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- /****************************************************************************
- * fs/driver/fs_mtdproxy.c
- *
- * 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.
- *
- ****************************************************************************/
- /****************************************************************************
- * Included Files
- ****************************************************************************/
- #include <nuttx/config.h>
- #include <sys/types.h>
- #include <sys/stat.h>
- #include <stdio.h>
- #include <string.h>
- #include <errno.h>
- #include <assert.h>
- #include <debug.h>
- #include <nuttx/kmalloc.h>
- #include <nuttx/mtd/mtd.h>
- #include <nuttx/semaphore.h>
- #include "driver/driver.h"
- /****************************************************************************
- * Private Data
- ****************************************************************************/
- static uint32_t g_devno;
- static sem_t g_devno_sem = SEM_INITIALIZER(1);
- /****************************************************************************
- * Private Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: unique_blkdev
- *
- * Description:
- * Create a unique temporary device name in the /dev/ directory of the
- * pseudo-file system. We cannot use mktemp for this because it will
- * attempt to open() the file.
- *
- * Input Parameters:
- * None
- *
- * Returned Value:
- * The allocated path to the device. This must be released by the caller
- * to prevent memory links. NULL will be returned only the case where
- * we fail to allocate memory.
- *
- ****************************************************************************/
- static FAR char *unique_blkdev(void)
- {
- struct stat statbuf;
- char devbuf[16];
- uint32_t devno;
- int ret;
- /* Loop until we get a unique device name */
- for (; ; )
- {
- /* Get the semaphore protecting the path number */
- ret = nxsem_wait_uninterruptible(&g_devno_sem);
- if (ret < 0)
- {
- ferr("ERROR: nxsem_wait_uninterruptible failed: %d\n", ret);
- return NULL;
- }
- /* Get the next device number and release the semaphore */
- devno = ++g_devno;
- nxsem_post(&g_devno_sem);
- /* Construct the full device number */
- devno &= 0xffffff;
- snprintf(devbuf, 16, "/dev/tmpb%06lx", (unsigned long)devno);
- /* Make sure that file name is not in use */
- ret = stat(devbuf, &statbuf);
- if (ret < 0)
- {
- DEBUGASSERT(errno == ENOENT);
- return strdup(devbuf);
- }
- /* It is in use, try again */
- }
- }
- /****************************************************************************
- * Public Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: mtd_proxy
- *
- * Description:
- * Create a temporary block driver using drivers/mtd/ftl to mediate block
- * oriented accessed to the mtd driver.
- *
- * Input Parameters:
- * mtddev - The path to the mtd driver
- * 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:
- * If zero, non-zero inode pointer is returned on success. This
- * is the inode pointer of the nameless block driver that mediates
- * accesses to the mtd driver.
- *
- * Errors that may be returned:
- *
- * ENOMEM - Failed to create a temporary path name.
- *
- * Plus:
- *
- * - Errors reported from ftl_initialize()
- * - Errors reported from open() or unlink()
- *
- ****************************************************************************/
- int mtd_proxy(FAR const char *mtddev, int mountflags,
- FAR struct inode **ppinode)
- {
- FAR struct inode *mtd;
- FAR char *blkdev;
- int ret;
- /* Create a unique temporary file name for the block device */
- blkdev = unique_blkdev();
- if (blkdev == NULL)
- {
- ferr("ERROR: Failed to create temporary device name\n");
- return -ENOMEM;
- }
- /* Wrap the mtd driver with an instance of the ftl driver */
- ret = find_mtddriver(mtddev, &mtd);
- if (ret < 0)
- {
- ferr("ERROR: Failed to find %s mtd driver\n", mtddev);
- goto out_with_blkdev;
- }
- ret = ftl_initialize_by_path(blkdev, mtd->u.i_mtd);
- inode_release(mtd);
- if (ret < 0)
- {
- ferr("ERROR: ftl_initialize_by_path(%s, %s) failed: %d\n",
- mtddev, blkdev, ret);
- goto out_with_blkdev;
- }
- /* Open the newly created block driver */
- ret = open_blockdriver(blkdev, mountflags, ppinode);
- if (ret < 0)
- {
- ferr("ERROR: Failed to open %s: %d\n", blkdev, ret);
- goto out_with_fltdev;
- }
- /* Unlink and free the block device name. The driver instance will
- * persist, provided that CONFIG_DISABLE_PSEUDOFS_OPERATIONS=y (otherwise,
- * we have a problem here!)
- */
- out_with_fltdev:
- unlink(blkdev);
- out_with_blkdev:
- kmm_free(blkdev);
- return ret;
- }
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