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1 /****************************************************************************
2  * fs/driver/fs_registerblockdriver.c
3  *
4  *   Copyright (C) 2007-2009, 2012 Gregory Nutt. All rights reserved.
5  *   Author: Gregory Nutt <gnutt@nuttx.org>
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in
15  *    the documentation and/or other materials provided with the
16  *    distribution.
17  * 3. Neither the name NuttX nor the names of its contributors may be
18  *    used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
25  * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
28  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
31  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
32  * POSSIBILITY OF SUCH DAMAGE.
33  *
34  ****************************************************************************/
35 
36 /****************************************************************************
37  * Included Files
38  ****************************************************************************/
39 
40 #include "vfs_config.h"
41 #include "sys/types.h"
42 #include "errno.h"
43 #include "fs/driver.h"
44 #include "vnode.h"
45 #include "string.h"
46 #include "path_cache.h"
47 #include "vnode.h"
48 #include "limits.h"
49 
50 /****************************************************************************
51  * Public Functions
52  ****************************************************************************/
53 
54 /****************************************************************************
55  * Name: register_blockdriver
56  *
57  * Description:
58  *   Register a block driver vnode the pseudo file system.
59  *
60  * Input parameters:
61  *   path - The path to the vnode to create
62  *   bops - The block driver operations structure
63  *   mode - inmode priviledges (not used)
64  *   priv - Private, user data that will be associated with the vnode.
65  *
66  * Returned Value:
67  *   Zero on success (with the vnode point in 'vnode'); A negated errno
68  *   value is returned on a failure (all error values returned by
69  *   vnode_reserve):
70  *
71  *   EINVAL - 'path' is invalid for this operation
72  *   EEXIST - An vnode already exists at 'path'
73  *   ENOMEM - Failed to allocate in-memory resources for the operation
74  *
75  ****************************************************************************/
76 
register_blockdriver(const char * path,const struct block_operations * bops,mode_t mode,void * priv)77 int register_blockdriver(const char *path,
78                          const struct block_operations *bops,
79                          mode_t mode, void *priv)
80 {
81   struct Vnode *vp = NULL;
82   int ret;
83 
84   if (path == NULL || strlen(path) >= PATH_MAX || strncmp("/dev/", path, DEV_PATH_LEN) != 0)
85     {
86       return -EINVAL;
87     }
88 
89   /* Insert an vnode for the device driver -- we need to hold the vnode
90    * semaphore to prevent access to the tree while we this.  This is because
91    * we will have a momentarily bad true until we populate the vnode with
92    * valid data.
93    */
94 
95   struct drv_data *data = (struct drv_data *)zalloc(sizeof(struct drv_data));
96 
97   data->ops = (void *)bops;
98   data->mode = mode;
99   data->priv = priv;
100 
101   VnodeHold();
102   ret = VnodeLookup(path, &vp, V_CREATE | V_DUMMY);
103   if (ret == OK)
104     {
105       /* We have it, now populate it with block driver specific information. */
106 
107       vp->type = VNODE_TYPE_BLK;
108       vp->data = data;
109       vp->mode = mode;
110     }
111 
112   VnodeDrop();
113   return ret;
114 }
115