diff options
Diffstat (limited to 'nuttx/fs/fs_readdir.c')
| -rw-r--r-- | nuttx/fs/fs_readdir.c | 230 |
1 files changed, 230 insertions, 0 deletions
diff --git a/nuttx/fs/fs_readdir.c b/nuttx/fs/fs_readdir.c new file mode 100644 index 000000000..8df1bf655 --- /dev/null +++ b/nuttx/fs/fs_readdir.c @@ -0,0 +1,230 @@ +/**************************************************************************** + * fs/fs_readdir.c + * + * Copyright (C) 2007-2009, 2011 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 <string.h> +#include <dirent.h> +#include <errno.h> + +#include <nuttx/fs/fs.h> +#include <nuttx/fs/dirent.h> + +#include "fs_internal.h" + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: readpsuedodir + ****************************************************************************/ + +static inline int readpsuedodir(struct fs_dirent_s *idir) +{ + FAR struct inode *prev; + + /* Check if we are at the end of the list */ + + if (!idir->u.psuedo.fd_next) + { + /* End of file and error conditions are not distinguishable + * with readdir. Here we return -ENOENT to signal the end + * of the directory. + */ + + return -ENOENT; + } + + /* Copy the inode name into the dirent structure */ + + strncpy(idir->fd_dir.d_name, idir->u.psuedo.fd_next->i_name, NAME_MAX+1); + + /* If the node has file operations, we will say that it is + * a file. + */ + + idir->fd_dir.d_type = 0; + if (idir->u.psuedo.fd_next->u.i_ops) + { +#ifndef CONFIG_DISABLE_MOUNTPOINT + if (INODE_IS_BLOCK(idir->u.psuedo.fd_next)) + { + idir->fd_dir.d_type |= DTYPE_BLK; + } + if (INODE_IS_MOUNTPT(idir->u.psuedo.fd_next)) + { + idir->fd_dir.d_type |= DTYPE_DIRECTORY; + } + else +#endif + { + idir->fd_dir.d_type |= DTYPE_CHR; + } + } + + /* If the node has child node(s), then we will say that it + * is a directory. NOTE: that the node can be both! + */ + + if (idir->u.psuedo.fd_next->i_child || !idir->u.psuedo.fd_next->u.i_ops) + { + idir->fd_dir.d_type |= DTYPE_DIRECTORY; + } + + /* Now get the inode to vist next time that readdir() is called */ + + inode_semtake(); + + prev = idir->u.psuedo.fd_next; + idir->u.psuedo.fd_next = prev->i_peer; /* The next node to visit */ + + if (idir->u.psuedo.fd_next) + { + /* Increment the reference count on this next node */ + + idir->u.psuedo.fd_next->i_crefs++; + } + + inode_semgive(); + + if (prev) + { + inode_release(prev); + } + + return OK; +} + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: readdir + * + * Description: + * The readdir() function returns a pointer to a dirent structure + * representing the next directory entry in the directory stream pointed + * to by dir. It returns NULL on reaching the end-of-file or if an error + * occurred. + * + * Inputs: + * dirp -- An instance of type DIR created by a previous call to opendir(); + * + * Return: + * The readdir() function returns a pointer to a dirent structure, or NULL + * if an error occurs or end-of-file is reached. On error, errno is set + * appropriately. + * + * EBADF - Invalid directory stream descriptor dir + * + ****************************************************************************/ + +FAR struct dirent *readdir(DIR *dirp) +{ + FAR struct fs_dirent_s *idir = (struct fs_dirent_s *)dirp; +#ifndef CONFIG_DISABLE_MOUNTPOINT + struct inode *inode; +#endif + int ret; + + /* Sanity checks */ + + if (!idir || !idir->fd_root) + { + ret = EBADF; + goto errout; + } + + /* The way we handle the readdir depends on the type of inode + * that we are dealing with. + */ + +#ifndef CONFIG_DISABLE_MOUNTPOINT + inode = idir->fd_root; + if (INODE_IS_MOUNTPT(inode) && !DIRENT_ISPSUEDONODE(idir->fd_flags)) + { + /* The node is a file system mointpoint. Verify that the mountpoint + * supports the readdir() method + */ + + if (!inode->u.i_mops || !inode->u.i_mops->readdir) + { + ret = EACCES; + goto errout; + } + + /* Perform the readdir() operation */ + + ret = inode->u.i_mops->readdir(inode, idir); + } + else +#endif + { + /* The node is part of the root psuedo file system */ + + ret = readpsuedodir(idir); + } + + /* ret < 0 is an error. Special case: ret = -ENOENT is end of file */ + + if ( ret < 0) + { + if (ret == -ENOENT) + { + ret = OK; + } + else + { + ret = -ret; + } + goto errout; + } + + /* Success */ + + idir->fd_position++; + return &idir->fd_dir; + +errout: + set_errno(ret); + return NULL; +} + |