diff options
Diffstat (limited to 'nuttx/fs/fs_open.c')
| -rw-r--r-- | nuttx/fs/fs_open.c | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/nuttx/fs/fs_open.c b/nuttx/fs/fs_open.c new file mode 100644 index 000000000..5b318b702 --- /dev/null +++ b/nuttx/fs/fs_open.c @@ -0,0 +1,206 @@ +/**************************************************************************** + * fs_open.c + * + * Copyright (C) 2007-2009, 2011-2012 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <gnutt@nuttx.org> + * + * 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. + * 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 <fcntl.h> +#include <sched.h> +#include <errno.h> +#ifdef CONFIG_FILE_MODE +#include <stdarg.h> +#endif +#include <nuttx/fs/fs.h> +#include "fs_internal.h" + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: inode_checkflags + * + * Description: + * Check if the access described by 'oflags' is supported on 'inode' + * + ****************************************************************************/ + +int inode_checkflags(FAR struct inode *inode, int oflags) +{ + if (((oflags & O_RDOK) != 0 && !inode->u.i_ops->read) || + ((oflags & O_WROK) != 0 && !inode->u.i_ops->write)) + { + return -EACCES; + } + else + { + return OK; + } +} + +/**************************************************************************** + * Name: open + * + * Description: + * Standard 'open' interface + * + ****************************************************************************/ + +int open(const char *path, int oflags, ...) +{ + FAR struct filelist *list; + FAR struct inode *inode; + FAR const char *relpath = NULL; +#if defined(CONFIG_FILE_MODE) || !defined(CONFIG_DISABLE_MOUNTPOINT) + mode_t mode = 0666; +#endif + int ret; + int fd; + + /* Get the thread-specific file list */ + + list = sched_getfiles(); + if (!list) + { + ret = EMFILE; + goto errout; + } + +#ifdef CONFIG_FILE_MODE +# ifdef CONFIG_CPP_HAVE_WARNING +# warning "File creation not implemented" +# endif + + /* If the file is opened for creation, then get the mode bits */ + + if (oflags & (O_WRONLY|O_CREAT) != 0) + { + va_list ap; + va_start(ap, oflags); + mode = va_arg(ap, mode_t); + va_end(ap); + } +#endif + + /* Get an inode for this file */ + + inode = inode_find(path, &relpath); + if (!inode) + { + /* "O_CREAT is not set and the named file does not exist. Or, a + * directory component in pathname does not exist or is a dangling + * symbolic link." + */ + + ret = ENOENT; + goto errout; + } + + /* Verify that the inode is valid and either a "normal" or a mountpoint. We + * specifically exclude block drivers. + */ + +#ifndef CONFIG_DISABLE_MOUNTPOINT + if ((!INODE_IS_DRIVER(inode) && !INODE_IS_MOUNTPT(inode)) || !inode->u.i_ops) +#else + if (!INODE_IS_DRIVER(inode) || !inode->u.i_ops) +#endif + { + ret = ENXIO; + goto errout_with_inode; + } + + /* Make sure that the inode supports the requested access */ + + ret = inode_checkflags(inode, oflags); + if (ret < 0) + { + ret = -ret; + goto errout_with_inode; + } + + /* Associate the inode with a file structure */ + + fd = files_allocate(inode, oflags, 0, 0); + if (fd < 0) + { + ret = EMFILE; + goto errout_with_inode; + } + + /* Perform the driver open operation. NOTE that the open method may be + * called many times. The driver/mountpoint logic should handled this + * because it may also be closed that many times. + */ + + ret = OK; + if (inode->u.i_ops->open) + { +#ifndef CONFIG_DISABLE_MOUNTPOINT + if (INODE_IS_MOUNTPT(inode)) + { + ret = inode->u.i_mops->open((FAR struct file*)&list->fl_files[fd], + relpath, oflags, mode); + } + else +#endif + { + ret = inode->u.i_ops->open((FAR struct file*)&list->fl_files[fd]); + } + } + + if (ret < 0) + { + ret = -ret; + goto errout_with_fd; + } + + return fd; + + errout_with_fd: + files_release(fd); + errout_with_inode: + inode_release(inode); + errout: + set_errno(ret); + return ERROR; +} |