/*
* Copyright (c) 2007 Jakub Jermar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - 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.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
/** @addtogroup fs
* @{
*/
/**
* @file vfs_open.c
* @brief VFS_OPEN method.
*/
#include <ipc/ipc.h>
#include <async.h>
#include <errno.h>
#include <futex.h>
#include <sys/types.h>
#include <stdlib.h>
#include "vfs.h"
void vfs_open(ipc_callid_t rid, ipc_call_t *request)
{
if (!vfs_files_init()) {
ipc_answer_0(rid, ENOMEM);
return;
}
/*
* The POSIX interface is open(path, flags, mode).
* We can receive flags and mode along with the VFS_OPEN call; the path
* will need to arrive in another call.
*/
int flags = IPC_GET_ARG1(*request);
int mode = IPC_GET_ARG2(*request);
size_t size;
ipc_callid_t callid;
if (!ipc_data_receive(&callid, NULL, &size)) {
ipc_answer_0(callid, EINVAL);
ipc_answer_0(rid, EINVAL);
return;
}
/*
* Now we are on the verge of accepting the path.
*
* There is one optimization we could do in the future: copy the path
* directly into the PLB using some kind of a callback.
*/
if (!path) {
ipc_answer_0(callid, ENOMEM);
ipc_answer_0(rid, ENOMEM);
return;
}
int rc;
if ((rc = ipc_data_deliver(callid, path, size))) {
ipc_answer_0(rid, rc);
return;
}
/*
* Avoid the race condition in which the file can be deleted before we
* find/create-and-lock the VFS node corresponding to the looked-up
* triplet.
*/
futex_down(&unlink_futex);
/*
* The path is now populated and we can call vfs_lookup_internal().
*/
vfs_triplet_t triplet;
rc = vfs_lookup_internal(path, size, &triplet, NULL);
if (rc) {
futex_up(&unlink_futex);
ipc_answer_0(rid, rc);
return;
}
/*
* Path is no longer needed.
*/
vfs_node_t *node = vfs_node_get(&triplet);
futex_up(&unlink_futex);
/*
* Get ourselves a file descriptor and the corresponding vfs_file_t
* structure.
*/
int fd = vfs_fd_alloc();
if (fd < 0) {
vfs_node_put(node);
ipc_answer_0(rid, fd);
return;
}
vfs_file_t *file = vfs_file_get(fd);
file->node = node;
/*
* The following increase in reference count is for the fact that the
* file is being opened and that a file structure is pointing to it.
* It is necessary so that the file will not disappear when
* vfs_node_put() is called. The reference will be dropped by the
* respective VFS_CLOSE.
*/
vfs_node_addref(node);
vfs_node_put(node);
/*
* Success! Return the new file descriptor to the client.
*/
ipc_answer_1(rid, EOK, fd);
}
/**
* @}
*/