2008-05-31 22:14:15 +02:00
|
|
|
/****************************************************************************
|
2014-09-28 19:06:21 +02:00
|
|
|
* fs/inode/fs_inode.c
|
2007-02-18 00:21:28 +01:00
|
|
|
*
|
2017-10-04 23:22:27 +02:00
|
|
|
* Copyright (C) 2007-2009, 2011-2012, 2016-2017 Gregory Nutt. All rights
|
|
|
|
* reserved.
|
2012-07-14 23:05:40 +02:00
|
|
|
* Author: Gregory Nutt <gnutt@nuttx.org>
|
2007-02-18 00:21:28 +01:00
|
|
|
*
|
|
|
|
* 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.
|
2008-05-31 22:14:15 +02:00
|
|
|
* 3. Neither the name NuttX nor the names of its contributors may be
|
2007-02-18 00:21:28 +01:00
|
|
|
* 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.
|
|
|
|
*
|
2008-05-31 22:14:15 +02:00
|
|
|
****************************************************************************/
|
2007-02-18 00:21:28 +01:00
|
|
|
|
2008-05-31 22:14:15 +02:00
|
|
|
/****************************************************************************
|
2007-02-18 00:21:28 +01:00
|
|
|
* Included Files
|
2008-05-31 22:14:15 +02:00
|
|
|
****************************************************************************/
|
2007-02-18 00:21:28 +01:00
|
|
|
|
|
|
|
#include <nuttx/config.h>
|
|
|
|
|
2017-02-03 18:23:57 +01:00
|
|
|
#include <unistd.h>
|
2007-02-18 00:21:28 +01:00
|
|
|
#include <semaphore.h>
|
2017-02-02 17:39:41 +01:00
|
|
|
#include <assert.h>
|
2007-02-18 00:21:28 +01:00
|
|
|
#include <errno.h>
|
|
|
|
|
2012-03-21 19:01:07 +01:00
|
|
|
#include <nuttx/fs/fs.h>
|
2011-04-05 23:18:03 +02:00
|
|
|
|
2014-09-29 15:14:38 +02:00
|
|
|
#include "inode/inode.h"
|
2007-02-18 00:21:28 +01:00
|
|
|
|
2008-05-31 22:14:15 +02:00
|
|
|
/****************************************************************************
|
2009-12-15 01:18:32 +01:00
|
|
|
* Pre-processor Definitions
|
2008-05-31 22:14:15 +02:00
|
|
|
****************************************************************************/
|
2007-02-18 00:21:28 +01:00
|
|
|
|
2017-01-27 15:50:01 +01:00
|
|
|
#define NO_HOLDER ((pid_t)-1)
|
2013-11-28 20:12:14 +01:00
|
|
|
|
|
|
|
/****************************************************************************
|
|
|
|
* Private Types
|
|
|
|
****************************************************************************/
|
2016-04-14 18:14:38 +02:00
|
|
|
|
2013-11-28 20:12:14 +01:00
|
|
|
/* Implements a re-entrant mutex for inode access. This must be re-entrant
|
|
|
|
* because there can be cycles. For example, it may be necessary to destroy
|
|
|
|
* a block driver inode on umount() after a removable block device has been
|
|
|
|
* removed. In that case umount() hold the inode semaphore, but the block
|
2013-11-28 20:30:06 +01:00
|
|
|
* driver may callback to unregister_blockdriver() after the un-mount,
|
2013-11-28 20:12:14 +01:00
|
|
|
* requiring the seamphore again.
|
|
|
|
*/
|
|
|
|
|
|
|
|
struct inode_sem_s
|
|
|
|
{
|
|
|
|
sem_t sem; /* The semaphore */
|
|
|
|
pid_t holder; /* The current holder of the semaphore */
|
|
|
|
int16_t count; /* Number of counts held */
|
|
|
|
};
|
|
|
|
|
2008-05-31 22:14:15 +02:00
|
|
|
/****************************************************************************
|
2016-02-22 01:08:58 +01:00
|
|
|
* Private Data
|
2008-05-31 22:14:15 +02:00
|
|
|
****************************************************************************/
|
2007-02-18 00:21:28 +01:00
|
|
|
|
2013-11-28 20:12:14 +01:00
|
|
|
static struct inode_sem_s g_inode_sem;
|
2007-02-18 00:21:28 +01:00
|
|
|
|
2008-05-31 22:14:15 +02:00
|
|
|
/****************************************************************************
|
2007-03-14 23:41:09 +01:00
|
|
|
* Public Functions
|
2008-05-31 22:14:15 +02:00
|
|
|
****************************************************************************/
|
2007-02-18 00:21:28 +01:00
|
|
|
|
2008-05-31 22:14:15 +02:00
|
|
|
/****************************************************************************
|
2014-10-06 16:11:37 +02:00
|
|
|
* Name: inode_initialize
|
2007-03-14 23:41:09 +01:00
|
|
|
*
|
|
|
|
* Description:
|
2012-07-14 23:05:40 +02:00
|
|
|
* This is called from the OS initialization logic to configure the file
|
|
|
|
* system.
|
2007-03-14 23:41:09 +01:00
|
|
|
*
|
2008-05-31 22:14:15 +02:00
|
|
|
****************************************************************************/
|
2007-02-18 00:21:28 +01:00
|
|
|
|
2014-10-06 16:11:37 +02:00
|
|
|
void inode_initialize(void)
|
2007-02-18 00:21:28 +01:00
|
|
|
{
|
2014-10-06 16:11:37 +02:00
|
|
|
/* Initialize the semaphore to one (to support one-at-a-time access to the
|
|
|
|
* inode tree).
