems_libio_allocate( void )
{
rtems_libio_t *iop;
rtems_status_code rc;
rtems_semaphore_obtain( rtems_libio_semaphore, RTEMS_WAIT, RTEMS_NO_TIMEOUT );
for (iop = rtems_libio_iops; iop <= rtems_libio_last_iop; iop++)
if ((iop->flags & LIBIO_FLAGS_OPEN) == 0) {
/*
* Got an IOP -- create a semaphore for it.
*/
rc = rtems_semaphore_create(
RTEMS_LIBIO_IOP_SEM(iop - rtems_libio_iops),
1,
RTEMS_BINARY_SEMAPHORE | RTEMS_INHERIT_PRIORITY | RTEMS_PRIORITY,
RTEMS_NO_PRIORITY,
&iop->sem
);
if ( rc != RTEMS_SUCCESSFUL )
goto failed;
iop->flags = LIBIO_FLAGS_OPEN;
goto done;
}
failed:
iop = 0;
done:
rtems_semaphore_release( rtems_libio_semaphore );
return iop;
}
/*
* rtems_libio_free
*
* This routine frees the resources associated with an IOP (file descriptor)
* and clears the slot in the IOP Table.
*/
void rtems_libio_free(
rtems_libio_t *iop
)
{
rtems_semaphore_obtain( rtems_libio_semaphore, RTEMS_WAIT, RTEMS_NO_TIMEOUT );
if (iop->sem)
rtems_semaphore_delete(iop->sem);
(void) memset(iop, 0, sizeof(*iop));
rtems_semaphore_release( rtems_libio_semaphore );
}
/*
* rtems_libio_is_open_files_in_fs
*
* This routine scans the entire file descriptor table to determine if the
* are any active file descriptors that refer to the atleast one node in the
* file system that we are trying to dismount.
*
* If there is at least one node in the file system referenced by the mount
* table entry a 1 is returned, otherwise a 0 is returned.
*/
int rtems_libio_is_open_files_in_fs(
rtems_filesystem_mount_table_entry_t * fs_mt_entry
)
{
rtems_libio_t *iop;
int result = 0;
rtems_semaphore_obtain( rtems_libio_semaphore, RTEMS_WAIT, RTEMS_NO_TIMEOUT );
/*
* Look for any active file descriptor entry.
*/
for ( iop=rtems_libio_iops ; iop <= rtems_libio_last_iop ; iop++ ) {
if ((iop->flags & LIBIO_FLAGS_OPEN) != 0) {
/*
* Check if this node is under the file system that we
* are trying to dismount.
*/
if ( iop->pathinfo.mt_entry == fs_mt_entry ) {
result = 1;
break;
}
}
}
rtems_semaphore_release( rtems_libio_semaphore );
return result;
}
/*
* rtems_libio_is_file_open
*
* This routine scans the entire file descriptor table to determine if the
* given file refers to an active file descriptor.
*
* If the given file is open a 1 is returned, otherwise a 0 is returned.
*/
int rtems_libio_is_file_open(
void *node_access
)
{
rtems_libio_t *iop;
int result=0;
rtems_semaphore_obtain( rtems_libio_semaphore, RTEMS_WAIT, RTEMS_NO_TIMEOUT );
/*
* Look for any active file descriptor entry.
*/
for ( iop=rtems_libio_iops ; iop <= rtems_libio_last_iop ; iop++ ) {
if ((iop->flags & LIBIO_FLAGS_OPEN) != 0) {
/*
* Check if this node is under the file system that we
* are trying to dismount.
*/
if ( iop->pathinfo.node_access == node_access ) {
result = 1;
break;
}
}
}
rtems_semaphore_release( rtems_libio_semaphore );
return result;
}
