diff options
Diffstat (limited to 'nuttx/fs/fs_write.c')
| -rw-r--r-- | nuttx/fs/fs_write.c | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/nuttx/fs/fs_write.c b/nuttx/fs/fs_write.c new file mode 100644 index 000000000..93dad92c4 --- /dev/null +++ b/nuttx/fs/fs_write.c @@ -0,0 +1,188 @@ +/**************************************************************************** + * fs/fs_write.c + * + * Copyright (C) 2007-2009, 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 <unistd.h> +#include <fcntl.h> +#include <sched.h> +#include <errno.h> + +#if defined(CONFIG_NET) && CONFIG_NSOCKET_DESCRIPTORS > 0 +# include <sys/socket.h> +#endif + +#include "fs_internal.h" + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +#if CONFIG_NFILE_DESCRIPTORS > 0 +static inline ssize_t file_write(int fd, FAR const void *buf, size_t nbytes) +{ + FAR struct filelist *list; + FAR struct file *this_file; + FAR struct inode *inode; + int ret; + int err; + + /* Get the thread-specific file list */ + + list = sched_getfiles(); + if (!list) + { + err = EMFILE; + goto errout; + } + + /* Was this file opened for write access? */ + + this_file = &list->fl_files[fd]; + if ((this_file->f_oflags & O_WROK) == 0) + { + err = EBADF; + goto errout; + } + + /* Is a driver registered? Does it support the write method? */ + + inode = this_file->f_inode; + if (!inode || !inode->u.i_ops || !inode->u.i_ops->write) + { + err = EBADF; + goto errout; + } + + /* Yes, then let the driver perform the write */ + + ret = inode->u.i_ops->write(this_file, buf, nbytes); + if (ret < 0) + { + err = -ret; + goto errout; + } + + return ret; + +errout: + set_errno(err); + return ERROR; +} +#endif + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/*************************************************************************** + * Name: write + * + * Description: + * write() writes up to nytes bytes to the file referenced by the file + * descriptor fd from the buffer starting at buf. + * + * Parameters: + * fd file descriptor (or socket descriptor) to write to + * buf Data to write + * nbytes Length of data to write + * + * Returned Value: + * On success, the number of bytes written are returned (zero indicates + * nothing was written). On error, -1 is returned, and errno is set appro- + * priately: + * + * EAGAIN + * Non-blocking I/O has been selected using O_NONBLOCK and the write + * would block. + * EBADF + * fd is not a valid file descriptor or is not open for writing. + * EFAULT + * buf is outside your accessible address space. + * EFBIG + * An attempt was made to write a file that exceeds the implementation + * defined maximum file size or the process' file size limit, or + * to write at a position past the maximum allowed offset. + * EINTR + * The call was interrupted by a signal before any data was written. + * EINVAL + * fd is attached to an object which is unsuitable for writing; or + * the file was opened with the O_DIRECT flag, and either the address + * specified in buf, the value specified in count, or the current + * file offset is not suitably aligned. + * EIO + * A low-level I/O error occurred while modifying the inode. + * ENOSPC + * The device containing the file referred to by fd has no room for + * the data. + * EPIPE + * fd is connected to a pipe or socket whose reading end is closed. + * When this happens the writing process will also receive a SIGPIPE + * signal. (Thus, the write return value is seen only if the program + * catches, blocks or ignores this signal.) + * + * Assumptions: + * + ********************************************************************************************/ + +ssize_t write(int fd, FAR const void *buf, size_t nbytes) +{ + /* Did we get a valid file descriptor? */ + +#if CONFIG_NFILE_DESCRIPTORS > 0 + if ((unsigned int)fd >= CONFIG_NFILE_DESCRIPTORS) +#endif + { + /* Write to a socket descriptor is equivalent to send with flags == 0 */ + +#if defined(CONFIG_NET_TCP) && CONFIG_NSOCKET_DESCRIPTORS > 0 + return send(fd, buf, nbytes, 0); +#else + set_errno(EBADF); + return ERROR; +#endif + } + + /* The descriptor is in the right range to be a file descriptor... write to the file */ + +#if CONFIG_NFILE_DESCRIPTORS > 0 + return file_write(fd, buf, nbytes); +#endif +} + |