|
2007-03-14 23:41:09 +01:00
|
|
|
*/
|
|
|
|
|
2017-10-03 20:51:15 +02:00
|
|
|
(void)nxsem_init(&g_inode_sem.sem, 0, 1);
|
2013-11-28 20:12:14 +01:00
|
|
|
g_inode_sem.holder = NO_HOLDER;
|
|
|
|
g_inode_sem.count = 0;
|
2013-11-28 20:30:06 +01:00
|
|
|
|
2007-03-14 23:41:09 +01:00
|
|
|
/* Initialize files array (if it is used) */
|
|
|
|
|
|
|
|
#ifdef CONFIG_HAVE_WEAKFUNCTIONS
|
|
|
|
if (files_initialize != NULL)
|
|
|
|
#endif
|
|
|
|
{
|
|
|
|
files_initialize();
|
|
|
|
}
|
2007-02-18 00:21:28 +01:00
|
|
|
}
|
|
|
|
|
2008-05-31 22:14:15 +02:00
|
|
|
/****************************************************************************
|
2007-03-14 23:41:09 +01:00
|
|
|
* Name: inode_semtake
|
2012-08-04 00:04:14 +02:00
|
|
|
*
|
|
|
|
* Description:
|
2013-11-28 20:12:14 +01:00
|
|
|
* Get exclusive access to the in-memory inode tree (g_inode_sem).
|
2012-08-04 00:04:14 +02:00
|
|
|
*
|
2008-05-31 22:14:15 +02:00
|
|
|
****************************************************************************/
|
2007-03-14 23:41:09 +01:00
|
|
|
|
|
|
|
void inode_semtake(void)
|
2007-02-18 00:21:28 +01:00
|
|
|
{
|
2013-11-28 20:12:14 +01:00
|
|
|
pid_t me;
|
|
|
|
|
|
|
|
/* Do we already hold the semaphore? */
|
|
|
|
|
|
|
|
me = getpid();
|
|
|
|
if (me == g_inode_sem.holder)
|
|
|
|
{
|
|
|
|
/* Yes... just increment the count */
|
|
|
|
|
|
|
|
g_inode_sem.count++;
|
2013-11-28 20:30:06 +01:00
|
|
|
DEBUGASSERT(g_inode_sem.count > 0);
|
2013-11-28 20:12:14 +01:00
|
|
|
}
|
|
|
|
|
2007-03-14 23:41:09 +01:00
|
|
|
/* Take the semaphore (perhaps waiting) */
|
|
|
|
|
2013-11-28 20:12:14 +01:00
|
|
|
else
|
2007-02-18 00:21:28 +01:00
|
|
|
{
|
2017-10-04 23:22:27 +02:00
|
|
|
int ret;
|
|
|
|
|
|
|
|
do
|
2013-11-28 20:12:14 +01:00
|
|
|
{
|
2017-10-04 23:22:27 +02:00
|
|
|
ret = nxsem_wait(&g_inode_sem.sem);
|
|
|
|
|
|
|
|
/* The only case that an error should occur here is if the wait
|
|
|
|
* was awakened by a signal.
|
2013-11-28 20:12:14 +01:00
|
|
|
*/
|
|
|
|
|
2017-10-04 23:22:27 +02:00
|
|
|
DEBUGASSERT(ret == OK || ret == -EINTR);
|
2013-11-28 20:12:14 +01:00
|
|
|
}
|
2017-10-04 23:22:27 +02:00
|
|
|
while (ret == -EINTR);
|
2013-11-28 20:12:14 +01:00
|
|
|
|
|
|
|
/* No we hold the semaphore */
|
2007-03-14 23:41:09 +01:00
|
|
|
|
2013-11-28 20:12:14 +01:00
|
|
|
g_inode_sem.holder = me;
|
|
|
|
g_inode_sem.count = 1;
|
2007-02-18 00:21:28 +01:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2008-05-31 22:14:15 +02:00
|
|
|
/****************************************************************************
|
2007-03-14 23:41:09 +01:00
|
|
|
* Name: inode_semgive
|
2012-08-04 00:04:14 +02:00
|
|
|
*
|
|
|
|
* Description:
|
2013-11-28 20:12:14 +01:00
|
|
|
* Relinquish exclusive access to the in-memory inode tree (g_inode_sem).
|
2012-08-04 00:04:14 +02:00
|
|
|
*
|
2008-05-31 22:14:15 +02:00
|
|
|
****************************************************************************/
|
2007-03-14 23:41:09 +01:00
|
|
|
|
|
|
|
void inode_semgive(void)
|
|
|
|
{
|
2013-11-28 20:12:14 +01:00
|
|
|
DEBUGASSERT(g_inode_sem.holder == getpid());
|
|
|
|
|
|
|
|
/* Is this our last count on the semaphore? */
|
|
|
|
|
|
|
|
if (g_inode_sem.count > 1)
|
|
|
|
{
|
|
|
|
/* No.. just decrement the count */
|
|
|
|
|
|
|
|
g_inode_sem.count--;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Yes.. then we can really release the semaphore */
|
|
|
|
|
|
|
|
else
|
|
|
|
{
|
|
|
|
g_inode_sem.holder = NO_HOLDER;
|
|
|
|
g_inode_sem.count = 0;
|
2017-10-03 23:35:24 +02:00
|
|
|
nxsem_post(&g_inode_sem.sem);
|
2013-11-28 20:12:14 +01:00
|
|
|
}
|
2007-03-14 23:41:09 +01:00
|
|
|
}
|