diff options
Diffstat (limited to 'nuttx/fs/fs_umount.c')
| -rw-r--r-- | nuttx/fs/fs_umount.c | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/nuttx/fs/fs_umount.c b/nuttx/fs/fs_umount.c new file mode 100644 index 000000000..5bf44e4f7 --- /dev/null +++ b/nuttx/fs/fs_umount.c @@ -0,0 +1,206 @@ +/**************************************************************************** + * fs/fs_umount.c + * + * Copyright (C) 2007-2009 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/mount.h> +#include <errno.h> +#include <nuttx/fs/fs.h> + +#include "fs_internal.h" + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ + +/**************************************************************************** + * Private Types + ****************************************************************************/ + +/**************************************************************************** + * Private Variables + ****************************************************************************/ + +/**************************************************************************** + * Public Variables + ****************************************************************************/ + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: umount + * + * Description: + * umount() detaches the filesystem mounted at the path specified by + * 'target.' + * + * Return: + * Zero is returned on success; -1 is returned on an error and errno is + * set appropriately: + * + * EACCES A component of a path was not searchable or mounting a read-only + * filesystem was attempted without giving the MS_RDONLY flag. + * EBUSY The target could not be unmounted because it is busy. + * EFAULT The pointer argument points outside the user address space. + * + ****************************************************************************/ + +int umount(const char *target) +{ + FAR struct inode *mountpt_inode; + FAR struct inode *blkdrvr_inode = NULL; + int errcode = OK; + int status; + + /* Verify required pointer arguments */ + + if (!target) + { + errcode = EFAULT; + goto errout; + } + + /* Find the mountpt */ + + mountpt_inode = inode_find(target, NULL); + if (!mountpt_inode) + { + errcode = ENOENT; + goto errout; + } + + /* Verify that the inode is a mountpoint */ + + if (!INODE_IS_MOUNTPT(mountpt_inode)) + { + errcode = EINVAL; + goto errout_with_mountpt; + } + + /* Unbind the block driver from the file system (destroying any fs + * private data. + */ + + if (!mountpt_inode->u.i_mops->unbind) + { + /* The filesystem does not support the unbind operation ??? */ + + errcode = EINVAL; + goto errout_with_mountpt; + } + + /* The unbind method returns the number of references to the + * filesystem (i.e., open files), zero if the unbind was + * performed, or a negated error code on a failure. + */ + + inode_semtake(); /* Hold the semaphore through the unbind logic */ + status = mountpt_inode->u.i_mops->unbind( mountpt_inode->i_private, &blkdrvr_inode); + if (status < 0) + { + /* The inode is unhappy with the blkdrvr for some reason */ + + errcode = -status; + goto errout_with_semaphore; + } + else if (status > 0) + { + errcode = EBUSY; + goto errout_with_semaphore; + } + + /* Successfully unbound */ + + mountpt_inode->i_private = NULL; + + /* Successfully unbound, remove the mountpoint inode from + * the inode tree. The inode will not be deleted yet because + * there is still at least reference on it (from the mount) + */ + + status = inode_remove(target); + inode_semgive(); + + /* The return value of -EBUSY is normal (in fact, it should + * not be OK) + */ + + if (status != OK && status != -EBUSY) + { + errcode = -status; + goto errout_with_mountpt; + } + + /* Release the mountpoint inode and any block driver inode + * returned by the file system unbind above. This should cause + * the inode to be deleted (unless there are other references) + */ + + inode_release(mountpt_inode); + + /* Did the unbind method return a contained block driver */ + + if (blkdrvr_inode) + { + inode_release(blkdrvr_inode); + } + + return OK; + + /* A lot of goto's! But they make the error handling much simpler */ + +errout_with_semaphore: + inode_semgive(); +errout_with_mountpt: + inode_release(mountpt_inode); + if (blkdrvr_inode) + { + inode_release(blkdrvr_inode); + } +errout: + set_errno(errcode); + return ERROR; +} + |