Add find/open/close_blockdriver()

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@796 42af7a65-404d-4744-a932-0658087f49c3

1 files changed, 129 insertions, 0 deletions

diff --git a/nuttx/fs/fs_findblockdriver.c b/nuttx/fs/fs_findblockdriver.c
new file mode 100644
index 000000000..b7c335a61
--- /dev/null
+++ b/nuttx/fs/fs_findblockdriver.c
@@ -0,0 +1,129 @@
+/****************************************************************************
+ * fs/fs_openblockdriver.c
+ *
+ *   Copyright (C) 2008 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * Redistribution and use in pathname and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of pathname 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.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <sys/types.h>
+#include <sys/mount.h>
+#include <debug.h>
+#include <errno.h>
+#include <nuttx/fs.h>
+
+#include "fs_internal.h"
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: find_blockdriver
+ *
+ * Description:
+ *   Return the inode of the block driver specified by 'pathname'
+ *
+ * Inputs:
+ *   pathname - the full path to the block driver to be located
+ *   mountflags - if MS_RDONLY is set, then driver must support write
+ *     operations (see include/sys/mount.h)
+ *   ppinode - address of the location to return the inode reference
+ *
+ * Return:
+ *   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
+ *
+ ****************************************************************************/
+
+int find_blockdriver(FAR const char *pathname, int mountflags, FAR struct inode **ppinode)
+{
+  FAR struct inode *inode;
+  int ret = 0; /* Assume success */
+
+  /* Sanity checks */
+
+  if (!pathname || !ppinode)
+    {
+      ret = -EINVAL;
+      goto errout;
+    }
+
+  /* Find the inode registered with this pathname */
+
+  inode = inode_find(pathname, NULL);
+  if (!inode)
+    {
+      fdbg("Failed to find %s\n", pathname);
+      ret = -ENOENT;
+      goto errout;
+    }
+
+  /* Verify that the inode is a block driver. */
+
+  if (!INODE_IS_BLOCK(inode))
+    { 
+      fdbg("%s is not a block driver\n", pathname);
+      ret = -ENOTBLK;
+      goto errout_with_inode;
+   }
+
+  /* Make sure that the inode supports the requested access */
+
+  if (!inode->u.i_bops || !inode->u.i_bops->read ||
+      (!inode->u.i_bops->write && (mountflags & MS_RDONLY) == 0))
+    {
+      fdbg("%s does not support requested access\n", pathname);
+      ret = -EACCES;
+      goto errout_with_inode;
+    }
+
+  *ppinode = inode;
+  return OK;
+
+errout_with_inode:
+  inode_release(inode);
+errout:
+  return ret;
+}